On 2016 Mar 10, Lydia Maniatis commented:

I'm interleaving my comments to Hoffman's last reply below:

Hoffman: The interface theory predicts that realism is false, and thus that Bell correlations exist. Were experiments to demonstrate that Bell correlations do not exist, then the interface theory would be falsified. Thus the interface theory is an empirical theory, and its prediction is experimentally testable.

LMM: There's a difference between constructing a theory and simply making a loosely argued assertion. Your “theory” doesn't have the logical consistency, respect for facts and specificity to actually predict Bell's correlations. Many people have said the real world doesn't exist, but that doesn't make them physicists, it doesn't make sense to say that they had in effect predicted Bell's correlations. The variables you use are much too vague to justify predictions at any level of specificity, let alone that required at the level of quantum physics.

Hoffman: The remaining experimental loopholes in tests of Bell correlations that Howard Wiseman cites in his paper “Physics: Bell’s theorem still reverberates” are the following: “… they lacked large separations and fast switching of the settings, opening the ‘separation loophole’: information about the detector setting for one photon could have propagated, at light speed, to the other detector, and affected its outcome.” These loopholes are now closed. Bell correlation is confirmed. See Hensen et al., 2015, “Loophole-free Bell inequality violation using electron spins separated by 1.3 kilometres”, Nature, 526, 682-686.

LMM: And there's an even more recent one. However, as I reread Wiseman's article, it is those who (unlike you) don't agree with the Bell's notion of hidden variables (b/c they are empirically inaccessible) need to forgo realism. They (according to Wiseman) must either conclude that some events are correlated for no reason or accept Bell's metaphysical hidden variables. So it's not even clear that Bell's supporters are not realists.

At this point, it seems that physicists are in a very difficult place, caught between two paradoxical options. This is the point at which ground-breaking new theories sometimes emerge. I don't think vision science has a lot to say here.

The fact remains that there are principles of visual perception (and of mechanics, to take an example from physics) that are close enough to the truth in our environment to make useful predictions, lead to useful applications, and to lead to ever more useful theories. That's the world that science lives in. You say this world doesn't exist, yet your story is full of assumptions about that world (natural selection, etc). All I'm saying is, you can't have it both ways.

On 2016 Mar 05, Donald D Hoffman commented:

The interface theory predicts that realism is false, and thus that Bell correlations exist. Were experiments to demonstrate that Bell correlations do not exist, then the interface theory would be falsified. Thus the interface theory is an empirical theory, and its prediction is experimentally testable.

The remaining experimental loopholes in tests of Bell correlations that Howard Wiseman cites in his paper “Physics: Bell’s theorem still reverberates” are the following: “… they lacked large separations and fast switching of the settings, opening the ‘separation loophole’: information about the detector setting for one photon could have propagated, at light speed, to the other detector, and affected its outcome.”

These loopholes are now closed. Bell correlation is confirmed. See Hensen et al., 2015, “Loophole-free Bell inequality violation using electron spins separated by 1.3 kilometres”, Nature, 526, 682-686.

When Wiseman states that “Most physicists are localists” that means that most physicists give up realism. You simply misunderstood him.

On 2016 Feb 17, Lydia Maniatis commented:

This is the status of Bell's theorem in the physics community:

Physics: Bell’s theorem still reverberates Howard Wiseman 19 June 2014

"...But 50 years on, the experimental verifications of these quantum correlations still have ‘loopholes’, and scientists and philosophers still dispute exactly what the theorem states.

...As of now, there are no loophole-free Bell experiments.

...Most physicists are localists: they recognize the two options but choose the first, because hidden variables are, by definition, empirically inaccessible [i.e. outside the realm of empirical science]. Quantum information scientists embrace irreducible randomness as a resource for secure cryptography3. Other physicists and philosophers (the ‘non-localist camp’) dispute that there are two options, and insist that Bell’s theorem mandates non-locality4."

Apparently perception scientists are supposed to side with the minority opinion in physics on an issue of extraordinary complexity, and in turn to figure out what this implies for their discipline. Meanwhile, physics goes on as usual.

Btw, the online descriptions of Bell's theorem often include the term "metaphysics." Again, we are not dealing with empirical science, i.e. testable claims.

The only apparent relevance of the metaphysical claims being put forth as the "interface theory" is that the fundamental assumptions that enable empirical science are false. Yet persistent and irresolvable metaphysical problems with "reality" haven't stopped scientific progress before.

With respect to "H1 and H2," the framing of the questions is paradoxical. What is "it" and what is doing the perceiving? How does the perceiver come into existence? What if no one perceives the perceiver? What if there were no perceivers?

In general, science can never prove that the world exists beyond perception, but it acts as though it could, and that seems to lead to some practical benefits.

On 2015 Dec 10, Donald D Hoffman commented:

Consider two hypotheses.

H1: When it is not perceived, an object has a definite value for each of its dynamical physical properties.

H2: When it is not perceived, an object does not have a definite value for each of its dynamical physical properties.

H1 is widely accepted by vision researchers. Is H1 falsifiable?

If yes: There is an experiment that can support H1 or its negation, viz., H2. Thus H1 is falsifiable iff H2 is falsifiable.

If no: H1 and H2 are both outside empirical science.

In fact H1 and H2 are both falsifiable, and within empirical science. Understanding this nontrivial fact was an intellectual achievement of John Stewart Bell, published in 1964.

Below are published papers presenting empirical tests of the falsifiable hypothesis H2. The results in each case support H2, and thus support the interface theory of perception. A gentle introduction to this literature, and to the remarkable theorem on which it relies, is the paper by Mermin. These experiments, and the theory behind them, are among the greatest achievements of modern science.

Ansmann, M., Wang, H., Bialczak, R. C., Hofheinz, M., Lucero, E., Neeley, M., . . . Martinis, J. M. (2009). Violation of Bell’s inequality in Josephson phase qubits. Nature, 461, 504–506. doi:10.1038/ nature08363

Bell, J. S. (1964). On the Einstein Podolsky Rosen Paradox. Physics 1 (3): 195–200.

Cabello, A., Estebaranz, J. M., & García-Alcaine, G. (1996). Bell– Kochen–Specker theorem: A proof with 18 vectors. Physics Letters A, 212, 183. doi:10.1016/0375-9601(96)00134-X

Giustina, M., Mech, A., Ramelow, S., Wittmann, B., Kofler, J., Beyer, J., . . . Zeilinger, A. (2013). Bell violation using entangled photons with- out the fair-sampling assumption. Nature, 497, 227–230. doi:10.1038/nature12012

Mermin, N. D. (1985). Is the moon there when nobody looks? Reality and the quantum theory. Physics Today, 38(4), 38–47. doi:10.1063/1. 880968

Pan, J.-W., Bouwmeester, D., Daniell, M., Weinfurter, H., & Zeilinger, A. (2000). Experimental test of quantum nonlocality in three-photon GHZ entanglement. Nature, 403, 515–519.

Rowe, M. A., Kielpinski, D., Meyer, V., Sackett, C. A., Itano, W. M., Monroe, C., & Wineland, D. J. (2001). Experimental violation of a Bell’s inequality with efficient detection. Nature, 409, 791–794.

Salart, D., Baas, A., van Houwelingen, J. A. W., Gisin, N., & Zbinden, H. (2008). Spacelike separation in a Bell test assuming gravitationally induced collapses. Physical Review Letters, 100, 220404.

Weihs, G., Jennewein, T., Simon, C., Weinfurter, H., & Zeilinger, A. (1998). Violation of Bell’s inequality under strict Einstein locality conditions. Physical Review Letters, 81, 5039.

On 2015 Dec 02, Lydia Maniatis commented:

Very brief summary: The "falsifiable prediction" that “No object has a position, or any other physical property, when it is not perceived” cannot be tested except by perceiving some objective property of a part of the world (e.g. the absence of an object)...while we are not perceiving it.

It's like turning around really quickly to check if the world behind you disappears when you're not looking at it. Whimsical, but not very scientific.

On 2015 Nov 24, Lydia Maniatis commented:

The authors' proposal NOT FALSIFIABLE (i.e. it is not testable, i.e. it does not belong to empirical science), for a number of reasons.

In addressing the falsifiability question explicitly, Hoffman et al say that “if either [of two predictions – see below] is false, then the interface theory is false” (p. 1501).

The “predictions” being referred to are the following: 1) “No object has a position, or any other physical property, when it is not perceived.” 2) “No object has any causal powers.

The problem should already be obvious. The “interface theory” says that we cannot perceive the state of the objective world, no way, no how – that even space-time is not a property of the physical world. Therefore, on what basis can we ever corroborate any claims regarding position/physical properties of objects? The same goes for “prediction” number 2. We would have to be able to say "Look, this here object HAS a position and physical properties x, y, z EVEN WHEN NOT PERCEIVED! I can't perceive it or any other object, but I can somehow access this information!" With no access to the physical world, we can provide no proof possible about claims regarding the physical world. The assumptions of the “theory,” in other words mean that PROVING IT WOULD BE TANTAMOUNT TO DISPROVING IT.

Another reason that the theory is unfalsifiable is that its computations are based on statements such as: W = a set of world states. How can we ever substitute any kind of numerical value here? I suggest that the “precision” the authors claim for their proposal collapses with this impossibility. (Perhaps as a non-mathematician I'm missing something...).

Also, as an analogy, the interface theory fails to make the case (and the analogy is pretty much the whole case). The claim is that, just as the e.g. square, blue file icon on the desktop doesn't correspond in its properties to the underlying electronics, so percepts don't correspond in any way to physical objects. But our perception of the blue square presumably corresponds to the spectral properties of the light, and the luminance relationships, of the surface of the computer. Hoffman et al can claim that our perception of the properties of the icon are not veridical, but not using the lack of correspondence between icon and electronics as evidence. No one claims that because we can't accurately perceive the shape of a tree because we can't also see the interior, back, atoms that compose it...

Basing broad, unfalsifiable statements such as those being made in this article on a particular, crude similation is not credible. The “non-linearity” assumptions are said to be frequent but not universal, and even the examples given don't hold up. We are told that “not enough water and one dies of thirst; too much and one drowns; somewhere in between is just right” (p. 1506). This is no argument against the accurate (linear) perception of quantity – seeing a lot of water doesn't mean we actually have to drink it all. We might want to decide to swim in it.

There's just no reason to claim that the refined optical structures and responses of organisms have no purpose in using reflected light to infer and represent the world veridically. It's absurd, and leads to absurdity and, again, unfalsifiable claims. There is absolutely no special relationship between this “theory” and the theory of evolution by natural selection; the implication that a fitness criterion is opposite to a veridical (as veridical as possible and necessary) outcome is unfounded (and, again, unfalsifiable). In fact, the normal assumptions about structure and function (based on perceived structures) are more consistent with evolutionary discussions (they are actually required to make such discussions rational).

The claim, in his comment on the article, by the Editor-in-Chief of this journal that “Our measurements...are species-specific and we should worry if they form the starting point for physical theories” (Hickok (2015, p. 1478) just recycles an old philosophical conundrum that is irrelevant to scientific progress. The “worry” cannot be resolved by science but also cannot, in principle and in practice, affect, let alone “be the future of the science of the mind” (p. 1479) - or of any science (otherwise physicists would also have a problem). It just takes us round in circles for the millionth time. The focus on quantum physics is silly, implying as it does that progress in perception depends on an understanding of the unsolved mysteries of that discipline.

On 2015 Nov 24, Lydia Maniatis commented:

The authors' proposal NOT FALSIFIABLE (i.e. it is not testable, i.e. it does not belong to empirical science), for a number of reasons.

In addressing the falsifiability question explicitly, Hoffman et al say that “if either [of two predictions – see below] is false, then the interface theory is false” (p. 1501).

The “predictions” being referred to are the following: 1) “No object has a position, or any other physical property, when it is not perceived.” 2) “No object has any causal powers.

The problem should already be obvious. The “interface theory” says that we cannot perceive the state of the objective world, no way, no how – that even space-time is not a property of the physical world. Therefore, on what basis can we ever corroborate any claims regarding position/physical properties of objects? The same goes for “prediction” number 2. We would have to be able to say "Look, this here object HAS a position and physical properties x, y, z EVEN WHEN NOT PERCEIVED! I can't perceive it or any other object, but I can somehow access this information!" With no access to the physical world, we can provide no proof possible about claims regarding the physical world. The assumptions of the “theory,” in other words mean that PROVING IT WOULD BE TANTAMOUNT TO DISPROVING IT.

Another reason that the theory is unfalsifiable is that its computations are based on statements such as: W = a set of world states. How can we ever substitute any kind of numerical value here? I suggest that the “precision” the authors claim for their proposal collapses with this impossibility. (Perhaps as a non-mathematician I'm missing something...).

Also, as an analogy, the interface theory fails to make the case (and the analogy is pretty much the whole case). The claim is that, just as the e.g. square, blue file icon on the desktop doesn't correspond in its properties to the underlying electronics, so percepts don't correspond in any way to physical objects. But our perception of the blue square presumably corresponds to the spectral properties of the light, and the luminance relationships, of the surface of the computer. Hoffman et al can claim that our perception of the properties of the icon are not veridical, but not using the lack of correspondence between icon and electronics as evidence. No one claims that because we can't accurately perceive the shape of a tree because we can't also see the interior, back, atoms that compose it...

Basing broad, unfalsifiable statements such as those being made in this article on a particular, crude similation is not credible. The “non-linearity” assumptions are said to be frequent but not universal, and even the examples given don't hold up. We are told that “not enough water and one dies of thirst; too much and one drowns; somewhere in between is just right” (p. 1506). This is no argument against the accurate (linear) perception of quantity – seeing a lot of water doesn't mean we actually have to drink it all. We might want to decide to swim in it.

There's just no reason to claim that the refined optical structures and responses of organisms have no purpose in using reflected light to infer and represent the world veridically. It's absurd, and leads to absurdity and, again, unfalsifiable claims. There is absolutely no special relationship between this “theory” and the theory of evolution by natural selection; the implication that a fitness criterion is opposite to a veridical (as veridical as possible and necessary) outcome is unfounded (and, again, unfalsifiable). In fact, the normal assumptions about structure and function (based on perceived structures) are more consistent with evolutionary discussions (they are actually required to make such discussions rational).

The claim, in his comment on the article, by the Editor-in-Chief of this journal that “Our measurements...are species-specific and we should worry if they form the starting point for physical theories” (Hickok (2015, p. 1478) just recycles an old philosophical conundrum that is irrelevant to scientific progress. The “worry” cannot be resolved by science but also cannot, in principle and in practice, affect, let alone “be the future of the science of the mind” (p. 1479) - or of any science (otherwise physicists would also have a problem). It just takes us round in circles for the millionth time. The focus on quantum physics is silly, implying as it does that progress in perception depends on an understanding of the unsolved mysteries of that discipline.

On 2015 Dec 02, Lydia Maniatis commented:

Very brief summary: The "falsifiable prediction" that “No object has a position, or any other physical property, when it is not perceived” cannot be tested except by perceiving some objective property of a part of the world (e.g. the absence of an object)...while we are not perceiving it.

It's like turning around really quickly to check if the world behind you disappears when you're not looking at it. Whimsical, but not very scientific.

On 2015 Dec 10, Donald D Hoffman commented:

Consider two hypotheses.

H1: When it is not perceived, an object has a definite value for each of its dynamical physical properties.

H2: When it is not perceived, an object does not have a definite value for each of its dynamical physical properties.

H1 is widely accepted by vision researchers. Is H1 falsifiable?

If yes: There is an experiment that can support H1 or its negation, viz., H2. Thus H1 is falsifiable iff H2 is falsifiable.

If no: H1 and H2 are both outside empirical science.

In fact H1 and H2 are both falsifiable, and within empirical science. Understanding this nontrivial fact was an intellectual achievement of John Stewart Bell, published in 1964.

Below are published papers presenting empirical tests of the falsifiable hypothesis H2. The results in each case support H2, and thus support the interface theory of perception. A gentle introduction to this literature, and to the remarkable theorem on which it relies, is the paper by Mermin. These experiments, and the theory behind them, are among the greatest achievements of modern science.

Ansmann, M., Wang, H., Bialczak, R. C., Hofheinz, M., Lucero, E., Neeley, M., . . . Martinis, J. M. (2009). Violation of Bell’s inequality in Josephson phase qubits. Nature, 461, 504–506. doi:10.1038/ nature08363

Bell, J. S. (1964). On the Einstein Podolsky Rosen Paradox. Physics 1 (3): 195–200.

Cabello, A., Estebaranz, J. M., & García-Alcaine, G. (1996). Bell– Kochen–Specker theorem: A proof with 18 vectors. Physics Letters A, 212, 183. doi:10.1016/0375-9601(96)00134-X

Giustina, M., Mech, A., Ramelow, S., Wittmann, B., Kofler, J., Beyer, J., . . . Zeilinger, A. (2013). Bell violation using entangled photons with- out the fair-sampling assumption. Nature, 497, 227–230. doi:10.1038/nature12012

Mermin, N. D. (1985). Is the moon there when nobody looks? Reality and the quantum theory. Physics Today, 38(4), 38–47. doi:10.1063/1. 880968

Pan, J.-W., Bouwmeester, D., Daniell, M., Weinfurter, H., & Zeilinger, A. (2000). Experimental test of quantum nonlocality in three-photon GHZ entanglement. Nature, 403, 515–519.

Rowe, M. A., Kielpinski, D., Meyer, V., Sackett, C. A., Itano, W. M., Monroe, C., & Wineland, D. J. (2001). Experimental violation of a Bell’s inequality with efficient detection. Nature, 409, 791–794.

Salart, D., Baas, A., van Houwelingen, J. A. W., Gisin, N., & Zbinden, H. (2008). Spacelike separation in a Bell test assuming gravitationally induced collapses. Physical Review Letters, 100, 220404.

Weihs, G., Jennewein, T., Simon, C., Weinfurter, H., & Zeilinger, A. (1998). Violation of Bell’s inequality under strict Einstein locality conditions. Physical Review Letters, 81, 5039.

On 2016 Feb 17, Lydia Maniatis commented:

This is the status of Bell's theorem in the physics community:

Physics: Bell’s theorem still reverberates Howard Wiseman 19 June 2014

"...But 50 years on, the experimental verifications of these quantum correlations still have ‘loopholes’, and scientists and philosophers still dispute exactly what the theorem states.

...As of now, there are no loophole-free Bell experiments.

...Most physicists are localists: they recognize the two options but choose the first, because hidden variables are, by definition, empirically inaccessible [i.e. outside the realm of empirical science]. Quantum information scientists embrace irreducible randomness as a resource for secure cryptography3. Other physicists and philosophers (the ‘non-localist camp’) dispute that there are two options, and insist that Bell’s theorem mandates non-locality4."

Apparently perception scientists are supposed to side with the minority opinion in physics on an issue of extraordinary complexity, and in turn to figure out what this implies for their discipline. Meanwhile, physics goes on as usual.

Btw, the online descriptions of Bell's theorem often include the term "metaphysics." Again, we are not dealing with empirical science, i.e. testable claims.

The only apparent relevance of the metaphysical claims being put forth as the "interface theory" is that the fundamental assumptions that enable empirical science are false. Yet persistent and irresolvable metaphysical problems with "reality" haven't stopped scientific progress before.

With respect to "H1 and H2," the framing of the questions is paradoxical. What is "it" and what is doing the perceiving? How does the perceiver come into existence? What if no one perceives the perceiver? What if there were no perceivers?

In general, science can never prove that the world exists beyond perception, but it acts as though it could, and that seems to lead to some practical benefits.

On 2016 Mar 05, Donald D Hoffman commented:

The interface theory predicts that realism is false, and thus that Bell correlations exist. Were experiments to demonstrate that Bell correlations do not exist, then the interface theory would be falsified. Thus the interface theory is an empirical theory, and its prediction is experimentally testable.

The remaining experimental loopholes in tests of Bell correlations that Howard Wiseman cites in his paper “Physics: Bell’s theorem still reverberates” are the following: “… they lacked large separations and fast switching of the settings, opening the ‘separation loophole’: information about the detector setting for one photon could have propagated, at light speed, to the other detector, and affected its outcome.”

These loopholes are now closed. Bell correlation is confirmed. See Hensen et al., 2015, “Loophole-free Bell inequality violation using electron spins separated by 1.3 kilometres”, Nature, 526, 682-686.

When Wiseman states that “Most physicists are localists” that means that most physicists give up realism. You simply misunderstood him.

On 2016 Mar 10, Lydia Maniatis commented:

I'm interleaving my comments to Hoffman's last reply below:

Hoffman: The interface theory predicts that realism is false, and thus that Bell correlations exist. Were experiments to demonstrate that Bell correlations do not exist, then the interface theory would be falsified. Thus the interface theory is an empirical theory, and its prediction is experimentally testable.

LMM: There's a difference between constructing a theory and simply making a loosely argued assertion. Your “theory” doesn't have the logical consistency, respect for facts and specificity to actually predict Bell's correlations. Many people have said the real world doesn't exist, but that doesn't make them physicists, it doesn't make sense to say that they had in effect predicted Bell's correlations. The variables you use are much too vague to justify predictions at any level of specificity, let alone that required at the level of quantum physics.

Hoffman: The remaining experimental loopholes in tests of Bell correlations that Howard Wiseman cites in his paper “Physics: Bell’s theorem still reverberates” are the following: “… they lacked large separations and fast switching of the settings, opening the ‘separation loophole’: information about the detector setting for one photon could have propagated, at light speed, to the other detector, and affected its outcome.” These loopholes are now closed. Bell correlation is confirmed. See Hensen et al., 2015, “Loophole-free Bell inequality violation using electron spins separated by 1.3 kilometres”, Nature, 526, 682-686.

LMM: And there's an even more recent one. However, as I reread Wiseman's article, it is those who (unlike you) don't agree with the Bell's notion of hidden variables (b/c they are empirically inaccessible) need to forgo realism. They (according to Wiseman) must either conclude that some events are correlated for no reason or accept Bell's metaphysical hidden variables. So it's not even clear that Bell's supporters are not realists.

At this point, it seems that physicists are in a very difficult place, caught between two paradoxical options. This is the point at which ground-breaking new theories sometimes emerge. I don't think vision science has a lot to say here.

The fact remains that there are principles of visual perception (and of mechanics, to take an example from physics) that are close enough to the truth in our environment to make useful predictions, lead to useful applications, and to lead to ever more useful theories. That's the world that science lives in. You say this world doesn't exist, yet your story is full of assumptions about that world (natural selection, etc). All I'm saying is, you can't have it both ways.