Phys TUs LVL 3

This quantity is related to isospin by the Gell-Mann-Nishijima equation. The electric flux through a surface is equal to this quantity over permittivity of space according to Gauss's law, and the time derivative of this quantity is current. One experiment involving this quantity balanced the buoyant force with the electric force using oil drops to prove that this quantity is quantized, and that experiment was conducted by Robert Millikan. For 10 points, name this quantity measured in Coulombs, which is positive for a proton.

Electric Charge

This person developed a device more complicated than a Wheatstone bridge that is used for measuring small resistances. The effect named for this person and James Joule [jool] explains the temperature change of a gas that expands without any heat transfer. He made improvements to the mirror galvanometer [gal-vah-NOM-ih-ter], which he used on his trans-Atlantic cable. Name this scientist whose work in thermodynamics led him to create an absolute temperature scale with its zero corresponding to absolute zero temperature.

1st Baron Lord Kelvin (or William Thomson)

This scientist corrected an instability in the van der Waals isotherm by proposing a namesake equal-area correction. He is the alphabetically later namesake of a distribution to which particles converge according to the H-theorem. Richard Feynman proposed a “Brownian ratchet†to implement one of this scientist’s thought experiments, which involves an observer who can (*) separate particles by speed. This man co-names the equilibrium distribution of an ideal gas’s speed with Ludwig Boltzmann. For 10 points, name this Scottish scientist who proposed a hypothetical “demon†that violates the Second Law of Thermodynamics.

James Clerk Maxwell <AF>

The Hagen-Poiseuille equation in fluid dynamics is often treated as the hydraulic analogue of this statement, and a magnetic analogue of this law states that magnetic reluctance equals magnetomotive force over magnetic flux; that statement is Hopkinson’s law. Kirchhoff expressed this law in continuum form as current density equals the product of (*) conductivity and electric field. Diodes do not obey this law, since their I-V curves are nonlinear. The namesake of this law also lends his name to the SI unit of resistance. For 10 points, name this law which states that current is equal to voltage divided by resistance.

Ohm’s law

Its antiparticle was first discovered by Chamberlain and Segrè, and the Tevatron is used to accelerate these particles to relativistic speeds. Grand unified theories have predicted that this particle has a half-life of ten to the thirty second years, although its decay has never been observed. Hydrogen is used in its namesake NMR spectroscopy, and they are composed of a down quark and two up quarks. These particles are bound together by the strong nuclear force, and the atomic number denotes the number of these in an atom. For 10 points, name these positively charged particles in the nucleus.

Protons

12. The ATRAP project collected one type of this substance from radioactive sodium-22 in a Penning trap. The existence of another type of this substance was proposed by Dirac to explain quantum states with negative energies and was first observed by Carl Anderson. Because the Sakharov conditions were satisfied, CP-symmetry violation explains why there is less of this substance produced than its (*) counterpart. This substance produces high-energy gamma rays when it comes into contact with normal particles, which have the same mass but opposite charge as particles of this type. The positron is an example of, for ten points, what type of material which rapidly annihilates with matter?

antimatter (accept antiparticles; prompt on positrons and antihydrogen and other specific antiparticles) <HX>

A homogeneous magnetic field and inhomogeneous electric field can be used to store this substance if it is charged. Andrei Sakharov proposed B violation to explain why this substance was less prevalent. This material is represented by a bar, indicating that it has undergone charge conjugation. The Dirac equation predicts this substance as holes in a Dirac sea, and along with its counterpart, this substance is produced in beta decay. A remnant of pair production, this substance interacts with its more common counterpart through annihilation. For 10 points, name this material consisting of particles like the positron, the opposite of matter.

antimatter [or antiparticles; anti-prompt for less specificity on "positron"]

22. Particles in these regions can be approximated by a wavefunction using Slater determinants and the Hartree-Fock method, and the Madelung rule describes how ones with lower n+l values have lower energy. They can be described by their principal, azimuthal, magnetic, and spin (*) quantum numbers, the last of which is governed by Hund’s rule and the Pauli exclusion principle. The Aufbau principle determines how electrons fill these entities, which are denoted by s, p, d, and f. For ten points, name these regions around an atomic nucleus where electrons can be found.

atomic orbitals [do NOT accept “molecular orbitalsâ€] <EC> Bonuses

Versions of these things named for photons are instabilities that can occur in the gas surrounding neutron stars. The Keller-Miksis formula describes the oscillations of these entities in a sound field, and their acoustic resonance is named for Minnaert. The radius of these entities can be found using the Rayleigh-Plesset equation, which is derived from the Navier-Stokes equation under the assumption of spherical symmetry. The (*) cavitation of these entities can cause the emission of light in sonoluminescence. For 10 points, name these entities that can be found on top of carbonated sodas.

bubbles

The old definition of this unit was based on blackbody radiation at the freezing point of platinum. This unit is based on a source of monochromatic radiation of frequency 5.4 times ten to the twelfth hertz and that has a radiant intensity in that direction of 1/683 watt per steradian. Luminance can be measured in this SI unit per square meter. Multiplying this unit by steradians gives the SI unit of luminous flux, the lumen, and multiplying this unit times steradians and dividing by square meters gives the SI unit of illuminance, the lux. Name this base SI unit.

candela [or standard candle]

This quantity is inversely proportional to resonant frequency squared times inductance. The “stray†form of this quantity is due to the proximity of circuit parts. For a circular disc, this quantity can be calculated as 8 times absolute permittivity times radius. The product of this quantity and resistance yields units of (*) time, and the inverse of this quantity is elastance. Adding a dielectric between two parallel plates can increase this quantity, which is calculated as charge over voltage. For 10 points, name this quantity defined as the ability to store electrical charge, measured in farads.

capacitance

The switched types of these devices are used as filters in integrated circuits and behave similarly to resistors. The common measurement of these devices is multiplied by resistance to calculate the time it takes them to discharge. These generally include an insulator called a dielectric between two conductors. Their common measurement is charge divided by electric potential difference. Name these devices whose strength is measured in farads.

capacitors

4. A certain quantity for spherical objects of this type is inversely proportional to the difference in reciprocals of the radii. These objects stop working when the breakdown voltage is reached. The time constant in systems with one of these objects and a resistor is equal to the resistance times a namesake quantity. That quantity is equal to permittivity times area divided by distance for a (*) parallel-plate one, is measured in farads, and can be increased by inserting a dielectric. For ten points, identify these circuit elements whose namesake unit equals charge over voltage, which store energy in an electric field.

capacitors <MS>

The namesake reference frame of this object has zero total momentum. This object is at the origin in barycentric coordinates. Euler’s first law sets momentum proportional to its velocity. The distance between a line and this object is squared in the parallel axis theorem. The (*) coordinates of this object are calculated by integrating the density times position over space. Rotational inertia is usually calculated for an axis passing through this object. This point is at the intersection of two plumb lines. The lower this point is, the more stable the system. For 10 points, name this point often at the centroid, which is where an object will freely balance.

center of mass [or CM; prompt on center of gravity; prompt on centroid]

This formula is generalized to higher orders by Faà di Bruno’s formula. For multivariable functions, this formula decomposes the Jacobian matrix into the product of two other Jacobians. This formula can be spuriously “proven†in an abuse of Leibniz’ notation by cancelling two (*) differentials as if derivatives were fractions. Indefinite integrals may be computed by reversing this formula in u-substitution. For two functions f and g of x, the result of this formula is f prime of g times g prime of x. For 10 points, name this formula that computes the derivative of the composition of two functions.

chain rule <Math â€" Dai> [Ed. French]

The discovery of weak currents in which this property is not transferred confirmed the GSW theory of the electroweak interaction. When combined with two other transformations, “conjugation†of this property is believed to be a fundamental symmetry of physics. The strong interactions of quarks are mediated by the (*) “color†type of this property. Quarks carry either plus-two-thirds or minus-one-third of the “elementary†value for this property, which was determined in Millikan’s oil drop experiment. For 10 points, name this property whose elementary unit is carried by a proton and is about “1.6 times 10-to-the minus-19 coulombs.â€

charge [accept electric charge; accept color charge] <SE>

In the lumped element model, this process predominates at low Biot [bee-OWE] number. The proportionality constant of this process has units of Watts per meter per Kelvin. The flux from this process varies with the negative gradient of the temperature in Fourier’s Law. This process shares its name with the lower-energy counterpart to the (*) valence band. Materials which permit this process often obey the free electron model and hold electrons loosely. This process will occur in contacting metals. For 10 points, name this method of heat transfer contrasted with convection and radiation, which does not occur in insulators.

conduction [or word forms]

This principle can be strengthened by a Cauchy continuity equation that can be used to derive the Navierâ€"Stokes equations. Any system which is invariant under translation in space will follow this principle, according to Noether’s theorem. This principle implies that a system’s center of mass will move with (*) constant velocity. This principle holds componentwise for both elastic and inelastic collisions, unlike a similar statement involving kinetic energy. For 10 points, name the principle according to which the product of mass and velocity remains fixed in the absence of external forces.

conservation of momentum [prompt on answers mentioning inertia; prompt on answers mentioning any of Newton’s laws] <SE>

The intensity of light passing through a polarizer equals its intensity times the square of this function with respect to the direction of polarization, according to Malus' Law. This function has a phase constant of zero for the position function of a mass-on-a-spring released from its maximum displacement. For a mass sitting on an inclined plane, the normal force is proportional to this function of the angle of the ramp. Dot products depend on this function of the angle between two vectors. The horizontal component of a projectile's velocity includes this function of the angle. For 10 points, name this function equal to sine divided by tangent or adjacent divided by hypotenuse.

cosine

21. The XENON100 experiment used particles scattering off liquid xenon to detect this entity, which is central to the Lambda-CDM parameterization of the Big Bang cosmological model. It commonly forms galactic halos, and Vera Rubin used this to explain how stars have a constant (*) rotational velocity independent of radial distance. In addition to axions, this substance interacts with gravity and the weak force in the form of WIMPs and MACHOs, and it is theorized to constitute 27% of the total mass-energy in the universe. For ten points, identify this substance that neither emits nor absorbs light and is thus unobservable.

dark matter [do NOT accept “dark energy†or “matter†or “antimatterâ€] <EC>

Objects with similar values of this quantity can display the muesli effect, or granular convection. Degrees Brix or degrees Plato are units used to measure this quantity which can be determined using a Baumé scale. Pi over the square root of 18 is the average value of this quantity in the solution to the (*) Kepler conjecture, which states that face-centered cubic crystals have the highest value of it. An isopycnic surface has a constant value for this quantity, whose ratio for a substance and for water is called specific gravity. For 10 points, name this quantity symbolized rho that is defined as mass divided by volume.

density

10. A pattern produced by this phenomenon is proportional to the square of the sinc [“sinkâ€] function. Kirchhoff's formula for this phenomenon models point sources as spherical wave packets. The Davisson-Germer experiment showed that a beam of electrons can undergo this phenomenon, which suggested that electrons have wavelike properties. Joseph Fraunhofer names the (*) far-field type of this phenomenon. Bragg’s Law describes the phase shift of X-rays undergoing this phenomenon. This phenomenon resulted in the interference fringes in Young’s double slit experiment. For 10 points, name this phenomenon in which waves bend around an obstacle.

diffraction <SAM>

A mathematical model of this phenomenon uses Green’s identities to derive the solution to a wave equation at an arbitrary point, while another model calculates its intensity using a Cornu spiral. The formula theta equals 1.22 times lambda over capital D estimates the angular resolution of this phenomenon; that is the (*) Rayleigh criterion. The Davissonâ€"Germer experiment showed electrons undergoing this phenomenon, whose near-field and far-field equations are named for Fresnel and Fraunhofer. The Airy disc is created from this phenomenon. For 10 points, name this optical phenomenon in which light bends around an obstacle.

diffraction HALFTIME

19. The intensity of this process for electrons is proportional to the structure factor squared, and one parameter for this phenomenon measures the ratio of aperture size squared to the product of distance and wavelength. Due to this process, every point on a wave front is considered a source of (*) secondary spherical wavelets, and this interaction creates an Airy disk that limits the focusing ability of lenses. Interference caused by this phenomenon creates alternating light and dark bands, which was observed in Young’s double-slit experiment. For ten points, identify this phenomenon where waves bend around an obstacle.

diffraction [accept x-ray scattering before “ratioâ€] <EC>

10. It’s not acceleration, but this quantity is squared in the numerator of the Larmor formula. The quantization of this quantity is provided for by the existence of a single magnetic monopole. This quantity is multiplied by the cross product of the velocity and the magnetic field in the formula for the Lorentz force. This quantity equals zero inside a perfect (*) conductor. The electric dipole moment equals this quantity times the separation, and this quantity multiplied by the electric field gives the force. For 10 points, name this quantity that is measured in coulombs.

electric charge [prompt on “qâ€] <SAM>

11. Minority carriers can produce the “diffusion†type of this quantity in a semiconductor. The closed loop integral of the H field equals the enclosed “free†type of this quantity. The magnetic moment of a loop equals this quantity times area. The inductance of an inductor can be found by dividing the magnetic flux by this quantity. This quantity divided by area equals conductivity times the electric field in the original formulation of (*) Ohm’s law, which also sets this quantity equal to voltage over resistance. For 10 points, name this quantity that is measured in amperes.

electric current [prompt on “Iâ€] <SAM>

Irving Langmuir is credited with a scientific rule involving eighteen of these objects; the rule predicts reactivity of metallic compounds. The classical radius of this object equals about 1.7 times 10 to the 20th Planck lengths. Ernst Ruska and Max Knoll used these particles to invent a (*) microscope. Cathode rays were early evidence for these particles, whose mass J.J. Thompson measured as much less than that of hydrogen atoms. Shells and orbitals outside the nucleus containâ€"for 10 pointsâ€"what particles that carry negative charge?

electrons (accept 18-electron rule and electron microscope)

In the exponential of wave functions for stationary states, this quantity is multiplied by negative i times t over h-bar. This quantity is equal to the time derivative of the action. The commutator of this quantity with time is negative i times h-bar, which means they have an uncertainty relation similar to Heisenberg’s. Two forms of this quantity are added together to give the (*) Hamiltonian. Quantum mechanical states are degenerate if they have the same value for this quantity. Work equals the change in this quantity. For 10 points, name this quantity that can come in potential and kinetic varieties.

energy [prompt on “Lagrangian†due to ambiguities with time derivative of action]

6. One estimate for this quantity, equal to 10.5 times the ideal gas constant, breaks down for liquids with strong intermolecular forces, thus deviating from Trouton’s rule. In one formulation, this quantity is proportional to the sum of the products of microstate probabilities and their respective natural logs. The change in this quantity can also be calculated as change in (*) heat divided by temperature. For an isolated system, this never-decreasing property has been challenged by Maxwell’s Demon, but otherwise holds true according to the Second Law of Thermodynamics. For ten points, name this property that measures the disorder in a system.

entropy <EC>

The mechanical balance equation over this quantity is actually an inequality. A Carnot cycle is a rectangle on a plot of it against temperature. Processes where this quantity changes don’t obey time reversal symmetry. The change in this quantity for a reservoir equals the heat over the (*) temperature of the reservoir. Separating a tepid stream into a hot and a cold stream decreases this quantity without added work. Irreversible processes cause it to increase due to inefficiencies, as shown by the Second Law of Thermodynamics. For 10 points, name this quantity measured in Joules per Kelvin, which is symbolized S and represents disorder.

entropy [or S until it is read]

This process does not change the density of matter over time in Fred Hoyle’s steady-state model. The Friedmann equations model this process, which implies an increasing scale factor. Alan Guth (gooth) proposed that this process occurred very quickly after the grand unification epoch to explain the absence of magnetic monopoles. Georges Lemaître’s (luh-MET-ruh’s) prediction of this process was confirmed by (*) Edwin Hubble’s measurements of galactic redshift. The Lambda-CDM model uses a positive cosmological constant to explain dark energy, which causes this process to accelerate. For 10 points, name this process by which points in the universe get further apart over time.

expansion of the universe [or expansion of space or cosmological expansion; accept word forms such as expanding universe; prompt on cosmic inflation; do NOT accept or prompt on “Big Bangâ€] <Astronomy â€" French> [Edited]

In order for this phenomenon to occur, the Stoner Criterion must be satisfied. This phenomenon cannot be accounted for in classical physics according to the Bohrâ€"van Leeuwen theorem. A generalization of a model describing this phenomenon was solved in two dimensions by Lars Onsager and is known as the (*) Ising model, and materials with this property exhibit hysteresis when the applied field is changed. This property disappears above the Curie point and occurs because of the alignment of spin states. For 10 points, name this attractive phenomenon exhibited by nickel, cobalt, and iron.

ferromagnetism

8. Materials that exhibit this phenomenon lie above the horizontal axis of a graph plotting exchange energy against the ratio a over r; that plot shows the Bethe-Slater curve. Objects exhibiting this phenomenon can produce popping noises in the Barkhausen effect. This phenomenon is described by a model where points on a model correspond to spin states of atoms, called the (*) Ising Model. This phenomenon occurs when the Weiss domains of an object align, which is only possible below the Curie temperature. For 10 points, name this phenomenon experienced by elements such as nickel, cobalt, and iron, which is a permanent form of magnetism.

ferromagnetism <Physics, VS><ed. VS>

The Nyquist value of this quantity is half the sampling value and is used for filters preventing aliasing [AE-lee-uh-seeng]. These values give the domain when a signal is broken down into its components using a Fourier [fur-ee-ay] transform. When the driving value of this quantity equals the natural value of this quantity for a system, resonance occurs. For a moving wave, this quantity equals speed divided by wavelength, and this is the reciprocal of period. Name this quantity measured in Hertz.

frequency (or frequencies)

Also called "gravitational drag", this term names a "dynamical formula" by Chandrasekhar [CHAN-duh-SEK-err] that describes bodies moving in outer space. This force studied by tribologists is proportional to normal load and independent of surface size according to laws by Guillaume Amontons. (*) Hydroplaning occurs when this is unintentionally reduced, and materials decreasing it are lubricants. For 10 pointsâ€"give this term for the force resisting materials sliding against each other, which you exploit to generate heat when you rub hands together.

friction (accept dynamical friction or Chandrasekhar friction)

15. Orest Khvolson studied one phenomenon caused by this force, which explains an optical effect centered on the Huchra galaxy. The redshift caused by a field of this force was measured in the Pound-Rebka experiment, and this force causes appearance of (*) Einstein rings. The n-body problem only considers objects affected by this force, which is central to the theory of general relativity. This force’s magnitude is inversely proportional to distance-squared, according to Newton’s Universal Law of it. For ten points, name this force that keeps Earth in orbit around the Sun.

gravity <MS>

Ernest Metzger's invention capable of measuring differences in this force is used in missile navigation and subsurface mineral detection. Loop theory is an effort to describe this in terms of quantum mechanics. It is approximately 10 to the 29th times weaker than the weak force. This force is proportional to the (*) masses of the bodies involved and inversely proportional to the square of the distance between them. For 10 pointsâ€"give this force which is only one-sixth as strong on the Moon's surface as on Earth's.

gravity [Metzger invented a gravity gradiometer]

Mascons are areas on the Moon where anomalies in this phenomenon occur, and spin foam is used as a model to observe the quantum type of this force. This phenomenon is described by the Ricci tensor plus metric times the cosmological constant, and its namesake (*) lensing causes light from massive objects in space to bend as it travels to the observer. LIGO detected this force’s waves, and if only this force is acting on an object on Earth, it will accelerate at 9.8 meters per second squared. For ten points, name this force that causes objects to attract to one another and the planets to orbit around the Sun.

gravity [accept word forms] <AG>

In quantum mechanics, the kinetic energy operator of a particle is “negative h-bar squared multiplied by del squared divided by massâ€, all multiplied by this constant. The relativistic Doppler shift is proportional to the quantity “one plus beta†over the quantity “one minus betaâ€, all raised to this constant (*) power. The moment of inertia through the axis of rotation of a solid disk is equal to this constant multiplied by the mass and radius squared. In classical mechanics, the distance traveled by a particle dropped in free fall is this constant multiplied by gravitational acceleration and time squared. For 10 points, the kinetic energy of a moving particle is equal to what fraction multiplied by mass and velocity squared?

half [or one half or 0.5; accept mathematical equivalents]

The Nusselt number is a ratio comparing two methods by which this scientific quantity is shifted. The Carnot [car-NOH] cycle gives an upper limit on the efficiency of converting this into another quantity expressible in ergs. If the universe reaches a state of maximum entropy, it may experience a "death" known by this term. (*) Sinks are devices that dissipate this, such as the devices with fans on computer processors. Conduction and convection are methods of transferringâ€"for 10 pointsâ€"what energy that moves from hotter to cooler systems?

heat (energy) (prompt on "energy"; do not accept "thermal energy" or “temperatureâ€)

This quantity's namesake equation can be stated as "partial derivative of u with respect to time equals alpha times Laplacian of u." For a system in which this quantity is zero, pressure times volume to a certain index is constant. The partial of this quantity with respect to entropy equals temperature. Its flux is proportional to the temperature gradient according to Fourier's Law for one method of its transfer. The change in internal energy equals this quantity minus work. In an adiabatic process, this quantity is kept constant. It is transferred by convection, conduction, and radiation. For 10 points, name this form of thermal energy.

heat [prompt on "thermal energy"; do not accept "temperature"]

Stephen Benton invented the most popular type of this phenomenon, the rainbow. In general, these are classified as either thin or thick, as amplitude or phase, and as transmission or reflection. Those classifications depend on the location of the reference beam when these are created and the spacing of their interference pattern. Dennis Gabor invented this technique whose creation was made practical by the development of lasers. Name these images which appear to be three-dimensional.

hologram (or holography)

The Lorentz-Lorenz equation relates this quantity to polarizability and density. In 1967, Victor Veselago showed that it is possible for a material to have a negative value for this quantity without breaking the laws of physics. It is required to know this quantity to calculate the angle at which reflected light will be perfectly (*) polarized off a surface. The critical angle between two surfaces can be calculated by taking the sine inverse of the ratio of this quantity in each medium. This quantity is often used along with the angle of incidence in Snell’s Law. For ten points, name this quantity of a material that is defined as the ratio of speed of light in a vacuum to the speed of light in a medium.

index of refraction <NG>

This value changes upon application of an electric field in the Kerr effect. Metamaterials have a negative value for this quantity which gains a complex part to account for absorption in opaque materials. When this value depends upon the polarity of light, different values of it can occur in a single material in a property known as (*) birefringence. The ratio of this quantity for two different materials is equal to the ratio of the angle of incidence and its namesake angle according to Snell's Law. For 10 points, name this ratio of the speed of light in a vacuum to the speed of a light in a given material.

index of refraction or refractive index (prompt on "n")

Grangier (gran-gee-AY), Roger (roh-JAY), and Aspect (a-SPECT) did not detect this process for a single photon using a device named for this process and Mach and Zehnder. Anti-reflective coatings maximize a form of this process that occurs when light reflects from the top and bottom surfaces of a thin film. A device named for this process did not detect evidence of the (*) luminiferous aether in the Michelson-Morley experiment. Along with diffraction, this process creates the fringes observed in the double slit experiment. The phase difference of two waves determines whether this process is constructive or destructive. For 10 points, name this process in which two waves combine to form a wave with a new amplitude.

interference [accept interferometer or interferometry or Mach-Zehnder interferometer or thin film interference or Michelson interferometer or constructive interference or destructive interference; prompt on diffraction before “diffractionâ€; prompt on superposition] <Physics â€" French> [Edited]

19. A quantity represented by this letter equals two pi over the wavelength and is termed the wavenumber. This letter represents a constant equal to one over four pi times the permittivity of free space, which appears in Coulomb’s Law. This letter also represents a constant multiplied by the displacement to give the (*) spring force according to Hooke’s law. A unit with this abbreviation has a value of 273.16 at the triple point of water and zero at absolute zero. For 10 points, name this letter that constitutes the abbreviation for the SI unit for temperature.

k <SAM>

3. The quantum mechanical operator for this quantity is negative h-bar divided by twice the mass times the Laplacian, and the virial theorem calculates the total amount of this quantity for a system of particles. By the equipartition theorem, it is equal to three halves Boltzmann constant times temperature. This quantity’s rotational analogue is proportional to moment of inertia times angular (*) velocity squared, and the change in this quantity is equal to the total work. Its linear form is equal to one-half mass times velocity squared. For ten points, identify this energy of objects in motion.

kinetic energy [prompt on “energy;†do NOT accept “potential energyâ€] <EC>

Some of these devices use exciplexes [EKS-ih-pleks-es], which are sometimes referred to as excited dimers [DIGH-mers], or excimers [EKS-ih-mers]. Those substances disintegrate when they are in the ground state, which means that a majority of them are in the excited state, a condition known as population inversion. That population inversion takes place within the gain medium of these devices, which is typically placed in an optical cavity. Early versions of these devices were monochromatic, and all of them produce an output that is very coherent. Name these devices capable of producing a very focused beam of light that can be used to read barcodes or DVDs.

lasers

13. The rate at which one process occurs in these devices is proportional to Einstein’s B-coefficient, and mode-locking can make them active for shorter periods of time. These devices typically require the gain medium to reach a state of population inversion, where there are more molecules in an (*) excited state than not. In 1960, Theodore Maiman used a ruby crystal in one of these devices not long after Charles Townes created a precursor to one of these objects that produced microwaves. For ten points, identify these devices that emit a very focused beam of light.

lasers (prompt on masers, accept light amplification by stimulated emission of radiation) <MS>

One of these devices uses the neodymium ion to dope a YAG host crystal. Optical tweezers operate from theforce created by these devices, which were used to cool rubidium-87 atoms in the creation of the first Bose-Einsteincondensate. Q-switching in these devices causes a phenomenon in which the number of particles in an excited stateexceeds the number in a lower energy state, called population inversion. The gain medium of these devices providesenergy during pumping, and the optical cavity consists of a pair of mirrors that allows the escape of photons. For 10points, name these devices that make light coherent through stimulated emission of radiation.

lasers [or light amplification by stimulated emission of radiation before "amplify"]

Though not synchotrons, one type of these devices makes use of wigglers to accelerate electrons through a transverse magnetic field. In 2012, physicists used one of these devices to create particles which were successfully quantum teleported 150 kilometers away. These devices use optical pumping to bring the system to a short-lived state which decays into the most populated metastable state. That's called population inversion. These devices, which come in a free-electron type, are used to create a transmission hologram. They create coherent photons through stimulated emission. For 10 points, name these devices which can make a monochromatic beam of light.

lasers [or light amplification by the stimulated emission of radiation; or masers before "light"]

The term vis viva refers to an early formulation of this law, which Gottfried Leibniz found applied to systems without collisions. A consequence of Noether’s theorem is that time-invariance symmetry implies this statement. An alternative to this principle used to formulate Hess’s law states that (*) Delta-U-equals-Q-minus-W. The first law of thermodynamics is another way of expressing this statement. It’s not the second law of thermodynamics, but perpetual motion machines that produce a work without an input violate this statement. For 10 points, name this statement that a quantity measured in Joules cannot be created or destroyed.

law of conservation of energy [accept first law of thermodynamics before “firstâ€] <DB, Physics>

For a particle, the generalized form of this quantity is equal to the derivative of the particle’s Lagrangian with respect to its generalized velocity. The center-of-mass frame is a special case of the center-of-[this quantity] frame, and thus, relative to the center of mass, the net amount of this quantity for a system is zero. Unlike (*) energy, this quantity is always conserved during explosions and collisions, as Newton’s second law states that external force equals the time derivative of this quantity. For 10 points, give this physical quantity equal to mass times velocity, generally understood as the impetus gained by a moving body.

linear momentum [or translational momentum; do not accept or prompt on “angular momentumâ€]

8. This quantity is plotted on the y axis of a one dimensional phase space diagram. For a photon, this quantity equals energy divided by the speed of light. The de Broglie wavelength of a particle equals Planck’s constant divided by this quantity. Heisenberg’s uncertainty principle states that this quantity and (*) position can not both be exactly known. Kinetic energy equals the square of this quantity divided by twice the mass. The change in this quantity is given by the impulse, and force is the derivative of this quantity with respect to time. For 10 points, name this quantity which is classically given by mass times velocity.

linear momentum [prompt on “pâ€] <SAM>

According to Alfvén’s Theorem, for a perfectly conducting fluid the flux of this entity through a surface is conserved. In order to account for this entity into its associated Lagrangian, a vector potential must be introduced. In the presence of a static one of these, a spectral line splits; that is the (*) Zeeman Effect. The strength of this entity can be measured for steady currents using the Biotâ€"Savart law. According to Maxwell’s equations, the divergence of this entity is 0. This vector field, when crossed with the product of velocity and charge, gives its associated force. For 10 points, name this field whose strength is measured in Teslas.

magnetic field (accept B-field or H-field, prompt on “B†or “Hâ€)

SQUIDs are devices that can measure the strength of this entity, and the Zeeman effect describes how spectral lines are split due to this entity. Because the force caused by it is perpendicular to the motion of a charged particle, this entity can do no work on them, and that force caused by this is known as the Lorentz force. The (*) Biot-Savart law describes one of these entities that is created by an electric current, and Gauss’ law states that the flux of this entity through a surface is zero. For ten points, name this vector field denoted by the capital letter B, the counterpart of the electric field.

magnetic field [accept B-field or H-field] <MS> BONUSES

Luminosity is proportional to this quantity raised to about the 7/2 power. This quantity is multiplied by 2 big G over c squared to calculate the Schwarzschild radius. Moment of inertia is defined as an integral over differentials of this quantity, and is equal to this quantity multiplied by (*) radius squared for a point. This quantity is multiplied by velocity to give an object’s momentum. For 10 points, name this quantity that is multiplied by little g to give weight on earth and is measured in kilograms.

mass

7. The de Broglie wavelength of a particle is equal to Planck’s constant divided by velocity times this quantity, and an object’s kinetic energy equals its momentum squared divided by two times this quantity. This quantity for sub-atomic particles is often measured in electronvolts divided by the speed of light squared, which can be derived from (*) Einstein’s famous equation.The force of gravity exerted by two objects is proportional to the product of this quantity for each object, and acceleration times this quantity equals force, according to Newton’s second law. For ten points, identify this quantity measured in kilograms and symbolized m.

mass (accept linear momentum before "velocity" is said) <MS>

An assay to detect binding affinity induces this phenomenon at electronic surface plasmons. Hermann von Helmholtz names a form of this effect occurring in an empty cavity. This process occurs at every normal mode, spaced by multiples of velocity over two times distance, for an open tube. An RLC circuit showing this effect has the least (*) energy loss. A pendulum, used as a mass damper, was installed into Taipei 101 to counteract this effect, which is often blamed for the collapse of a bridge in Tacoma. For 10 points, name this wave phenomenon which occurs at the natural frequency and results in a sudden increase in amplitude, such as in a tuning fork.

mechanical resonance [or acoustic resonance; or word forms]

One of these devices was oriented at 7 degrees relative to the canal ray tube in an experiment that proved time dilation. These devices surround the gain medium in lasers. They were placed at the center and at the ends of the arms of the Michelson interferometer. Two divided by the radius of (*) curvature of these devices equals one over the distance to the object, plus one over the distance to the image. Planar ones always produce virtual images of the same size. These devices are silvered, and they always invert an object from left to right. For 10 points, name these devices which reflect light.

mirrors [or specific types of mirrors]

The stretch rule states that this quantity does not change when an object is distorted along its axis of rotation. The tensor for this quantity is symmetric, and is diagonal in some orientation, defining an object's principal axes. If this value is given for one axis of rotation it can be found for certain others using the (*) parallel axis theorem. It is calculated by summing or integrating mass times distance from an axis squared, and rotational kinetic energy is equal to this quantity times the square of the angular velocity. For 10 points, identify this quantity, the rotational analog of mass, which often has units of kilograms times meters squared, symbolized I.

moment of inertia

The conjugate form of this quantity is equal to the partial derivative of the Lagrangian with respect to q dot. In quantum mechanics, the canonical commutation relation between position and this variable is i h-bar. In three-dimensional quantum mechanics, this quantity’s operator is negative i (*) h-bar times the gradient operator. The total energy of a free particle is this quantity squared divided by 2 times the mass. For massless particles, special relativity defines this quantity as the energy divided by the speed of light. For ten points, name this quantity, whose time derivative is force and in mechanics is equal to mass times velocity.

momentum

An equation named for this quantity sets the differential of the flow velocity field equal to the curl of the stress tensor, divided by density. That equation is named for Augustin-Louis Cauchy and is a restatement of this quantity’s conservation. This quantity is the conjugate variable of position. Kinetic energy can be given as this quantity (*) squared over two times mass. Impulse is the change in this quantity. This quantity is equal to the time derivative of force by Newton’s second law and it is conserved in both inelastic and elastic collisions. For 10 points, name this quantity symbolized p, the product of mass and velocity.

momentum [or Cauchy momentum equation; or conservation of momentum; prompt on p] <DB, Physics>

A non-zero electron dipole moment for this particle would violate CPT symmetry. The results of an earlier experiment by Irene and Frederic Joliot-Curie involving polonium, beryllium and paraffin wax was explained as the emission of this particle.  Because its’ radiative capture cross-section has no regions of resonance, Boron-10 is used to control the(*) radiation of these particles in thermal reactors. They consist of one up and two down quarks. Isotopes have the same number of protons, but different numbers of these particles. For 10 points, name these particles discovered by James Chadwick, which have no electric charge.

neutrons <David Dennis>/<ed. HB>

13. Fusors can eject beams of these particles, which are often produced from a spallation source. These particles have magnetic moment equal to 1.9 times the nuclear magneton, but it is unknown whether or not their electric dipole moment is zero. Boron-10 is very able to (*) “capture†these particles, which are composed of two down and one up quark. A nuclear chain reaction depends on the release of these particles, and they were discovered by James Chadwick. For ten points, identify these 1 atomic mass unit particles which have no charge.

neutrons <MS>

8. The RaLa Experiment tested devices that initiate this process. One quantity important for this process is inversely proportional to density squared and includes a fudge factor for deviations from spherical geometry. For this process to be sustained, the effective (*) neutron multiplication factor must be greater than or equal to one. Boron is used to capture neutrons released as a byproduct of this process. This process can only occur past the critical mass, and it often takes place in breeder reactors. The most common fuel for this process is enriched uranium-235. For 10 points, name this process in which the nucleus of an atom splits into smaller parts.

nuclear fission <SAM>

5. This reaction’s “triple product†of density, temperature, and time is a generalization of the earlier Lawson criterion for it. Muons can catalyze this process by replacing electrons in hydrogen bonds, and the beam-target variety of this reaction loses too much energy to bremsstrahlung. Failing to account for the less-than-100% Faraday-efficiency in the (*) electrolysis of water led Pons and Fleischmann to falsely claim this process had occurred at room temperature, its “cold†type. This type of reaction is central to the CNO cycle and the proton-proton chain. For ten points, identify this process in which multiple atomic nuclei are combined.

nuclear fusion <MS>

1. In order for this process to achieve breakeven, n times the confinement time must be greater than a certain minimum. That requirement is known as Lawson’s criterion. The technique of inertial confinement achieves this process by breaking the Coulomb barrier. This process occurs in stellarators and (*) tokamaks. Fleischmann and Pons falsely claimed to have achieved the “cold†form of this process. In stars, this process may occur through the proton-proton chain or the CNO cycle. For 10 points, name this process in which multiple nuclei combine to form a heavier one, contrasted with fission.

nuclear fusion <Physics, DY><ed. KLei>

A scale ranging from zero cents to a dollar measures the activity of these devices. SCRAM mechanisms are safety measures used with these devices. A fudge factor literally called the “fudge factor†is used to calculate their critical masses. The first of these devices was built on a squash court underneath the University of (*) Chicago football field. Heavy water is used as a coolant and moderator by some of these devices. They have control rods made out of boron to absorb neutrons. Those rods usually surround a fuel composed of uranium-235 or plutonium-239. For 10 points, name these devices which produce energy through nuclear fission.

nuclear reactors [or nuclear power plants; or similar answers; or nuclear piles; prompt on reactors; prompt on nuclear bombs or nuclear weapons or similar answers]

For a body undergoing circular motion due to gravity, total energy equals potential energy times this factor. In special relativity, length contraction is proportional “one minus beta-squared†all raised to this power. The reduced mass of a pair of identical bodies equals this number times the mass of one body. For a solid disk in the x-y plane, the moments of inertia about the x and y axes both equal (*) this constant times the moment of inertia about the z axis. This fraction appears in the potential energy formula for a harmonic oscillator, and it multiplies “a t-squared†in the acceleration term for projectile motion. Kinetic energy equalsâ€"for 10 pointsâ€"what fraction, times mass times velocity-squared?

one half [or one over two; or 0.5] <AF>

Access to one of these machines at Brookhaven enabled James Cronin and Val Fitch to discover CP violation. The proposal to build one of these near Waxahachie [WAWK-sah-HATCH-ee], Texas was canceled in 1993. Rolf Widerøe and Ernest Lawrence designed versions of these devices using magnets. Many modern ones are (*) circular and the largest examples, such as the one used to detect the Higgs Boson, have diameters measured in kilometers. For 10 pointsâ€"give the term for these devices that propel particles to near the speed of light.

particle accelerators or atom smasher or supercollider (accept hadron collider or synchrotron or cyclotron)

These devices are used in the König and Persoz hardness tests of paints. Henry Barton created one of these to demonstrate resonance. An experiment that exploits precession to demonstrate the rotation of the Earth used one of these devices designed by Léon (*) Foucault [foo-COH]. The quantity 2 pi times the root of length over gravity gives the period of these objects. Galileo studied them after observing a moving chandelier, and Christiaan Huygens [HOY-gens] used them in clocks. For 10 pointsâ€"give the term for these swinging weights.

pendulum

A team led by Nevil Maskelyne used one of these objects to calculate the density of the Earth. These objects were once used to calculate the momentum of a speeding bullet. The differential equation “d squared theta d t squared equals negative g over L sine theta†describes these objects; that equation is then solved by assuming sine theta equals (*) theta. One of them placed at the dome of the Pantheon was used to demonstrate the rotation of the Earth by Foucault. Their periods are independent of mass. For 10 points, name these simple harmonic oscillators which consist of a bob on a string, used in grandfather clocks.

pendulums [or pendula; or ballistic pendulum; or Foucault’s pendulum]

The Shockley-Queisser formula gives efficiency goals of these devices, one of which Charles Fitts invented by coating selenium with gold. Like the trend of computer processors, Swanson’s law says these devices’ prices have halved every ten years. A gallium arsenide semiconductor was used in the ones of these on the rovers (*) Spirit and Opportunity. Dow chemical formerly integrated them into roof shingles. About one percent of current U.S. energy consumption is generated byâ€"for 10 pointsâ€"what devices that won’t produce much electricity in a dark room?

photovoltaic cells (or system) or solar cells (accept solar panels or solar battery; prompt on “solar powerâ€)

The distribution function of this substance obeys a collisionless form of the Boltzmann equation called the Vlasov equation. The distance at which the electric potential of a charge carrier is screened by a factor of one over e in this substance is called the Debye length. Hannes Alfven founded a field of study focused on this substance called (*) magnetohydrodynamics. This substance is confined using poloidal and toroidal magnetic fields in a tokamak. Particles must be in this state of matter for natural nuclear fusion to occur. For 10 points, name this “fourth state of matter†which consists of a very hot gas of ions and makes up the Sun.

plasma <Physics â€" Gurazada> [Edited]

The Alfven time of waves in these substances is equal to the inner radius of a device used to contain them divided by the Alfven velocity. Rapid oscillations of electron density in these substances are known as (*) Langmuir waves. The extent to which charge carriers can have electrostatic effects in these substances is known as the Debye length. Magnetic fields are used to confine these substances in a toroidal shape in tokamaks. For 10 points, name these ionized substances known as the fourth state of matter.

plasmas

The LHC's ALICE is an experiment to create a substance of this type consisting of asymptotically free quarksand gluons. The average number of electrons in a substance of this type in a Debye sphere is this substance'snamesake parameter lambda. A tokamak magnetically confines substances of this type to a torus. Substances of thistype are studied by Langmuir probes and created through the Townsend discharge. The heliosphere is defined by theextent of a substance of this type emitted by the sun, the solar wind, and these are created by ionizing a gas at hightemperatures. For 10 points, name this fourth state of matter present in stars, neon signs, and lightning.

plasmas

The time evolution of the distribution function of this substance is described by the Vlasov equation, and Birkeland currents are driven by the bulk motion of this substance. One phenomenon in this substance consists of ions oscillating in response to tension on magnetic field lines; those low-frequency oscillations in this substance are called (*) Alfven waves. This substance is treated as a single fluid in magnetohydrodynamics, and this substance can be confined in the shape of a torus by a tokamak. The interior of the Sun is a fully ionized example of this substance, while lightning storms are only partially ionized. The most abundant form of ordinary matter in the universe is--for 10 points--what highly ionized substance deemed the “fourth state of matter�

plasmas

5. Reconnection occurs much quicker in examples of these substances with high Lundquist numbers than predicted by a theory that combines the Navier-Stokes equations with Maxwell’s equations to describe them. Alfvén waves in these substances are a type of MHD wave. Z-pinches were historical devices to contain this substance. Electric fields get screened out of these substances up to the (*) Debye [[“duh-byeâ€]] length. Magnetic reconnection in these substances can cause solar flares, as this substance makes up most of the mass of the Sun. For 10 points, name this type of highly ionized gas often called the fourth state of matter.

plasmas <Physics, VS><ed. KLei>

This particle’s namesake “annihilation spectroscopy†is used to study defects in solids. The emission of this particle is used in potassium-argon dating. This particle was discovered from observations of its curved track on a lead plate by (*) Carl Anderson. Fluorodeoxyglucose is a source of this particle used to generate gamma rays in their namesake “emission tomographyâ€. These particles were predicted from negative energy solutions to the Dirac equation. A Dalitz pair is composed of one of these particles and an electron. For 10 points, name this positively charged fermion symbolized e+.

positron

8. A “screened†one of these things includes a rapidly decaying exponential and is named for Hideki Yukawa. The “effective†type of this thing includes a term proportional to the square of the angular momentum and is used to calculate orbits. Force equals the negative gradient of this thing. For an inverse square law, a type of energy associated with this thing is inversely proportional to one over the distance. In a uniform gravitational field, that (*) energy equals the mass times g times the height. For 10 points, name this scalar field that describes a type of energy contrasted with kinetic energy.

potential [accept potential energy after “energyâ€] <SAM>

One type of this quantity can be calculated as one-half the volume integral of the H-vector dotted with the B-vector. That type is periodically exchanged with another type of this quantity in an LC circuit. An electric field E contributes a density of this quantity equal to “one-half epsilon-nought times E-squared.†A capacitor holding a charge Q has a value of (*) “one-half Q-squared over C †for this quantity. For a single charge, this quantity equals the charge times the voltage at which it is held, and it can be calculated as the work required to move that particle into its position. For 10 points, name this amount of energy stored in a system.

potential energy [prompt on energy until mentioned; do not accept or prompt on “(electric) potentialâ€] <SE>

General relativity predicts a type of this effect named for de Sitter, also called the geodetic effect, while in one form of this process a torque is caused by a magnetic field. A system undergoing this effect has a changing first Euler angle, and this effect is often combined with (*) nutation, which causes irregularities in this effect. A time-varying moment of inertia causes the torque-free type of this effect, and this effect during the Earth’s orbit causes the motion of the equinoxes along the ecliptic and the changing seasons. A classic example of a system undergoing this effect is a spinning top wobbling over time. For 10 points, name this effect in which the rotation axis of an object changes orientation.

precession

20. This quantity is equal to the negative partial derivative with respect to volume of the Helmholtz free energy. The log of one form of this quantity is related to constants A, B, C, and temperature in the Antoine equation. Gas solubility is directly proportional to a type of this quantity. High values of one form of this quantity are found in (*) volatile substances; that property is calculated for a solution using Raoult’s Law. This quantity is held constant in any isobaric process, and this quantity times V equals nrt [[“n-r-tâ€]] by the ideal gas law. For 10 points, name this quantity, measured in Pascals and defined as force per unit area.

pressure [accept partial pressure or vapor pressure, prompt on P] <Chemistry, CT><ed. KLei> Bonuses

10. One coefficient of this phenomenon can be found with Schlick’s approximation, and its diffuse form is applied in Lambert’s cosine law. This phenomenon notably does not occur for a certain polarization at Brewster’s angle. At values above the critical angle, the (*) total internal type of this phenomenon occurs, and the law of it states that the angle at which this process occurs is equal to the angle of incidence. For ten points, identify this phenomenon in which a wave returns to its original medium after contacting a surface, easily observed with mirrors.

reflection (accept word forms) <EnC> HALFTIME

In metals, this process only occurs in the absence of Langmuir waves below the plasma frequency. The intensity of this process is given by the square of “n-1 minus n-2, over n-1 plus n-2†according to the Fresnel equations. For a properly polarized input, this process does not occur at Brewster’s angle. Light propagating above the (*) critical angle is transmitted in optical fibers via the “total internal†type of this process. After the specular type of this process, the angle of the outgoing ray equals the angle of incidence. For 10 points, name this optical process in which light bounces off of surfaces like mirrors.

reflection [accept total internal reflection; accept specular reflection] <SE>

In telecommunications, the coefficient of this phenomenon is displayed graphically using a Smith chart. Spectralon is useful in photospectrometry because it has near-perfect levels of the Lambertian diffuse type of this phenomenon. In metals, the coefficient of this phenomenon is related to their conductivity using the(*) Hagen-Rubens relation. Perfectly polarized light does not experience this phenomenon when transmitted at Brewster's angle. Above the critical angle, the “total internal†variety of this phenomenon occurs. For 10 points, name this process in which light bounces off of surfaces like mirrors.

reflection [or Total Internal Reflection] <David Dennis>/<ed. HB>

This phenomenon is not observed in a thin film if the thickness times the index of refraction is a half-integer multiple of wavelength. This phenomenon introduces "s-polarization" at an angle equal to the arctangent of the ratios of the indies of refraction, at Brewster's angle. It can be "specular" or "diffuse." Above the critical angle, the sparkle of diamonds occurs due to the "total internal" form of this phenomenon. In general, this phenomenon results in an angle symmetric to the angle of incidence, with respect to the normal. For 10 points, name this phenomenon in which light turns around when it hits an object, such as a mirror.

reflection [or total internal reflection]

The change in a quantity describing this phenomenon is directly proportional to the square of an applied electricfield in the Kerr effect. In anisotropic crystals, polarization of light into ordinary and extraordinary rays causes thedouble form of this process, also known as birefringence. One law describing this process sets the ratio of the sinesof the angle of incidence and namesake angle equal to the ratio of two phase velocities. Dividing the speed of lightin a vacuum by the speed of light in a substance yields its namesake index, which appears in Snell's Law. For 10points, name this bending of light as it travels through a surface that separates two media.

refraction

This phenomenon explains why it is easier to hear noises across a lake at nighttime rather than during the day. This physical process is skewed in people who suffer from keratoconus [keh-rah-toe-KOE-nus] or astigmatism, and it can be impacted by direction in materials with birefringence [bie-ree-FRIN-jens]. Beyond a critical angle, total internal reflection occurs instead of this wave phenomenon. Name this phenomenon quantified by Snell's Law, the bending of light as it changes from one medium to another.

refraction (accept word forms such as refract or refracting, do not accept diffraction)

One formulation of this law states that the closed line integral of the heat absorbed by the system over temperature is less than or equal to zero. Loschmidt's paradox arises from a statement of this law that breaks time-reversal symmetry known as (*) Boltzmann’s H-theorem. This law states that heat cannot spontaneously flow from a colder object to a warmer object. A thought experiment that would violate this law involves the opening and closing of a gate to allow particles of different speeds through, that is Maxwell’s Demon. For 10 points, name this law that states that the entropy of a closed system cannot decrease.

second law of thermodynamics

Calculations for the behavior of electrons in these substances assign the electrons an effective mass that varies inversely with the second derivative of the electric field and has nothing to do with actual mass. The two carriers in these materials cancel each other out during the recombination process. These substances used in photovoltaic cells typically have band gaps between 0.1 and 10 electron volts where no electrons can exist. Some of these materials conduct holes instead of electrons, and are known as p-type. Name these substances that can be doped to improve efficiency and which are often based on germanium or silicon.

semiconductors

The energy eigenspectrum associated with this system’s quantum analogue can be solved for analytically using Hermite Polynomials or algebraically using the creation and annihilation operators. If its potential is truncated quadratically in the Taylor series centered around the minimum potential, any arbitrary system can be (*) modelled by this system. The general homogeneous solutions to this system’s equations of motion are complex exponentials in time. Approximating sine of x to first order allows for the use of this system for ideal pendulums at small angles. For ten points, name this physical system which can be used to model frictionless, Hookean springs.

simple harmonic oscillators (accept SHOs, prompt on “harmonic oscillatorsâ€) Bonuses

The dye-sensitized form of these devices contains a porous layer of titanium dioxide nanoparticles. Perovskites are of interest as forming the active layer in these devices. These devices rely on a phenomenon which occurs when charge carriers become excited and produce excitons, generating an electric potential difference. That phenomenon involving these devices is sometimes contrasted with the (*) photoelectric effect, since the charge carriers stay within the material. A simple silicon p-n junction can act as these devices, since electrons become excited upon incident light. For 10 points, identify these devices, which can convert sunlight into electricity.

solar cells [or photovoltaic cells; or PVs; or solar panels] <GC, Physics>

This constant appears raised to the negative fourth power on one side of the EFE. The square of this constant multiplies the time component of the line element for Minkowski space. Velocity squared is divided by the square of this constant in the definition of the (*) Lorentz factor. The index of refraction for a medium is equal to this value in a vacuum divided by this value in the medium. The energy of a particle at rest equals mass times this constant squared according to Einstein. For 10 points, name this constant that represents how fast electromagnetic waves travel in a vacuum.

speed of light [accept c]

For a given spatial position and time, this quantity is the ratio between the magnitude of the electric field and the magnetic field for a wave. Maxwell discovered that the square of this quantity equals the reciprocal of the product of vacuum permittivity and permeability. The meter is defined using this value, which was found to be constant in any direction in the Michelson-Morley experiment. Index of refraction is the quotient of this value in a material and this value in a vacuum. The square of it is the proportionality constant in Einstein's mass-energy equivalence. For 10 points, name this constant equal to about 3.0 times ten to the eighth meters per second, symbolized c.

speed of light [or c before mentioned]

For an ideal gas, this quantity equals the square root of the adiabatic index times the gas constant times temperature over molar mass, a result which can be derived from a more general formula equating it to the square root of the bulk modulus over the density. For air, this quantity varies based on humidity and temperature. An object (*) exceeding this quantity will cause the formation of a cone of condensation due to the formation of a shock wave, which is also accompanied by a loud boom. For 10 points, identify this speed equal to Mach one, the rate at which phenomena such as thunder and voices propagate through a medium.

speed of sound (accept Mach one before mentioned)

The square of this quantity equals the expectation of X squared minus the square of the expectation of X. GE developed an industrial quality benchmark symbolized by six times this quantity. This quantity times the Z-score is used to calculate a confidence interval. The “sample†and “population†forms of this quantity use N-1 and N in the (*) denominator, respectively. This quantity is the square root of the central second moment. The empirical rule sets 68, 95, and 99.7% of the data within one, two, and three times this quantity away from the mean. For 10 points, name this square root of the variance, a measure of data spread symbolized sigma.

standard deviation [or sigma until it is read; or Six Sigma; accept uncertainty until "Z-score" is read; prompt on s]

In general relativity, this quantity, energy, and momentum are the components of a four by four matrix tensor, which generalizes a three by three matrix tensor named for Cauchy. Although this quantity is not unitless, a nonzero value of it produces the Poisson effect. This quantity is on the Y axis of a curve that contains an elastic region and a plastic region. The (*) “shear†type of this quantity acts parallel to the cross-sectional surface. For an elastic material, Young’s modulus is equal to this quantity divided by the strain. For 10 points, name this quantity measured in Pascals that describes the internal force acting on a deformed object.

stress [prompt on “pressureâ€] <SAM>

One equation describing a form of this phenomenon sets the potential proportional to the negative exponential of radius divided by radius; that equation for the Yukawa potential describes the residual form of this phenomenon. Confinement of a certain quantity prevents the free “emission†of this phenomenon, and instead leads to the production of jets of massive particles. This phenomenon is described by quantum (*) chromodynamics, since this interaction’s carrier particle possesses a color charge; that carrier particle is the gluon. The force that binds quarks together into nucleons and protons and neutrons together into atomic nuclei is--for 10 points--what fundamental force with a strength approximately 137 times that of electromagnetism?

strong interaction [or strong nuclear force; accept strong force or nuclear strong force]

Attempts to understand this force have included Regge [REG-gee] theory, dual resonance, and string theory. The existence of this force caused Hideki Yukawa to predict the existence of mesons, and his predictions matched the measurements of pions [PIE-ons]. This force is currently explained by quantum chromodynamics, which describes the interactions of gluons and quarks. Name this interaction with a very small range that is used to explain the attractions of particles in an atomic nucleus.

strong nuclear force (or strong interaction, accept color force before "chromodynamics", prompt color force after "chromodynamics")

Bednorz and Muller discovered this property in a lanthanum-based cuprate perovskite material, paving the way for the creation of materials like MgB2. A characteristic depth of materials exhibiting this property represents the distance at which the magnetic field equals the surface magnetic field over the fundamental charge; that depth is named for London. Bardeen (*), Cooper, and Schrieffer explained this property as a superfluid of Cooper pairs, and materials exhibiting this property may expel a magnetic field in the Meissner effect, which can be used to make small model maglev trains. For 10 points, name this phenomenon in which a material exhibits zero electrical resistance.

superconductivity

Objects with this property have a characteristic coherence length and London penetration depth, and can be used in SQUID magnetometers. It can be described by Ginzburg-Landau theory, and a perovskite-based compound can maintain this property at a temperature above 77K, and is called (*) YBCO. The Type I of this phenomenon is explained as the condensation of electrons into Cooper pairs by BCS theory and this effect causes the expulsion of magnetic fields in the Meissner effect, which can allow materials with this property to levitate. For 10 points, materials lowered below their critical temperature have what property in which there is no resistance?

superconductivity [accept superconductors]

This quantity is inversely proportional to the wavelength at which blackbody radiation intensity is maximized, according to Wien’s Law. The radiant power of a black body equals the Stefanâ€"Boltzmann constant times this quantity raised to the fourth power. It’s not color, but the Harvard system, which groups stars into (*) O, B, A, F, G, K, and M types, classifies stars based on this property. The HR diagram plots luminosity against this variable, which is much greater for blue giants than for red supergiants. This quantity is much greater in the corona than at the sun’s surface. For 10 points, name this quantity that, for the center of the sun, is approximately 15 million Kelvin.

temperature <AF>

This variable appears in the denominator of thermodynamic beta. In a throttling process, the change in this quantity is described by the Joule-Thomson effect. Three-halves times this variable is proportional to the kinetic energy of a gas. Equilibrium with respect to this quantity is transitive according to the zeroth law of (*) thermodynamics. Gases have a standard value for pressure and this quantity, which is zero on one scale. One can add 273 to change between two scales for this quantity, while another conversion can be made by multiplying by nine-fifths and then adding 32. For 10 points, name this quantity with Kelvin, Celsius, and Fahrenheit scales.

temperature (prompt on "T")

The derivative of this order of position is found in the numerator of the formula for the Abraham-Lorentz force. In the formula for the power radiated by an accelerating point charge, the denominator contains this power of the speed of light; that is the Larmor formula. The Nernst-Simon statement is a version of a law of this number that is usually stated with the unattainability principle; that law originally concerns the (*) entropy of a perfect crystal at absolute zero. This many non-time dimensions are present in Minkowski space, and the action-reaction law is Newton’s law of this number. For ten points, name this number of laws in both Kepler and Newton’s sets of laws.

three [or third derivative /power / law of thermodynamics, or Newton’s third law; accept cube(d); prompt on “jerk†with “Which is how many derivatives of displacement?â€]

5. The general Schrödinger equation is described as “dependent†on this quantity. The partial derivative of  magnetic field strength with respect to it equals the curl of the induced electric field, according to the Maxwell-Faraday law of induction. This quantity also describes a constant in the exponential term of equations describing (*) LC circuits. Taking the derivative of velocity with respect to this quantity gives acceleration, and this quantity is unified with space in the theory of relativity. For ten points, identify this quantity from physics, typically measured in seconds.

time <MS>

A converter named for this concept is in cars with automatic transmissions instead of a clutch, allowing drivers to use the brakes without harming the car. To find this quantity on a loop of wire, start with the product of current times vector area, and cross that with the external magnetic field. Work can be found by integrating this quantity with respect to angle, and this quantity is equal to the time derivative of angular momentum. Name this quantity equal to both moment of inertia times angular acceleration and to position vector cross force, the rotational analogue of force.

torque

22. One device comprised of “sun†and “planetary†gears multiplies this quantity, which is responsible for gyroscopic precession. Despite having the same units as energy, this quantity is equal to energy divided by the angle of displacement. This quantity is sometimes expressed as (*) moment of inertia times angular acceleration, since it is also the time derivative of angular momentum. More commonly, the right-hand rule is applied when determining this quantity because it is the cross product of radius and force. When this net quantity equals zero, an object does not rotate. For ten points, identify this rotational analogue of force.

torque [accept moment of force; prompt on "tau"] <EC> Bonuses

In one theory of this phenomenon, viscosity cubed over rate of energy dissipation all to the one-fourth power gives its smallest length scale. The energy cascade from large to small scales during this phenomenon is driven by vortex stretching. Once Kolmogorov microscales are reached, the kinetic energy necessary for this phenomenon to occur is lost as heat due to molecular viscosity. This phenomenon occurs at (*) high values of inertial forces divided by viscous forces, which is referred to as the Reynolds number. Laminar flow is contrasted with, for 10 points, what chaotic fluid flow that can cause unpleasant plane rides?

turbulence [or “turbulent flowâ€]

21. The Frank-Tamm formula explains why this type of emission is most common when an electron traveling faster than the phase velocity of light emits Cherenkov radiation. Wien’s approximation favors this type of emission, which was predicted to lead to infinitely powerful black body radiation according to the Rayleigh-Jeans law; that dilemma is its namesake (*) “catastrophe.†People with aphakia are able to witness this phenomenon, which occurs in a range between 10 and 400 nanometers in wavelength. For ten points, name this part of the electromagnetic spectrum with wavelength longer than x-rays but shorter than visible light.

ultraviolet or UV light <EC>

19. Researchers have recently used an array of SQUIDs to produce photons in this medium, and electron interaction with this medium accounts for the small energy difference between the 2s and 2p energy levels. Particle interactions between a pair of metal plates in this medium is described in the (*) Casimir effect, and evaporation into this medium is known as outgassing. This medium sets a benchmark for the speed of light, and it is where true freefall occurs. Often achieved in laboratories by using an air pump, this medium is approximated by outer space. For ten points, give this condition that describes a space devoid of matter.

vacuum [prompt on “free spaceâ€] <EC>

When two values of this vector quantity are added together, you are supposed to divide the initial sum by one plus the product of the values over the maximum value of this quantity squared. This vector quantity's magnitude is squared and multiplied by half of fluid density when Bernoulli's principle is written in terms of pressure. This quantity is crossed with magnetic field strength and multiplied by charge to find the force of a magnetic field. The magnitude of this vector quantity is squared and divided by radius to find centripetal acceleration. Name this vector quantity equal to displacement divided by time.

velocity

The Laplacian of this quantity equals charge density over epsilon-nought, according to an application of Poisson’s equation. This quantity due to an infinite line of charge is proportional to the logarithm of distance, while this quantity due to an electric dipole is proportional to distance to the negative second power. The charge stored in a capacitor equals capacitance times the (*) difference in this quantity. In physics without calculus, this quantity divided by distance is the electric field. The power emitted by a resistor equals this quantity times current. For 10 points, name this quantity which, according to Ohm’s law, is equal to current times resistance.

voltage [or electric potential or scalar potential or electric scalar potential; accept voltage difference or electric potential difference or scalar potential difference or electric scalar potential difference; prompt on V or phi or delta-V or delta-phi; do NOT accept or prompt on “vector potentialâ€] <Physics â€" Gurazada> [Ed. French]

One type of this quantity is multiplied by one minus the scattering angle to yield the Compton shift. That type of this quantity is equal to Planck’s constant over mass times the speed of light. Another type of this quantity equals Planck’s constant divided by momentum. That type of this quantity is defined for all matter and is named for (*) de Broglie (BROY-glee). Electromagnetic radiation with the lowest value for this quantity is classified as gamma radiation. The velocity of a wave divided by this quantity gives the wave’s frequency. For 10 points, name this quantity, the spatial distance between consecutive peaks of a wave.

wavelength [accept Compton wavelength or de Broglie wavelength; prompt on lambda] <Physics â€" Gurazada> [Edited]

The equation governing these phenomena can usually be written as the d'Alembertian of a field being equal to zero, and "packets" of these phenomena obey the Fourier uncertainty principle. In dispersive media, their phase and group velocities may differ, and in moving media they undergo the (*) Doppler effect. Nodes and antinodes are seen in their "standing" variety, and depending on their mode of propagation, they may be longitudinal or transverse. Traveling ones move at a speed equal to the product of their namesake length and their frequency. For 10 points, name these phenomena, such as light or sound.

waves (accept electromagnetic waves before "nodes" is read)

The Kleinâ€"Gordon equation generalizes the partial differential equation named for these things, which relates a function’s second partial derivatives with respect to time and position. Solitons are examples of these things that move with constant velocity without broadening. In matter, a characteristic property of these things was calculated as (*) Planck's constant over momentum by Louis de Broglie. When two of these things with similar frequencies overlap, they exhibit beats. Those that do not transfer energy and have fixed nodes of zero amplitude are called “standing.†Young’s double-slit experiment showed that light acts as both a particle andâ€"for 10 pointsâ€"what type of time-varying oscillation?

waves [accept more specific types of waves, such as light waves, sound waves, or water waves; accept wave packets] <SE>

Technicolor theories describe the particles that carry this force without introducing the Higgs mechanism. Feynman and Gell-Mann proposed the vector minus axial vector Lagrangian for this force. Madame Wu demonstrated that this force violates P-symmetry. The hierarchy problem asks why the strength of this force is so much greater than (*) gravity. This force governs the flavor changing of quarks. The detection of W and Z bosons confirmed the unification of this force with electromagnetism. For 10 points, name this nuclear force that governs particle decay.

weak force

A graphical construct used to visualize this interaction is the unitarity triangle. A matrix named for Cabibbo, Kobayashi, and Maskawa explains reactions mediated by this interaction. Stochastic cooling of proton beams was used to discover the mediators of this interaction, leading to the Nobel Prize of (*) Carlo Rubbia and Simon van der Meer. Cronin and Fitch used kaon decay to show that this interaction violates CP-symmetry. This force was unified with electromagnetism by Salam, Weinberg, and Glashow. For 10 points, name this fundamental force mediated by the W and Z bosons and responsible for beta-decay.

weak force (accept weak interaction)

The Duane-Hunt Law describes the maximum frequency of this type of radiation that can be produced by the deceleration of electrons in a process known as bremsstrahlung. It is the weaker of the types of radiation that undergo Compton scattering, and the different forms of this radiation are called hard and soft. While experimenting with a Crookes tube, (*) William Röntgen discovered this radiation. This type of radiation is more energetic than UV light but less so than gamma rays. For 10 points, name this type of radiation often used for its penetrating strength to take medical pictures of bones.

x-rays (or x-radiation; accept Röntgen rays before mention)

This value names a limit first surpassed in 2013, using a quantum gas of potassium atoms. This is the total spin of a particle or particles in a singlet state. This number’s law of thermodynamics states that thermal equilibrium is transitive. According the kinetic theory, this is the volume of each particle in an (*) ideal gas. This is the change in Gibbs free energy for a system at equilibrium. By the third law of thermodynamics, this is the entropy of a perfect crystal at a temperature with this name. Minus 273.15 degrees Celsius is the “absolute†temperature named forâ€"for 10 pointsâ€"what value?

zero [accept zeroth law of thermodynamics; accept absolute zero] <AF/JR>

Cap sealing takes advantage of this phenomenon, since this can be used to temporarily heat aluminum foil. Explained soon after a related discovery by Hans Christian Oersted, its direction is given by Lenz's Law. This is used in a squirrel-cage or asynchronous motor. Name this phenomenon whose explanation is often credited to Michael Faraday and which involves the creation of an electric potential difference by a change in a magnetic field.

(electromagnetic) induction

For a particle in circular motion in a magnetic field, this quantity equals linear momentum divided by the product of radius and magnetic field strength. The force of a magnetic field on any particle equals this quantity times the cross product of velocity and magnetic field. This quantity also equals the force of an electric field divided by its field strength, and this equals work divided by electric potential difference. Name this quantity that can be measured in coulombs [koo-lomes].

(net) electric charge

The waves named for this person, which are very similar to Lamb waves, travel along solid surfaces and are generated by earthquakes. His name also is used for the situation when the minimum amplitude of one diffraction image coincides with the maximum amplitude of another, his namesake criterion. This person is also named for the elastic scattering of light, which is used to explain why the sky is blue. Name this scientist whose namesake scattering is often contrasted with Raman [RAH-mun] scattering.

3rd Baron Lord Rayleigh (or John William Strutt)

This scientist showed a quantitative link between Rayleigh scattering and critical opalescence, and he also created a theory of stimulated emission for use in lasers. This scientist who names a set of ten field equations worked with Rosen and Podolsky to develop the EPR paradox. With Satyendra Bose, he developed statistics predicting the behavior of bosons, and this physicist won the Nobel Prize for his explanation of the photoelectric effect. For 10 points, name this developer of the theories of special and general relativity.

Albert Einstein

This man proposed a model which helped to explain the Dulong-Petit law at high energies, and he said quantum entanglement was “spooky action at a distanceâ€. This man’s paper “On the Electrodynamics of Moving Bodies†was part of his groundbreaking (*) Annus Mirabilis papers, which he published while working at a patent office in Bern. This scientist proposed that an object’s length would appear to shorten if it is travelling near the speed of light, and won the Nobel Prize for his work on the photoelectric effect. For ten points, name this 20th century physicist who famously stated that energy is equal to mass times the speed of light squared.

Albert Einstein <AG>

Materials similar to these objects were made vertically aligned carbon nanotube arrays in 2014. One law relating to these objects can be written as nu cubed over an exponential term minus one. Early remnants of the universe can be modelled as these objects. These objects are modelled as a cavity with a (*) hole in it. Rayleigh and Jeans created a law involving the radiation of these entities. That law failed at ultraviolet wavelengths and was improved upon by Planck’s Law. For 10 points, name these idealized objects that absorb light uniformly at all wavelengths.

Blackbodies

When resistors are connected to these devices in a circuit, the time constant for the decay of current is directly proportional to both the resistance and their strength. The impedance of these devices is inversely proportional to the frequency, and energy stored in them is proportional to voltage squared. The strength of these devices can be increased by a dielectric, and their namesake quantity adds when they are placed in parallel in a circuit. Their strength is given by the amount of charge they store per volt, which is measured in farads. They frequently consist of two parallel plates. For 10 points, name these components that store electric charge.

Capacitors

The Majorana particle must contain a value of zero for this quantity. Weak interactions were shown to violate symmetry related to parity, time, and this quantity. Surface integrating the electric field gives this quantity according to (*) Gauss’ law. In a capacitor, this quantity can be written as the product of capacitance and voltage. Coulomb’s law can be used to find the force between objects as a function of distance and this quantity. For 10 points, name this quantity that is positive for protons, negative for electrons, and is the reason for force in an electromagnetic field.

Charge

One result of this is that objects feel heavier or lighter depending on direction of motion, which is known as the Eötvös effect. The Ekman spiral is caused by this, and the ratio of inertial forces to forces caused by it is known as the Rossby number. Acceleration due to this effect is equal to negative two times the cross product of the system's angular velocity and the particle's velocity. It is directed radially inward for high pressure systems, and cyclones rarely form at the equator due to the absence of this effect. For 10 points, name this effect in which objects appear to deflect from a straight line when viewed from a rotating reference frame.

Coriolis Effect [accept Coriolis Force]

One equation named for this man can be used to determine the conditions under which cavitation will occur, and that equation states that density times gravitational acceleration times elevation plus one-half density times velocity squared plus pressure is a constant. That equation mathematically expresses another concept named for this man which explains the Venturi effect in a narrowing pipe. For 10 points, name this Swiss mathematician whose principle states that if a fluid's velocity along a streamline increases, its pressure decreases.

Daniel Bernoulli

One statement describing this process utilizes a constant with dimensions of length squared over time, and that law sets the time derivative of concentration proportional to the second derivative of concentration with respect to position. A third law describing it states that the rate at which this process occurs is inversely proportional to the square root of the molar mass, and an example of this process governed by Fick's and Graham's laws is the movement of water across a semipermeable membrane. Osmosis is a type of, For 10 points, what process in which particles move from regions of high concentration to those of low concentration?

Diffusion [accept Effusion; prompt on Osmosis before mention]

In an application of this phenomenon, cesium atoms can be slowed down in atomic clocks because the atoms absorb photons, recoil, and lose momentum. Steven Chu won a Nobel Prize for investigating the "cooling" mechanism of this effect. A relativistic factor for this effect equals the square root of one plus beta over one minus beta. It was used to prove general relativity in the Pound-Rebka experiment. This effect includes a term for the source velocity and the observer's velocity. For 10 points, name this effect which causes a shift in observed frequencies for moving objects, which is why ambulance sirens change pitch.

Doppler Effect

The cooling named for this effect is a type of laser cooling that impacts particles within a certain range of speeds. A profile named for this effect is used to find the temperature of a gas based on the way that this effect broadens spectral lines. The transverse type of this effect is explained by the time dilation of special relativity and was confirmed by the Ives-Stilwell experiment. Astronomical measures of this effect led to the development of Hubble's Law and the belief that the universe is expanding. Name this change of frequencies such as redshifts and blueshifts caused by relative velocities between a source and observer.

Doppler effect [accept Doppler shift or equivalents, prompt on "redshift" or "blueshift"]

Canal ray tubes were used to investigate a form of this phenomenon predicted by special relativity in the Ives-Stillwell experiment. This phenomenon has a transverse form, and the Lorentz transformation is used to derive the relativistic form of this effect, which can be used to measure the radial velocity of galaxies. Changes in spectral lines caused by this effect are known as blueshift and redshift. For 10 points, name this perceived change in the frequency of a wave from a moving source, exemplified by sirens on fire trucks.

Doppler effect [accept Doppler shift]

The deceleration parameter is equal to one plus the time derivative of a value named for this scientist divided by that same value squared. That value named for him is equal to the time derivative of the cosmic scale factor divided by the scale factor. The age of the universe can be approximated as the inverse of his namesake (*) constant. His namesake law states that the recessional velocity of a galaxy is equal to its distance from us multiplied by his namesake constant. For 10 points, name this American astronomer who is the namesake of an optical space telescope launched by NASA in 1990.

Edwin Hubble

One over the product of c and permeability of free space is multiplied by the square of this quantity in a formula for instantaneous energy flow rate, and according to Gauss's law, the surface integral of this quantity is equal to enclosed charge over permittivity of free space. This quantity is equal to zero at all points inside a charged conducting sphere, and namesake lines indicate the direction a positive test charge would move in one of these. For 10 points, name this quantity defined as the electric force per unit charge.

Electric Field

The quantum type of this quantity is named for Klaus von Klitzing, and it is applied in the quantum Hall effect. This quantity varies with temperature because of the Kondo effect, and at low temperature many materials see a drop in it according to the Anderson Model. This quantity’s inverse is measured in Siemens. After the turn on voltage, (*) this quantity is zero in an ideal diode. The component named for this quantity denotes its value through the use of colored bands. This quantity is added to reactance to yield impedance. For 10 points, name this opposition to the flow of current, equal to voltage divided by current according to Ohm’s law.

Electrical resistance

The deceleration of these particles when fired at a metal target causes Bremsstrahlung, and these particles exhibit the Lamb Shift. These particles scatter photons in the Compton Effect, and beta decay ejects an antineutrino of these particles along with one. Their mass and charge were measured in Millikan's oil drop experiment, and they were discovered in experiments with cathode rays conducted by J. J. Thomson. For 10 points, name these negatively charged particles which orbit the atomic nucleus.

Electrons

Particles named for this physicist have antisymmetric wavefunctions under exchange. A result named for him gives the probability of transitions between quantum states. Neutron stars can be modelled as his namesake type of "gas" supported by degeneracy pressure. Particles that obey the Pauli Exclusion principle follow statistics named for him and Dirac. With Leo Szilard, this man was responsible for Chicago-Pile 1, the first nuclear reactor. He gives his name to particles with half-integer spin, contrasted with bosons. For 10 points, name this Italian-born physicist who worked on the Manhattan project.

Enrico Fermi

The acceleration named for this person can take place when particles repeatedly cross the shock front caused by a supernova. The type of gas named for this person exerts pressure even at absolute zero. This person and Paul Dirac worked out the statistical distribution of particles that obey the Pauli Exclusion Principle, which is why such particles are named for this person. Those particles, which have non-integer spins, are contrasted with particles named for Satyendra Nath Bose. Name this Italian American who created Chicago Pile-1 in 1942, the first man-made nuclear chain reaction.

Enrico Fermi

Two isotopes of Helium oddly have a negative value of this quantity when undergoing fusion. At a constant volume, temperature can be defined as a partial derivative of this quantity with respect to the internal energy. One formulation of this quantity is the natural logarithm of the number of microstates times(*) Boltzmann’s constant. As each step keeps either temperature or this quantity constant, charting a plot of them for a Carnot [“car-nowâ€] cycle forms a rectangle. This quantity can only increase over time, according to the Second Law of Thermodynamics. For 10 points, name this quantity, symbolized S, that represents disorder.

Entropy [prompt on S before it is read] <David Dennis>/<ed. HB>

This man coined the terms “alpha†and “beta†to describe specific types of radiation, and used the former to produce Oxygen-17 and a proton, proving the latter’s existence. This man’s namesake effect takes advantage of the Coulomb potential of two objects, leading to it often being called Coulomb (*) scattering. This scientist, who names the 104th element, with symbol Rf, challenged the plum-pudding model in his most famous experiment, which he carried out with his students Hans Geiger and Ernest Marsden. For ten points, name this man who discovered the existence of the nucleus with his “gold foil†experiment.

Ernest Rutherford <CL> BONUSES

The fact that this property emerges from interaction with regions separated by Néel or Bloch walls is demonstrated by the Barkhausen effect. Lithium gas has been shown to exhibit this property at low temperatures. A statistical model named for Ising describes the phase changes in this property. Hysteresis allows this property to persist until an external effect, such as heat, is applied. For 10 points, name this effect, which disappears completely above the Curie temperature, exhibited by substances such as cobalt and iron.

Ferromagnetism

A shortened version of this person's name is used for the CGS unit of acceleration. The spacecraft named for this person, launched from the Space Shuttle Atlantis, was the first orbiter of Jupiter. This person stated that mathematics is the language of science in his book The Assayer, and he supported the work of Copernicus in his Dialogue Concerning the Two Chief World Systems. Name this scientist who was put under house arrest and who, according to legend, dropped cannonballs from the Leaning Tower of Pisa.

Galileo Galilei (accept either)

Doppler redshift associated with this force was measured by the Pound-Rebka experiment, and waves associated with this force are being searched for by the LIGO project. The constant associated with this force was first measured by Henry Cavendish, and it is caused by spacetime curvature in general relativity. This force between two objects can be calculated as the products of their masses over radius squared times its namesake constant, and on Earth, acceleration due to it is approximately 9.8 meters per second squared. For 10 points, name this fundamental force that gives objects weight.

Gravity [accept Gravitational Force; do not accept "Weight"]

This man generalized Cayley's formula into a theorem giving the number of spanning trees in a graph; that is his matrix tree theorem. A set of laws named for him includes the statement that a gas at a high temperature and low pressure will emit an emission-line spectrum, and with Piola, he names a stress tensor. With a colleague, this man discovered (*) cesium and rubidium; that colleague was Robert Bunsen. One of this man's rules states that the potential differences across all elements around any closed circuit loop must be zero. For 10 points, identify this German physicist who coined the term "black body radiation" and names two circuit rules.

Gustav Kirchhoff

The type of thruster named for this effect traps electrons, neutralizing what would be positively-charged material pushed out of it. This effect is used to measured electron mobility, and its coefficient equals mobility times resistivity. The voltage created by this effect, which is zero on a Corbino disk, varies inversely with the product of charge density and strip thickness. Its voltage also varies directly with the product of current and magnetic field strength. Name this effect created when a conducting strip carrying a current is placed into a magnetic field, pushing the electrons towards one side.

Hall effect [or Hall voltage]

11. Robertson generalized this statement to any Hermitian operators. One attempted refutation of this statement concerns letting a photon escape, then re-weighing a box named after Einstein. This theorem sets one side equal to the reduced Planck’s constant over two, which is less than or equal to the product of a certain function applied to two (*) non-commuting variables, like energy at time. For ten points, identify this theorem, one formulation of which states that both position and momentum of a particle cannot be known simultaneously, formulated by Werner Heisenberg.

Heisenberg uncertainty principle (accept things like Heisenberg principle before his name is mentioned) <MS>

The canonical commutation relation between the variables involved in this relation implies that no state can be an eigenstate of the variables at the same time. This relation is a special case of the Robertson-Schrödinger inequality, and it was introduced through a thought experiment that involved a gamma-ray microscope. One way of representing this principle involves energy and time, and this principle states that electrons can only have definite positions when they are in a state in which their energy is undefined. For 10 points, name this principle which states that the momentum and position of a particle cannot be precisely measured simultaneously.

Heisenberg's Uncertainty Principle

Robertson names a generalization to this statement that applies to general self-adjoint operators. In a modification of this statement, energy and time replace two quantities in one side of an inequality. This statement’s namesake created a thought experiment involving a (*) gamma-ray microscope, and this statement is a consequence of two quantities having a non-zero commutator. This statement can be stated as an inequality involving h-bar over two. For 10 points, give this principle, which states that it is impossible to measure a particle’s momentum and position simultaneously with complete confidence.

Heisenberg’s uncertainty principle

This particle has a similar mass to cesium but is much shorter lived. This particle carries a force of the same name, and the discovery of this particle led to the experimental verification of the Standard Model (*) of particle physics and was the basis for the 2013 Nobel Prize in Physics. The Large Hadron Collider was constructed in order to confirm the existence of this particle. This particle has a spin of zero, making it a fundamental scalar rather than a gauge, like the W and Z. For 10 points, name this “God†particle that carries mass fundamental to particles, experimentally confirmed to exist by CERN in 2012.

Higgs Boson

Voigt notation can be used to express this law in a six-by-six matrix. This law was generalized to three dimensions by Cauchy. Young’s modulus multiplied by cross-sectional area over length is equal to this law’s force constant. This law begins to break down at the (*) elastic limit. The proportionality constant of this law has units of Newtons per meter, and objects obeying this law are an example of simple harmonic motion. For 10 points, name this governing law of simple two-dimensional springs, which states that the restorative force acting on a spring is negative and proportional to the displacement from equilibrium, or that F equals negative kx.

Hooke’s Law

In minerals, the Gladstone-Dale relation can be used to compute this quantity, while the Lorentz-Lorenz equation is used to relate it to polarizability. The Lensmaker's formula gives the focal length of a lens in terms of the radii of curvature of the two lens surfaces and this quantity, while Brewster's angle is the arctangent of the ratio of this quantity for each medium. Objects exhibiting birefringence possess multiple values for this quantity, which also gives the ratio of the sines of the angles of incident light waves in Snell's law. For 10 points, name this quantity, the ratio of the speed of light in some substance to the speed of light in a vacuum.

Index of Refraction [accept Refractive Index]

One representation of this quantity is equal to the momentum squared over two times mass, and it is represented in the Lagrangian with a capital T. The equipartition theorem dictates that for molecules in an ideal gas, this quantity is equal to three-halves times the Boltzmann constant times temperature. The change in this quantity is equal to power times time, and inelastic collisions do not conserve this quantity. For 10 points, name this quantity defined as one-half times the mass times velocity squared, the energy possessed by objects in motion.

Kinetic Energy [prompt on Energy]

The rotation of plane-polarized light traveling along the direction of one of these entities can be calculated using the Verdet constant. Particles segregate by charge when a current flows perpendicular to one of these entities in the Hall effect, and Ampere's law states that the line integral of this quantity is proportional to the current passing through a closed loop. One of these entities is produced to oppose a change in flux according to Lenz's law, and a current flowing through a solenoid produces one of these. For 10 points, name this field measured in Teslas, the counterpart to the electric field.

Magnetic Field [accept B-field or H-field; prompt on Field before mention]

This entity's presence in a two-dimensional conductor creates Landau levels in the quantum hall effect. The Lorentz force on a particle is given by charge times velocity cross this entity, which is equal to the curl of the vector potential. They are expelled from superconductors in the Meissner effect, and Faraday's law of induction describes how a changing one produces an electrical current. They are formed when an electrical current passes through a solenoid, and Gauss showed that the divergence of these entities is zero unless monopoles exist. For 10 points, name this entity most commonly associated with objects with north and south poles.

Magnetic Field [accept B-field]

The Kolmogorov forward equation is equivalent to a probability density function formulated by this man andAdriaan Fokker. This man extended Wien's law to low frequencies and disproved a prediction of the Rayleigh-Jeanslaw. In addition to resolving the ultraviolet catastrophe, this man created a law that raises wavelength to the negativefifth power, his namesake law of radiation, which finds the energy of a blackbody. His constant multiplied byfrequency yields the energy of a photon and has a reduced form of h over two pi. For 10 points, name this Germanrecipient of the 1918 Nobel Prize in Physics who developed quantum theory.

Max Karl Ernst Ludwig Planck

If bosons are considered massless in the Bose-Einstein distribution, the distribution reduces to one named for this person. He derived Wien’s law before creating his namesake law, which tends to the Rayleigh Jeans law and Wien’s law at low and high frequencies, respectively. This scientist names an era in the early universe roughly 10 to the -43 seconds after the (*) Big Bang when the four fundamental forces were combined, as well as a set of units including the shortest measurable length. In his namesake postulate, this man related energy, frequency, and his eponymous constant, which is equal to 6.63 times 10 to the -34 meters squared times kilograms over seconds. For ten points, name this German founder of quantum theory.

Max Planck <AG>

This man used an experiment containing a charged metal ball, insulating thread, and an ice-pail to confirm Gauss's law. Liquids may contain this man's namesake ripples, and alongside Joseph Henry, this man discovered that moving a magnet near a conducting loop can cause a current in the loop. The creator of a (*) direct-current generator that produces an emf constant in time, this man names a device that causes the total electric field at every point inside it to be zero; that is his namesake "cage." For 10 points, name this man with a namesake law of induction and whom the SI unit of capacitance is named after.

Michael Faraday

A generalization of this statement to quantum mechanical operators is known as the Ehrenfest theorem. The motion of simple harmonic oscillators can be described by setting Hooke's law equal to one form of this statement, and when mass is not constant, one side of it is rewritten as the time derivative of momentum. Free body diagrams are often used in conjunction with this statement, and weight is found by replacing one term in this law with a constant approximately equal to 9.8 meters per second squared. For 10 points, name this law of motion which states that force is equal to mass times acceleration.

Newton's Second Law of Motion [prompt on partial answer]

The "halo" variety of these objects is found near drip lines. An equation modeling these objects includes pairing, asymmetry, and surface terms and is based on Gamow's liquid drop model. That equation fails to predict the increase in stability in these objects at certain "magic numbers" such as 2 and 8. Their existence was discovered in an experiment in which alpha particles were deflected by a sheet of gold, and J. J. Thomson's plum pudding model of the atom lacked this structure. For 10 points, name this center of an atom which contains protons and neutrons.

Nucleus [accept Nuclei]

This quantity is mapped to its inverse hyperbolic tangent in Fisher’s z-transformation. When analyzing rank-ordered data, this quantity is replaced by a quantity named for Spearman. This quantity equals the covariance between two variables divided by the product of their standard deviations. For two variables X and Y, the square of this quantity is the proportion of the variance of Y that is explained by a simple (*) linear relationship with X. If there is a perfect positive linear relationship between two variables, then this quantity will equal one. For 10 points, name this quantity that measures how well a line fits a collection of points.

Pearson correlation coefficient [or Pearson’s r or Peason product-moment correlation coefficient or PPC or PPMCC] <Math â€" Dai> [Ed. French]

These systems can be mathematically described by using an elliptic integral to solve a second-order differential equation; those solutions are often simplified to a linear description by using Taylor expansion to replace the sine theta term with theta for small angles. The period of these systems can be approximated as two pi times the square root of length over gravitational acceleration. The double kind of these exhibits chaotic motion, and one of these used to demonstrate the rotation of the Earth was named for Foucault. For 10 points, name these physical systems used to model simple harmonic motion that consist of a mass connected to a string.

Pendulums [accept Pendula; prompt on Simple Harmonic Oscillators before "length"]

This phenomenon causes space crafts to develop a positive charge when exposed to sunlight. Philipp Lenard first observed this phenomenon while working with cathode tubes, initially considering the term “corpuscles†to describe the particles involved. Eventually, he settled on deeming those particles the quanta (*) electrons. The proof of this phenomenon, not of relativity, was the reason for Einstein receiving the Nobel Prize in 1921. For 10 points, name this effect in which electrons are ejected from an object after being excited by incident photons.

Photoelectric effect

One of these items escapes in the thought experiment of Einstein’s box. In QED theory, the creation of the virtual type of these items gives rise to the Casimir effect.  CCDs exploit an effect these items undergo when they contact silicon to enable digital imaging. The momentum of these items can be given by the spatial (*) angular frequency times h-bar. These gauge bosons for the electromagnetic force have spin 1, but are chargeless and massless. For 10 points, name these particles, the quanta of light.

Photons <David Dennis>/<ed. HB>

For an electric dipole, this quantity can be computed as the negative dot product of momentum and electric field, and for a two-particle system, this quantity is equal to the negative product of big G and the particles' masses over r. For a spring this is equal to one-half k times displacement-squared, and the negative change in this quantity is work. Coming in elastic and gravitational varieties, For 10 points, name this energy of a system associated with its configuration, often contrasted with kinetic energy.

Potential Energy

This quantity has a negative value if the cosmological constant causes a positive vacuum energy density. Like kinematic viscosity, the kinematic version of this quantity can be used to compute the Navier-Stokes equation, and one law states that the change in this quantity is equal to density times gravity times the change in height. For an ideal gas, this quantity is equal to the number of moles times temperature times the ideal gas constant, all divided by volume. A change in this quantity in an incompressible fluid is transmitted equally throughout the fluid according to Pascal's law. For 10 points, name this quantity equal to force divided by unit area.

Pressure

The Bergeron diagram method can be used to calculate the effects of this phenomenon for electrical signals. This phenomenon can be modeled for surfaces with parallel grooves by the Heidrich-Seidel distribution, and its diffuse form is described by a model named for Lambert. This phenomenon does not occur at Brewster's angle, and the total internal type of this phenomenon occurs at the critical angle. The angle at which this phenomenon occurs is equal to the angle of incidence. For 10 points, name this phenomenon which occurs when light hits a surface and bounces back, commonly exhibited by mirrors.

Reflection

Solids with a high value for this quantity possess a large bandgap between the valence and conduction bands. One modification of this quantity is calculated using the reactance, which is used for AC circuits and is known as impedance. For a wire, it is proportional to length over cross-sectional area, and power dissipated can be calculated as current squared times this quantity. The inverse of it is known as conductance, and one law gives voltage as the product of current and this quantity. For 10 points, name this quantity measured in ohms.

Resistance [do not accept "Resistivity"]

Shortly after Yuri Manin [MAH-neen] wrote Computable and Uncomputable, this scientist gave a talk titled "Simulating Physics with Computers" that discussed building a quantum computer. Based on work with John Archibald Wheeler, this scientist developed the use of path integrals. Freeman Dyson showed that this person's work on quantum electrodynamics was equivalent to work by Tomonaga and Schwinger [SHWEENG-er]. Name this person who used arrows and wavy lines to demonstrate quantum interactions in his namesake diagrams.

Richard Feynman

The precession rate of a gyroscope is equal to Mgr over the product of omega and this quantity, and the term M times h-squared is added to this quantity at the center of mass when using the parallel-axis theorem. Formulas for this quantity are derived from the integral of radius squared with respect to mass. The product of angular velocity and this quantity is equal to angular momentum, and the product of angular acceleration and this quantity is equal to torque. For 10 points, name this angular analogue of mass.

Rotational Inertia [accept Moment of Inertia]

Following this experiment, it was predicted that s is proportional to Q sub n squared and inversely proportional to the sine of phi over two to the fourth power. A later version of this experiment uses a conical glass tube sealed with mica containing “radium emanation†and bismuth-214 to emit particles at a (*) zinc sulfide screen. A scintillator was used to count the flashes of light created by the backward scattering of alpha particles in this experiment, which disproved J. J. Thomson’s plum-pudding model of the atom. For 10 points, name this experiment, which led to the discovery of a positively charged nucleus.

Rutherford experiment (accept Gold Foil experiment or Geigerâ€"Marsden experiment)

5. While not Hugh Everett, the formulator of this construct was motivated by the EPR paradox and wished to contradict the idea of wavefunction collapse. Influenced by complementarity, this argument sought to reveal the limitations in the Copenhagen interpretation, leading Everett to propose the many-worlds interpretation to resolve this (*) paradox. Demonstrating the principle of superposition, this formulation involves the spontaneous decay of an atom, which ends up breaking a vial of hydrocyanic acid and killing the namesake animal. For ten points, identify this scenario in which a certain feline is both alive and dead.

Schrodinger’s cat <EC>

This law can be applied to determine the degree of completion of chemical reactions, and one statement of this law, which breaks time reversal symmetry, is known as Boltzmann's H-theorem. Another formulation of this law states that heat cannot convert energy completely into work. A thought experiment proposed to violate this law allowed one side of a chamber to heat up quickly, and Clausius is credited with the first formulation of this law, which is violated by Maxwell's demon. For 10 points, name this law which states that the entropy of the universe is always increasing.

Second Law of Thermodynamics

A quantum analog of one formula named for this man is named for Ehrenfest (AIR-en-fest). Interference patterns due to an air film between a lens and a glass are called this man's "rings." Another law named for this man is also called the law of inertia, while a third law is often summarized as saying that for every action, there is an equal and opposite reaction. For 10 points, name this British physicist whose three laws of motion include the equation F equals m a.

Sir Isaac Newton

This theory requires Poincaré symmetry, which includes boosts, rotations, and translations. The Michelson-Morley experiment confirmed one postulate of it by showing that the speed of light is constant in all reference frames, and it is associated with the twin paradox. It incorporates a factor symbolized gamma that is the square root of one minus beta squared and is only valid in inertial reference frames. Lorentz factors are used for calculations in this theory that predicts time dilation and length contraction. For 10 points, name this theory regarding objects traveling at near-light speeds proposed by Albert Einstein, which is contrasted with its more general form.

Special Relativity [prompt on Relativity; do not accept "General Relativity"]

Radiative power is inversely proportional to this quantity cubed times 6-pi-epsilon according to the Larmor formula. This quantity is in the numerator in the formula for the index of refraction. When a charged particle exceeds this quantity while in a medium, it produces Cherenkov radiation. This(*) quantity is equal to one divided by the square root of the product of the vacuum permittivity and permeability. This quantity is constant in all inertial reference frames. For 10 points, name this value symbolized c, that is about 30 million meters per second.

Speed of Light <David Dennis>/<ed. HB>

The temperature named for this person is similar to the Unruh [un-ruh] Temperature, though it is based on gravitational field strength rather than acceleration. He worked closely with Roger Penrose, applying Penrose's work on singularities to the state of the universe before the Big Bang. This person's later work led to predictions that Black Holes would eventually use up their energy and vanish because they emit his namesake radiation. Name this scientist who suffers from ALS and wrote A Brief History of Time.

Stephen Hawking

In this formulation, the Nambu-Goto and Polyakov actions govern the movement of objects which move along surfaces known as D-branes. Â This formulation depends on a large number of free parameters, making it practically untestable. Ed Witten used conformal field theory to unite various versions of it in an eleven-dimensional extension, known as(*) M-theory. It attempts to reconcile gravity and quantum mechanics. For 10 points, name this theory that all elementary particles are made up of the namesake vibrating, one-dimensional shapes.

String Theory <David Dennis>/<ed. HB> Bonuses

Little and Parks showed that a large fraction of electrons in these materials behave essentially as a single quantum particle, and a current flowing through two of them forms a Josephson junction. Based on the strength of their critical fields, they can be classified into Type I and Type II. The(*) BCS theory posits that they are formed by the condensation of electrons below the Fermi energy into Cooper pairs. These materials are natural diamagnets, as they eject a magnetic field in the Meissner effect. For 10 points, name these materials which have zero electrical resistance.

Superconductors <David Dennis>/<ed. HB>

The value of virial coefficients depend on this quantity. The wavelength corresponding to the maximum intensity of radiation emitted by a black body is inversely proportional to this quantity, according to Wien’s law, and the total intensity of radiation is proportional to the (*) fourth power of this quantity. According to the Joule-Thomson effect, this quantity decreases for a gas upon expansion, as it is directly proportional to volume, as well as pressure. For 10 points, name this quantity which is measured in Celsius or Kelvins.

Temperature

This property can be measured using a Zahn cup, and for special cases, shear stress can be calculated as the product of shear strain and this property. Measuring this is the goal of the pitch drop experiment, and one unit this quantity is measured in is poise. Stokes' law gives drag force for a spherical object as six pi times radius times velocity times this property, and the Reynolds number is the ratio of inertial forces to forces caused by this. This property has a constant value for Newtonian fluids, and it exists in kinematic and dynamic forms. For 10 points, name this term for a fluid's resistance to flow.

Viscosity

Though he did not coin the term, this physicist proposed the concept of isospin from the similarities between protons and neutrons. He’s not Wheeler, but this physicist developed S-matrix theory to describe a system undergoing scattering. He published his matrix formulation of quantum mechanics in a series of papers with (*) Max Born and Pascual Jordan. A statement named for this man can be stated as h-bar over two is less than or equal to the product of the standard deviations of two conjugate variables, position and momentum. For 10 points, name this German physicist who developed the uncertainty principle.

Werner Heisenberg

21. One theorem named after this man states that the change in circulation of an ideal fluid around a closed curve acted upon by conservative forces is zero. With a German, he names a mechanism of heat production caused by the gravitational contraction of an astronomical body. This discoverer of (*) magnetoresistance and Joule both name a method of cooling a gas by causing it to expand. This coiner of the term “kinetic energy†was the first to find the correct value of absolute zero, setting it as the bottom of his scale. For ten points, identify this man, after whom the SI unit of temperature is named.

William Thomson, 1st Baron Kelvin (accept either underlined name) <MS>

The maximum energy of these things created by a given voltage is given by the Duane-Hunt law. Like electrons, they were discovered using a Crookes tube. Riccardo Giacconi won his Nobel Prize for figuring out how these could be used in astronomy, and Max von Laue won his Nobel Prize for work on the diffraction of these things. These things were used by Rosalind Franklin to make an image of DNA molecules, and these are measured by the Chandra Observatory. This electromagnetic radiation is more energetic than ultraviolet light but less energetic than gamma rays. Name this radiation discovered by Wilhelm Röntgen, used to observe bones.

X-rays [prompt on photons or electromagnetic radiation or EM radiation]

Wheeler’s delayed choice experiment questions whether the inputs to this experiment can “sense†its outcome, and one modification of this experiment is the quantum eraser experiment. A variant of the apparatus used to conduct this experiment was made by Mach and Zehnder, and the namesake pattern resulting from this experiment main apparatus was linked to de Broglie’s pilot (*) wave hypothesis. Heavily attenuated light and discrete electrons both produced the same results in this experiment, and thus this experiment showed that waves can behave like particles. For 10 points, name this experiment that used the namesake structure to observe the wave-particle duality of light.

Young’s double-slit experiment

This effect is given a different name if its magnetic field is strong enough to couple the orbital and spin angular momentums. Its size can be calculated by assuming two electrons are spinning in opposite directions in the same plane and finding the change in velocity and therefore energy of the electrons caused by adding a magnetic field. Because this was discovered before the concept of electron spin was understood, a common version of it is called anomalous. Name this weaker version of the Paschen-Back effect in which a magnetic field acting on an atom causes the splitting of spectral lines.

Zeeman [ZAY-mun] effect

Magnetic field equals the curl of a quantity denoted by this letter, the vector potential. The universal quantifier is symbolized by an upside-down one. Though not F, a value denoted by this letter equals internal energy minus temperature times entropy. The HTML tag for a hyperlink uses this letter of the alphabet. This letter, which stands for Helmholtz free energy, multiplies e raised to the negative activation energy over RT in the Arrhenius equation. It equals ten in hexadecimal. A purine symbolized by this letter base-pairs with thymine. Retinol is this vitamin, important for eye health. For 10 points, name this letter which symbolizes the time derivative of velocity, acceleration.

a [or A]

The change in the ratio of this quantity to Gibbs free energy is equal to the negative of enthalpy divided by thisquantity squared. An engine's maximum efficiency is equal to one minus the ratio of this quantity measured at twodifferent reservoirs according to Carnot's theorem. The energy of a blackbody is proportional to the fourth power ofthis quantity by the Stefan-Boltzmann law. Three-halves times this quantity times the Boltzmann constant equals aparticle's average kinetic energy. The third law of thermodynamics states that entropy is zero at the unattainablelower bound of this quantity, known as absolute zero. For 10 points, name this quantity measured in kelvins.

absolute temperature [prompt on "T"]

This function’s properties include being “multiplicative,†“subadditive†and “positive definite.†This piecewise linear function is differentiable everywhere except 0. For complex numbers in polar form, this quantity is symbolized r. This function’s properties are generalized by metrics and norms, since this function of “x minus y†gives the number-line (*) distance between x and y. This function of “x plus y†is less than or equal to “this function of x†plus “this function of y,†by the triangle inequality. This function of x equals the “square root of x-squared.†For 10 points, name this function that gives the value of a number without its sign, denoted by vertical bars.

absolute value [or modulus; or magnitude; prompt on “valueâ€] <JR> Tiebreaker

This condition is 559.725 on a calibration system by Joseph-Nicolas Delisle. D-Wave Systems builds quantum computers that operate near this condition, which is also sought in many superconductivity and superfluidity experiments. The third law of (*) thermodynamics states that crystals at this value have no entropy. It is the lowest value on the Rankine and Kelvin scales and equals negative 273.15 degrees Celsius. For 10 pointsâ€"give this lowest possible temperature.

absolute zero

When this quantity is measured in a rotating reference frame, it contains a correction term equal to “omega cross omega cross r.†This quantity, whose CGS unit is the gal, is squared and multiplied by charge-squared in the numerator of the Larmor formula for radiative power. This vector quantity points radially (*) inward with magnitude “v-squared over r†for uniform circular motion. This quantity, whose standard value due to gravity is denoted by a lowercase g, is multiplied by mass on the right-hand side of Newton’s second law. For 10 points, name this quantity that results from forces acting on an object, the rate of change of velocity.

acceleration <SE>

The enormous range of timescales on which these particles are produced are related to their energies by the Geigerâ€"Nuttall law. George Gamow modeled the production of these particles in terms of quantum tunneling out of a potential well. The production of these charged particles by (*) americium-241 underlies the operation of smoke detectors. The production of these particles decreases both the atomic number and mass number of their neutron-rich sources, and they have same constituents as a helium-4 nucleus. A sheet of paper can easily stop â€"for 10 pointsâ€"what form of ionizing radiation, composed of two protons and two neutrons?

alpha particles [or alpha radiation; or helium-4 nucleus before mention; do not accept or prompt on “helium†or “helium atomâ€] <SE>

Litz wire is used to minimize the efficiency losses that this phenomenon suffers due to the skin effect. Power transfer due to this phenomenon can be maximized by using a three-phase system. This phenomenon is the input to, but not the output from, a diode bridge. Its strength is reported in terms of the root-mean-square amplitude, which is less than the (*) peak amplitude by a factor of the square root of 2. This phenomenon is converted into its counterpart by a rectifier, and its voltage can be stepped up or down at a transformer. For 10 points, name this type of electrical current that follows a sinusoidal pattern, unlike direct current.

alternating current [prompt on AC] <SE>

This man’s book What is Life? predicted DNA would be in structures he called aperiodic crystals. In his representation of quantum mechanics, observables are kept fixed while state vectors evolve. He names an equation stating total energy equals kinetic energy plus potential energy, which is written with the (*) wave function. He also proposed a hypothetical experiment in which an organism is both alive and dead until it is directly observed. For 10 pointsâ€"name this Austrian physicist who described a box containing a cat.

Erwin Schrödinger

This scientist's work on surface tension was unified with work done by Pierre-Simon Laplace [luh-PLAHS] in an equation worked out by Carl Friedrich Gauss. He was a doctor, and his early work on light led to the discovery of astigmatism and the theory that three types of photoreceptors are used in sight. His paper "On the nature of light and colours" supported the wave theory of light by describing what happens when two portions of light from the same original source are combined. Identify this namesake of the measure of the elasticity of a substance, who found interference patterns while performing his double-slit experiments.

Thomas Young

For a current-carrying coil of wire, this quantity is equal to the product of magnetic field, number of coils, current, area, and sine of theta, which is equivalent to the cross product of magnetic dipole moment and magnetic field. Work associated with rotation is the integral of this quantity with respect to angular displacement, and although it is not energy, it is measured in Newton-meters. Defined as the cross product of the position vector and force, For 10 points, name this action on a body which produces twisting.

Torque

The Stefan-Boltzmann law says blackbody luminosity is proportional to this quantity squared and the fourth power of temperature. For a torus this equals four pi squared times the product of the inner and outer radii and this is radical three times side length squared in a tetrahedron. This quantity in a rectangular box is (*) two times the quantity width length, plus height length, plus height width, and is related to the paper needed to wrap such a box as a gift. For 10 pointsâ€"give this term for the two-dimensional measurements on the outside of a three dimensional object.

(lateral) surface area (prompt on "area")

Spin is projected onto this vector to find helicity [heh-LIH-sih-tee]. This quantity is equal to the derivative of a Lagrangian [luh-GRAHN-jee-un] with respect to velocity. Squaring this quantity and dividing by twice the mass gives kinetic energy. Newton's 2nd Law can be expressed by setting the derivative of this quantity with respect to time for constant mass systems equal to net force. The change in this quantity is equal to the impulse, and this quantity is conserved even in inelastic collisions. Name this quantity equal to mass times velocity.

(linear) momentum

This angle is the critical angle above which total internal reflection occurs in a material whose refractive index equals the square root of 2. The worldline of an object moving at the speed of light makes this angle with respect to the y-axis on a Minkowski diagram. For a granular material with a coefficient of static friction of 1, this is the value of the angle of repose. A projectile launched at this angle from the horizontal will (*) maximize its range for a given initial speed. Doubling this angle gives the angle between a normal force and the friction force it produces. For 10 points, give this angle equal to pi over 4 radians, which is the measure of both acute angles in an isosceles right triangle.

45 degrees [or pi over 4 radians before it’s mentioned] <SE>

The Wigner-Eckart theorem describes operators based on eigenstates of this quantity, and the Laplace-Runge-Lenz vector is calculated as the cross product of linear momentum and this quantity. Kepler's second law is derived from the fact that this quantity is conserved, which can be derived from the principle of rotational invariance. The time derivative of this quantity is equal to torque, and this quantity is equal to a body's moment of inertia times angular velocity. For 10 points, name this quantity symbolized "L," the rotational analog of linear momentum.

Angular Momentum [accept "L" until mention; do not accept or prompt on "Momentum"]

The product of this quantity, reaction cross-section, and the square root of 8kT over pi times mu gives the collision frequency. This quantity is a proportionality constant in the Starkâ€"Einstein law. This value can be obtained through X-ray crystallography of (*) silicon lattices. The number is the quotient of Faraday’s constant and elementary charge. Boltzmann’s constant is defined as the ideal gas constant divided by this value, which is similar to Loschmidt’s constant. For 10 points, name this constant defined as number of units per mole, approximately 6.022*10^23.

Avogadro’s number (accept Avogadro’s constant)

This letter is used to denote terms for absorption and stimulated emission in the Einstein coefficients. Leon Lederman discovered the quark denoted by this letter, which is the second-heaviest known quark. A quantity denoted by this letter is the curl of the vector potential and is sometimes called the “flux density†to distinguish it from a related quantity symbolized (*) H. This letter denotes a quantity that always has a divergence of zero, and which is crossed with velocity in the Lorentz force law. Since M is already used for magnetization, magnetic fields are denoted byâ€"for 10 pointsâ€"what letter?

B <SE>

This principle, which can be derived from Euler's [OY-ler's] continuity and momentum equations, is used to explain the Venturi effect. This applies to inviscid [in-VIH-sid] situations, meaning a lack of viscosity, and can be derived from the Navier-Stokes equation. This principle is based on the conservation of energy along a streamline, including the energy attributable to pressure. Identify this equation named for a Swiss scientist showing that a decrease in pressure leads to an increase in speed for fluid flow.

Bernoulli's Principle (accept Bernoulli Equation or similar answers)

A specific case of this equation sets velocity equal to the square root of 2gh. Venturi meters and pitot tubes measure velocity using this equation, which is only applicable to compressible substances with low Mach numbers.This equation is expressed as Torricelli's theorem when pressure is constant. This equation can be derived from the conservation of energy, and it contains terms corresponding to the kinetic and potential energies for fluids. It explains the net upward force experienced by airplane wings, known as dynamic lift. For 10 points, name this equation that states that an increase in the speed of a fluid is accompanied by a decrease in pressure, named for a Swiss scientist.

Bernoulli's equation [or Bernoulli's principle]

In a derivation of this condition, a mass gap is realized in the spectrum to avoid the absurd condition in which the addition of particles does not alter the particle density. This condition results when the interparticle distance approaches the thermal de Broglie wavelength of the particles in the ensemble. The fermionic (*) analogue to this phenomenon results from the interactions between electronic and nuclear spins and was first realized by Deborah Jin. For ten points, name this state of matter first observed by Eric Cornell and Carl Wieman, a condition in which the particles of a system collapse to the ground state at low temperatures.

Boseâ€"Einstein condensate (accept BEC)

This phenomenon was used by Jean Perrin to calculate Avogadro’s number. This phenomenon seems to allow a violation of the second law of thermodynamics, the Feynman ratchet, to produce workable energy from random motion. This phenomenon can be described as gas particles taking (*) random walks. This phenomenon was first observed by the man for which it is named while observing pollen in water. That observation was explained by Albert Einstein in a 1905 paper. For 10 points, name this phenomenon in which small particles move about randomly because of the motion of gas or liquid particles surrounding them.

Brownian motion

Phenomenons driven by this force can be estimated with the Boussinesq [“Boo-sin-eskâ€] approximation. Gauss’s formula for closed surface integrals can be used to calculate this force, as the product of the divergence of the Cauchy [“Co-sheeâ€] stress tensor and “d v.†The ratio of this force to viscosity is given by the Grashof(*) number. For a given object, this force is equal to total weight of all the fluid displaced by that object, according to Archimedes' Principle. For 10 points, name this upward-pointing force that keeps objects afloat.

Buoyancy <David Dennis>/<ed. HB>

The potential associated with this quantity can be calculated as one-half times this quantity times voltage-squared. Certain materials increase this quantity by a factor called a dielectric constant, which is equal to one for a vacuum. For one type of device, this quantity is calculated as the electric constant times area over distance between two parallel plates, and this quantity is defined as charge over voltage. Measured in farads, For 10 points, name this measure of the strength of a capacitor.

Capacitance

This quantity increases by a factor of one plus the amplitude gain in the Miller effect, and the reciprocal of this quantity is elastance. It can be calculated for an isolated sphere as 4 pi times epsilon naught times the sphere radius, and the energy in devices associated with this quantity is one half this quantity times voltage squared. Dielectrics can increase it, and for two parallel plates this quantity increases with area and decreases with distance. This quantity is also equal to charge over voltage. For 10 points, name this quantity typically measured in farads that is associated with devices capable of storing charge.

Capacitance

Because the curl of an electrostatic field is zero, these devices must have a fringe field on their edges. A freely-suspended one of these objects was the central item in the Trouton-Noble experiment. A low pass filter is created when one of these devices is placed parallel to a source in series with a resistor, and its cutoff frequency will be(*) 1 over two pi RC. The simplest type of these devices has a dielectric between its parallel plates, and early examples of them are Leyden Jars. For 10 points, name these devices that store electrical charge, whose namesake quantity is measured in Farads.

Capacitors <David Dennis>/<ed. HB>

One law named for this person states that the divergence of gravitational field strength is proportional to mass density. This person's name is sometimes used for the system of CGS [c-g-s] units, and he is the namesake of the CGS unit of magnetic field strength that corresponds with the MKS [M-K-S] unit tesla. Another law named for this person, which is incompatible with the existence of magnetic monopoles, states that a closed surface integral of a magnetic field is zero. Name this famous mathematician whose flux laws for electricity and for magnetism are two of Maxwell's four equations.

Carl Friedrich Gauss

The most common cgs system of units is named for this physicist. This scientist is the namesake of the process of demagnetization. This scientist lends his name to the equation "del dot B equals zero.". He first gained fame for predicting Ceres' orbit. Â A law named for this physicist considers symmetric surfaces enclosing charge. and is useful for calculating the (*) electric field.. He and Tesla are the namesakes of the units of magnetic field. He names two of Maxwell's equations. For 10 points, name this physicist who also discovered and named the normal distribution, or bell curve.

Carl Friedrich Gauss

9. He devised a method of mapping surfaces in three dimensional space to the surface of a sphere, and he reformulated classical mechanics in a formalism known as his principle of least constraint. The fact that the gravitational field increases linearly with radius in the interior of a planet can be derived from his flux theorem of gravity. The (*) electromagnetic coilgun is often called this scientist’s rifle.The eponym of the process of eliminating magnetic fields and the CGS unit of magnetic field, for 10 points, name this German scientist who used the divergence theorem to formulate a namesake law of magnetism.

Carl Friedrich Gauss <RK>

5. This scientist’s namesake temperature bound is inversely proportional to the lifetime of excited states, and applies to a technique named for this scientist in which atoms absorb and re-emit photons emmitted by a laser, causing them to cool. Echocardiograms use a phenomenon named for this man to measure the direction and velocity of blood flow. Canal rays underwent the (*) transverse form of his namesake effect in the Ivesâ€"Stilwell experiment. The recessional velocity of galaxies are measured by noting how this scientist’s namesake effect changes absorption spectra of stars. For 10 points, name this scientist whose effect causes redshift and explains the frequency change in moving sirens.

Christian Doppler [accept (transverse or relativistic) Doppler effect or (sub) Doppler cooling or Doppler temperature] <Physics, LMH><ed. VS>

This idea can be proven using time symmetry along with Noether’s theorem. The relative speed of a body is proportional to two over the distance between the bodies because of an application of this idea, called the Vis Viva equation. The escape velocity can be found by applying this idea to (*) gravity, and this idea is applied in fluid dynamics as Bernoulli’s Law. One law that is derived from this idea states that U equals Q minus W, and that law is the first law of thermodynamics. For 10 points, name this idea in physics that the total amount of energy in a closed system is constant.

Conservation of Energy [prompt on partial answer]

The J term in the Fock operator is named for this law. The method of images is used if this law cannot be directly applied. It gives the potential used to solve the Schrödinger equation for the hydrogen atom. This law was discovered by the inventor of the torsion balance. Its constant is one over four pi times the permittivity of free space, or, in base SI units, is about 9 times ten to the (*) ninth. This law has a similar form as universal gravitation, with a negative-second power dependence on distance. For 10 points, name this law giving the force between two charges, whose French namesake also lent his name to the SI unit of charge.

Coulomb’s Law

A man with this surname names the equation that sets magnetization inversely proportional to temperature, and died when a carriage cracked open his skull. Frederic Joliot [JOLL-ee-oh] and a scientist with this surname discovered alpha decay. A non-SI unit equal to 37 billion becquerels has this name. The point at which (*) magnetic domains align without an external field is named for a physicist with this surname, and defines the transition from ferro·magnetism to para·magnetism. The first female professor at the Sorbonne married into this last name and discovered radium. For 10 points, give this surname of Nobel Laureates Pierre and Marie.

Curie family Bonuses

In the Navier-Stokes equations, if this quantity is constant, then the divergence of u equals zero. Dynamic viscosity can be written as the product of kinematic viscosity and this quantity. Incompressible fluid flows are ones with a (*) constant value for this quantity, and the ratio between an entity's value for this quantity and water’s value for this quantity is known as specific gravity. Items sink or float depending on their value for this quantity. For 10 points, name this quantity, which for a material is the amount of mass per volume and can be measured in kilograms per meter cubed.

Density

One equation describing this phenomenon sets the sine of theta equal to the extreme path difference over the distance, and another equation employs a factor of 1.22. That equation is the Rayleigh criterion, which gives minimum resolution due to this phenomenon. Rosalind Franklin employed this phenomenon with X-rays to obtain images of DNA. Airy disks are formed by this process, of which there are Fraunhofer and Fresnel types, and it is described using Bragg's law. It is explained using a principle that treats every point on a wavefront as a wave source, which is named for Huygens. For 10 points, name this term for the bending of light around an obstacle.

Diffraction

The Fraunhofer type requires the use of a Fresnel-Kirchoff integral. A grating of this type is used to split light into its various wavelengths, and consists of closely placed parallel slits. Patterns of it can be used to determine spacing between layers of atoms through an application of Bragg's law. Using the de Broglie wavelength, occurrence of this for neutrons and electrons was one of the main arguments for quantum mechanics. The X-ray type of this was used to determine the shape of macromolecules like the alpha helix of proteins discovered by Linus Pauling and the double helix shape of DNA. FTP, name this wave phenomenon exhibited by light as it curves around a thin opening, the subject of Young's double slit experiment.

Diffraction (Prompt on Crystallography after X ray)

Binary pulsars display a quadratic form of this phenomenon known as the Shklovskii effect.A form of this phenomenon predicted by special relativity was measured using canal ray tubes in the Ives-Stillwell experiment, and the Lorentz transformation is used to derive its relativistic form. It can be employed with the Faber-Jackson relation or the Tully-Fisher relation to estimate the distance to a galaxy using the redshift or blueshift produced by this effect. This effect results in a shift in frequency between a source and an observer moving relative to that source. For 10 points, name this effect exemplified by the change in pitch when a siren passes by.

Doppler Effect

Inducing this effect via a persistent current in BEC’s allows the measurement of the background flow velocity of phonon modes. Walter Kundig used the Mossbauer effect with an ultracentrifuge rotor to verify the transverse form of this quantity that formed the basis of the Ives-Stilwell experiment.(*) Echocardiograms use this phenomenon to measure the speed of blood flow, and Hubble used this phenomenon to prove the expansion of the universe. For 10 points, name this effect in which the pitch of a sound drops as the source moves away from the observer.

Doppler Effect <David Dennis>/<ed. HB>

An echocardiogram uses this phenomenon to determine the velocity of blood, and the Mössbauer rotorexperiments measured one form of this phenomenon through the emission of gamma rays. One experiment usedcanal ray tubes to measure the transverse form of this phenomenon, and Lorentz transformations are used whencalculating this effect's relativistic form. The altering of spectral lines as a result of this effect causes blueshift andredshift, which are used to measure the radial velocities of galaxies. For 10 points, name this effect named for anAustrian physicist, the perceived change in frequency of a wave relative to its observer, which alters the pitch of asiren.

Doppler effect [or Doppler shift]

The presence of this phenomenon in a semiconductor causes band-bending. The divergence of this quantity is the charge density over permittivity according to Gauss' Law, and Maxwell added the displacement current term to Ampere's Law to describe how a magnetic field is produced by a time-varying one of these. It is always zero inside a conducting sphere by the shell theorem, and it is inversely proportional to the square of distance for charged particles. For 10 points, name this vector field defined as force per unit charge.

Electric Field [accept E-field]

One of these particles is emitted when a vacancy in an atom is filled in the Auger effect, and these particles were scattered off a nickel target to demonstrate their wave behavior in the Davisson-Germer experiment. These particles scatter photons in the Compton effect, and one experiment reached equilibrium between buoyant and gravitational forces on oil drops to measure the charge of these particles, an experiment conducted by Robert Millikan. This particle was discovered through a cathode ray experiment by J.J. Thomson, and its antiparticle is the positron. For 10 points, name this particle that orbits the nucleus with a negative charge.

Electron

One model describing this phenomenon is named for Tomlinson, which results in a slip-stick variety if a namesake parameter is greater than 1. For a belt-pulley system, this quantity is proportional to e to the angle the belt makes leaving the pulley versus entering it. One law by Coulomb and two laws by Amonton describe it, and its usual mechanical form is given by the normal force of an object times its namesake coefficient. It comes in static and kinetic varieties, and this force always opposes the direction of motion. For 10 points, name this force that results from two surfaces being in contact.

Friction

One problem in modern physics is that this phenomenon cannot be renormalized in quantum field theory, and this interaction is carried by a spin-2 gauge boson. Particles only affected by this force move along geodesics due to its equivalence principle, and a constant associated with this force was measured with a torsion balance in the Cavendish experiment. In general relativity, this force results from the curvature of spacetime, and it is inversely proportional to the square of the distance between two bodies. For 10 points, name this force that causes an acceleration of about 9.81 meters per second squared on Earth, first described by Isaac Newton.

Gravity [accept equivalents such as Gravitational Force]

When this statement's operators are related by Fourier transforms, it can be derived from the Cauchy-Schwarzinequality. This statement was explained by its namesake in a thought experiment of a gamma-ray microscope. TheBohr model violates this condition because it assigns a fixed angular momentum to each quantized orbital. One formof this statement multiples energy and time, and this principle's most common form sets the product of two standarddeviations as greater than or equal to h-bar over two. For 10 points, name this principle that states it is impossible todetermine the position and momentum of a particle simultaneously, named for a German physicist.

Heisenberg uncertainty principle [prompt on "uncertainty principle"; prompt on "principle of indeterminacy"]

Stueckelberg action is a special case of the process named for this entity, and the non-zero vacuum expectation value for this entity is essential to its namesake process. A complex spinor with four real components represents this particle's field, and the collision of a fermion and an antifermion is thought to form a virtual W or Z boson that can emit this particle. This particle emerged during the cooling of the universe when spontaneous symmetry breaking occured, and the Large Hadron Collider at CERN detected this particle in 2012. For 10 points, name this elementary particle responsible for mass.

Higgs Boson [accept Higgs Field before "particle" is mentioned]

The inability to explain the extremely small but nonzero size of the field with this name is the hierarchy problem. The mechanism with this name involves the absorbtion of NambuÂâ€"Goldstone bosons and includes the process of spontaneous symmetry breaking. This mechanism explains why the weak force has a short range, because the weak force carriers have mass. The particle with this name was the 17th and final elementary particle found in the Standard Model. Give this name for a boson that was confirmed to exist by recent experiments at the Large Hadron Collider at CERN.

Higgs [accept more specific answers; accept gravity or gravitational until the 2nd sentence is completed]

In one form of this phenomenon, air is forced via a gas compressor, and engines that run on that are contrasted with naturally aspirated engines. Symmetry associated with this phenomenon led Albert Einstein to develop the theory of special relativity. Unwanted entities in these phenomena are known as eddies, and this phenomenon scales linearly with the (*) number of coils. Faraday’s Law describes this phenomenon as the change in magnetic flux, and Lenz’s Law gives the direction of the resulting electric current. For 10 points, name this phenomenon in which a changing magnetic field creates an electric current.

Induction

The average value for this quantity can be determined by the virial theorem, and this quantity is lowest when the center of the mass of a reference frame is stationary. This quantity is equal to a body's momentum squared divided by twice its mass, and the Lagrangian is calculated as this quantity symbolized T minus a related quantity. The change in this quantity is equal to the net work done on an object, and its rotational variety is equal to one-half times the moment of inertia times angular velocity squared. For 10 points, name this quantity which is equal to one-half times mass times velocity squared, the energy of an object due to its motion.

Kinetic Energy [prompt on Energy before mention]

Noether's theorem shows that this quantity is conserved when the Lagrangian of a system possesses translational invariance, and its quantum mechanical operator is equal to negative i h-bar times the gradient operator. The de Broglie wavelength is inversely proportional to it, and the derivative of this quantity with respect to time is force. Impulse equals the change in this quantity, which is conserved by all collisions of a closed system. For 10 points, name this quantity often symbolized as p, the product of mass and velocity.

Linear Momentum

19. An equation named for this man is derived using the molecular chaos assumption and probabilistically describes the kinetics of a system not at equilibrium. A theorem named for this man claims a quantity denoted H will always decrease and is analogous to the second law of thermodynamics. After the base definition shift in the SI, the Kelvin is now defined based on a value named for this man. (*) Three-halves times the temperature times this man’s namesake constant is equal to a particle’s kinetic energy. That constant is equal to the gas constant divided by Avogadro’s number. For 10 points, name this scientist who names a constant symbolized k-sub-b.

Ludwig Boltzmann [accept the Boltzmann Transport equation, Boltzmann H-Theorem, or Boltzmann’s constant; prompt on k-sub-b before mention] <Physics, VS><ed. OC>

This man names a self aware “brain†which arises randomly from chaos. The BGK collision operator is used in this man’s namesake equation, from which the H-theorem can be derived. The energy of the band gap of a superconductor is equal to 3.5 times a critical temperature times this man’s namesake constant. Along with James (*) Clerk Maxwell, this man names a distribution which describes the speeds of particles in an ideal gas. This man names a law which states that the energy of a blackbody is proportional to the fourth power of temperature with Josef Stefan. For ten points, name this Austrian physicist whose namesake constant is equal to the ideal gas constant divided by Avogadro’s constant.

Ludwig Eduard Boltzmann <AG>

This quantity is the denominator in the formula for reluctance, and this quantity can be calculated by taking a line integral of the magnetic vector potential. The line integral of the electric field around a closed loop is equal to the negative change in this quantity with respect to time according to Faraday's law of induction. According to Gauss's law for magnetism, this quantity is equal to zero for a closed surface, and this quantity is equal to the dot product of magnetic field and area. Measured in webers, For 10 points, name this measure of the strength of the magnetic field through a surface.

Magnetic Flux [prompt on Flux]

Henry Adams compared militant Germany to this thought experiment. Leó Szilárd noted that it has to have someway of acquiring and storing information, thereby refuting its formulator's claims. The Brownian ratchet is similarto this thought experiment, but Richard Feynman proved that it cannot actually produce useful work because themechanism will not work under the theorized conditions. The title entity controls a gate between two gas chambersand is able to cause a temperature difference, thus causing a decrease in entropy. For 10 points, name this thoughtexperiment formulated by a Scottish physicist, which seems to defy the second law of thermodynamics.

Maxwell's demon

One of the confirmations of this experiment was performed by Gustaf Wilhelm Hammar in Idaho after this was brought into question by experiments performed by Dayton Miller on top of Mount Wilson. Originally moved from Berlin to Potsdam because of vibrations, this experiment eventually was conducted on a stone slab floating in a pool of mercury in Cleveland. Its null result was explained at first by drag but is now explained by relativity. Name this attempt to measure the luminiferous ether [loo-meh-NIH-fuh-rus EE-thur].

Michelson-Morley Experiment

This experiment was contradicted by an earlier experiment that took place in water and was conducted by Fizeau. Kennedy and Thorndike improved on this experiment to show that its results were independent of velocity. An (*) interferometer was used in this experiment to compare the interference pattern between two beams of light. In this experiment, a beam splitter split light into running in two different directions, and the speed of the two beams was shown to be the same. For 10 points, name this experiment that took place at Case Western Reserve University and disproved the existence of the luminiferous aether.

Michelson-Morley Experiment

Ehrenfest's theorem reduces to this equation in the limit of large quantum numbers. Adding a term to this equation for variable mass due to spent fuel yields the rocket equation. A simple harmonic oscillator’s motion can be described by setting(*) Hooke’s law equal to one form of this equation. The rotational analogue of this equation sets torque equal to the product of the moment of inertia and the angular acceleration. For 10 points, name this law written as F equals m a.

Newton’s Second Law of Motion <David Dennis>/<ed. HB>

This man declined an invitation to advise the Fifth Lateran Council on calendar reform, and his observation of an eclipse of Aldebaran helped him determine the diameter of the Moon. The seven assumptions of the model in this man's Little Commentary includes the belief in perfect, circular orbits, though the evidence gathered in his On the Revolutions of the Celestial Spheres was used by Galileo to promote a change in the way people viewed the solar system. Arguing against the Ptolemaic system of astronomy, name this Polish scientist who developed the heliocentric model of the universe.

Nicolaus Copernicus [or Mikołaj [MEE-koh-wye] Kopernik]

This scientist and Hendrika Johanna van Leeuwen [LAY-ven] discovered independently that classical physics could not explain the spontaneous magnetization of iron. A conference he spoke at in Gottingen [GOE-tin-gen] in 1922 became known as his festival and was where he met his future student Werner Heisenberg. His interpretation of quantum mechanics allowing mutually exclusive measurements was known as complementarity and became known as the Copenhagen Interpretation. Name this physicist who explained energy levels using circular orbits in his model of the hydrogen atom.

Niels Bohr

This physicist names the natural unit for the magnetic moment of an electron due to its spin and orbital angular momentum. Sommerfeld modified a model named for this physicist to account for its failure to explain the Stark and Zeeman effects. The most probable distance between the nucleus of hydrogen and its electron is this physicist’s (*) radius. This physicist explained Rydberg’s formula for the wavelength of spectral lines by considering transitions between discrete energy levels, which are indexed by the principal quantum number n. For 10 points, name this physicist who proposed that electrons orbit the nucleus like planets in the Solar System.

Niels Bohr [accept Bohr magneton or Bohr-Sommerfeld model or Bohr radius or Bohr model] <Physics â€" Schwartz> [Ed. French]

This man names a method of determining the allowed quantized states of a system with Sommerfeld. He criticized the EPR paradox as part of his debates on quantum mechanics with Albert Einstein, and the wave-particle duality is an example of this man's complementarity principle. The Rydberg formula was derived from one of his theories, and he codified his work on quantum mechanics with Werner Heisenberg in the Copenhagen interpretation. For 10 points, name this Danish scientist who names a model of the atom in which electrons travel in orbits that are fixed distances from the nucleus.

Niels Henrik David Bohr

5. One theorem formulated by this scientist claims that, if quantum numbers are large enough, quantum systems behave similarly to classical systems. A quantity named for this scientist approximates the magnetic moment of an electron, while another, approximating the distance from a nucleus to an (*) electron, is his “radius.†This man explained why hydrogen’s spectral lines have distinct, discrete wavelengths by proposing that electrons have fixed energy levels in a model that superseded the Rutherford and plum pudding models. For 10 points, electrons have circular orbits around a nucleus in which Danish physicist’s atomic model?

Niels Henrik David Bohr [accept the Bohr radius or the Bohr magneton or the Bohr model] <Physics, VS><ed. VS>

"A counterpart to it involves reluctance and is known as Hopkinson’s Law. It can be applied to hydraulics in describing the relationship between pressure and flow rate. The continuum form of this law can be combined with the integral of the electric field and the cross-section area to get another form. Another version of this law expresses two of the values in root mean square and switches another of the terms for impedance. Modified versions of this law include one force. FTP, name this law that states that voltage is equal to the product of current and resistance."

Ohm's Law

In the particle-in-a-box model, this quantity is infinity outside of the box, and zero inside the box. Â Particles penetrate a barrier of this quantity in quantum tunnelling. Â This quantity denoted by a capital V is subtracted from a counterpart in the expression for the Lagrangian. Kirchhoff's(*) loop rule can be interpreted as a statement of the conservation of this quantity, as voltage equals this quantity per unit charge. This quantity is symbolized as U and is the amount of energy stored in an object. For 10 points, name this type of energy that is often contrasted with kinetic energy.

Potential Energy <David Dennis>/<ed. HB>/<ed. JO> Bonuses

The magnetic form of this quantity is computed by finding the negative dot product of the dipole moment and the magnetic field strength. It is subtracted from a related quantity in the Lagrangian, where it is symbolized V, and equilibrium occurs when this quantity is an extremum with respect to x. For a spring, it is equal to one-half times the spring constant times displacement squared, while the gravitational form of this quantity is mass times gravitational acceleration times height. For 10 points, name this energy stored in a system due to configuration or position, which is converted into kinetic energy.

Potential Energy [prompt on Energy; do not accept "potential"]

In an AC circuit, the ratio of resistance to impedance gives this quantity's namesake factor. For an electromagnetic wave, this quantity per unit area is described by the Poynting vector, which gives the wave's intensity. In a circuit, this quantity is equal to current squared times the resistance, or alternatively current times the voltage dropped. For a rotational system, it is torque times angular velocity, or it can also be computed as the dot product of force and velocity. For 10 points, identify this quantity measured in Watts, which is equal to the work done over the time.

Power

The Oren-Nayar model is a generalization of the Lambertian model of this phenomenon's diffuse form. The waves involved in this phenomenon lie in the same plane as the normal to the medium interface, and this phenomenon does not occur for a particular polarization at Brewster's angle. A wave undergoes the "total internal" variety of this phenomenon at the critical angle, and the angle at which this phenomenon occurs is equal to the angle of incidence. FTP, name this change in direction of a wave back into the original medium, easily observable using mirrors.

Reflection

Telescopes that are named for this phenomenon are preferred because they are cheaper and larger to their counterpart, and an example of that telescope is named for Isaac Newton. When arcsine n2 over n1 is defined, the (*) total internal type of this phenomenon can occur. Lenses cannot undergo this phenomenon, and the angle of incidence equals the angle of this phenomenon. For 10 points, name this phenomenon that occurs when light bounces off a mirror.

Reflection [accept word forms; do NOT accept “Refractionâ€]

This person's Caltech lectures were the basis of his books Six Easy Pieces and Six Not So Easy Pieces. This person worked with Murray Gell-Mann to explain the weak interaction, and he extended work by Paul Dirac on path integrals. This person shared a Nobel Prize with Schwinger and Tomonaga for his work on quantum electrodynamics, and much later he investigated the Space Shuttle Challenger explosion. He included a space axis and a time axis and often showed two arrows meeting a squiggly line in his namesake diagrams. Name this practical joker who wrote the autobiography What Do You Care What Other People Think?

Richard Feynman

Grassmann numbers are used to allow one of this man's formulations to represent fermionic fields, and he developed a quantum mechanical explanation of Landau's theory of superfluidity. This man names a time symmetric theory of electrodynamics with Wheeler, and along with Shinichiro Tomonaga and Julian Schwinger, this man was awarded the 1965 Nobel Prize in Physics for his work in quantum electrodynamics. This man's namesake diagrams show particle interaction, and he gave a famous series of lectures that were compiled into a three volume set. For 10 points, name this physicist and CalTech professor who was quite the bongo player.

Richard P. Feynman

The Dirac equation can be solved in 1+1 dimensions using this physicist’s namesake “checkerboard,†and can be simply expressed using his namesake slash notation. Green’s functions give the propagator of a particle on constructs named for this physicist, who introduced a theory where the exponential of the action is proportional to path contribution. He shared a nobel prize with (*) Schwinger and Tomonaga for his work on quantum electrodynamics. Antiparticles are depicted travelling backwards in time on his namesake diagrams. For 10 points, name this physicist whose class at Caltech was converted into his Lectures on Physics.

Richard P. Feynman

One of this man’s approximations is used in molecular spectroscopy to simplify energy calculations as a result of electronic and vibrational effects. An upper bound on the mass of neutron stars is named for Tollman, Volkoff, and this man. Along with Max (*) Born, this man names an approximation that the wavefunction can be split into electronic and nuclear components. This man quoted the Bhagavad Gita in saying “Now I am become death, the destroyer of worlds.†For 10 points, name this “father of the atomic bomb†who led the Manhattan project.

Robert Oppenheimer Packet 9 â€" Bonuses

An altered form of this process is described by an equation which includes the additional term e raised to the negative bt over two m. Acceleration in this process can be calculated as the negative of omega squared times displacement, and equations multiplying either the square root of I over mgh or the square root of L over g by two pi describe this process for different devices. For small amplitudes, this process can approximate the motion of pendulums. For 10 points, name this type of periodic motion exemplified by springs.

Simple Harmonic Motion [prompt on Harmonic Motion]

A quanta of energy is added to one of these systems when a creation operator is applied to it, and solutions of these are given by Hermite polynomials. The energy eigenvalues of these systems can be found using the ladder method, and h-bar omega over two is equal to the minimum energy level of the quantum version of these systems. The angular frequency of these systems is given by the square root of the quantity stiffness divided by mass, and these systems can experience damping. For 10 points, name these systems which have a restoring force proportional to displacement, examples of which include pendulums and mass-spring systems.

Simple Harmonic Oscillators [accept Quantum Harmonic Oscillators]

The Einstein model of solids considers each atom as a quantum mechanical version of one of these systems. They can be classified using a quantity given by 2 pi times the energy stored over the energy dissipated, also known as the Q factor. These systems may undergo damping, and the frequency of these objects is equal to the square root of the stiffness k over mass. Pendulums are an example of these systems at small amplitudes, and they can be described mathematically by setting Newton's Second Law equal to Hooke's Law. For 10 points, name these objects, exemplified by a mass on a spring.

Simple Harmonic Oscillators [accept Simple Harmonic Oscillation or Simple Harmonic Motion or SHO or SHM; prompt on partial answer]

Calculations related to one of these systems are dependent on a distance quantity called the pitch, and in one of these systems, the torque produced by an external force affects a component concentrated closer to the center of mass. For two of these systems, the ratio of outer radius to inner radius and the ratio of sloped length over width give the ideal form of a quantity defined as the output force divided by the input force called mechanical advantage. For 10 points, name these devices which include the pulley, wedge, and inclined plane.

Simple Machines

A thought experiment attributed to this person involved a cannon on top of a mountain. This person is the namesake of the relationship making heat loss proportional to the temperature difference between an object and its environment. Generally credited with building the first useful reflecting telescope, he explained why Kepler's laws of planetary motion are true in his Principia [prin-KIP-ee-uh], which also included this man's law of universal gravitation. Name this scientist whose three laws of motion are a basis of classical physics, the namesake of the SI unit of force.

Sir Isaac Newton

The energy of a photon can be described as the product of its momentum and this quantity. Cherenkov radiation is produced when this value is exceeded, and this quantity divides velocity squared in the Lorentz factor. The ratio of this value in a vacuum to this value in a particular medium is the refractive index, and it is squared and multiplied by rest mass in an equation formulated by Einstein. For 10 points, name this theoretical limit on the speed of objects, which in a vacuum is approximately equal to three times ten to the eighth meters per second.

Speed of Light [accept c]

This quantity’s namesake electron g-factor slightly differed from two, which resulted in one-loops on a Feynman diagram in one effect. That effect was not predicted by the Dirac equation and is known as the Lamb Shift. Three Hermitian matrices used to calculate this quantity’s interaction with a magnetic field are named for Pauli. Silver (*) atoms were deflected because of a magnetic field in the Stern-Gerlach experiment in order to prove the quantization of this property. For 10 points, name this property that separates fermions from bosons and is the intrinsic measure of angular momentum.

Spin [prompt on “angular momentum†before mentioned]

Yang and Mills created a theory of this force that is a non-abelian gauge theory. Another theory describing this force has a lattice variety, and that theory describing this force takes place in an SU(3) symmetry group. Pions were believed to carry this force but it is now known that this is mediated by the exchange of (*) gluons. Color confinement is a consequence of this force that is described by quantum chromodynamics, or QCD. For 10 points, name this force that confines quarks into hadrons, is the most powerful of the four fundamental forces, and holds atomic nuclei together.

Strong Nuclear Force

The distance at which a magnetic field exponentially decays by a factor of one over e in one of these materials is known as the London penetration depth. They exist in Type I and Type II varieties, and they are mathematically described using Ginzburg-Landau theory. One theory models these materials using the condensation of Cooper pairs, and YBCO is a high-temperature example of them. Some of them act as perfect diamagnets that expel internal magnetic fields through the Meissner effect, and they are governed by BCS theory. For 10 points, name these materials that exhibit zero electrical resistance.

Superconductors [accept Superconductivity]

A variant on this experiment using a barium borate crystal is named for a certain "eraser", and the nature of detection is critical in John Wheeler's "delayed choice" variant on this experiment. Electrons were used in a variation of it done by Claus Johnson, and the original version of this experiment used two barriers and a viewing (*) screen. The light from the openings in those barriers used in this experiment produced a pattern of bright and dark parallel bands called fringes. For 10 points, identify this experiment performed by Thomas Young, which demonstrated the wave nature of light and utilized a pair of namesake openings.

Thomas Young's double slit experiment [accept either underlined part before "Young" is read; after his name is read, accept only double slit experiment and generously prompt on Young experiment]

For an electric dipole, this quantity can be calculated as the cross product of its dipole moment and the electric field. Two forces which cause a net force of zero but a nonzero value for this quantity are known as a couple. The direction of this quantity can be determined with the right hand rule, and it is the time derivative of angular momentum. It is computed as the cross product of lever arm and force, or alternatively as the product of angular acceleration and moment of inertia. For 10 points, name this rotational analogue of force.

Torque [accept Moment of Force; do not accept "Moment of Inertia"]

The Gummel-Poon model describes one of these devices that is subject to the Early effect. Two of these objects can be used to create a Darlington pair, and an "ion sensitive" variety can measure ion concentrations in solution. Electric field controls the drainage voltage in field effect types of these devices, which include MOSFETs, and bipolar types of them come in PNP and NPN types. These electrical components were introduced by a team from Bell Labs and are useful in amplifying signals. For 10 points, name these circuit components that replaced vacuum tubes in computers and are useful as switches.

Transistors

This quantity is equal to the dot product of electric field and displacement, and the change in this quantity around a loop is equal to zero according to Kirchhoff's laws. The power of a resistor is equal to the square of this quantity divided by resistance, and this quantity is constant for resistors wired in parallel. Referred to as the electromotive force when generated by a battery, For 10 points, name this quantity which, according to Ohm's law, is the product of current and resistance.

Voltage

A change in magnetic flux generates this quantity according to Faraday's law, and electric field is the negative partial derivative of this quantity with respect to x. An oscilloscope plots this quantity with respect to time, and Kirchoff's laws state that the net change in it around a loop in a circuit must be zero. Measuring this in a circuit requires an instrument with a very high resistance connected in parallel. For a point charge it is proportional to charge over radius, and it can also be referred to as potential difference. For 10 points, name this term used for work per unit charge, often symbolized V.

Voltage [accept Electric Potential Difference before mention; accept EMF or Electromotive Force before "derivative"]

This quantity is equal to the line integral of the electric field, and on a Josephson junction made of two superconductors coupled by a weak link, current flows indefinitely without this quantity being applied. At the tip of an antenna, this quantity becomes extremely high, which is caused by the impedance approaching infinity. The electric field is perpendicular to the contour lines of this quantity, and around a closed loop, the sum of this quantity is equal to zero. This quantity is known as electromotive force when produced by a battery. For 10 points, name this quantity which, according to Ohm's Law, is equal to current times resistance.

Voltage [accept Electric Potential Difference]

The square of both charge and this quantity is proportional to the power emitted by a point charge in the Larmor formula. This quantity is by definition zero in an inertial reference frame. Velocity squared divided by radius equals this quantity for an object undergoing centripetal motion. The rotational analogue of this quantity multiplies moment of inertia to give (*) torque. This quantity is the time derivative of velocity. The symbol little g represents this quantity at the surface of the Earth, where it is equal to approximately 9.8 meters per second squared. For 10 points, the product of mass and what quantity equals force, by Newton’s second law?

acceleration [accept gravitational acceleration; accept angular acceleration; accept rotational acceleration; prompt on a; prompt on alpha] <GC, Physics>

Classically, this quantity squared times charge squared is proportional to the radiative power of a point charge. This quantity for a reference frame must be zero for the frame to be inertial. Radius times angular frequency squared has units of this quantity, as does linear velocity squared divided by radius, for an object in (*) uniform circular motion. This quantity’s angular counterpart, symbolized alpha, multiplies the moment of inertia to give net torque. Analogously, this quantity times mass equals the net force. For 10 points, name this second derivative of position, and the first derivative of velocity, which is measured in meters per second squared.

acceleration [or a]

One form of this quantity for a particle in a rotating system is equal to minus 2 times the cross product of the angular velocity and the particle’s velocity with respect to the system. Charged particles being reflected by a moving interstellar magnetic field can randomly experience the second-order Fermi(*) type of this quantity. This quantity is zero for an idealized Atwood machine. For 10 points, name this quantity, measured in meters per second squared equal to the rate of change of velocity.

acceleration [prompt on A or A net] <David Dennis>/<ed. HB>

10. In Minkowski space, the four-vector form of this quantity is computed as the derivative of U with respect to proper time and represents a curvature vector along a world line. For a simple harmonic oscillator, this quantity equals negative omega squared x, while its (*) centripetal variety is directed towards the center. Holding this value constant results in a line with constant slope on a velocity-time graph. This quantity can be found by dividing force by mass according to Newton’s Second Law, and is equal to 9.8 meters per second squared due to Earth’s gravity. For ten points, identify this rate of change in velocity.

acceleration [prompt on “aâ€] <EC>

5. The terminal velocity of an object acted upon by a drag force is proportional to the square root of its mass times this quantity, and a launched object has escape velocity equal to the square root of 2r times this quantity. The maximum height a launched projectile reaches is inversely proportional to this quantity, and the projectile’s vertical velocity equals initial velocity  minus this quantity times time. This quantity is equal to (*) big-G times M over R-squared, and a certain type of potential energy has magnitude mass times height times this quantity. For ten points, identify this quantity which on Earth is about 9.8 meters per second-squared, often symbolized little-g.

acceleration due to gravity (accept any answer with both the underlined words or word forms; prompt any answer with one of them, accept little-g or lowercase-g before mention, prompt on just “Gâ€) <MS>

Pressure is proportional to the exponential of this quantity in the hypsometric equation. Devices measuring this quantity often have three pointers and use an aneroid barometer. As this quantity increases, temperature decreases, then increases, then decreases again, since the lapse rate changes sign. The Karman line is defined as the limit of this quantity at which (*) lift velocity equals orbital velocity. Gravitational acceleration decreases with the square of this quantity. It increases from the mesosphere to the thermosphere to the exosphere. For 10 points, name this quantity, the distance an object is from the surface of the earth.

altitude [or height; or elevation; prompt on distance or radius]

Immanuel Kant and Pierre-Simon Laplace had trouble explaining why this quantity was so low for the sun relative to the planets. This value and energy are both quantized in the Bohr atomic model. When an object absorbs light, this quantity changes by the amount of energy absorbed divided bythe light's angular frequency. This quantity is measured in units of force multiplied by distance multiplied by time, and its derivative with respect to time is torque. The intrinsic form of this value is called spin. Name this conserved quantity equal to moment of inertia times angular velocity.

angular momentum

This value is quantized so that it must equal an integer times the reduced Planck constant. Its components do not commute, so they are complementary variables in Heisenberg's Uncertainty Principle. Its derivative with respect to time, which can be found using the product rule, gives one term equal to zero and the other equal to torque. This conserved quantity equals moment of inertia times angular velocity. Name this quantity equal to the cross product of position with linear momentum.

angular momentum (do not accept "momentum")

14. An experiment that proved that this quantity is coupled with the magnetic moment of individual atoms by magnetizing an iron cylinder was run by Einstein and de Haas. For a charged particle, this quantity is related to the magnetic dipole moment by a factor of q over 2m, the gyromagnetic ratio. By Noether’s [[“NOY-thursâ€]] theorem, this quantity is conserved due to (*) rotational invariance. This quantity has both spin and orbital forms. Torque is the derivative of this quantity with respect to time. This quantity is equal to the moment of inertia times angular velocity. For 10 points, name this quantity, symbolized L, the rotational analogue of linear momentum.

angular momentum [accept rotational momentum or spin angular momentum or orbital angular momentum prompt on L, do not accept “momentum†or “linear momentumâ€] <Physics, DY><ed. VS>

The radius of this structure is proportional to a measure of its mass to the one-third power. Because of this structure, a relatively large number of particles following a hyperbolic path will have a very small impact parameter. This structure absorbs gamma radiation in the Mössbauer effect. When this structure (*) binds together, it release energy responsible for the mass defect. This structure’s charge is denoted by a Z. In a refutation of the “plum-pudding†model, this structure was discovered in Rutherford’s gold-foil experiment. For 10 points, name this structure made of the protons and neutrons at the center of an atom.

atomic nucleus <JR>

14. One formula approximating the mass of these objects contains an asymmetry term and is named after Bethe and Weizsacker. George Gamow proposed the liquid drop model to explain the shape of these objects. The composition of these structures relate to “magic numbers†as predicted by the shell model, though deformations must be accounted for in their (*) “island of stability.†These entities were notably missing from the J.J. Thomson’s “plum pudding†model and were shown to exist in an experiment in which Rutherford fired alpha particles at a piece of gold foil. For ten points, identify these structures consisting of protons and neutrons that are located at the center of an atom.

atomic nucleus (or nuclei, do not accept or prompt on “atomâ€) <MS>

One type of this particle would create long-range fluctuations with little energy cost, according to the Merminâ€"Wagner theorem. In theories with gauge symmetry, one type of this particle becomes massive and is longitudinally polarized by the (*) “Goldstone†variety of this particle. BCS theory describes superconductivity as caused by the condensation of Cooper pairs, which behave like these particles. The weak interaction is mediated by the W+, W-, and Z0 subtypes of these elementary particles, which have integer spin. For 10 points, name this particle whose “Higgs†variety is responsible for mass.

boson

The Richardson number is a ratio of this kind of force to shear forces. To simulate microgravity, the Sonny Carter training facility keeps this force neutral to train astronauts. Because the density of wax balls changes upon heating, a formula that can be written as density times gravity times volume explains this force in (*) lava lamps. That principle by Archimedes says this vertical force on an object equals the weight of the fluid the object displaces. For 10 pointsâ€"give this term that also means the ability of an object to float in water.

buoyancy or buoyant force (accept word forms; accept Neutral Buoyancy Laboratory; prompt on "floating" or "sinking" until "float")

The band filling / emptying effect alters the quantum form of this quantity for low density of state systems. For two concentric spheres, this quantity is equal to 4pi epsilon naught divided by the reciprocal of the inner radius minus the outer radius. One divided by the product of angular frequency and this quantity gives its namesake (*) reactance. In a namesake device, increasing the dielectric constant increases this quantity. This quantity is defined as charge over voltage and is measured in farads. For 10 points name quantity that measures the ability to store charge.

capacitance

Solving the Laplace equation for a constant potential calculates this quantity. This quantity is calculated as four pitimes the permittivity of free space times radius for a sphere, and the reciprocal of this quantity is elastance. Thisquantity is found by summing the inverse of each individual value when their associated devices are connected inseries, while it is summed directly when the devices are in parallel. An early device associated with this quantity isthe Leyden jar. This quantity is more commonly found by dividing charge by voltage for a namesake parallel-platedevice. For 10 points, name this quantity that measures the ability of a body to store electrical charge.

capacitance [prompt on "C"; prompt on "capacitors"]

1. Examples of these devices that are powerful for their volume are made from thin oxidized layers of tantalum. These devices can smooth the waveform of full-bridge rectifiers by preventing the drop off that occurs when AC switches polarity. They aren’t inductors, but the reactance of these devices helps them function while in parallel with a load in a low-pass filter. These devices’ namesake quantity is equal to (*) charge divided by voltage. Inserting a dielectric between two parallel plates creates one of these devices. The strength of these circuit devices is typically measured in microfarads. For 10 points, name these circuit devices that can hold current for short amounts of time.

capacitors <Physics, VS><ed. VS>

3. For a non-uniform three-dimensional object, this entity is represented by the vector X such that integrating the difference between X and a given point times the density at that point with respect to volume is zero. For two binary objects moving elliptically, their speeds are greatest the closer they are to this entity. It can be found experimentally by intersecting two plumb lines, and the (*) parallel-axis theorem demonstrates that moment of inertia is minimized when an axis goes through this point. It is the point at which gravitational torque is zero, and for uniform objects it is located at the centroid. For ten points, identify this location, the weighted average of a system’s mass.

center of mass (or center of gravity) <MS>

The conservation of this quantity’s equation can be derived by taking the divergence of the differential form of Ampere’s law. The flux through a surface is equivalent to this quantity enclosed over the permittivity of free space, according to Gauss’s law. One over 4 pi times the vacuum permittivity is the constant of proportionality in an equation involving two particles with (*) non-zero values for this quantity. Capacitance is defined as this quantity over voltage. The force between particles as a function of distance and this quantity is calculated in an equation named for Coulomb. For 10 points, name this property, symbolized q, that is positive for protons and negative for electrons.

charge [do NOT accept or prompt on “current’] <LZ, Physics>

The Hermitian adjoint of a matrix A equals this function applied to each entry of A transpose. In quantum mechanics, the probability density of a particle’s position equals the wavefunction times this function of the wavefunction. Applying this function to “r times e to the i theta†is equivalent to replacing theta with negative theta. It’s not the identity, but if x is a root of a real polynomial, then so is this function of x. For a (*) complex number z, z times this function of z equals the square of the absolute value of z. This function is denoted with a horizontal bar over the variable. For 10 points, name this function that transforms “a plus b i†into “a minus b i.â€

complex conjugate <Math â€" French> [Edited]

This function appears squared in the Klein-Nishina formula. The change in wavelength due to Compton scattering is given as the Compton wavelength times 1 minus this function. This function is squared in Malus’s law for the intensity of (*) polarized light.  The magnitude of the normal force for a mass on an incline is equal to weight times this function of the inclination angle. The dot product of two vectors equals their magnitudes times this function of the angle between them. For 10 points, name this function that for a right triangle represents the adjacent leg over the hypotenuse.

cosine

A value described by this adjective is often decreased using a “tamper,†which is a kind of neutron reflector. A value described by this adjective occurs at the intersection of the binodal and spinodal curves. No amount of pressure can liquefy a substance above this kind of (*) temperature. This adjective also describes the temperature below which materials become superconductors. Liquids and gases do not exist beyond a value described by this adjective; that “point†described by this adjective can be visualized on a phase diagram. Nuclear reactions become self-sustaining after reachingâ€"for 10 pointsâ€"what kind of “mass?â€

critical [accept critical point; accept critical temperature; accept critical coagulation concentration; accept critical mass] <AF>

In one system for classifying these materials, negative integers are written with a bar on top, and the three integers h, k, and l are used to represent a vector in reciprocal space. The Burgers vector describes "edge" and "screw" dislocations in these structures. The formation of these materials requires the presence of a "seed" to begin(*) nucleation. These structures, which are classified by Miller indices, can contain defects and vacancies among their lattice planes. For 10 points, name this ordered material structure, exhibited by diamond.

crystals [or crystalline] <Joe Stitz >/<ed. AR>

Perovskite types of these entities can be embedded with colloidal quantum dots to create hyper efficient LEDs. Burgers vectors describe the magnitude and direction of dislocations in these entities. PZT is one of these entities, which displays (*) piezoelectric properties. Miller index notation is used to describe the Bravais lattices of these entities. They can be body or face centered cubic and their liquid variety is used in television displays. For 10 points name these solids with a regular repeated pattern of atoms.

crystals [prompt on lattice]

The Laplacian of the magnetic vector potential is equal to the negative product of the permeability of free space and this quantity. The magnetic dipole moment is equal to area times this quantity. This quantity is multiplied by the cross product of the length and displacement vectors in the numerator of the (*) Biot-Savart law. This quantity is equal to the time derivative of charge and is also equal to voltage over resistance. For 10 points, name this quantity that quantifies the amount of flowing charge, measured in amperes.

current

One version of this value is given as the quotient of the determinants of the two fundamental forms. The derivative of the unit tangent vector is equal to this quantity times the unit normal vector. By the Theorema Egregium, this value is invariant under local isometry. The product of the two “principal†forms of this quantity is equal to its (*) Gaussian form. This quantity and torsion are the two scalars present in the Frenet-Serret formulas. This value for a circle is given as one over its radius. For 10 points, name this mathematical quantity intuitively defined as how unstraight a line is.

curvature

This concept has been more successful than Modified Newtonian [new-TOE-nee-un] dynamics at explaining the galaxy rotation problem. An equation relating average kinetic energy to potential energy called the virial[VEHR-ee-ul] theorem and observations of the Coma cluster were used by Fritz Zwicky in 1933 to predict the existence of this substance. Accounting for about 27 percent of the mass-energy of the universe, identify this substance that does not absorb or emit light and therefore cannot be seen directly.

dark matter (do not accept "dark energy")

Voltage regulators may use a type of these devices designed to undergo avalanche breakdown at the Zener voltage. Four of these devices form a “bridge†which helps convert AC to DC in full-wave rectifiers. A p-n junction acts as a simple one of these devices. Like an electrolytic capacitor, the anode of one of these devices is the side with the (*) longer lead. On circuit diagrams, these devices are represented by a triangle whose point connects to a straight line. For 10 points, name these devices which only allow current to flow in one direction, some of which are “light emitting.â€

diodes [accept light emitting diodes or LEDs] <Physics â€" Schwartz> [Ed. French]

These entities account for the “L equals one†contribution to the electric potential, which is described by first-order spherical harmonics. A time-varying one of these entities produces the radiation emitted from “rabbit ears†and other simple antennas. These entities, which experience a torque when placed in an electric field, produce an electric potential that falls off with the (*) square of distance and a field that falls off with the cube of distance. The strength of one of these entities, which is measured in debyes and calculated as “q times d,†is known as its “moment.†For 10 points, name these entities that consist of separated positive and negative charges.

electric dipoles [accept electric dipole moment] <SE>

Though it's not voltage, this quantity can be found using the method of image charges, and this quantity crossed with the H field gives the energy flux vector, also called the Poynting vector. In electrostatics, the energy per unit volume stored in this quantity equals one half times permittivity times the magnitude of this quantity squared, and this quantity equals the negative gradient of (*) potential. Faraday’s law states that this vector quantity is produced by a change in magnetic flux, while Gauss’ law gives the divergence of this quantity as rho divided by epsilon-naught. This quantity is zero inside a conductor. For 10 points, give this quantity, the force per unit charge at every point in space due to Coulombic forces, symbolized E.

electric field [accept E-field before the end ]

The displacement current in Ampere's Law is proportional to the time rate of change of this quantity. Current density equals conductivity times this value, according to a variant of Ohm's Law. This quantity is independent of distance from a charged sheet according to Gauss' Law, which is used to calculate it for charge distributions. It is constant inside a capacitor and zero inside a metal. The negative integral of it equals the change in potential between two points. This quantity can be calculated by dividing both sides of Coulomb's Law by a test charge and noting it equals force divided by charge. For 10 points, name this quantity, the field from charged particles.

electric field [or E; accept electric flux until "independent of distance"]

14. This quantity multiplied by electron mobility gives the drift velocity. Both this quantity and velocity are multiplied by q in the equation for the Lorentz Force. The Poynting vector is equal to this quantity crossed with the auxiliary (*) magnetic field vector. The flux of this quantity through a surface is proportional to the enclosed charge according to Gauss’s Law. The magnitude of this quantity inside any conductor is zero. This quantity, which typically has units of Newtons per Coulomb, is defined at a point as the electrostatic force exerted on a test charge placed at that point. For 10 points, name this vector field generated by all charged objects, symbolized E.

electric field [prompt on E before mention] <Physics, CT><ed. VS>

One formula to find force multiplies two values of this quantity divided by distance times vacuum permeability divided by two pi. The double integral of the density of this quantity is equal to the closed line integral of a magnetic field. This quantity times the differential of length is crossed with displacement in the Biot-Savart law. One measurement of power squares this quantity and multiplies it times resistance. This quantity equals voltage divided by resistance according to Ohm's Law. Name this quantity equal to charge per time that is commonly measured in amperes.

electric(al) current

9. One tool for analyzing these objects is the star-mesh transform, a generalization of the three-node Y-delta technique. Tellegen’s Theorem about these objects can be derived from two other rules, and certain simplifications of these entities are guaranteed by Norton’s and Thévenin’s Theorems. A certain induced quantity for these systems is equal to the derivative of (*) flux with respect to time as it moves through a magnetic field. The LC variety of these contain inductors and capacitors, and junction and loop rules named for Kirchhoff can be applied to them. For ten points, identify these electrical networks that often contain batteries and resistors.

electrical circuits (accept electrical networks before mentioned, prompt on graphs) <MS>

Bela Karlovitz used magneto-hydro-dynamic theory to invent one of these devices. Faraday invented consisting of a rotating flywheel. A type of these devices relies on conductive brushes rubbing against the conducting armature on a mechanical commutator. Magnetos are used for this purpose. A hollow metal globe in which static charges (*) accumulate due to friction is one of these devices. These devices in electrical circuits are usually either dynamos or alternators, depending on if the result is alternating or direct. For 10 points, name these devices, exemplified by an object named for van de Graaff, which create electrical currents.

electrical generators [or van de Graaff generators; prompt on dynamos; prompt on alternators]

. The fine-structure constant is equal to the square of a quantity associated with this particle divided by the product of h-bar and c. The magnetic moment of this particle is referred to as the Landé g factor. These particles are represented on Feynman diagrams by straight lines pointing forwards in time. Hertz discovered that sufficiently energetic (*) photons striking metal can cause the emission of these particles. Millikan attempted to measure their charge in his oil drop experiment. For 10 points, name these particles that travel in clouds around the nucleus, with the opposite charge of protons.

electrons

These objects diffuse slowly, with a drift velocity proportional to time between collisions, but they easily move through an empty lattice, in the Drude-Sommerfeld [DROO-duh SUM-er-feld] model. The hydraulic analogy explains their movement. Recombination occurs between these objects and holes. Deflection of these particles by an external (*) field creates a transverse voltage in the Hall effect. The left-hand rule is used for the magnetic field created by these particles. These particles move against conventional current. The oil drop experiment measured their charge. For 10 points, name these particles that flow through electrical circuits, which have a negative charge.

electrons

A multiplicative term that corrects the magnetic moment of this particle is called the Landé g-factor. In one technique, these particles are fired through an ultrathin sample to form an image. Phonon-created lattice distortions cause these particles to form composite bosons called Cooper pairs. One of these particles will be ejected from a material if the energy of an incident photon is greater than the (*) work function. Tauons and muons are more massive counterparts of these charged leptons. These particles are ejected from metals in the photoelectric effect. For 10 points, name these negatively charged subatomic particles which make up atoms with protons and neutrons.

electrons [accept electron magnetic moment or electron magnetic dipole moment or electron microscopy or electron microscope or transmission electron microscopy or transmission electron microscope or scanning transmission electron microscopy or scanning transmission electron microscope or high-resolution transmission electron microscopy or high-resolution transmission electron microscope; prompt on leptons or fermions; prompt on TEM imaging or STEM imaging or HRTEM imaging or HREM imaging or the photoelectric effect with "what particle is involved in that process?"] <Physics â€" Gurazada> [Edited]

Ballistic transport occurs when the mean free path of these particles is far larger than macroscopic dimension. The Drude-Sommerfeld model is a quantum mechanical treatment of these particles as an ideal gas, in which they are “free.†These particles cannot exist in the band gap. These particles are the majority carrier in n-type materials. These particles travel at the (*) drift velocity. Interactions between phonons and these particles, along with impurities and these particles, are responsible for a material’s resistivity. The motion of these particles is opposite the direction of conventional current. For 10 points, name these negatively charged particles which can carry current.

electrons [prompt on charge carriers] <GC, Physics>

In quantum statistical mechanics, the thermal expectation value of this property is obtained by taking the negative partial derivative with respect to beta of log of the exponential trace of the Hamiltonian. In classical mechanics, the conservation of this property is guaranteed by (*) time translational symmetry through Noether’s theorem. Quantum fields cannot attain 0 for their zero-point forms of this property due to the Uncertainty Principle. In particle physics, the vacuum form of this property causes the Lamb Shift in the spectral lines of hydrogen. For ten points, name this property whose rest form in special relativity is equivalent to mass times the speed of light squared.

energy

8. This function of -st [“negative ‘s’ ‘t’] appears in the integrand for a Laplace transform, and it is also equal to the sum of hyperbolic sine and hyperbolic cosine. It can be represented as the Taylor series x to the n over n factorial for nonnegative integers n, and this function is a solution to the differential equation y’=y [“y prime equals yâ€], which means the derivative of this function is (*) itself. This function lies entirely above the x-axis, and is equal to the limit as n approaches infinity of quantity “one plus x over n†raised to the nth power. For ten points, identify this function, the inverse of the natural logarithm, that raises Euler’s constant to a power of x.

exponential function [accept y = e^x; read “e to the x powerâ€] <EC>

5-dehydro-m-xylylene exhibits the “anti-†form of this property due to its violation of Hund’s Rule. A team of physicists from MIT discovered that Lithium gas exhibits this property below 1 Kelvin. The XY model describes this phenomenon and is a generalization of the one-dimensional Ising model. Materials exhibiting this property display a (*) hysteresis loop and have aligned spins. This property, which disappears above the Curie temperature, is present in materials such as iron and cobalt. For 10 points, name this phenomena, a form of magnetism present in permanent magnets.

ferromagnetism

14. In fluid dynamics, the continuity equation sets the time derivative of this quantity equal to the negative divergence of this quantity times velocity. The speed of sound in a material equals the square root of the bulk modulus divided by this quantity. The kinematic viscosity equals the dynamic viscosity divided by this quantity. This quantity is constant in (*) incompressible flow. The ratio of this quantity to that of water is the specific gravity. This quantity times g times depth equals pressure, according to Pascal’s law. For 10 points, name this quantity equal to mass divided by volume.

fluid density [prompt on “rhoâ€] <SAM>

1. This quantity is equal to the derivative of the scalar stream function with respect to a coordinate. The divergence of this quantity is zero for an incompressible fluid flow. Streamlines are tangent to the vector of this quantity. The square of this quantity is proportional to dynamic pressure. A decrease in pressure or height in a system in which energy is conserved results in a corresponding (*) increase in this quantity, according to Bernoulli’s principle. The product of cross-sectional area and this quantity is equal to volumetric flow rate. For 10 points, name this quantity, which represents how quickly the particles of a fluid are moving, equal to distance over time.

fluid flow velocity [accept velocity vector] <GC, Physics>

If a fluid is incompressible, the divergence of this quantity is zero. The sum of pressure head, elevation head, and this quantity's namesake head is constant. This quantity times diameter over viscosity equals the Reynolds number. This quantity times density times area is constant by the conservation of mass. This quantity is squared in (*) Bernoulli's equation, which shows that it goes up if pressure goes down. Volumetric flow rate equals this quantity times cross-sectional area. Often symbolized u, this quantity for a compressible fluid in a pipe cannot be greater than Mach 1. For 10 points, name this quantity measured in meters per second.

fluid velocity [or speed; prompt on v; prompt on u]

9. In an air column with one end closed, the wavelength of the first harmonic equals this multiple of the length of the air column. The magnetic permeability constant equals this coefficient of pi times ten to the negative seventh, and a typical Wheatstone bridge contains this many (*) resistors. The Stefan-Boltzmann law relates the power of blackbody radiation to this power of temperature. Maxwell names a set of this many equations governing electromagnetism, which is one out of this many fundamental forces in nature. For ten points, identify this number equal to the atomic mass of an alpha particle, which contains 2 protons and 2 neutrons.

four <EC>

A constant representing this phenomenon equals 64 over the Reynolds number for laminar flow. The arctangent of a constant associated with this phenomenon gives the angle of repose. This phenomenon results in the only net torque through the center of mass on a ball rolling down a hill. It is responsible for the buildup of static charges in the triboelectric effect. Most damping is caused by a form of this phenomenon. Its magnitude is proportional to the normal force with a coefficient symbolized mu. It comes in static and kinetic forms, and its magnitude can be reduced with lubricants. For 10 points, name this force which dissipates heat when two objects are rubbed against each other.

friction [prompt on "drag"; prompt on "air resistance"]

8. A tip-surface interaction is quantified by a parameter for this phenomenon symbolized eta in a model developed by Prandtl. The head loss occurring due to this phenomenon is modeled by a quantity found on the left y-axis of a Moody chart in the Darcyâ€"Weisbach equation. The effect of the entrainment velocity on this phenomenon is shown in the Stribeck Curve. Application of this force transfers charge in the (*) triboelectric effect. Ball bearings are used to reduce the effect of this force. The strength of this force is proportional to the strength of the normal force by a coefficient of it symbolized µ [[“mewâ€]]. For 10 points, “rolling,†“kinetic,†and “static†are types of what force that resists motion?

frictional force [accept triboelectric effect before its read] <Physics, VS><ed. VS>

15. This letter represents a quantity defined as Gibbs free energy per surface area in the Young-Laplace equation. Relativistic mass equals rest mass times a quantity represented by this letter, which is equal to the derivative of time with respect to proper time. That quantity is also expressed as one divided by the square root of one minus v squared over c squared, known as the (*) Lorentz factor. In addition to symbolizing surface tension and photons, this letter names a type of high-energy decay and radiation carrying more energy than X-rays. For ten points, identify this third letter of the Greek alphabet.

gamma [accept gamma radiation or gamma decay] <EC>

Joseph Weber proposed to detect one consequence of this phenomenon using a set of ringing aluminum cylinders. The “A+†upgrade will double the sensitivity of another instrument that observes the effects of this phenomenon. The equivalence principle states that the force due to this entity is indistinguishable from the force experienced in a (*) non-inertial frame. The Poundâ€"Rebka experiment verified the redshift due to this phenomenon. During black hole mergers, it creates “waves†that have been detected by LIGO. For 10 points each, name this weakest of the four fundamental forces, which results from curved spacetime according to Einstein’s general relativity.

gravity [accept gravitational waves; accept gravitational redshift; accept gravitational force] <AF>

One theory of this phenomenon replaces a constant with a variable scalar field, the Brans-Dicke model. The balance between outward radiation and this phenomenon acting inwardly on a body is known as the Eddington luminosity, and the bending of light due to this phenomenon is known as its namesake lensing. This force, which Einstein visualized as the curvature of spacetime in his field equations, is proportional to the inverse square of radius and the product of two masses according to a universal law named for Newton. For 10 points, name this weakest of the fundamental forces that causes objects to accelerate on Earth at 9.8 meters per second squared.

gravity [or gravitational force]

When the equation describing one of these systems has a double root, the object will cross a certain point once before slowing to a stop, and an RLC circuit acts like one of these systems. When the external force on a certain type of these systems has the right frequency, it will exhibit pure (*) resonance. Using the small angle approximation lets a pendulum be modeled as one of these systems, and setting Newton’s 2nd Law equal to Hooke’s Law gives the equation that models the “simple†type of these systems. For ten points, name these systems which can be “damped†and “simple,†and exhibit periodic motion, an example of which is a spring.

harmonic oscillator [prompt on “springs†and “pendulum†before mention, accept critically damped harmonic oscillator, accept simple harmonic oscillator, accept any of those with harmonic motion instead of oscillator] <MS>

The energy levels of this model are proportional to n plus one-half in its quantum analogue. Using a Taylor series quadratic expansion, any stable equilibrium can be modeled using the general equation for one of these systems. RLC circuits are an electrical example of these systems, one case of which sets omega equal to the square root of the length over gravity; that case uses the (*) "small angle" assumption. For one of these systems, the square root of k over the mass gives the angular frequency. Hooke's law can be used to create these systems. A restoring force creates, for 10 points, what systems which springs exemplify the "simple" type of?

harmonic oscillators (accept simple harmonic oscillator; accept damped oscillator; prompt on "oscillator"; prompt on "spring" or "pendulum")

One derivation of this law equates the dot product of the position and force vectors to the surface integral of the force exerted by the walls of a container; that method uses statistical mechanics. Adding the terms lowercase a and b to this law to account for the forces between particles and the space they fill gives the (*) Van der Waals equation. It can be rearranged to give density and the molar mass. When the kinetic molecular theory's assumptions fail at low temperature and high pressure, this law fails as well. Charles's and Boyle's Laws are included within, for 10 points, what law usually stated P V equals n R T?

ideal gas law

19. The complex form of this quantity includes the addition of an imaginary term for absorption loss, and this property is also equal to the square root of the product of permeability and permittivity. The Abbe number relates this value to a material’s dispersion. Metamaterials with negative values for this property have the potential to cloak objects. The arctangent of the ratio of two of these quantities gives (*) Brewster’s angle. It appears as the coefficient in Snell’s law, which relates it to the sine of the angle of incidence. For ten points, name this value that is the ratio of the speed of light in a vacuum to that in a given medium.

index of refraction [accept refractive index; prompt on “nâ€] <EC>

This quantity can be expressed as a complex number, the imaginary part of which is called the extinction coefficient. An applied electric field may induce a change in this quantity in the Kerr effect. Similarly, calcite experiences birefringence, in which this property for a material depends on polarization. The angle equal to the arctangent of the ratio of two of these quantities is named for (*) Brewster. The ratio of this quantity for two different materials is equal to the ratio of the sines of the angles of incidence by Snell’s Law. For 10 points, identify this material property, defined as the ratio of the speed of light in a vacuum to that in the material.

index of refraction [or refractive index; prompt on n] <LZ, Physics> Bonuses

A property of these objects holds in a disc of radius “one-over the “lim sup†of the nth-root of the absolute value of c-sub-n.†Analytic functions can be given by one of these objects. One of these objects was shown by Euler to equal “pi-squared over six,†as the solution to the Basel Problem. For a k-times-differentiable function f, truncating one of these objects gives the best degree-k (*) polynomial approximation of f, according to Taylor’s theorem. The terms “one-over-n†for natural numbers n comprise the “harmonic†one, which diverges. An infinity-superscripted capital sigma often denotesâ€"for 10 pointsâ€"what mathematical object, the sum of an infinite sequence?

infinite series [accept more specific answers like power series, Taylor series, or harmonic series; accept infinite summations; prompt on just summations; do not accept or prompt on “sequencesâ€] <JR>

This is the value of the highest energy level of the quantum harmonic oscillator. In the absence of damping, the Q-factor of a resonant system takes on this value. This is the maximum number of particles that can occupy the same quantum state in a Boseâ€"Einstein condensate. In high-energy physics, renormalization is a process of canceling terms that take this value. Max Planck fixed the (*) Rayleighâ€"Jeans law by removing a limit in which the radiated power tends to this value. For 10 points, name the length of time that Zeno incorrectly believed Achilles would take to catch a tortoise, which in reality is the value to which divergent quantities tend.

infinity [accept infinite] <SE>

12. The use of a photographic filter exposed to light in this part of the spectrum gives the appearance of a surreal glowing foliage in the Wood effect. It was first predicted by Émilie du Châtelet, and FSO takes advantage of this part of the spectrum over the use of cables. One technique performed with this phenomenon identifies specific molecules in the (*) fingerprint region, while the near type of it is used in night vision goggles. For ten points, identify this form of electromagnetic radiation used in spectroscopy and thermal imaging cameras that has longer wavelengths than red light.

infrared or IR light/waves/radiation <EnC>

For an object in a circular orbit, this quantity equals big G times the mass of each object all divided by twice the distance of separation. In special relativity, this quantity equals “gamma minus one†times “m c squared.†In Hamiltonian mechanics, this quantity is usually denoted with a capital T. For a rotating body, this quantity is proportional to the moment of inertia times the (*) square of angular frequency. This quantity decreases in an inelastic collision. In classical mechanics, this quantity equals “one-half m v-squared.†For 10 points, name this energy of motion.

kinetic energy [accept just kinetic after “energyâ€; prompt on K or KE or E sub K; prompt on T before “Tâ€; prompt on energy before “energyâ€; do NOT accept or prompt on “potential energyâ€] <Physics â€" Gurazada> [Ed. French]

William Bertozzi found that an electron’s value for this quantity after striking aluminum agreed closely with those predicted by special relativity. An object’s value for this quantity is equal to linear momentum squared divided by twice the object’s mass, and the rotational form of this quantity is proportional to the square of angular (*) velocity. This quantity is conserved in elastic collisions, and escape velocity can be found by setting this quantity equal to the negative of potential energy. For ten points, name this quantity equal to one half mass times velocity squared, the energy of motion, symbolized K.

kinetic energy [prompt on “energyâ€, do NOT accept “potential energyâ€] <MS+AG>

This letter represents a constant whose namesake problem arises from a 122 order of magnitude difference between QFT calculations of the vacuum and astrophysical observations. This letter titles a prominent contemporary astrophysical model which treats both dark energy and dark matter; in that model, it is concatenated with (*) “CDMâ€. This letter appears as the proportionality constant in an equation in which the velocity v of a wave is related to its frequency f. For ten points, name this letter whose uppercase is used to denote the cosmological constant and whose lower case is used to denote the wavelength of a wave.

lambda

Many of these devices use erbium- or neodymium-doped YAG (yag). A type of “tweezers†uses these devices to hold and move individual micron-sized particles. The output of these devices can be pulsed using mode-locking or Q-switching and is heavily collimated. These devices amplify radiation using a material that is in a state of (*) population inversion. The gain medium within these devices has high rates of stimulated emission. The output of these devices is spatially coherent and often at a single wavelength. For 10 points, name these devices that emit a single beam of light and are often used in pointers.

lasers [or light amplification by stimulated emission of radiation; accept masers] <Physics â€" Gurazada> [Edited]

2. One type of these devices is capable of producing Bessel beams with minimal diffraction. Another types of these devices is created by layering a set of concentric annular sections. Their bestform type minimize comas formed from deviations from the optical axis. One formula sets the difference between inverse radii proportional to their power, which is measured in (*) diopters and is equal to the inverse of focal length. A larger, virtual image appears behind the observer if he is standing closer than the focal length of the convex type. For ten points, identify these optical devices contrasted with mirrors, which are curved and found in microscopes and glasses.

lenses [accept specifics like concave or convex lenses] <EC>

The first term of the multipole expansion for this quantity is always zero. This quantity is the curl of the vector potential, which is denoted A. This quantity is inversely proportional to radial distance inside a torus, while it is constant inside a (*) solenoid. Change in this quantity’s flux generates an electromotive force, according to Faraday’s law. A particle with charge q and velocity v undergoes a force equal to “q v cross†this quantity. The Biot-Savart law (Bee-oh Savart law) or Ampere’s law can be used to calculate this quantity from current. For 10 points, name this quantity denoted B that is measured in teslas.

magnetic field [accept B-field before “Bâ€; prompt on B] <Physics â€" Schwartz/Gurazada> [Ed. French]

20. Landau quantization in two dimensional systems can explain effects due to this entity, which produces a toroidal shape in tokamaks, and is also equal to the curl of the vector potential A. A potential difference is formed when this is applied perpendicularly to the current in the Hall effect, and charge is multiplied by velocity cross this quantity to find the (*) Lorentz force. One can integrate this quantity around a closed loop to find the enclosed current according to Ampere’s law, and Gauss’s Law states that the net flux of this through a surface is zero. The SI unit of Tesla measures, for ten points, what counterpart to the electric field?

magnetic field [accept B] <EC>

The line integral of current times the differential of length all crossed with the displacement vector is the numerator in a line integral set equal to this quantity in one law. This quantity is the curl of the vector potential, and its partial is equal to the negative curl of electric field, per Faraday’s law. Velocity is crossed with this quantity and multiplied by charge in the Lorentz force formula. (*) Gauss’ law states that the flux of this vector field through a surface is zero. The Biot-Savart and Ampere’s laws are used to find the value of this vector quantity generated by a current. For 10 points, name this vector field symbolized B and often contrasted with the electric field.

magnetic field [or B-field] <DB, Physics> Bonuses

The strength of this object for sunspots was calculated by George Hale using spectral Zeeman splitting. An induced example of this object can affect the polarization of light due to the Faraday effect. The magnitude of this quantity is proportional to the current over the square of the distance from the wire according to the Biotâ€"Savart Law. (*) As it is mutually perpendicular to the velocity and the resulting acceleration of a charged particle, a common right-hand rule can be used to find--for 10 points-- what vector field measured in Teslas that is symbolized by a B?

magnetic field [or strength of magnetic field; or B field before “B†is read] <David Dennis>/<ed. HB>

2. This quantity is imparted by spontaneous symmetry breaking via a mechanism described by a Mexican hat potential. Neutrinos possess a nonzero value for this quantity due to flavor oscillations. The reciprocal of the sum of the reciprocals of two values of this quantity gives the “reduced†form of this quantity. This quantity is generated by a field mediated by the (*) Higgs boson. Einstein’s equivalence principle relates the gravitational and inertial types of this quantity. Two measures of this quantity are multiplied in Newton’s law of gravity. For 10 points, name this quantity which equals energy when multiplied by the square of the speed of light.

mass [prompt on “mâ€] <SAM>

8. Binnig, Quate, and Gerber invented one type of these devices that measures piezoelectric forces on a cantilever, called the atomic force one, while a dichroic filter can be used as a beam splitter in the fluorescence type of them. Ernst Ruska built one type of these instruments that can analyze surface topology through raster scanning of (*) electrons, and Anton van Leeuwenhoek used the optical variety of these devices to obtain the first observations of blood cells and bacteria. For ten points, identify these instruments used to view objects that are too small for the naked eye.

microscopes (accept specific types, like atomic force microscopes) <EnC>

The operator of this quantity is equal to negative i times h-bar times the gradient, and de Broglie’s equation states that this quantity for a particle is equal to h divided by its wavelength. Another theorem states that the product of the standard deviation of this quantity and the standard deviation of position is greater than or equal to (*) h-bar over two, and that statement is Heisenberg’s Uncertainty Principle. The derivative of this quantity with respect to time is force, and the change in this quantity over a period of time is known as impulse. Measured in Newton-seconds, For ten points, name this quantity which is equal to the product of the mass and velocity of an object.

momentum <MS>

The Gargamelle [GAHR-guh-mel] bubble chamber at CERN [sern] that was used to make early quark measurements was designed to detect these particles. It gave evidence of these particles during the 1970s by finding evidence of interactions involving W and Z bosons in the electroweak force. The oscillation of these particles and the discovery that they have mass explains why we detect fewer of these from the Sun than were expected earlier. Name these leptons, each type of which correlates with one of the other leptons.

neutrino

The Cowan-Reines experiment sought these particles that Bruno Pontecorvo predicted would oscillate. These particles arrive hours before photons, allowing astronomers to position telescopes in advance of supernovas. There exist tau, muon, and electron flavors. The KATRIN experiment hopes to detect the mass of these particles by measuring the products of (*) tritium decay. These particles rarely interact with normal matter and trillions pass through you each second. For 10 pointsâ€"give these particles whose name means "little neutral one".

neutrino (accept antineutrino) [KATRIN stands for Karlsruhe Tritium Neutrino]

W bosons are formed from the collisions of electrons and the antiparticles of these things in Glashow resonance. The PMNS matrix describes the quantum states of these particles, and devices built to detect them, such as IceCube, must be very large and are often underwater. These particles were initially proposed by Wolfgang Pauli to satisfy the law of conservation of energy during beta decay. This particle’s three flavors, (*) electron, mu, and tau, oscillate over time, and the Homestake experiment affirmed that the Sun emits these particles as a result of nuclear fusion. For ten points, name these extremely small, chargeless particles, whose name in Italian literally means “little neutral oneâ€.

neutrinos <AG>

These particles interact with electrons in matter in the MSW effect. The DONUT experiment discovered the last of these particles, while the Homestake experiment measured only one third of the predicted amount of these particles emitted by the sun, an anomaly later explained by the (*) flavor oscillation of these particles. In 2011, faulty data from the OPERA experiment showed these particles travelling faster than the speed of light, and due to their small masses, these particles were once thought to be massless. For 10 points, give these neutral fermions that interact only via the weak force and gravity, and that come in electron, mu, and tau varieties.

neutrinos [accept electron neutrinos, mu neutrinos, or tau neutrinos; prompt on “fermionsâ€]

These particles make up the humorously named "Swiss cheese" and "spaghetti" phases in certain stars. These particles consist of two down quarks and an up quark and are the heavier of two common baryonic hadrons. This particle may emit electron antineutrinos and electrons to become a proton in the process of (*) beta decay. These particles were discovered in 1932 by James Chadwick. Nuclear fission involves bombardment of nuclei with these particles, and the number of these particles is the difference between the atomic mass and the atomic number. For 10 points, name this heavier of the two particles in the nucleus, a particle with neutral charge.

neutron

These particles are captured in the s-process of asymptotic giant branch stars. The namesake activation analysis ofthese particles determines the identity and quantity of elements in a sample. The beta decay of these spin one-halfbaryons results in the emission of a proton, an electron, and an antineutrino. Nuclear power plants use these particlesto bombard uranium-235 and induce a chain reaction. These particles consist of an up quark and two down quarks,and they were discovered by James Chadwick. The number of these particles in an atom determines its isotope. For10 points, name these chargeless particles that are found together with protons in the nucleus.

neutrons

This term is applied to the points where an orbital path crosses a plane such as the ecliptic. This term also describes the lines on Chladni plates. The angular momentum quantum number determines how many planar, or angular, types of these things that an electron orbital has, and some electron orbitals also have radial types of these. In a ripple tank, these are the points where destructive interference is maximized. These do not exist at the end of an open-end air column, but one of these is at a closed-end. Name this location on a standing wave where there is minimal motion.

nodes

In the indirect drive method, this process is achieved by firing a laser into a hohlraum, a method utilized at the National Ignition Facility. Muons can catalyze this process by increasing density. This process requires exceeding the Coulomb barrier. The “inertial confinement†method achieves this process by rapidly heating and compressing a (*) deuterium-tritium pellet. This process occurs in the core of stars through the proton-proton chain or the CNO cycle, generating helium nuclei from protons. For 10 points, identify this process in which nuclei are combined to release energy, contrasted with nuclear fission.

nuclear fusion [accept inertial confinement fusion; accept thermonuclear fusion; accept muon-catalyzed fusion; prompt on ICF with “what does ICF stand for?â€; do not accept or prompt on “nuclear fissionâ€] <GC, Physics>

Two of these devices are combined to build a harmonograph, which can be used to draw Lissajous [lees-ah-zhoo] figures. The double rod types of these objects are often used to demonstrate chaotic motion, while a set of these in a row make up a Newton's cradle. One of these was used to demonstrate the rotation of the Earth by Frenchman Léon Foucault. Derivations of the most common formulas associated with these objects approximate that theta equals the sine of theta for small oscillations. Name these devices whose period varies with the square root of its length and which consist of a mass able to swing back and forth.

pendulums

5. These entities are described by a modified form of the Sakuma-Hattori equation which contains a term proportional to wavelength to the negative fifth power. In these things, peak wavelength is inversely proportional to temperature according to Wien’s displacement law. Under certain assumptions, these things were predicted to have (*) infinite energy, which led to the ultraviolet catastrophe. These objects have power proportional to the fourth power of temperature according to the Stefan-Boltzmann law. For 10 points, name these things which emit more energy than any other object with the same temperature and absorb all incoming electromagnetic radiation.

perfect black body <Physics, CT><ed. KLei>

The cross section of this phenomenon is proportional to atomic number raised to the fifth. One way to measure this phenomenon experimentally is to measure the stopping potential. This phenomenon is used for the function of night-vision goggles. A plot of the energy of this phenomenon graphed against frequency has an x-intercept at the threshold frequency, a y-intercept at the negative work function, and a slope of Planck's constant. It was first demonstrated by Heinrich Hertz, and Einstein won a Nobel Prize for explaining it. For 10 points, name this effect in which electrons are ejected from a metal when light is shined on it.

photoelectric effect

The paper explaining this phenomenon begins with a section critical of the theory of blackbody radiation, showing that an integral of energy with respect to volume equals infinity. That problem is solved by assuming that energy "is discontinuously distributed in space." Some of the measurements of this effect, which used to be associated with ultraviolet light, were made by Philipp Lenard, who discovered that light intensity did not impact the amount of voltage required to stop rays produced by light striking metal. Name this effect explained when the Planck hypothesis was applied by Albert Einstein, leading to Einstein's Nobel Prize.

photoelectric effect

13. APDs work by using avalanche multiplication on the output of this effect. The ratio of output to input from this effect is the quantum efficiency. This effect can be quantified by the stopping potential. The maximum kinetic energy of particles emitted by this process equals Planck’s constant times the frequency, minus the (*) work function. Even if the intensity of the stimulus is high, this effect cannot be initiated unless the frequency is high enough. The 1921 Nobel Prize was awarded to Albert Einstein for his explanation of this effect. For 10 points, name this effect in which light causes metals to emit electrons.

photoelectric effect <SAM>

These particles are collided together in the hypothetical Breit-Wheeler process. These spin 1 particles carry a force described by the U(1) symmetry group. Two of these particles are created in the annihilation of an electron and a positron, and they are symbolized by (*) gamma. One of these particles is created with identical properties to the incident one in stimulated emission. Fluorescent materials emit these particles. Their energy is given as Planck’s constant times their frequency. For 10 points, name these massless particles that are the quanta of light.

photons

A scattering event in which one of these particles is the incident particle is characterized by a factor of “one minus the cosine of the scattering angle.†These particles are exchanged in interactions between charged particles according to QED and they’re responsible for radiation pressure. These particles are incident in both (*) Compton scattering and Rayleigh scattering. The energy of one of these particles equals its momentum times the speed of light or Planck’s constant times its frequency. Einstein posited these bosons to explain the photoelectric effect. For 10 points, name these quanta of light that have zero mass.

photons <AF> Bonuses

5. BKS theory concerns the interaction between matter and these particles, whose polarization is used to test the EPR paradox. Their energy can be expressed as h-bar times angular frequency, and the Klein-Nishina formula can be used to find the differential cross section of these particles as they undergo (*) Compton scattering. The energy of these particles equals Planck’s constant times frequency. Their wave-particle duality and interaction with surface electrons in metals led Albert Einstein to discover a namesake effect and support the idea of quantized energy. For ten points, identify these bosonic particles that carry the electromagnetic force.

photons <EC>

In 2015, three independent groups claimed to have performed a “loophole-free†experiment involving two of these particles, which they performed to experimentally violate Bell’s inequality. The exchange of the virtual form of these particles mediates the electromagnetic force. Self-interference of these particles was observed in Thomas (*) Young’s double-slit experiment. These particles scatter off electrons in Compton scattering. The energy of these particles is equal to Planck’s constant times frequency. For 10 points, name these massless, chargeless particles that are the quanta of light.

photons <GC, Physics>

One branch of physics named for two of these entities describes single and double resolved processes which result in the formation of a vector meson. Their differential cross section is proportional to the square of the fine structure constant, and is given by the Klein-Nishina formula. Pair production describes their interaction with a (*) nucleus, creating a positron and an electron. The wavelength of one of these particles decreases in an effect named for the winner of the 1927 Nobel Prize in Physics, and is caused by their collision with electrons. For 10 points, identify these particles whose energy is decreased in Compton scattering, the quanta of light.

photons [accept gamma rays]

A gas of these particles has zero chemical potential and is described by the Planck spectrum. These particles gain energy in scattering described as “anti-Stokes.†Accelerating charged particles produce these particles in bremsstrahlung. These particles lose energy when they collide with charged particles in (*) Compton scattering. These particles appear as wavy lines on Feynman diagrams, and their energy is equal to Planck’s constant times frequency. According to QED, these gauge bosons mediate the electromagnetic force. For 10 points, name these massless quanta of light.

photons [prompt on gamma or bosons] <Physics â€" Schwartz> [Ed. Gurazada]

A theorem determining the form of physical laws, given units of other quantities, is named for Buckingham and this letter. Multiple iterations of multiplication are symbolized using notation with this capital letter. The Morse equation gives a formula for osmotic pressure, which is symbolized with this letter. The lighest mesons are named for this letter. When p orbitals overlap parallel to the bonding axis, the bond formed is described with this Greek letter. Another quantity symbolized by this letter is transcendental and is multiplied by i in Euler's identity. For 10 points, name this constant approximated as 22/7 or 3.14.

pi

In a rotating frame of reference, the fictitious Euler (OY-ler) force is proportional to minus the angular acceleration of the frame cross this vector. Problems involving torque are often simplified by selecting the origin so that this vector equals zero. By definition, (*) central forces are always antiparallel to this vector. This vector sweeps out equal areas in equal times according to Kepler’s second law. Angular momentum equals the cross product of this vector and momentum. For a planetary orbit, this vector traces out an ellipse. For 10 points, name this vector that points from the origin to the location of an object in space.

position [or radius or radial position or distance or position vector or radius vector or radial vector or radial position vector or distance vector; accept relative position or relative position vector; accept location or location vector before “locationâ€; prompt on r or x or s; do NOT accept or prompt on “displacement†or “displacement vectorâ€] <Physics â€" French> [Edited]

When this quantity is constant, the solutions to the time-independent Schrodinger equation are complex exponentials, and the shape of the graph of this quantity is square for an infinite square well. In the Hamiltonian or Lagrangian, it is often denoted uppercase V. Negative the gradient, or spatial derivative, of this property is equal to force, and it is equal to one-half a constant times the (*) displacement squared for a spring. The chemical form of this property is contained in bonds, and its gravitational form is proportional to the weight times the height. A swing at its peak has the maximum value of, for 10 points, what type of energy contrasted with kinetic?

potential energy (prompt on uppercase "P" or uppercase "V"; prompt on "energy"; do not accept or prompt on "kinetic energy")

One type of this quantity can be expressed as Young's Modulus times area times the change in length squared, all over twice the initial length. The magnetic variety of this quantity is equal to the negative magnetic moment dot the magnetic field, while the (*) electric variety of this quantity is equal to q times V. F can be expressed as the negative gradient of this quantity, and work is expressed as the negative change in this quantity. For a spring, this quantity is equal to one-half times the spring constant times displacement squared. For 10 points, identify this quantity most commonly written as m g h, often contrasted with kinetic energy.

potential energy [prompt on just energy; do not accept or prompt on kinetic energy]

This quantity is the negative of the magnetic moment dotted with the magnetic field. The virial theorem multipliesthis quantity by negative one-half and equates it to a related quantity. When plotting position against this quantity, asystem experiences an unstable equilibrium phase at a local maximum. This quantity for a spring is equal to one-halftimes the spring constant times displacement squared, and the change in this quantity is the negative of work. Thisquantity for an object in Earth's gravity is mgh. For 10 points, name this type of stored energy that arises from anobject's position within a system, contrasted with kinetic energy.

potential energy [prompt on partial answer; prompt on "U"]

In the first component of four-force, this quantity is divided by the opposite of the speed of light. The SI unit of this quantity per square meter is divided by ten to the negative twelfth in decibel calculations. For circular motion this quantity equals torque times angular velocity, and for linear motion this quantity equals force times velocity. Name this quantity that equals energy per time and that is often measured in watts.

power

This quantity's namesake factor is the ratio between real and apparent values of this quantity and is calculated bydividing resistance by impedance. This quantity's namesake gain is defined as the ratio of this quantity at a load to asource. This quantity over unit area yields intensity, and in fluid systems this quantity equals pressure times thevolumetric flow rate. This is the product of the electric potential difference and the current. For rotational systems,the cross product of torque and angular velocity yields this quantity, which is equal to the dot product of force andvelocity in linear systems. For 10 points, name this amount of work done per unit time, whose SI unit is the watt.

power [prompt on "P"]

This type of motion impacts climate by creating Milankovitch [mee-lahn-KOE-vich] Cycles. The axial type of this motion causes a Platonic [plah-TAH-nik] Year, which for Earth is almost twenty-six thousand times longer than a standard year. The apsidal [AP-si-dul] type of this motion is the change of an orbital path, and the theory of general relativity explained this type motion by the planet Mercury. Also observed in everyday objects, this motion can be explained by the conservation of angular momentum when a force acts at an angle to spinning motion. Name this motion seen in gyroscopes when there is rotation of a rotating axis.

precession

When this quantity is divided by specific weight and measured in units of length, it's called its namesake "head." Compressibility equals the partial derivative of volume with respect to this quantity, divided by volume. One form of this quantity can be calculated as the product of fluid density, gravity, and the height below the surface. This quantity equalizes in all locations of an incompressible fluid according to Pascal's principle. Work done by a gas equals this quantity times its change in volume. At constant height, an increase in fluid velocity will lead to a decrease in this quantity. For 10 points, name this quantity equal to force over area, measured in pascals.

pressure [or pressure head; or gauge pressure; or hydrostatic pressure]

1. These particles and their antiparticles annihilate during the Drell-Yan process. These particles were proven to exist during deep inelastic scattering experiments. Information about these particles' interaction with the weak force is contained within the CKM matrix. Due to color (*) confinement, these particles are never found in isolation. These particles are the only particles to interact with all four fundamental forces. One of these particles and its antimatter counterpart make up mesons, and three of these particles make up baryons. For 10 points, name these particles that come in six flavors, such as strange, up and down, which are bound together to form protons and neutrons.

quark <Physics, NR><ed. VS>

11. Quantum chromodynamics predicts that these particles cannot be isolated and observed due to confinement, and they remain bound to each other because they experience asymptotic freedom. With gluons, these particles constitute a “plasma†that forms under extremely high temperatures and densities. Half of these particles have a charge of (*) two thirds, while the other have a charge of negative one-third. Three of these particles comprise a baryon, and one of these bound to its antiparticle comprises a meson. For 10 points, name these subatomic particles which come in flavors like top and charm and comprise protons and neutrons.

quarks <SAM>

Note to moderator: Read this question slowly, as the pronouns are a little bit dicey and the teams will likely get confused.The Lense-Thirring effect causes these things to "drag". Euler forces result when these things rotate non-uniformly. Einstein's equivalence principle states that gravity and acceleration depend only on these things. Galilean transformations convert between these things, as do "boosts" involving the Lorentz factor, when these are moving close to the speed of light. According to special relativity, none of these is absolute. Fictitious forces arise when these are accelerating; for example, a rotating one is responsible for the observed deflection of objects in the Coriolis effect. For 10 points, name these hypothetical coordinate systems used by observers in physics problems.

reference frames [or inertial reference frames; or frames of reference]

A 1921 publication of four Princeton lectures is titled for "The Meaning of" this scientific premise. Two tests that verified parts this work were the Ives-Stilwell experiment and Arthur Eddington's detection of gravitational lensing. Frame-dragging is one of its effects, and (*) GPS must account for it by adjusting satellite clocks 38 microseconds a day. For 10 pointsâ€"name this theory of Albert Einstein that has special and general components.

relativity (accept The Meaning of Relativity; accept special relativity or general relativity)

2. A spectroscopic technique that relies on this process may be aided by surface plasmons caused by adsorbed nanoparticles in a “surface enhanced†version. This central process of DLS has a subtype that can be classified as either Stokes or anti-Stokes. A form of this process with low wavelength dependence is named for (*) Mie, while another form is named for Raman. A correlation with the inverse fourth power of wavelength appears in the elastic Rayleigh form of this process that is responsible for the sky's blue color. For 10 points, name this process in which particles are deflected by other particles in their path.

scattering [accept dynamic light scattering or Raman scattering or Raman spectroscopy or Mie scattering or Rayleigh scattering; prompt on SERS or DLS before mention] <Chemistry, VS><ed. VS>

22. One type of these materials are said to be strongly confined when their radii are smaller than the exciton Bohr radius, and they fluoresce under excitation; those objects are quantum dots. These materials are modulated by the Schottky barrier and Fermi level found in the bandgap region, and are fabricated through (*) etching and lithography. They can be classified based on the presence of electron holes or free electrons, both of which are found at a p-n junction, and they can be incorporated into rectifiers and diodes. For ten points, identify these materials with properties between those of an insulator and a conductor.

semiconductors [accept quantum dots before mention] <EC> Bonuses

An equation modelling a type of these systems can be decomposed into a transient solution and a steady-state solution. When the quality factor of one of these systems is one half, it is critical and minimizes the amount of time in which it reaches equilibrium. These systems obey a differential equation in which the second derivative of position is proportional to position. By making the (*) small-angle approximation, pendulums can be modelled as one of these systems. The restoring force in these systems is proportional to displacement, meaning they obey Hooke’s law. For 10 points, a mass on a spring is an example of the “simple†type of what system?

simple harmonic oscillators [or SHO; accept specific types of harmonic oscillators like driven or damped harmonic oscillators] <GC, Physics>

In contrast to the Schrödinger equation, the predictions of this theory are applied to quantum mechanics by the Klein-Gordon and Dirac wave equations. The “pole in the barn†paradox that arises in a naive treatment of this theory is resolved by the fact that absolute simultaneity does not exist within this theory. In this theory, the reciprocal of the square root of one minus velocity squared divided by c squared is the (*) Lorentz factor. This theory predicts the existence of length contraction and time dilation for objects moving at close to the speed of light. For 10 points, identify this 1905 theory proposed by Albert Einstein 10 years before a related “general†theory.

special relativity [or SR; prompt on relativity; do not accept or prompt on general relativity or GR] <GC, Physics>

6. The force per unit area of the Casimir effect is equal to this quantity times h-bar times pi-squared all over 240 times distance to the fourth power, and an object’s Schwarzchild radius is inversely proportional to the square of this quantity. This quantity is equal to a certain quantity times the (*) index of refraction of a material, and, according to relativity, it is invariant for all observers. Hypothetical “tachyons†can exceed this value, and OPERA mistakenly claimed they had measured neutrinos going faster than this speed. For ten points, identify this value often symbolized c and approximated as 3 times 10 to the 8th meters per second, the rate at which photons move in a vacuum.

speed of light (or c before mentioned) <MS>

1. This value was measured by the Fizeau [[“fee-zohâ€]] experiment, which appeared to support Fresnel’s drag hypothesis. An object’s Schwarzschild radius is inversely proportional to the square of this constant. The Lorentz factor is given as one minus velocity squared over this value squared, all to the power of negative one-half. An experiment used an interferometer to disprove the existence of (*) luminiferous aether, a hypothetical medium in which this constant would differ from a vacuum; that experiment was the Michelson-Morley experiment. Energy is given as mass times this constant squared. For 10 points, name this constant, approximately equal to 300 million meters per second.

speed of light [accept c] <Physics, DS><ed. KLei>

When constructing molecular orbitals, the letters alpha and beta symbolize the eigenfunctions of this quantity. In the singlet state, the net value of this quantity equals zero. Metals with low splitting energy prefer to maximize this quantity according to Hund's rule of maximum multiplicity. This quantity explains why two lines appeared when silver atoms were passed through an inhomogeneous magnetic field in the Stern-Gerlach experiment, as it "couples" with orbital angular momentum. This quantity is opposite in sign for two electrons in an orbital according to the Pauli exclusion principle, and has a magnitude of 1/2. For 10 points, name this intrinsic angular momentum of a particle.

spin

For a general bound system, the effective form of this quantity is the second-order coefficient of the Taylor expansion of potential energy about a local minimum. When modelling continuous materials in the linear elastic region, this extensive quantity can be replaced by an intensive analog that maps stress to strain. That analog of this quantity is (*) Young’s modulus. The square of the frequency of a simple harmonic oscillator equals the quotient of this quantity and mass. The restoring force of this quantity’s namesake device equals negative this constant times displacement. For 10 points, name this constant denoted k that appears in Hooke’s law.

spring constant [or stiffness; accept effective spring constant; accept spring after “constantâ€; accept Hooke’s law constant before “Hooke’s lawâ€; prompt on k before “kâ€; prompt on Young’s modulus before “Youngâ€; prompt on elastic modulus or elasticity before “elasticâ€] <Physics â€" French> [Edited]

In 2008, this phenomenon was found in iron-based arsenic oxide by Hosono et al. It was the subject of a 1986 publication by Bednorz and Müller, who reported evidence for it in an oxide of barium, lanthanum, and copper. Replacing lanthanum with yttrium in that compound yields (*) YBCO, which demonstrates the high temperature variety of this phenomenon, which is described by Ginzburg-Landau theory. Materials that exhibit this phenomenon characteristically expel their magnetic fields in the Meissner effect. Governed by BCS theory, for 10 points, identify this phenomenon in which a material exhibits zero electrical resistance.

superconductivity [or just superconductors]

15. Muon spin spectroscopy can be used to measure the London penetration depth of these materials, and a current flowing through two of them forms a Josephson junction. The type-I form of these materials can reach an intermediate state described by Landau, while flux pinning requires the type-II form of them. The BCS theory posits that they are formed by the condensation of (*) Cooper pairs, and one of these objects can be levitated over a magnet after expulsion of their magnetic fields in the Meissner Effect. For ten points, name these materials which, when cooled below the critical temperature, have no resistance to current.

superconductors (accept word forms) <HX>

When the parameter kappa is greater than the square root of one-half, these materials can be penetrated by flux quanta that form Abrikosov vortices. Two of these materials are separated by a thin insulator or a weak one of these materials in a Josephson junction. Cuprite perovskites such as BSSCO (B-S-S-C-O) or (*) YBCO (Y-B-C-O) act as so-called “high temperature†examples of these materials, which can be cooled to their critical temperature using just liquid nitrogen. These materials expel magnetic field lines in the Meissner (MICE-ner) effect, which can cause diamagnetic levitation. For 10 points, name these materials in which current flows with zero resistance.

superconductors [accept superconductivity; accept type I superconductors or type II superconductors or type I superconductivity or type II superconductivity; do NOT accept or prompt on “conductorsâ€] <Physics â€" Gurazada> [Ed. French]

A theory governing these materials calculates their free energy as a function of the parameter psi, and one typeof these materials consists of normal cores surrounded by vortices. Described by Ginzburg-Landau theory, thesematerials are limited by a factor of one over e, their London penetration depth, and the exchange of phonons in thesecauses electrons to form Cooper pairs. These materials are distinguished as Type I or Type II based on the strengthof their critical fields. Substances that transform into these materials eject a magnetic field in the Meissner effect.For 10 points, name these materials that exhibit zero electrical resistance at low temperatures.

superconductors [do not prompt on or accept "conductors"]

When an object is wrapped around a round object by static friction, this quantity grows exponentially with angle, and when divided by cross-sectional area this quantity yields stress. In an Atwood machine, these forces oppose gravity and can be set equal to each other to solve the (*) pulley system. In a pendulum, this force moves the weight sideways, although it does no work, as it is perpendicular to the weight's motion. Its effects on springs are described by Hooke's law, and if it is absent, the system is said to be in slack. For 10 points, what is this force everywhere inside a string, contrasted with compression?

tension

The detonation-deflagration transition occurs at this quantity. For an ideal gas, this quantity is equal to the square root of the quantity adiabatic index times pressure over density, or equivalently the square root of bulk modulus over density, by the Newton-Laplace equation. This quantity is often estimated with an equation with a 0.6 times temperature term. Exceeding this quantity causes a (*) shock wave to form. The ratio of flow velocity to this quantity is the Mach number. In air at room temperature, this quantity is approximately 343 meters per second. For 10 points, name this quantity, the velocity at which acoustic waves propagate.

the speed of sound [or the velocity of sound; accept Mach 1 before “Machâ€] <GC, Physics>

When the scientific quantity jounce is integrated with respect to this, the result is called jerk. It appears in the denominators of the Sievert and Becquerel when expressed as SI base units. In fluid dynamics, steady flows do not see conditions change with respect to this variable. For a falling body, this equals the (*) positive square root of 2 times distance over acceleration due to gravity. It also equals work divided by power and distance divided by velocity. For 10 pointsâ€"give this scientific quantity that can be measured in fortnights, milleniums, or seconds.

time (accept minute; accept seconds before given)

The Poinsot construction depicts motion free of this quantity. Euler’s equations relate the components of this quantity to the inertia matrix and omega. For a current carrying loop exposed to a magnetic field, this quantity equals NIAB sine theta. This quantity causes (*) precession by acting perpendicular to angular momentum. This quantity is the time derivative of angular momentum. This quantity is equal to the cross product of the moment arm and force. For 10 points, name this rotational analogue of force.

torque

During the invention of this device, the so-called "traitorous eight" founded Fairchild. John Pierce coined the name of this invention, which began as strips of gold attached to a plastic triangle called the "point-contact" type. This device, which replaced Lee De Forest's triode tube, was easier to manufacture in the "bipolar junction" form than the "field effect" form. Every 18 months, the number of these which can fit on an IC doubles, according to Moore's Law. Bell Labs scientists Brattain, Bardeen, and Shockley won the 1956 Nobel for inventing this device. For 10 points, name these semiconductor-containing devices used as amplifiers and switches.

transistors

A specialized kind of these devices includes a “wordline†attached to “control†and “floating†components. These devices and their connecting wires are often produced from an oxide layer that’s partially removed in photolithography. Quantum tunneling is used by these devices in solid-state (*) memory storage. A drain and a source are connected when a gate receives voltage in the “field effect†variety of these devices, which include MOSFETs. A “bipolar junction†was once used to make these three-terminal circuit components, which often serve as amplifiers. For 10 points, name these semiconductor-based switches, which store “1â€s and “0â€s in a computer’s integrated circuits.

transistors <JR>

Powers of a type of this quantity are multiplied by powers of the energy dissipation rate in the Kolmogorov microscales. A type of this quantity obeys the Oswald-de Waele (Oswald de-Whale) power-law in dilatant and pseudoplastic materials, while it decreases over time in thixotropic materials. That type of this quantity is the ratio of shear stress to shear rate. According to Stokes’ law, the (*) drag on a sphere is equal to six pi times radius times flow velocity times a type of this quantity. This quantity, which has “kinematic†and “dynamic†varieties, is constant in Newtonian fluids and is equal to zero in superfluids. For 10 points, name this quantity which describes a fluid’s resistance to flow.

viscosity [accept dynamic viscosity or kinematic viscosity or absolute viscosity; prompt on eta, mu, or nu] <Physics â€" Schwartz> [Ed. French]

14. The Kolmogorov length scale is proportional to the one-fourth power of this quantity cubed over epsilon. An equation setting shear stress equal to this quantity times the shear rate does not hold for materials such as dilatants and Bingham Plastics. One equation sets a force equal to 6 pi times big-R times v times this quantity. Because the Reynolds number is inversely proportional to this quantity, (*) turbulence tends to occur when it is low. Besides radius and velocity, Stokes’ law shows drag is proportional to this quantity. Dividing by the density yields the kinematic form of this quantity from its dynamic form. For 10 points, name this measure of a fluid’s resistance to flow.

viscosity [accept kinematic, dynamic, or shear viscosity; prompt on eta or mu or nu] <Physics, VS><ed. VS>

One form of this quantity over the rate of thermal diffusivity is the Prandtl number, and Sutherland's formula calculates this quantity for an ideal gas as a function of temperature. The Navier-Stokes equations reduce to the Euler equations when heat conduction and this quantity are zero. It is independent of stress for Newtonian fluids,and the ratio of the inertial forces to the forces caused by this property is known as the Reynolds number. This quantity's kinematic form is found by dividing its dynamic form by the substance's density. This quantity, which is zero in superfluids, contributes to turbulence when decreased. For 10 points, name this quantity, a fluid's resistance to flow.

viscosity [prompt on "eta" or "mu"]

13. A Refutas equation can be used to calculate this quantity for a mixture, and one form of it is the numerator of the Prandtl number. The ratio of buoyant force to the force caused by it is given as the Grashof number. This property is increased when rheopectic substances are agitated, while it is reduced for (*) thixotropic compounds. It can be measured using a Zahn cup, and its kinematic form can be calculated by dividing its absolute form by mass density. This property can be characterized by a Reynolds number, and it is constant for Newtonian fluids and zero for superfluids. For ten points, identify this measure of a fluid’s resistance to flow.

viscosity or viscous force <EnC>

9. The Fermi level uses thermodynamic work to explain this property, one form of which equals inductance times the time derivative of current. It is related to the change in magnetic flux for time-varying magnetic fields, and the point at which insulators fail is known as the (*) “breakdown†point of this quantity. For static fields, the sum of this quantity around a loop equals zero, according to Kirchhoff’s second law. Power is expressed as current multiplied by this quantity, which is required for current to flow, and otherwise expressed as current times resistance in Ohm’s law. For ten points, identify this electrical quantity stored in batteries.

voltage [accept electric potential energy difference, electric tension, electric pressure, or electromotive force] <EC>

Johnsonâ€"Nyquist noise is typically expressed in terms of the uncertainty in this quantity. One type of this quantity is proportional to current times magnetic field, and arises when a charge carrier is subject to an electromagnetic force. This quantity equals inductance times the time-derivative of current, by (*) Faraday’s Law. Kirchoff’s second law states that the sum of of this quantity around a loop equals zero. For a point charge, this quantity scales with one-over distance, and, in general, the gradient of this quantity gives the electric field. This quantity equals current times resistance. For 10 points, name this quantity also known as EMF or electric potential.

voltage [or EMF (electromotive force) until it’s mentioned; or electric potential until it’s mentioned; prompt on “potentialâ€; accept Hall voltage] <AF>

When Planck’s law is stated as a function of temperature and this quantity, it appears raised to the fifth power in the denominator. The maximum value for this quantity is inversely proportional to temperature according to Wien's law. Constructive interference is greatest at angles theta such that 2d times the sine of theta is equal to an (*) integer multiple of this value according to Bragg’s law. This quantity, usually symbolized lambda, is equal to velocity divided by frequency. For 10 points, name this quantity equal to the distance between two identical points on a wave.

wavelength

One type of this quantity represents the region of space over which a particle can be localized and is equal to “h over mc.†The Davisson-Germer experiment validated a theory that assigned a type of this quantity to massive particles. The de Broglie hypothesis equates a form of this quantity for a moving object to Planck’s constant over momentum. This quantity times (*) frequency equals the velocity of a wave. This value is longest for red light and shortest for violet, and it is typically denoted “lambda.†For 10 points, name this term for the distance between peaks of a wave, equal to 2 pi for the sine function.

wavelength [accept Compton wavelength; accept de Broglie wavelength; prompt on length; prompt on lambda] <DB, Physics>

One theorem states that the maximum efficiency of a heat-engine is this quantity divided by the heat put into the system, which is maximized when the engine is a Carnot engine. In an isobaric environment, the magnitude of this quantity for an ideal gas is equal to pressure times the (*) change in volume, and because the force generated by it is always perpendicular to the particle it acts on, this quantity due to a magnetic field is zero. This quantity is also zero on a closed path, and though not potential energy, this quantity due to gravity is equal to mass times gravity times the change in height. For ten points, name this quantity, equal to the product of a force and the distance through which it is applied.

work <MS>

This statement includes a term equal to the kinetic energy per unit volume, often called the "dynamic pressure". A law giving the speed of outflow for a hole in a tank a certain height above the ground is derived from this law, as is an effect in which pressure is lowered in a constricted section of pipe. (*)Â Torricelli's law and the Venturi effect result from this principle, a statement of the conservation of energy in a fluid. This principle explains why an increase in fluid speeds results in a decrease in pressure and is often falsely used to explain lift on airplanes. For 10 points, name this fundamental principle of fluid dynamics, named for a Swiss mathematician.

 Bernoulli's principle or law or equation or effect (or other reasonable equivalents)

In special relativity, this equation is modified by multiplying by gamma or gamma cubed, depending on whether two vectors are perpendicular or parallel. Adding a term including the change in mass with respect to time, or the thrust, to this law produces the rocket equation. A (*)Â free body diagram can be used to examine all the components involved in this law. The rotational analogue of this law equates the torque to the product of the moment of inertia and the angular acceleration. Its original form equates the time derivative of momentum to force, but one side is most often given in terms of acceleration. For 10 points, name this law of motion which states F equals m times a.

 Newton's Second Law (prompt on "Newton's laws" of motion)

These devices are used with resistors in high-pass filters, because unlike a complementary device, they do not allow persistent DC current. Their namesake quantity is usually proportional to the permittivity, and although it decreases in series, it is added when they are placed in parallel. These devices possess a breakdown voltage which can be increased by strengthening the (*)Â dielectric. The namesake property of these devices is equal to the charge over the voltage and is measured in farads. An early example of these devices was the Leyden jar, while a common version consists of two parallel plates. For 10 points, name these devices which store charge.

 capacitor

This property is present in elements above the horizontal axis in the Bethe-Slater curve, and it only occurs in materials with one or more easy axes. Coercivity and remanence are characteristic properties of materials with this property that increases in discrete steps as shown by the Barkhausen effect. Owing to a (*)Â hysteresis loop, this property remains in a material even after an applied field is removed, though it disappears when a material is raised above the Curie temperature. Bulk materials with this property consist of domains of aligned spins. Cobalt, but not copper, possesses, for 10 points, what form of permanent magnetism named after iron?

 ferromagnetism [accept word forms; prompt on magnetism]

This entity is equal to the curl of the vector potential. The divergence of this entity is zero, while the enclosed current is proportional to a closed loop around this entity according to Ampere's Law, which can be used to show that its strength is increased inside the loops of solenoids. This entity has units of either (*)Â gausses or teslas, and is denoted capital B. Rotating examples of these form alternating current, while their formation from electric currents drive generators. Iron fillings can be used to show, for 10 points, the lines denoting what entity associated with north and south poles?

 magnetic field (or B-field; do not accept or prompt on simply "magnetism")

9. The ground state energy of the quantum harmonic oscillator equals this constant times h-bar omega. The areal velocity of a moving particle equals this constant times the cross product of position and velocity. The electric field from an infinite plane equals this constant times charge density over the permittivity of free space. The moment of inertia of a (*) uniform disk is this number times M R squared. The period of a pendulum is proportional to l over g raised to this power. For 10 points, name this number that is multiplied by mass times velocity squared to give kinetic energy.

½ [or 0.5] <SAM>