Physics am I right?
the big bang is thought to have occurred about
14 billion years ago
Velma passes Mort at a speed of 0.75c. At this speed, the time dilation factor is 1.5. in other words, Mort observes a 1-second tick of Velma's clock to take 1.5 seconds. Suppose that they are born at the same time, and that Mort observes himself to live 30 years. As Mort dies, how old will he observe Velma to be?
20 years
Suppose that a certain atom had just 4 different energy levels. How many different frequencies could be emitted by this atom?
6
Continuing the preceding two questions, whose observations are really correct?
Both
As evidence for the cosmic inflation hypothesis, this hypothesis explains
Both of these
Mort stands on Earth. Velma moves away from him in a rocket, slower than light speed. Mort sends a laser beam toward Velma. As the tip of the beam passes her rocket, Mort observes...?
Both of these
Which quantum characteristics would quantum computers exploit in order to achieve great computational power with only a few individual quantum elements of quibits
Both uncertainty and entanglement
Velma, inside a train moving at 20 m/s, throws a rock in the forward direction of 5 m/s. According to her the rock moves at 5 m/s. According to Mort, standing on Earth outside the train, the rock moves at approx 25m/s. Who is correct?
Both, relative to their own reference frames.
How do we know the shape of the universe?
By observation of the angular size of a typical wavelike disturbance in the cosmic microwave background
What is the universe mostly made of?
Dark energy
According to the uncertainty principle, a particle such as an electron...?
Does not have a precise position or a precise velocity
What feature of Einsteins theory of relativity is demonstrated by the phenomenon of matter-antimatter annihilation?
E=mc2
According to the principle of relativity, an observer who has no communication with the world outside of her laboratory will be unable to detect?
Her laboratory's velocity
Velma passes Mort at a high speed. Each holds a meter stick, oriented parallel to the direction of relative motion. Mort observes that...?
His meter stick is 1m long, and Velma's meter stick is less than 1m long
Planck's constant is about 7x10-34, in metric units. Suppose that Planck's constant were larger than it actually is. Which of the following would then occur?
Individual photons would have larger energies, making it easier to observe individual photons
Which of the following provides evidence that light is made of waves?
Interference effects seen when light passes through a narrow opening
You separate two magnets that are initially held together by magnetic forces. How does this affect the mass and energy of the system of magnets?
It creates additional mass, located in the space between the two magnets, and also additional energy.
What happens to a particle's wave packet when a highly accurate position measurement is performed?
It suddenly makes a transition into a state of smaller uncertainty in position and greater uncertainty in velocity
You are in a spaceship moving past Earth at nearly lightspeed and you observe Mort, who is on Earth. You measure his mass, pulse rate, and size. How are they different from the values measured by Mort himself?
Mass has increased, pulse rate has slowed down, and size is reduced along the direction of motion
Who discovered that radiation is quantized?
Max Planck
The post-Newtonian age began in the 1900 when?
Max Planck introduced the quantum of energy
Which of the following is one way of stating the principle of relativity?
No physical experiment, conducted entirely within your own lab, can tell you how fast you are moving relative to anything outside the lab.
Can a rock be accelerated up to light speed?
No, because any material objects mass becomes infinite as the object approaches lightspeed.
According to the theory of relativity, is everything relative?
No, light speed in not relative
Which chemical elements were created during the first few minutes of the big bang that started our universe?
Only the first three elements, hydrogen, helium and lithium
Werner Heisenberg and Bohr believed that
Quantum theory is correct and leads us to a new view of reality at the microscopic level
If Planck constant were smaller than it actually is, how would the uncertainty principle be affected?
Quantum uncertainties would be smaller
Cosmic inflation caused the universe to expand, for a brief period, at faster than light speed. But special relativity says that nothing can move faster than light speed. How can this contradiction be resolved?
Special relativity says nothing can move through space at faster than light speed, but doesn't restrict the speed at which space can expand
Einstein believed that the principle of relativity should apply to Maxwell's theory of electromagnetism. Which basic principle or law did this lead Einstein to propose?
The constancy of lightspeed
Which of the following provides for the quantization of light?
The individual dots seen on a photographic plate when a photo is taken at extremely short exposure times
Mort stands on Earth. Velma moves away from him in a rocket, slower than light speed. Mort sends a laser beam toward Velma. As the tip of the beam passes her rocket, Velma observes that...?
The laser beam moves past her at 300,000 km/s
Unless you look outside, you cannot tell how fast you are going. This is one way of stating?
The principle of relativity
In the special theory of relativity, what does the word special refer to?
This theory is restricted to the observations of non-accelerated observers
Mort is on Earth and Velma passes him at a high speed. Mort and Velma each carry a standard kilogram. Concerning the kilograms, Mort observes that...?
Velma's is more massive than 1 kilogram and Mort's has a mass of 1 kilogram.
Which of the following colors has the most energy per photon?
Violet
How does quantum uncertainty differ from the uncertainty involved in a coin flip?
With sufficient information, a coin flips outcome can be predicted, but no amount of information can remove quantum uncertainties
A certain star is 1000 light years from Earth. According to the theory of relativity, is it physically possible for Mort to travel from Earth to this star during Mort's normal lifetime?
Yes, by traveling at nearly lightspeed
Velma, who is moving past you at a high rate of speed, holds a meter stick and a standard kilogram. Is it possible that your measurements could show the standard kilogram to have a mass of 2 kg while the meter stick still has its normal length of 1m?
Yes, if Velma holds the meter stick perpendicular to its direction of motion.
Can anything go faster than light?
Yes, space can expand faster than light speed
The 1964 experiment that checked the validity of the principle of constancy of lightspeed involved?
a fast-moving sub-atomic particle that emitted radiation both forward and backward
A photon is
a particle-like quantum of radiation
In the double-slit experiment, the entire matter field of EM field instantaneously collapses to the single interaction point when the field interacts with the screen. This is an example of
a quantum nonlocality
Schroedinger discovered
a way to predict the wave patterns seen in experiments involving matter waves
In coming to the conclusion that light beams are bent by gravity, Einstein reasoned that
accelerated observers would find that light beams bend so gravity must also bend light beams
Which of the following is a consequence of Heisenbergs uncertainty principle?
all of these
During the double-slit experiment with light, the region between the slits and the screen contains
an electromagnetic field
When an atom emits radiation
an electron makes a quantum jump from one quantum state to another
Neils Bohr is known
as the leading philosophical interpreter of quantum theory
According to the theory of cosmic inflation, at what time in the history of the universe did inflation occur
at a tiny fraction of the first second, but not quite at the very beginning of the big bang
Recent evidence from a very distant supernova explosions indicates that the universe is expanding
at an increasing rate
One similarity between electrons and photons is
both are the quanta of a field
According to quantum theory
both of these
The difference between the ground state and an excited state for a hydrogen atom is
both of these
the big bang created
both of these
Quantum theory was developed
by Planck, Schroedinger, Einstein and many other scientists
Which one has the smallest range of possibilities or quantum uncertainty range?
dust grain
Which one has the largest range of possibilities or quantum uncertainty range?
electron
The double-slit experiment with electrons illustrates the surprising idea that
electrons sometimes behave like waves
When an atom undergoes a quantum jump into a lower-energy state, the atom
emits a photon
According to Bell's nonlocality princple
entangled particles exhibit correlations that are explainable only by real, instantaneous connections between them
According to the theory of cosmic inflation, during a brief early inflationary period the universe
expanded at a speed that exceeded lightspeed
According to the principle of equivalence, acceleration is equivalent to
gravity
According to Heisenberg's uncertainty principle, electrons are more unpredictable than protons. This is because electrons
have a smaller mass
Higher energy photons have
higher frequency
When we say that an electromagnetic field is quantized we mean that it
is allowed to have only certain particular values of total energy
One unusual aspect of dark matter is
it does not interact with electromagnetic radiation
What happens to an electron's wave packet if an accurate velocity measurement is performed?
it suddenly changes to a new wave packet having a very small uncertainty in velocity, but a large uncertainty in position
If a microscopic particles uncertainty in velocity is reduced
its uncertainty in position must increase enough to satisfy the uncertainty principle
In an open universe, the angles of a triangle add up to
less than 180 degrees
The amount of dark matter in the universe is
many times more than the amount of visible matter
A conclusion that follows from E=mc2 is that, at the microscopic level,
matter is made of force fields
The electron microscope is based on the use of
matter waves
In a closed universe, the angles add up to
more than 180 degrees
One experimental observation that demonstrates Einsteins ideas on the relativity of time, is..?
muons, live longer when moving rapidly than they do when they are at rest
In the context of the double-slit experiment, quantum uncertainty refers to
our inability to precisely predict a point at which a spread-out matter field or EM will interact with the screen
According to the theory of cosmic inflation, the large-scale clumping of matter that we observe tin the universe had its origin in
quantum uncertainties that were then stretched by the expansion of the universe
The two main theories of 20th century physics are...?
relativity and quantum theory
In quantum theory , a wave packet
represents one particle having a range of possible positions and a range of possible velocities
Velma zooms past Mort at half of light speed. Velma observes Mort's clock to run
slow
Velma zooms past Mort at half of lightspeed. Mort observes Velmas clock. Mort observes that her clock runs?
slow
A certain type of atom has only four energy levels. The spectral lines produced by this element are all visible, except for one ultra-violet line. The quantum jump that produces the UV line is
states 4 and 1
According to Einstein, gravity is
the bending of space that is causes by masses
The evidence favors a universe whose overall geometry is flat. That evidence comes from observations of
the cosmic background radiation
Which of the following experiments demonstrates the fact that the mere act of observation, or detection, causes changes in the microscopic world?
the electron double-split experiment with a detector placed behind once of the slits.
The standard picture of the hydrogen atom as a tiny proton with an electron moving in an en ellipse around it is extremely oversimplified. The main thing wrong with this picture is?
the electron should be pictured as a spread-out matter field
The basic difference between the special and general theories of relativity is that
the first deals with non-accelerated observers and the second deals with accelerated observers
In the double-slit experiment with light
the impact point of each photon cannot be predicted, but overall the pattern can be predicted
Nineteenth-century scientists thought the "ether" to be?
the medium for the propagation of light waves
The cosmic microwave background is
the now-cooled radiation that was released by the big bang
Which of the following is a feature of quantum physics but not a feature of Newtonian physics?
the observation process must be included as part of the theory
One experiment that informs us that gravity bends lightbeams is
the observed bending of light from stars as the light passes the sun
In the electron double-slit experiment, the Schroedinger equation enables scientists to predict
the overall pattern made by a large number of electron impacts on the screen
When we speak of the spectrum of a radiation source, we are referring to
the set of frequencies that the source can emit
Galaxies seem to be made mostly of dark matter. One type of evidence for this comes from the observations of
the speeds at which gas clouds orbit the centers of galaxies
Material objects cannot be accelerated up to light speed because
their inertia increases toward infinity as they approach lightspeed
In quantum theory, entanglement refers to
two particles sharing a single quantum field with each other
