Citation for this page in APA citation style.           Close


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 Barrett
William Belsham
Henri Bergson
George Berkeley
Isaiah Berlin
Richard J. Bernstein
Bernard Berofsky
Robert Bishop
Max Black
Susanne Bobzien
Emil du Bois-Reymond
Hilary Bok
Laurence BonJour
George Boole
Émile Boutroux
Daniel Boyd
F.H.Bradley
C.D.Broad
Michael Burke
Lawrence Cahoone
C.A.Campbell
Joseph Keim Campbell
Rudolf Carnap
Carneades
Nancy Cartwright
Gregg Caruso
Ernst Cassirer
David Chalmers
Roderick Chisholm
Chrysippus
Cicero
Tom Clark
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
Austin Farrer
Herbert Feigl
Arthur Fine
John Martin Fischer
Frederic Fitch
Owen Flanagan
Luciano Floridi
Philippa Foot
Alfred Fouilleé
Harry Frankfurt
Richard L. Franklin
Bas van Fraassen
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
Frank Jackson
William James
Lord Kames
Robert Kane
Immanuel Kant
Tomis Kapitan
Walter Kaufmann
Jaegwon Kim
William King
Hilary Kornblith
Christine Korsgaard
Saul Kripke
Thomas Kuhn
Andrea Lavazza
Christoph Lehner
Keith Lehrer
Gottfried Leibniz
Jules Lequyer
Leucippus
Michael Levin
Joseph Levine
George Henry Lewes
C.I.Lewis
David Lewis
Peter Lipton
C. Lloyd Morgan
John Locke
Michael Lockwood
Arthur O. Lovejoy
E. Jonathan Lowe
John R. Lucas
Lucretius
Alasdair MacIntyre
Ruth Barcan Marcus
Tim Maudlin
James Martineau
Nicholas Maxwell
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.Nowell-Smith
Robert Nozick
William of Ockham
Timothy O'Connor
Parmenides
David F. Pears
Charles Sanders Peirce
Derk Pereboom
Steven Pinker
U.T.Place
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
Jean-Paul Sartre
Kenneth Sayre
T.M.Scanlon
Moritz Schlick
John Duns Scotus
Arthur Schopenhauer
John Searle
Wilfrid Sellars
David Shiang
Alan Sidelle
Ted Sider
Henry Sidgwick
Walter Sinnott-Armstrong
Peter Slezak
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
C.F. von Weizsäcker
William Whewell
Alfred North Whitehead
David Widerker
David Wiggins
Bernard Williams
Timothy Williamson
Ludwig Wittgenstein
Susan Wolf

Scientists

David Albert
Michael Arbib
Walter Baade
Bernard Baars
Jeffrey Bada
Leslie Ballentine
Marcello Barbieri
Gregory Bateson
Horace Barlow
John S. Bell
Mara Beller
Charles Bennett
Ludwig von Bertalanffy
Susan Blackmore
Margaret Boden
David Bohm
Niels Bohr
Ludwig Boltzmann
Emile Borel
Max Born
Satyendra Nath Bose
Walther Bothe
Jean Bricmont
Hans Briegel
Leon Brillouin
Stephen Brush
Henry Thomas Buckle
S. H. Burbury
Melvin Calvin
Donald Campbell
Sadi Carnot
Anthony Cashmore
Eric Chaisson
Gregory Chaitin
Jean-Pierre Changeux
Rudolf Clausius
Arthur Holly Compton
John Conway
Jerry Coyne
John Cramer
Francis Crick
E. P. Culverwell
Antonio Damasio
Olivier Darrigol
Charles Darwin
Richard Dawkins
Terrence Deacon
Lüder Deecke
Richard Dedekind
Louis de Broglie
Stanislas Dehaene
Max Delbrück
Abraham de Moivre
Bernard d'Espagnat
Paul Dirac
Hans Driesch
John Eccles
Arthur Stanley Eddington
Gerald Edelman
Paul Ehrenfest
Manfred Eigen
Albert Einstein
George F. R. Ellis
Hugh Everett, III
Franz Exner
Richard Feynman
R. A. Fisher
David Foster
Joseph Fourier
Philipp Frank
Steven Frautschi
Edward Fredkin
Benjamin Gal-Or
Howard Gardner
Lila Gatlin
Michael Gazzaniga
Nicholas Georgescu-Roegen
GianCarlo Ghirardi
J. Willard Gibbs
James J. Gibson
Nicolas Gisin
Paul Glimcher
Thomas Gold
A. O. Gomes
Brian Goodwin
Joshua Greene
Dirk ter Haar
Jacques Hadamard
Mark Hadley
Patrick Haggard
J. B. S. Haldane
Stuart Hameroff
Augustin Hamon
Sam Harris
Ralph Hartley
Hyman Hartman
Jeff Hawkins
John-Dylan Haynes
Donald Hebb
Martin Heisenberg
Werner Heisenberg
John Herschel
Basil Hiley
Art Hobson
Jesper Hoffmeyer
Don Howard
John H. Jackson
William Stanley Jevons
Roman Jakobson
E. T. Jaynes
Pascual Jordan
Eric Kandel
Ruth E. Kastner
Stuart Kauffman
Martin J. Klein
William R. Klemm
Christof Koch
Simon Kochen
Hans Kornhuber
Stephen Kosslyn
Daniel Koshland
Ladislav Kovàč
Leopold Kronecker
Rolf Landauer
Alfred Landé
Pierre-Simon Laplace
Karl Lashley
David Layzer
Joseph LeDoux
Gerald Lettvin
Gilbert Lewis
Benjamin Libet
David Lindley
Seth Lloyd
Werner Loewenstein
Hendrik Lorentz
Josef Loschmidt
Alfred Lotka
Ernst Mach
Donald MacKay
Henry Margenau
Owen Maroney
David Marr
Humberto Maturana
James Clerk Maxwell
Ernst Mayr
John McCarthy
Warren McCulloch
N. David Mermin
George Miller
Stanley Miller
Ulrich Mohrhoff
Jacques Monod
Vernon Mountcastle
Emmy Noether
Donald Norman
Alexander Oparin
Abraham Pais
Howard Pattee
Wolfgang Pauli
Massimo Pauri
Wilder Penfield
Roger Penrose
Steven Pinker
Colin Pittendrigh
Walter Pitts
Max Planck
Susan Pockett
Henri Poincaré
Daniel Pollen
Ilya Prigogine
Hans Primas
Zenon Pylyshyn
Henry Quastler
Adolphe Quételet
Pasco Rakic
Nicolas Rashevsky
Lord Rayleigh
Frederick Reif
Jürgen Renn
Giacomo Rizzolati
A.A. Roback
Emil Roduner
Juan Roederer
Jerome Rothstein
David Ruelle
David Rumelhart
Robert Sapolsky
Tilman Sauer
Ferdinand de Saussure
Jürgen Schmidhuber
Erwin Schrödinger
Aaron Schurger
Sebastian Seung
Thomas Sebeok
Franco Selleri
Claude Shannon
Charles Sherrington
Abner Shimony
Herbert Simon
Dean Keith Simonton
Edmund Sinnott
B. F. Skinner
Lee Smolin
Ray Solomonoff
Roger Sperry
John Stachel
Henry Stapp
Tom Stonier
Antoine Suarez
Leo Szilard
Max Tegmark
Teilhard de Chardin
Libb Thims
William Thomson (Kelvin)
Richard Tolman
Giulio Tononi
Peter Tse
Alan Turing
C. S. Unnikrishnan
Francisco Varela
Vlatko Vedral
Vladimir Vernadsky
Mikhail Volkenstein
Heinz von Foerster
Richard von Mises
John von Neumann
Jakob von Uexküll
C. H. Waddington
John B. Watson
Daniel Wegner
Steven Weinberg
Paul A. Weiss
Herman Weyl
John Wheeler
Jeffrey Wicken
Wilhelm Wien
Norbert Wiener
Eugene Wigner
E. O. Wilson
Günther Witzany
Stephen Wolfram
H. Dieter Zeh
Semir Zeki
Ernst Zermelo
Wojciech Zurek
Konrad Zuse
Fritz Zwicky

Presentations

Biosemiotics
Free Will
Mental Causation
James Symposium
 
N David Mermin
N David Mermin is professor emeritus of physics at Cornell University. He is perhaps best known for his contributions to the foundations of physics, especially his mechanisms for describing Bell's Theorem, his contributions to quantum information science, and his defense of QBism.

In 1981, Mermin wrote the very popular and widely cited paper "Quantum Mysteries for Anyone."

Mermin wrote a similar and more provocative paper in Physics Today in 1985, "Is the Moon There When Nobody Looks?."

In these papers Mermin described what he called a "very simple version" of John Bell's "gedanken" experiment. Mermin says his "EPR Apparatus" exhibits all the experimental behavior of Bell's version, without any reference to the "underlying mechanism that makes the gadget work." He provides samples of (hypothetical) data produced by the apparatus, which presumably matches (statistically) the data produced in real experimental tests of Bell's Theorem.

Two years later, Mermin published a variation on his original apparatus at a 1987 Notre Dame conference on Bell's Theorem. In this work, "More Experimental Physics from EPR," his new device has different switch settings but more data is provided to exhibit the mysterious entanglement (perfect correlations) between widely separated measurements. In this paper, Mermin gave a definite answer to his earlier question about the moon, "We now know that the moon is demonstrably not there when nobody looks." (p.50)

Perfect Correlations Depend on Polarizer Angles
In real EPR tests (e.g., the Aspect experiment), the settings of polarizers at A and B are adjusted to a few specific angles, for example 0°, 22.5°, 45°, 67.5°. The angles chosen are expected to show the greatest differences between Bell's inequality predictions and quantum mechanics.

In particular, when the polarizers measure the same angle, so their angle difference is 0°, the photon spin correlation (or anti-correlation for spin-1/2 electrons) is perfect.

In Mermin's EPR device, different polarizer angles are represented by different switch settings on the detectors
(11, 12, 13, 21, 22, 23, 31, 32, 33). But he does not tell us the angle difference between the measurements.

Mermin's cases of "switches set the same" correspond to detectors measuring the same angle. For Mermin's device, lights flashing the same color (RR or GG) shows the correlations are perfect.

When polarizers are set at different angles, it is well known that the transmission of light falls off as the square of the cosine of the angle difference θ, cos2θ. This is known as the "law of Malus." At 45 degrees, only half of the photons pass through. The other half is absorbed. At 0° all pass through. At 90° all are absorbed. For Merlin's device, when lights are different colors, there is a loss of correlation.

Mermin's hypothetical data illustrate the fact that at some polarizer angles (when detector switches are set the same) the correlation between measurements is perfect. (For Bohm's electron spins it is perfect anti-correlation - if one spin is up, the other is down.) Mermin's data are for Aspect spin-1 photons, which are initially entangled with spins in the same direction.)

Mermin divides his results into two cases:

Case (a). In those runs in which each switch ends up with the same setting (11,22, or 33) both detectors always flash the same color: RR and GG occur with equal frequency; RG and GR never occur.

Case (b). In those runs in which the switches end up with different settings (12,13, 21, 23, 31, or 32) both detectors flash the same color only a quarter of the time (RR and GG occurring with equal frequency); the other three quarters of the time the detectors flash different colors (RG and GR occurring with equal frequency).

The quantum physics behind the reduced correlations in Mermin's case (b) is that light passing through polarizers falls off as the square of the cosine of the angle between the polarizers. This is the "law of Malus." See Stuckey et al (2020).

In his classic book Principles of Quantum Mechanics, Paul Dirac describes photons in terms of his quantum state vectors. He tells us a diagonally polarized photon can be represented as a superposition of vertical | v > and horizontal | h > quantum states, with complex number coefficients 1/√2 that represent "probability amplitudes," which are squared to get probabilities.

Thus, a diagonally polarized photon is

| d > = ( 1/√2) | v > + (1/√2) | h >          (1)

Dirac illustrates this

The physical meaning of a superposition of quantum states is that in a large number of identical experiments, the probability of a | d > photon passing through a vertical polarizer is 1/2.

Switches set the same: highlighted to pick out those runs in which both detectors had the same switch settings as they flashed. Note that in such runs the lights always flash the same colors.

Can Perfect Correlations Be Explained by Conservation Laws?
David Bohm, Eugene Wigner, and even John Bell suggested that conservation of angular momentum (or particle spin) tells us that if one spin-1/2 electron is measured up, the other must be down. Albert Einstein used conservation of linear momentum in his development of the EPR Paradox.

David Bohm and Yakir Aharonov wrote in 1957,

We consider a molecule of total spin zero consisting of two atoms, each of spin one-half. The wave function of the system is therefore

ψ = (1/√2) [ ψ+ (1) ψ- (2) - ψ- (1) ψ+ (2) ]

where ψ+ (1) refers to the wave function of the atomic state in which one particle (A) has spin +ℏ/2, etc. The two atoms are then separated by a method that does not influence the total spin. After they have separated enough so that they cease to interact, any desired component of the spin of the first particle (A) is measured. Then, because the total spin is still zero, it can immediately be concluded that the same component of the spin of the other particle (B) is opposite to that of A.

Bohm and Aharonov also wrote that in classical mechanics, the molecule could have all three components of the spin well-defined, but this is impossible for quantum mechanics, since at most one component of the spin can be well-defined...

If this were a classical system, there would be no difficulty in interpreting the above results, because all components of the spin of each particle are well defined at each instant of time. Thus, in the molecule, each component of the spin of particle A has, from the very beginning, a value opposite to that of the same component of B; and this relationship does not change when the atom disintegrates. In other words, the two spin vectors are correlated. Hence, the measurement of any component of the spin of A permits us to conclude also that the same component of B is opposite in value. The possibility of obtaining knowledge of the spin of particle B in this way evidently does not imply any interaction of the apparatus with particle B or any interaction between A and B.

In quantum theory, a difficulty arises, in the interpretation of the above experiment, because only one component of the spin of each particle can have a definite value at a given time. Thus, if the x component is definite, then the y and z components are indeterminate and we may regard them more or less as in a kind of random fluctuation.

N David Mermin made a similar argument in 1988, arguing that in the absence of spooky actions, it appears that both photons must have definite polarizations along every conceivable direction...
Both photons must have had definite polarizations along α. Furthermore, since the conclusion that one photon has a definite polarization along the direction α does not require an actual measurement of the polarization of the other along that direction (again, in the absence of spooky connections), and since not measuring polarization along a direction α is the same as not measuring it along any other direction, we are led to conclude that both photons must have definite polarizations along every conceivable direction.

In our analysis we show how a hidden constant of the motion can carry common causes of entanglement to the "separated" particles. It is not that atoms and electrons must have spins along all three directions or that both photons must have definite polarizations along every conceivable direction.

It is that the two-particle wave function is spherically symmetric with no definite spins in any direction, that is, until the measurements, which each create one bit of information and the perfectly correlated spins.

Eugene Wigner wrote in 1962

If a measurement of the momentum of one of the particles is carried out — the possibility of this is never questioned — and gives the result p, the state vector of the other particle suddenly becomes a (slightly damped) plane wave with the momentum -p. This statement is synonymous with the statement that a measurement of the momentum of the second particle would give the result -p, as follows from the conservation law for linear momentum. The same conclusion can be arrived at also by a formal calculation of the possible results of a joint measurement of the momenta of the two particles.

Writing a few years after Bohm, and one year before Bell, Wigner explicitly describes Einstein's conservation of linear momentum example as well as the conservation of angular momentum (spin) that explains perfect correlations between angular momentum (spin) components measured in the same direction
One can go even further: instead of measuring the linear momentum of one particle, one can measure its angular momentum about a fixed axis. If this measurement yields the value mℏ, the state vector of the other particle suddenly becomes a cylindrical wave for which the same component of the angular momentum is -mℏ. This statement is again synonymous with the statement that a measurement of the said component of the angular momentum of the second particle certainly would give the value -mℏ. This can be inferred again from the conservation law of the angular momentum (which is zero for the two particles together) or by means of a formal analysis.

John Bell wrote in 1964,

With the example advocated by Bohm and Aharonov, the EPR argument is the following. Consider a pair of spin one-half particles formed somehow in the singlet spin state and moving freely in opposite directions. Measurements can be made, say by Stern-Gerlach magnets, on selected components of the spins σ1 and σ2. If measurement of the component σ1a, where a is some unit vector, yields the value + 1 then, according to quantum mechanics, measurement of σ2a must yield the value — 1 and vice versa. Now we make the hypothesis, and it seems one at least worth considering, that if the two measurements are made at places remote from one another the orientation of one magnet does not influence the result obtained with the other.
"pre-determination" is too strong a term. The first measurement just "determines" the later measurement. We shall see that the second measurement is synchronous with the "first" in a "special" frame
Since we can predict in advance the result of measuring any chosen component of σ2, by previously measuring the same component of σ1, it follows that the result of any such measurement must actually be predetermined.

Since the initial quantum mechanical wave function does not determine the result of an individual measurement, this predetermination implies the possibility of a more complete specification of the state.

Just like Bohm and Wigner, Bell is implicitly using the conservation of total spin.

Albert Einstein made the same argument in 1933, shortly before EPR, though with conservation of linear momentum, asking Leon Rosenfeld,

Suppose two particles are set in motion towards each other with the same, very large, momentum, and they interact with each other for a very short time when they pass at known positions. Consider now an observer who gets hold of one of the particles, far away from the region of interaction, and measures its momentum: then, from the conditions of the experiment, he will obviously be able to deduce the momentum of the other particle. If, however, he chooses to measure the position of the first particle, he will be able tell where the other particle is.

Supporters of the Copenhagen Interpretation (including Mermin?) claim (correctly) that the properties of the particles (like angular or linear momentum) do not exist until they are measured. It was Pascual Jordan who claimed the measurement creates the value of a property. This is true when the preparation of the state is in an unknown linear combination (superposition) of quantum states.

In our case, the entangled particles have been prepared in a superposition of states, both of which have total spin zero. The two-particle wave function is

ψ = (1/√2) [ ψ+ (1) ψ- (2) - ψ- (1) ψ+ (2) ]

So whichever of these two states is created by the preparation, it will put the two particles in opposite spin states, randomly + - or - + , but still supporting the views of Bohm, Wigner, and Bell, that they will be perfectly (anti-)correlated when measured.

As long as nothing interferes with either entangled particle as they travel to the distant detectors, they will be found to be perfectly correlated if (and only if) they are measured (by prior agreement) at the same angle. Otherwise. the correlations should fall off as the square of the cosine of the angle difference. Oddly, Bell's inequality predicts a linear falloff with the angle difference, and a strange non-physical "kink" at angles 0°, 90°, 180°, and 270° (which Bell himself pointed out).

We can illustrate the straight-line predictions of Bell's inequalities for local hidden variables, the cosine curves predicted by quantum mechanics and conservation of angular momentum, and the odd "kinks" at angles 0°, 90°, 180°, and 270°, with what is called a "Popescu-Rorhlich box."
This square box is also called the Bell polytope.

It shows Bell’s local hidden variables prediction as four straight lines of the inner square. The circular region of quantum mechanics correlations are found outside Bell's straight lines, "violating" his inequalities. Quantum mechanics and Bell's inequalities meet at the corners, where Bell's predictions show a distinctly non-physical right-angle that Bell called a "kink."

All experimental results have been found to lie along the curved quantum predictions called the "Tsirelson bound."

In 1976, Bell gave us this diagram of the "kinks" in his local hidden variables inequality. He says,

Unlike the quantum correlation, which is stationary in θ at θ = 0, at the hidden variable correlation must have a kink there
Bell provides us no physical insight into the "kinky" square shape of his "local hidden variables" inequality.

The Ithaca Interpretation of Quantum Mechanics
the predictions of quantum mechanics are fundamentally probabilistic rather than deterministic, quantum mechanics only can make sense as a theory of ensembles. Whether or not this is the only way to understand probabilistic predictive power, physics ought to be able to describe as well as predict the behavior of the natural world. The fact that physics cannot make a deterministic prediction about an individual system does not excuse us from pursuing the goal of being able to construct a description of an individual system at the present moment, and not just a fictitious ensemble of such systems.

I shall not explore further the notion of probability and correlation as objective properties of individual physical systems, though the validity of much of what I say depends on subsequent efforts to make this less problematic. My instincts are that this is the right order to proceed in: objective probability arises only in quantum mechanics. We will understand it better only when we understand quantum mechanics better. My strategy is to try to understand quantum mechanics contingent on an understanding of objective probability, and only then to see what that understanding teaches us about objective probability.

So throughout this essay I shall treat correlation and probability as primitive concepts, “incapable of further reduction . . . a primary fundamental notion of physics.” The aim is to see whether all the mysteries of quantum mechanics can be reduced to this single puzzle. I believe that they can, provided one steers clear of another even greater mystery: the nature of ones own personal consciousness.

Now Richard Feynman, a great admirer of Mermin's "contraption", said the only mystery was exhibited by the two-slit experiment. Does Mermin agree? Mermin is correct that "the predictions of quantum mechanics are fundamentally probabilistic" and that the probability of different possibilities is "objective." The first desideratum of his Ithaca interpretation of quantum mechanics is "The theory should describe an objective reality independent of observers and their knowledge."

Whose Knowledge?
Mermin has puzzled over the distinction between information and knowledge. In an article with the title "Whose Knowledge?" in the book Quantum [Un]Speakables by R.A.Bertlmann and A.Zeilinger, he notes
[K]nowledge is not on Bell's now famous list of

"words which, however legitimate and necessary in application, have no place in a formulation with any pretension to physical precision".

But "information" is on the proscribed list, the charge against it being

"Information? Whose information? Information about "what?"

Mermin asked

Suppose Alice now goes to the right qubit and secretly measures it in the computational basis. She does not report to Bob the result of her measurement or even whether she has measured at all. Since the right qubit is far away and does not interact with the left qubit...

The fundamental theory of standard quantum mechanics is that any measurement of, or even an environmental interaction with, the two-particle wave function Ψ12, it "collapses" instantaneously into the product of single-particle wave functions Ψ1•Ψ2. Mermin is correct that it is not an "interaction." It is not Einstein's "spooky action at a distance." It is instead "knowledge at a distance."

Alice's measurement of the right qubit now gives her knowledge of the state of Bob's left qubit, as both David Bohm and John Bell said clearly.

I argue that this knowledge is the consequence of the conservation of total spin angular momentum that I call a "hidden" constant of the motion, a common cause emanating from the apparatus located between Alice and Bob (in their past light cone) which entangled the qubits in a non-separable two-particle wave function.

And What about the Moon?
Mermin's 1981 article appeared to settle Einstein's question on the Moon's existence
The questions with which Einstein attacked the quantum theory do have answers; but they are not the answers Einstein expected them to have. We now know that the moon is demonstrably not there when nobody looks.
But four years later Mermin mentioned the question again, without resolving it further, in an article for The Great Ideas Today...
References
"Bringing home the atomic world: Quantum mysteries for anybody." American Journal of Physics 49(10) (1981): 940-943.

"Quantum Mysteries for Anyone." The Journal of Philosophy, 78(7), (1981) 397-408.

"Is the Moon There When Nobody Looks? Reality and the Quantum Theory." Physics Today 38.4 (1985): 38-47.

"Spooky actions at a distance, mysteries of the quantum theory," The Great Ideas Today 1988. p.2 (Encyclopedia Britannica). Reprinted in Boojums All The Way Through (1990), Cambridge University Press, p.110

"More Experimental Physics from EPR," in Philosophical Consequences of the Quantum Theory, Reflections on Bell's Theorem, J.T.Cushing and E. McMullin, eds. Notre Dame, (1989) pp. 38-59

"Quantum Mysteries Revisited," American Journal of Physics 58.8 (1990) 731-734.

"What is Quantum Mechanics Trying to Tell Us? (correlations!)," American Journal of Physics 66.9 (1998) 753-767.

The Ithaca Interpretation of Quantum Mechanics, PRAMANA - J. Phys., Indian Academy of Sciences, Vol. 51, No. 5, November 1998 pp. 549-565

"An Introduction to QBism," American Journal of Physics 82.8 (2014) 749-754.

"Making better sense of quantum mechanics," Reports on Progress in Physics, arXiv:1809.01639v1 [quant-ph] 5 Sep 2018

"Answering Mermin’s Challenge with Conservation per No Preferred Reference Frame," Stuckey, W, Silberstein, M, McDevitt, T. and Le, T.D. (2020) researchgate.net

Normal | Teacher | Scholar