Philosophers
Mortimer Adler Rogers Albritton Alexander of Aphrodisias Samuel Alexander William Alston Anaximander G.E.M.Anscombe Anselm Louise Antony Thomas Aquinas Aristotle David Armstrong Harald Atmanspacher Robert Audi Augustine J.L.Austin A.J.Ayer Alexander Bain Mark Balaguer Jeffrey Barrett William Belsham Henri Bergson George Berkeley Isaiah Berlin Richard J. Bernstein Bernard Berofsky Robert Bishop Max Black Susanne Bobzien Emil du BoisReymond Hilary Bok Laurence BonJour George Boole Émile Boutroux F.H.Bradley C.D.Broad Michael Burke C.A.Campbell Joseph Keim Campbell Rudolf Carnap Carneades Ernst Cassirer David Chalmers Roderick Chisholm Chrysippus Cicero Randolph Clarke Samuel Clarke Anthony Collins Antonella Corradini Diodorus Cronus Jonathan Dancy Donald Davidson Mario De Caro Democritus Daniel Dennett Jacques Derrida René Descartes Richard Double Fred Dretske John Dupré John Earman Laura Waddell Ekstrom Epictetus Epicurus Herbert Feigl John Martin Fischer Owen Flanagan Luciano Floridi Philippa Foot Alfred Fouilleé Harry Frankfurt Richard L. Franklin Michael Frede Gottlob Frege Peter Geach Edmund Gettier Carl Ginet Alvin Goldman Gorgias Nicholas St. John Green H.Paul Grice Ian Hacking Ishtiyaque Haji Stuart Hampshire W.F.R.Hardie Sam Harris William Hasker R.M.Hare Georg W.F. Hegel Martin Heidegger Heraclitus R.E.Hobart Thomas Hobbes David Hodgson Shadsworth Hodgson Baron d'Holbach Ted Honderich Pamela Huby David Hume Ferenc Huoranszki William James Lord Kames Robert Kane Immanuel Kant Tomis Kapitan Jaegwon Kim William King Hilary Kornblith Christine Korsgaard Saul Kripke Andrea Lavazza Keith Lehrer Gottfried Leibniz Jules Lequyer Leucippus Michael Levin George Henry Lewes C.I.Lewis David Lewis Peter Lipton C. Lloyd Morgan John Locke Michael Lockwood E. Jonathan Lowe John R. Lucas Lucretius Alasdair MacIntyre Ruth Barcan Marcus James Martineau Storrs McCall Hugh McCann Colin McGinn Michael McKenna Brian McLaughlin John McTaggart Paul E. Meehl Uwe Meixner Alfred Mele Trenton Merricks John Stuart Mill Dickinson Miller G.E.Moore Thomas Nagel Otto Neurath Friedrich Nietzsche John Norton P.H.NowellSmith Robert Nozick William of Ockham Timothy O'Connor Parmenides David F. Pears Charles Sanders Peirce Derk Pereboom Steven Pinker Plato Karl Popper Porphyry Huw Price H.A.Prichard Protagoras Hilary Putnam Willard van Orman Quine Frank Ramsey Ayn Rand Michael Rea Thomas Reid Charles Renouvier Nicholas Rescher C.W.Rietdijk Richard Rorty Josiah Royce Bertrand Russell Paul Russell Gilbert Ryle JeanPaul Sartre Kenneth Sayre T.M.Scanlon Moritz Schlick Arthur Schopenhauer John Searle Wilfrid Sellars Alan Sidelle Ted Sider Henry Sidgwick Walter SinnottArmstrong J.J.C.Smart Saul Smilansky Michael Smith Baruch Spinoza L. Susan Stebbing Isabelle Stengers George F. Stout Galen Strawson Peter Strawson Eleonore Stump Francisco Suárez Richard Taylor Kevin Timpe Mark Twain Peter Unger Peter van Inwagen Manuel Vargas John Venn Kadri Vihvelin Voltaire G.H. von Wright David Foster Wallace R. Jay Wallace W.G.Ward Ted Warfield Roy Weatherford William Whewell Alfred North Whitehead David Widerker David Wiggins Bernard Williams Timothy Williamson Ludwig Wittgenstein Susan Wolf Scientists Michael Arbib Walter Baade Bernard Baars Leslie Ballentine Gregory Bateson John S. Bell Charles Bennett Ludwig von Bertalanffy Susan Blackmore Margaret Boden David Bohm Niels Bohr Ludwig Boltzmann Emile Borel Max Born Satyendra Nath Bose Walther Bothe Hans Briegel Leon Brillouin Stephen Brush Henry Thomas Buckle S. H. Burbury Donald Campbell Anthony Cashmore Eric Chaisson JeanPierre Changeux Arthur Holly Compton John Conway John Cramer E. P. Culverwell Charles Darwin Richard Dawkins Terrence Deacon Lüder Deecke Richard Dedekind Louis de Broglie Max Delbrück Abraham de Moivre Paul Dirac Hans Driesch John Eccles Arthur Stanley Eddington Gerald Edelman Paul Ehrenfest Albert Einstein Hugh Everett, III Franz Exner Richard Feynman R. A. Fisher Joseph Fourier Philipp Frank Lila Gatlin Michael Gazzaniga GianCarlo Ghirardi J. Willard Gibbs Nicolas Gisin Paul Glimcher Thomas Gold A.O.Gomes Brian Goodwin Joshua Greene Jacques Hadamard Patrick Haggard Stuart Hameroff Augustin Hamon Sam Harris Hyman Hartman JohnDylan Haynes Donald Hebb Martin Heisenberg Werner Heisenberg John Herschel Art Hobson Jesper Hoffmeyer E. T. Jaynes William Stanley Jevons Roman Jakobson Pascual Jordan Ruth E. Kastner Stuart Kauffman Martin J. Klein Simon Kochen Hans Kornhuber Stephen Kosslyn Ladislav Kovàč Leopold Kronecker Rolf Landauer Alfred Landé PierreSimon Laplace David Layzer Benjamin Libet Seth Lloyd Hendrik Lorentz Josef Loschmidt Ernst Mach Donald MacKay Henry Margenau James Clerk Maxwell Ernst Mayr John McCarthy Ulrich Mohrhoff Jacques Monod Emmy Noether Abraham Pais Howard Pattee Wolfgang Pauli Massimo Pauri Roger Penrose Steven Pinker Colin Pittendrigh Max Planck Susan Pockett Henri Poincaré Daniel Pollen Ilya Prigogine Hans Primas Adolphe Quételet Juan Roederer Jerome Rothstein David Ruelle Erwin Schrödinger Aaron Schurger Claude Shannon David Shiang Herbert Simon Dean Keith Simonton B. F. Skinner Roger Sperry John Stachel Henry Stapp Tom Stonier Antoine Suarez Leo Szilard Max Tegmark William Thomson (Kelvin) Giulio Tononi Peter Tse Vlatko Vedral Heinz von Foerster John von Neumann John B. Watson Daniel Wegner Steven Weinberg Paul A. Weiss John Wheeler Wilhelm Wien Norbert Wiener Eugene Wigner E. O. Wilson H. Dieter Zeh Ernst Zermelo Wojciech Zurek Konrad Zuse Fritz Zwicky Presentations Biosemiotics Free Will Mental Causation James Symposium 
The History of Quantum Physics
The critical developments in quantum physics that are of greatest importance to information philosophy are not the works of the socalled "founders of quantum mechanics" in the late nineteentwenties. Instead, they are the work of Albert Einstein between 1905 and 1917 that established the reality of atoms, discrete localized particles of matter, with his study of Brownian motion, but also discrete particles of energy, lightquanta that are just as localized as matter is. In 1917 Einstein established the presence of irreducible chance in the universe, whenever matter and radiation interact.
Quite apart from his great theories of special and general relativity, Einstein was one of the most important creators of quantum mechanics. His three 1905 papers on relativity, Brownian motion, and the lightquantum hypothesis (mischaracterized by many historians as the photoelectric effect, which was just one of three examples of light quanta), not only quantize the radiation field (Planck had only quantized the energy in his virtual oscillators), but they also show on a careful reading that Einstein was concerned about fasterthanlight actions thirty years before his EinsteinPodolskyRosen paper popularized the mysteries and paradoxes of quantum nonlocality and entanglement. Despite his foundational work quantizing radiation, Einstein rarely gets any credit for his contributions. There are a number of important reasons for this, which lead historians of quantum theory to start with Planck's quantum of action, then jump over Einstein's 1905 papers and his 1909 work on waveparticle duality to Niels Bohr's "old quantum theory" of the atom in 1913. Today, Bohr's "quantum jump" of an electron between stationary states is described as emitting or absorbing a "photon" of energy hν. In actuality, Bohr fought against Einstein's lightquantum hypothesis until the mid1920's. Besides quantizing energy and seeing the interchangeability of radiation and matter, E = mc^{2}, Einstein was the first scientist to see many of the most fundamental aspects of quantum physics, e.g., nonlocality and instantaneous actionatadistance (1905), waveparticle duality (1909), statistical elementary processes that introduce indeterminism and acausality whenever matter and radiation interact (191617), coherence, interference, and the indistinguishability of elementary particles (1925), and the nonseparability and entanglement of interacting particles (1935). Ironically, and even tragically, Einstein could never accept most of his quantum discoveries, because they conflicted with his basic idea that nature is best described by a continuous field theory using differential equations that are functions of "local" variables, primarily the spacetime fourvector of his general relativistic theory. Einstein's idea of a "local" reality is one where "actionatadistance" is limited to causal effects that propagate at or below the speed of light, according to his theory of relativity. Einstein's believed that quantum theory, as good as it is (and he saw nothing better), is "incomplete" because its statistical predictions (phenomenally accurate in the limit of large numbers of identical experiments  "ensembles" Einstein called them), tell us nothing about individual systems. Even worse, he thought that the wave functions of entangled systems predict fasterthanlight correlations of properties between events in a spacelike separation, violating his theory of relativity. This was the heart of his famous EPR paradox paper in 1935, but we shall see that Einstein was already concerned about fasterthanlight transfer of energy in his earliest paper on quantum theory.
The lightquantum hypothesis (1905)
Waveparticle duality (1909)
Einstein greatly expanded his lightquantum hypothesis in a presentation at the Salzburg conference in September, 1909. He argued that the interaction of radiation and matter involved elementary processes that are not reversible, a deep insight into the irreversibility of natural processes. While incoming spherical waves of radiation are mathematically possible, they are not practically achievable. Nature appears to be asymmetric in time. He speculates that the continuous electromagnetic field might be made up of large numbers of light quanta  singular points in the field that superimpose to create the wavelike behavior. Although he could not formulate a mathematical theory that does justice to both the oscillatory and quantum structures  the wave and particle pictures, Einstein argued that they are compatible over a decade before wave mechanics and quantum mechanics. And because gases behave statistically, he knows that the connection between wave and particles may involve probabilistic behavior, which he will prove in 1916.
When light was shown to exhibit interference and diffraction, it seemed almost certain that light should be considered a wave. Perhaps the major reason for historians of quantum mechanics (writing since the Copenhagen Interpretation) to largely ignore Einstein is that he was the single most important critic of the quantum mechanics formulated in the late 1920's by Niels Bohr, Werner Heisenberg, Max Born, Pascual Jordan, Wolfgang Pauli, and Paul DIrac, whose work became the "standard orthodox" interpretation of quantum mechanics. So Einstein today is remembered more for his attacks than for his truly extraordinary fundamental contributions to quantum theory. Einstein's major objection was that quantum mechanics is a statistical theory, one that predicts probable results for a large number of experiments, but nothing about specific events, like the exact time of a radioactive decay or the direction of spontaneous emission of a photon. This "chance" behavior of individual systems was something that Einstein himself pointed out in his early papers. But without the ability to predict individual events with certainty, he maintained that quantum mechanics must remain an incomplete theory. Quantum mechanics can specify only as many physical variables as classical mechanics. Because of the indeterminacy principle, only one of each pair of noncommuting observables (momentum or position, for example) can be specified precisely. In this sense, classical theory is more complete. But rather than simply accept Einstein's description and terminology, Bohr, Heisenberg and others engaged in linguistic debates, claiming that quantum theory is itself "complete." They simply denied that more could be known about an underlying reality. A second concern for Einstein was that the wave function ψ for an isolated free particle evolves in time to occupy all space. All positions become equally probable. Yet when we observe the particle, it is always located at some particular place. This does not prove that the particle had a particular place before the observation, but Einstein had a commitment to "elements of reality" that he thought no one could doubt. One of those elements is a particle's position. He asked the question, "Does the particle have a precise position the moment before it is measured?" The Copenhagen answer was sometimes "no," more often "don't know." If there is only one possible prior position for the particle, its path in fourdimensional spacetime is fixed and determinate independently of the time. Complete path information is constant for all time. Quantum theory, by contrast, allows alternative possibilities (with calculable probabilities) that are critical if there is to be more than one possible future.
The Old Quantum Theory
The socalled "old" quantum theory began at the turn of the twentieth century when Max Planck assumed that a physical property called action, the product of momentum and position (or of energy and time) was not a continuous variable, but comes in discrete packets he called h, the "quantum of action." It was just a year after J. J. Thomson had discovered the electron as a material particle and Ludwig Boltzmann's insight into the statistical mechanics of atoms was starting to find acceptance by most physicists.
Planck considered his assumption merely a mathematical hypothesis needed to make his theoretical formula for the distribution of continuous electromagnetic radiation correspond to experimental evidence. He did not believe in the reality of discrete energy quanta for many years, if he ever accepted them fully. It is curious that the first assumption of discreteness came from the theory of the continuous spectrum of electromagnetic waves, because the first hints of discreteness, and even the first appearance of quantum numbers as integers came from the study of spectral lines in the nineteenth century. Of course the chemists of the early nineteenth century assigned integers to atoms based on the discrete ratios of combinations with other atoms, H_{2}O and CaCl_{2}, for example.
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