History & Philosophy of Science Final

Robert Hooke

Micrographia

Copernicus

Model: heliocentric, circular motion, constant speed, epicycles, sphere of fixed stars, eliminates equant point. Fudge factor of model: didnt reflect or model reality.

Tycho Brahe

Model:geocentricism bc couldn't detect stellar parallax, keeps epicycles, constant speed and perfect circles. Sun and moon orbit earth. Everything else orbits sun.

Joannes Kepler

Model:heliocentric, planets don't move in perfect circles or constant speed. ellipses. formulated 3 laws: 1) the orbits of planets were ellipses, with the sun at one focus of the ellipse 2) the line joining the planet to the sun sweeps out equal areas in equal times as the planet travels around the ellipse. 3) ratio of the squares of the revolutionary periods for 2 planets is equal to ratio of the cubes of their semi major axes.

Prior to Kuhn's, publication how has history typically presented the development of science?

Paradigm shifts are generally viewed not as revolutions but as additions to scientific knowledge, and because the history of the field is represented in the new textbooks that accompany a new paradigm, a scientific revolution seems invisible. Science textbooks present the inaccurate view that science has reached its present state by a series of individual discoveries and inventions that, when gathered together, constitute the modern body of technical knowledge - the addition of bricks to a building.

Marie Curie

Pioneering research on radioactivity, first woman to win nobel prize. Also won twice

quantization of energy

Plank showed that in electromagnetic radiation the E can't come in any number

Socrates

Plato's teacher. Socratic method

What aspect of Quantum Theory would you suppose a person of faith would be most comforted about?

Quantum mechanics implies that the choices you make are indeed real choices as probability is built in; we have free-will.

Democritas

Supported acquisition of knowledge by experiences and senses (like milesians). Chang is REAL. matter philosopher

Francis Bacon

The Great Instauration containing The New Organon)

What revolutionary new ideas were presented in the Principia? Why are they labeled revolutionary?

The Principia states Newton's 3 laws of motion, forming the foundation of classical mechanics, Newton's law of universal gravitation, and a derivation of Kepler's laws of planetary motion. They are labeled revolutionary because Newton mathematized science, changing it from qualitative to quantitative.

Galileo

The Starry Message, Dialogo di Massimi Sistemi del Mondo - Dialogue of the Two Chief Systems of the World, Discourses Concerning the Two New Sciences)

Describe the Many Worlds interpretation of quantum theory.

The wave function never collapses, that is the superposition of states continues, even after the photon reaches the detector. The reason we don't experience this superposition of states is because you and I are part of one of the states making up the superposition of states. Whereas we saw this state occur, our counterparts saw another, etc. For example, if the electron went through the left slit in this universe, it went through the right in another, both in another, and neither in another. We can't say this is untrue because this could be the universe that we just don't figure it out.

Albert Einstein

Theoretical physicist, developed theory of general relativity (theory of gravity), quantum mechanics, E=mc^2, explained photoelectric effect, brownian motion

What is normal science?

What all of us do; science that further elaborates and extends on the paradigm. Research firmly based upon the paradigm.

paradigm

specific worldview for particular field of study, determines how you experiment and interpret results, its is incomplete so you continue to flesh out details w normal science

Hippocratus

father of western medicine. Tried to separate medicine from religion

Normal Science

fleshing out of the paradigm, mopping up posse ends of the paradigm.

Plato

greek philosopher. study of the eternal (intelligible) world-knowledge

wave function

includes all possible states (superposition of states)

Thomas Aquinas

made his works reconcilable w church doctrine. reconciled faith, reason, and logic; use logic to reconcile the apparent contradictions between faith and reason.

Galileo

made own telescope, realized moon was not made of aether (blemishes), new stars, sunspots (sun not made of aether), Venus had phases, moons on jupiter.

space-time

mathematical model combining space and time into an interwoven continuum

Collapse of wave function

wave function appears to reduce to single state after interaction w measuring apparatus

Discrete spectrum

what you see in the absorbance patterns of different elements

Ultraviolet catastrophe

when observing abs of UV rays E would go to infinity which is impossible (a black body should have showed a continues spectrum but would mess up when UV part was reached

crisis

when you lose faith in current paradigm.

Ptolemy P

(Almagest - Mathematike Syntaxis)

Vesalius P

(De humani corporis fabrica - On the structure of the human body)

Copernicus P

(De revolutionibus orbium coelestium - On the revolution of the heavenly orbs)

Einstein

(On the Electrodynamics of Moving Bodies [Special Theory of Relativity], On a Heuristic Viewpoint Concerning the Production and Transformation of Light [Photoelectric Effect], On the Motion of Small Particles Suspended in a Stationary Liquid, as Required by the Molecular Kinetic Theory of Heat [Brownian Motion], Does the Inertia of a Body Depend Upon Its Energy Content? [E = mc2])

Newton P

(Philosophiæ Naturalis Principia Mathematica Mathematical Principles of Natural Philosophy)

Aquinas

(Summa Theologica, although we did not specifically identify this work)

Compare and contrast the major philosophical features of the Aristotelian, Newtonian, and modern Worldviews.

-Aristotle: jigsaw puzzle, universe is like an organism that has parts that function so as to accomplish goals, perfect circles and constant motion and earth center of universe; universe was teleological and essentialistic, a purposeful universe full of objects working toward essential, inherent, natural goals -Newton: mechanistic universe (like a machine), one in which objects behave as they do because of external forces acting on those objects -modern: scientific theories are approximations of reality, there is no objective reality-only that which we create/observe

Describe some of the variations of the standard view of quantum mechanics.

-Mild measurement dependent reality=quantum entity refers only to the most basic elementary particles such as electrons, neutrons, protons, photons, etc. Only these can exist in a superposition of states and almost any sort of measurement suffices to collapse the wave function. -Moderate measurement dependent reality= although almost any object can in principle exist in superposition of states, measurements generally suffice to collapse them. Everything is quantum entity, but measurement is seen as broad. -Radical= everything is quantum entity, but measurement is seen as narrow. Suppose only human consciousness constitutes genuine measurement; wave functions are not collapsed until human observation is involved, so unobserved situations exist in superposition of states.

Galilean Relativity

1) laws of motion are the same in all inertial frames 2) applies to accelerating as well as inertial frames (theory of gravity-applies to all frames of reference)

Early Middle Ages

500-1000 AD

Pythagoreans

571-495 BCE

Leucippas/Democritas/Hippocritus

5th Century BCE/ 460-370 BCE

Thales

624-546 BCE

Great Universties and Creation of Holy Roman Empire

800 AD

Ptolemy

90-168 (After year 0) AD

What is an anomaly? The usual response of a scientist to an anamoly is to ignore it. When is it impossible for scientists to do this?

An anomaly is an outcome of an experiment that doesn't follow what the paradigm predicts. It is impossible for scientists to ignore them when anomalies begin to accrue and resist.

Aristotle P

Aristotle's publications (Organon which includes Prior Analytics, Posterior Analytics; Physics, and many others)

Kepler P

Astronomia Nova - New Astronomy, Harmonices Mundi - Harmony of the World, Mysterium Cosmographicum))

Spectrum

Band of colors produced by separation of components of light by different degrees of refraction according to wavelength

Aristotle

Greek philosopher. study of natural world to gain knowledge.

What are the quantum facts that support quantum theory?

If electrons are particles they should produce one sort of outcome, the particle effect, and if electrons are waves, they should produce a quite different sort of outcome, the wave effect. Quantum entities do not have definite attributes until they are measured to have those attributes.

Isaac Newton

Invented calculus, newtons 3 laws of motion, and universal law of gravity. he shifted the field of chemistry from qualitative to quantitative.

Cladius Ptolemy

modeled first solar system that was used until time of kepler. Mathematician. ptolemaic model-eccentric and equant points were philosophically discordant as the Earth wasn't at the center of the universe (eccentric) and constant angular speed is only observed at the equant point. But couldn't make predictions about planet's locations.

revolution

change from one paradigm to another.

Augustine of Hippo

churchman not scientist. significant influence of development of church doctrines and teachings. said bible not taken literally!

fluxiones

differential calculus described by newton?

Ignaz Semmelweiss

discovery of antiseptic procedures to drastically reduce childbed fever (perpetual fever) incidences in obstetrical clinics. People argued that it was exposure to decaying organic matter and that Semmelweiss was relying on minuscule amounts of decaying matter to make claims.

Discovery of Neptune

1864

Marie Curie

1876-1934

Albert Einstein

1879-1955

Michelson-Morley

1887

Radio Activity discovered

1896

Electron Discovered

1897

Development of Quantum Mechanics

1901

Karl Popper

1902-1994

Annus Mirabilis

1905

Aristotle

384-322 BCE

Socrates

399 BCE

Academy Founded (plato)

400 BCE

Eudoxos

408-355 BCE

Plato

428-347 BCE

Fall of Rome

476 AD

Describe the counter-intuitive (hard to believe) consequences of the special theory of relativity.

1) time dilation: time slows down as you approach the speed of light; from your perspective, you feel like time is moving normally 2) length contraction: length contracts in the direction of travel 3) mass inflation: mass becomes more massive as you approach the speed of light (denominator in equation gets really small, making the numerator very large)

Scholasticism

1100-

Thomas Aquinas

1225-1274

Galen

129-200 AD

Great Famine

1315-17

Hundred Years War

1337-1453

Printing Press Invented

1440

Fall of Byzantium

1453

Copernicus

1453-1543

Almagest via Ptolemy

150 AD

Vesalius

1516-1564

Reformation

1517

Counter Reformation

1545-1648

Tycho Brahe

1546-1601

Giordano Bruno

1548-1648

Galileo

1564-1652

Johannes Kepler

1571-1630

New Star

1572

Great Comet

1577

Isaac Newton

1643-1726

Principa Published

1686

Discovery of Uranus

1781

Ignaz Semmelweiss

1818-1865

Why is 1905 called the Annus Mirabilis?

1905 is called the miracle year because four landmark papers were published: 1) photoelectric effect 2) Brownian motion (random motion of particle attributed to its reacting with the other molecules; vibrational, translational, and rotational motion at molecular level-grain in water moves because it is being influenced by the 3 motions of the water molecules) 3) special relativity (only applies to inertial frames either not moving or moving at a constant rate) 4) mass/energy equivalence (e=mc2, energy and mass are 2 forms of the same thing)

General Theory of Relativity

1915

Proton discovered and solar eclipse

1919

Neutron Discovered

1920

Development of atomic structure

1922

Thomas Kuhn

1922-1996

The Lyceum (Aristotle)

225 BCE

Augustine

354-430 AD

According to Kuhn, what is a scientific revolution?

A scientific revolution is when extraordinary science creates a new paradigm that rationalizes the previous anomalies (paradigm shift). A scientific revolution is a non-cumulative developmental episode in which an older paradigm is replaced in whole or in part by an incompatible new one.

What is the role of rules in normal science?

A shared commitment to a paradigm ensures that its practitioners engage in the paradigmatic observations that its own paradigm can do most to explain (13), i.e., investigate the kinds of research questions to which their own theories can most easily provide answers.

Why is the Newtonian view of absolute space and time incorrect? What is the absolute part? What is the current view of time and space?

According to Newton, absolute time and space respectively are independent aspects of objective reality. Absolute time exists independently of any perceiver and progresses at a consistent pace throughout the universe. The current view of time and space is that they are not absolute empirical facts. Measurements across inertial frames show distortion of time and space-Observers taking measurements from different frames may not agree on time or space measurements (no simultaneity).

What is a paradigm?

Achievements that some particular scientific community acknowledges for a time as supplying the foundation for its further practice. Paradigms help scientific communities to bound their discipline in that they help the scientist to create avenues of inquiry, formulate questions, select methods, etc.

What is meant by the concept of "action at a distance"? What is the philosophical relevance of this concept? How does this concept apply to gravity? What was Newton 's opinion of this concept as applied to gravity?

Action at a distance was used to explain gravity; any cause and effect without discernable contact (couldn't see gravity). Newton's critics attributed this action at a distance to an occult force (paranormal/hidden/unmeasurable). Newton treated gravity instrumentally, he just new that the mathematics behind it worked.

Why does Dewitt conclude that it may not be possible to develop a metaphor to describe the modern Worldview similar to that used to describe the Newtonian Universe?

Because we live in a universe that is not like anything with which we are familiar-a universe that allows for instantaneous influences between events that have no connection whatsoever between them.

Galen

Dissected monkeys and pigs to try and study anatomy

How did Einstein explain gravity? Why do we still teach Newtonian gravity?

Einstein proved that gravity is not cause by two bodies attracting eachother. Gravity is a consequence of the fact that space is warped; the presence of matter in the universe alters the geometry of space. Mass tells space how to warp and space tells mass how to move. Newtonian gravity is taught instrumentally for practicality reasons and because they still work for explaining things on an earthbound scale.

What were the two basic assumptions Einstein made when he developed the special theory?

Einstein's first principles-axioms were 1) principle of relativity: there is no privileged point of view to say who is at rest and who is in motion, all observers will derive Newton's Laws and 2) principle of the constancy of the speed of light: the speed of light measured in a vacuum will always be the same

How was Einstein's General Theory of Relativity confirmed? Explain the famous experiment and how it showed that Einstein was correct.

Einstein's general theory was confirmed during a solar eclipse; the light from stars was observed as bent when crossing through the curved space near the sun. What should've been observed under Newtonian gravity is no bending of the star's light as a photon has a weight of 0 and should not be subject to gravity (two bodies attracting eachother).

What did Einstein have to say about Quantum Theory? What do you think? Why?

Einstein's view was that there simply could not be the sort of lack of knowledge. He was uncomfortable with this idea and tried to disprove it.

Pythagoras

Founder of mathematics. Pythagorean Theorem (others already knew it, he was 1st to write it down). Believed earth was stationary sphere, perfect solid. Physician-acquired most knowledge of anatomy from his travel to egypt

Give an overview of the standard (Copenhagen) interpretation of quantum theory.

It holds that quantum mechanics does not yield a description of an objective reality but deals only with probabilities of observing, or measuring, various aspects of energy quanta, entities that fit neither the classical idea of particles nor the classical idea of waves. The most accepted explanation for why the same quantum particle may behave in different ways was the Copenhagen interpretation. It says that a quantum particle doesn't exist in one state or another, but in all of its possible states at once. It's only when we observe its state that a quantum particle is essentially forced to choose one probability, and that's the state that we observe. Since it may be forced into a different observable state each time, this explains why a quantum particle behaves erratically. In Schrödinger's experiment, the cat was sealed in the box. During its stay there, the cat came to exist in an unknowable state. Since it could not be observed, it could not be said whether the cat was alive or dead. It existed instead in the state of both life and death.

When the structure of the atom became clear, in what way did the scientists have to "cheat" to explain it? (It's in one of the videos.)

It was known that a proton and any atom were grouped in the small central region called the nucleus and that electrons were somehow arranged in comparatively large distances outside the nucleus. If the electron were stationary, it would fall into the nucleus since the charges on the particles would cause attraction. To solve this, it was found that electrons were allowed to have discrete values of angular momentum in its orbit around the nucleus and that the electron radiating away its energy "just didn't happen." They only radiate energy when they jump from one orbit to another.

What aspects of the worldview suggested by Newton's work did people find so troubling? Why would they have preferred the discredited Aristotelian worldview instead?

Newton couldn't explain the nature of gravity, orbit of the moon (if number of particles is 3+, equations cannot be solved exactly), perturbation in Jupiter and Saturn orbits (mutual perturbations-two planet's orbital periods are nearly in sync), and deviations from exact elliptical planetary motion (other planets-Uranus and Neptune). Since gravity could not even be explained by Newton, it existed as a magical invisible force that many people couldn't accept; therefore, they preferred Aristotle's view of the natural laws since it had a concrete explanation.

What is meant by the clockwork universe? How was this substantially different from the old Aristotelian view of the universe and nature?

Newton's solutions closely matched observations (solutions of differential equations give all past and future planetary positions) forming the idea that objects in universe follow unique pre-determined paths - Clockwork Universe (governed by the laws of physics). The Aristotelian idea that things move because they have an internal desire to (need to maintain natural order) and the Aristotelian hierarchy were rejected by Newton. A once cozy, teleological universe became a mechanistic, mediated by impersonal forces of matter universe. Newton held that things move as a reaction to an external stimulus. This Clockwork Universe places God as a "watchmaker"/observer rather someone who is involved in everyday life.

How was Newton's work spectacularly verified?

Newton's work was spectacularly verified as he could derive an equation to explain the movements of the celestial orbs (derives Kepler's Laws) from his laws. Also, two more planets, Uranus (Herschel) and Neptune (LeVerrier and Galle), were discovered via the utilization of Newton's laws of motion and gravitation. Once Uranus was discovered, people started to observe it and noticed that its motion wasn't exactly correct; that it deviated slightly from Kepler's and Newton's laws. They knew this would happen if there was another object (planet) out there pulling on it so they made calculations of its location based upon the unusual motions of Uranus, and found Neptune. These discoveries were seen as triumph for Newtonian Mechanics-reinforced the idea of a Clockwork Universe.

What were the minor "clouds" that Newtonian physics could not explain?

Newtonian physics couldn't explain gravity (requires action at a distance-occult force), blackbody radiation (ultraviolet catastrophe), line spectra (atoms only emit and absorb energy at discrete values instead of a continuous spectrum), light waves require aether (medium-Michaelson Morley experiment fails to find it), cathode rays (beam of electrons), x-rays (short wavelength form of electromagnetic radiation), and radioactivity (looked like it violated the law of conservation of energy-energy created out of no where).

Kuhn also says that the decision to adopt a new paradigm is like a religious conversion. What does he mean by this?

One must transfer allegiance from one paradigm to another. Proponents of a paradigm often devote their lives and careers to it; therefore, it is a big change and the new paradigm they adopt will guide them through their research.

Why (according to Einstein) is the speed of light known as the ultimate speed of limit? What stops you from going faster?

The closer to the speed of light you get a particle, the more energy is required to go faster. This is because the particles themselves get more massive in proportion to the increased velocity. If you wanted to accelerate a single electron to 'light speed', you would need an infinite amount of energy due to the electron becoming infinitely heavy. There isn't enough energy in the entire universe to propel just a single electron to the speed of light.

Kuhn says that new paradigms are usually produced by those who are younger or new to the field. Why is this so?

The older generation is stuck in their ways and resistant to paradigm change.

At the time Kuhn originally wrote his book, the prevalent view of the scientific community regarding paradigm shifts was that the new paradigm derives from or is an addition to the one it replaces. How has Kuhn's book changed the views of the scientific community in this regard?

The reception of a new paradigm often necessitates a redefinition of the corresponding science. Revolution is transformation, not cumulation.

When a scientific revolution does occur (large or small) what are the characteristics of those leading the change, at least according to Kuhn?

The reception of a new paradigm often necessitates a redefinition of the corresponding science. The normal-scientific tradition that emerges from a scientific revolution is not only incompatible but often actually incommensurable with that which has gone before.

What is the ultraviolet catastrophe? How did the solution of the problem change the field of physics? How does this solution also explain the photoelectric effect?

The ultraviolet catastrophe was the prediction that a black body will emit radiation with infinite power-when you try to model the classical theory, the curve blows up with ultraviolet wavelengths and there is an infinite area under the curve. To solve this, Planck assumed that light was quantized, marking the beginning of quantum mechanics. Shining a light upon a metal plate can release electrons from the plate, but the light has to have a certain wavelength before a single electron is released. The light striking the plate has to be coming in discrete bundles and unless a single bundle has enough energy to free an electron from its captivity it would remain trapped. The wavelength and frequency of light was a measure of how much energy each bundle carried.

What is the dual nature of matter? Explain how this view has been confirmed experimentally.

This is the statement from quantum physics that matter exhibits both wave and particle properties. This has been confirmed experimentally with electrons. Electrons were shot at two slits and an interference pattern was observed on the back panel (wave property). This was repeated, but an observer was placed by the slits and the electrons reverted back to acting as a particle, two lines were observed on the back panel.

Giordano Bruno

a cosmologist that proposed stars were just distant suns, the universe was infinite and had no celestial body as its center, he was tried for heresy.

relativistic

all pov are subjective-combats the deterministic view of the universe that eh Newonian WV provided. (einstein showed there is uncertainty built into very fabric of universe bc we are composed of quantum particles that wave in and out of existence and we can only know certain things at certain precision).

deterministic

no free ail, newton world view left God as spectator instead of active ruler. (God as watch maker). bc we are matter being guided and ruled by laws of physics as everything else is.

Thales

noted as first scientist, since he was one of the pre-socratic philosophers who rejected supernatural, or mythical explanations for natural phenomena. First to ask what world made of.

length contradiction

object grows shorter in direction of travel when moving close to speed of light

absolute time

one universal clock (minute on earth same everywhere)

absolute space

one universal ruler (an inch on earth is the same distance throughout universe)

Superposition principle

quanta can't exist in different spaces all at once. (once we measure quanta entities, will collapse into one space)

Wave-particle duality

quanta entities exhibit behavior of both a wave and a particle, although when observed act like a particle

extraordinary science

science in a scientific rev sparks by several anomalies that can no longer be ignored that weaken the current paradigm.

Heisenbergs uncertainty principle

scientific principle states its impossible to determine w perfect accuracy both position and momentum of particle at any given moment in time

Continuous spectrum

scientist first expected a continuous spectra when looking at the line spectra of elements

quanta

smallest quantity of radiant energy

anomaly

violates current paradigm (generally ignored or assumed incorrect at first)