What is the wave function about?

Demystifier

Perhaps you are missing the context, which is the paper mentioned in post #38.

Demystifier

At some points I don't really understand your reasoning, so it's hard to tell wheather I agree or not.

ThomasT

There's at least two ways to view determinism. Either the universe is evolving and we're part of that evolution, or we're travelling through a static universe. In the case of the former, going back or sending messages back in time is nonsensical because the past refers to spatial configurations that no longer exist. The latter case, on the other hand, suggests that we're somehow distinct from the universe, ie., travelling/evolving in some way separate from it, which seems to be prima facie nonsensical and anyway leads to all sorts of nonsensical stuff.

So, we choose the former view, the view that we're part of an evolving universe, and in that view it's impossible to send messages back in time or to revisit the past, even if we could send messages or transport ourselves instantaneously to any part of the universe.

Properly interpreted, in an evolving universe which we're a part of, there's no frame of reference wrt which even a FTL signal is actually travelling backward in time.

Thus, 'free will' has nothing to do with it. 'Superdeterminism' is a superfluous extension of determinism, because if the universe is evolving deterministically, then free will (in the sense of choices being independent of prior conditions/configurations) is ruled out anyway.

In your paper you say that "By assumption, superluminal signals are inherently quantum phenomena responsible for nonlocal correlations between entangled particles ..." . But this assumption isn't necessary for a certain understanding of the correlations between the angular difference of polarizer settings and coincidental photon flux, and in fact posits the existence of an entirely new class of physical (or nonphysical in the case of instantaneous action-at-a-distance) phenomena for which there's absolutely no physical evidence.

You say that, "The Bell theorem [1] shows that quantum mechanics (QM) is not compatible with local reality.", which isn't precisely correct. Bell's theorem shows that QM is not compatible with LRHV models of quantum entanglement (ie., coincidental photon flux). QM is quite compatible with LRHV models of photon flux at the individual detectors. In general, standard QM is essentially nonrealistic and so is not incompatible with an understanding of quantum entanglement via purely local transmissions and interactions.

You further say that, "This suggests that reality might be nonlocal." . But this isn't at all what's suggested if one looks at the correlations wrt established optics principles, and if one evaluates the meaning of Bell's theorem wrt the formal constraints on LRHV models of entanglement. In this view, LRHV models of entanglement are ruled out even if the universe is evolving strictly in accordance with local determinism.

ThomasT

Which lines of reasoning in post #27 are unclear? Maybe I can further clarify them.

ThomasT

@ Demystifier,

You said, "We see that the equation of motion (23) is nonlocal, because the velocity of one particle for some value of s depends on the positions of all other particles for the same value of s." .

Should this be taken to mean that the motional properties of particles are physically determining the motional properties of other particles light years away, or can it be taken to mean that given certain antecedent conditions/configurations and motional properties, then certain things can be deduced about the evolution of a system?

Demystifier

Yes.

bohm2

I've come across a number of arguments (not just the compatibilist ones) suggesting that determinism is compatible with 'free will'. Others argue that the converse is also true; that is, indeterminism doesn't help the 'free will' cause at all. Carl Hoefer writes:

For reasons that Kant first realized, indeterminism at the microphysical level does not seem to help. The randomness, if any, in microscopic phenomena does not seem to “make room” for free will, but rather only replaces a sufficient physical cause with (at least in part) blind chance. The presumption in favor of upward causation and explanation (from microphysical to macrophysical) that comes with causal completeness is what cuts free agency out of the picture, whether this causation is deterministic or partly random.

http://www2.lse.ac.uk/CPNSS/pdf/DP_w...%2016%2001.pdf

Carl Hoefer then suggests that:

Physics, particularly 20th century physics, does have one lesson to impart to the free will debate; a lesson about the relationship between time and determinism. Recall that we noticed that the fundamental theories we are familiar with, if they are deterministic at all, are time-symmetrically deterministic. That is, earlier states of the world can be seen as fixing all later states; but equally, later states can be seen as fixing all earlier states. We tend to focus only on the former relationship, but we are not led to do so by the theories themselves.

Nor does 20th (21st) -century physics countenance the idea that there is anything ontologically special about the past, as opposed to the present and the future. In fact, it fails to use these categories in any respect, and teaches that in some senses they are probably illusory.[9] So there is no support in physics for the idea that the past is “fixed” in some way that the present and future are not, or that it has some ontological power to constrain our actions that the present and future do not have. It is not hard to uncover the reasons why we naturally do tend to think of the past as special, and assume that both physical causation and physical explanation work only in the past present/future direction (see the entry on thermodynamic asymmetry in time). But these pragmatic matters have nothing to do with fundamental determinism. If we shake loose from the tendency to see the past as special, when it comes to the relationships of determinism, it may prove possible to think of a deterministic world as one in which each part bears a determining—or partial-determining—relation to other parts, but in which no particular part (i.e., region of space-time) has a special, stronger determining role than any other. Hoefer (2002) uses these considerations to argue in a novel way for the compatiblity of determinism with human free agency.

http://plato.stanford.edu/entries/de...sal/#DetHumAct

Personally, I'm unconvinced by any of these arguments (both the pro or anti- free-will arguments) and tend to agree with McGinn that stuff like 'free will' is beyond our cognitive reach. Many humans seem to have this "God-like" complex thinking their cognitive powers have no limits. Consider what an ape's understanding of the universe is compared to ours. They could never understand what we are capable of: science, biology, physics, abstract algebra, etc. We are qualitatively different, so we think. Assume that even our cognitive abilities are only slightly more advanced than an ape's. Of course, from our perspective it doesn't appear that way. Assume reality is extremely complex. The ape's mind might be able to understand/pick up .001% of it. The human mind may have access to about .01% of it. Big improvement but still a miniscule part of all of reality/totality of "true" theories?

ThomasT

I don't agree with either Hoefer's or McGinn's take on this. Our thoughts and actions are somewhat unique from person to person, but they're not free in the sense that the term 'free' refers to absence of constraints. If the universe is evolving deterministically, then our wills, our thoughts and actions, aren't free.

We assume, for lots of good reasons, that the universe is evolving deterministically, and that we're an inseparable part of that deterministic evolution. That is, there aren't any subsystems of the universe that are isolated from its deterministic evolution.

Anyway, my point was that considerations of free will are irrelevant to interpreting the physical meaning of Bell's theorem.

In my view, the proper interpretation of Bell's theorem provides no basis for assuming the existence of action-at-a-distance 'influences' or FTL propagations.

Wrt your OP, we know that the wave equation and wave function are mathematical constructions which generate probabilities regarding measurement results. Anything else one might want to attribute to them is a matter of speculation, as there's no way to ascertain how they might approximate the reality underlying instrumental behavior.

bohm2

I don't think most philosophers/scientists who espouse the compatibility of determinism and free will are arguing against constraints. In fact, they argue that without some constraints to limit options/choices, creativity/theory construction/human behaviour, etc. would be impossible. I'm thinking about Peirce's argument here (e.g. innate property of mind that 'puts a limit upon admissible hypotheses',). The argument, however, is that we are free to choose among those variety of options innately given to us, I think; that is, "we could have done otherwise". That's how I understood "free will" as argued by these authors.

ThomasT

Yes, I agree. My statement was maybe misleading. I wanted to differentiate between two connotations of the term, free will. One of which is, 1) that our choices are actually free of constraints, ie., are not a function of prior physical conditions/configurations, and the other of which is, 2) that our choices are partially determined by prior physical conditions/configurations, and partially indeterminate, with the indeterminate part being due to some sort of incomprehensible mental activity (McGinn).

2) is meaningless, imo. So, we're left with 1), and it's incompatible with us being an inseparable part of a deterministically evolving universe.

I'm not familiar with Peirce's argument. (I only just learned about Hoefer's and McGinn's positions since you posted them.) Anyway, I don't see how it could matter.

Ok, but the arguments fail, imo, because if we're an inseparable part of a deterministically evolving universe, then our choices and actions are as determined by prior conditions/configurations as the behavior of electrons, atoms, rocks, trees, etc. is. That is, if we're an inseparable part of a deterministically evolving universe, then there's no sense in which the the assertion that "we could have done otherwise" could be correct. Assuming that we're a part of such a universe, there's also no possibility of transmissions or anything else travelling 'backward in time'.

The "block world" that Hoefer refers to shouldn't, imo, be taken literally as description of reality any more than the wave function should. We know that it's a mathematical construction (and it might be more convenient in some respects to think of reality in those terms), but real world observations, and inferences therefrom, suggest that it shouldn't be taken seriously as a representation of reality.

The assumption that we're an inseparable part of a deterministically evolving universe is an assumption which (somewhat ironically?) underlies, at least tacitly, our (apparently, to some observers, at least somewhat free) 'choices' and actions in any endeaver, from 'art' and science to the more mundane activities of everyday life.

bohm2

That makes sense to me, also. In my opinion, the strongest argument put forth for the possibility of "free will" is positions that are able to challenge the following premise posted above:

The presumption in favor of upward causation and explanation (from microphysical to macrophysical) that comes with causal completeness is what cuts free agency out of the picture, whether this causation is deterministic or partly random.

If it can shown that there exists the possibility for some type of 'downward' or 2-way causation between the macroscopic/microscopic domains, then maybe "free will" can occur? I think apeiron suggested something along these lines and I posted a paper by authors who interpreted Bell's experiments as suggesting such a possibility. I realize you don't favour those interpretations but I thought I'd post the relevant quotes from the paper. The argument put forward by these authors, assuming I understand them, is that if microphysical systems themselves can have properties not possessed by individual parts (e.g. existence of holistic relations), then so might any system composed of such parts. So you can have a type of top-down (or bi-directional) causation that may allow for the possibility for free will, etc?:

"The classical picture offered a compelling presumption in favour of the claim that causation is strictly bottom up-that the causal powers of whole systems reside entirely in the causal powers of parts. This thesis is central to most arguments for reductionism. It contends that all physically significant processes are due to causal powers of the smallest parts acting individually on one another. If this were right, then any emergent or systemic properties must either be powerless epiphenomena or else violate basic microphysical laws. But the way in which the classical picture breaks down undermines this connection and the reductionist argument that employs it. If microphysical systems can have properties not possessed by individual parts, then so might any system composed of such parts...

Were the physical world completely governed by local processes, the reductionist might well argue that each biological system is made up of the microphysical parts that interact, perhaps stochastically, but with things that exist in microscopic local regions; so the biological can only be epiphenomena of local microphysical processes occurring in tiny regions. Biology reduces to molecular biology, which reduces in turn to microphysics. But the Bell arguments completely overturn this conception."

http://faculty-staff.ou.edu/H/James....ments_Toll.pdf

ThomasT

I think that "what cuts free agency out of the picture" is the assumption that we're part of a deterministically evolving universe.

Not if the universe is evolving deterministically.

It's pretty clear that what the global measurement parameter (eg., crossed polarizers) in Bell tests is measuring is a relationship between the entangled entities. This relationship is an underlying global parameter which is presumably produced via local interactions and transmissions, and is not incompatible with the assumption that the universe is evolving deterministically, and it doesn't change the meanings of the terms "free will" and "determinism", which are mutually exclusive.

There's no particular reason to assume that causation is strictly bottom up. Imo, it obviously isn't. Systems exhibit collective properties not possessed by their parts. Scale reductionism is slowly giving way to dynamical law reductionism (ie., the search for more and more general, say, wave mechanical dynamics which pervade all behavioral scales).

bohm2

I have trouble understanding this concept. Assume the universe is non-deterministic. I can't see how that would help the "free will" position anymore than a deterministic universe. Wouldn't that just lead to some sort of "random will" versus truly "free will"? I'm just having trouble understanding the importance of determinism versus non-determinism with respect to allowing "free will" to occur. Both seem irrelevant to me. Maybe I'm mistaken but I just can't see one position (either determinism or indeterminism) providing a better background within which free will is possible.

ThomasT

Taking free will to mean that you could have done something other than what you did:

Free will entails that given the universal configurations (uc1) that immediately preceded the universal configurations (uc2) wrt which you were engaged in formulating and writing your reply, then some other set of universal configurations (uci), not determined by uc1, and wrt which you were not engaged in formulating and writing your reply, could have occured.

A universe where uc2 doesn't necessarily follow uc1 is a universe evolving nondeterministically. So, free will entails a nondeterministically evolving universe in which any universal configuration from the apparently unbounded set, uci (eg., even one from the distant past or one from our imaginings of the distant future) might manifest at any instant, and is incompatible with a deterministically evolving universe in which each instantaneous spatial configuration is unique and very much like its immediate predecessors and successors, and in which the speed of change has a finite limit (most likely c) which prohibits uc1 --> uci.

We invariably observe a universe in which uc1 --> uc2, and we call that "deterministic evolution". We never observe a universe in which uc1 --> uci. (Not being able to predict the outcomes of dice throws or quantum experiments is a different consideration, and neither is incompatible with the assumption that the universe is evolving deterministically.)

I hope this clarifies, at least somewhat, why I think that the assumption that we're part of a deterministically evolving universe is incompatible with (and why the assumption that we're part of a nondeterministically evolving universe is compatible with) the assumption that you could have done something other than what you did (free will).

apeiron

But if a person can anticipate the future course of events, then yes, a person does have choices.

The course of physical events may be highly determined - drop a stone and it will fall - but that just makes them very easy to anticipate and so control.

Like Demystify, you are making the classic mistake of assuming all causality to be local effective or proximate cause. Whatever happens is being driven by immediate past events. But human freewill is all about being driven by anticipation of future consequences. We imagine what might be the case of alternative courses of action and act accordingly.

The same more complex view of causality can be taken in physics too. So we can talk about dynamical systems being entrained to structural attractors, dissipative structures entrained to the second law of thermodynamics, or quantum systems betraying evidence of contextuality and retrocausality.

Clearly, you are deeply committed to the belief that reality is simply deterministic - the only causality is local/material/effective. And so you want to make both QM and human freewill fit that deep belief about nature.

But that is just one theory about causality. There are other ways to think about the facts.

Maui

We can do much better than that... we can manipulate possible outcomes to our preferences. That's a powerful ability. Science has no explanation for that except to say - "it's what we observe taking place in a deterministic universe" and that's really not saying much.

apeiron

Well, in fact I have rather frequently argued that there is such a theory in the systems science approach. This is based on a different dichotomy to random~determined. It argues for local degrees of freedom in interaction with global constraints. Or vague indeterminacy organised into the crisply definite.

Simple "deterministic" physical systems are then argued to be pretty helpless about the constraints that prevail in their world. A system self-organises in the fashion of a symmetry breaking where any "choice" - or indeterminacy - is quickly eliminated in the transition to a new state of equilibrium. A cooling iron bar loses its local degrees of freedom as a general magnetic field orientation - a global state of constraint - freezes in a direction that seems deterministic.

But a complicated system - like a "far from equilibrium" dissipative structure - maintains a considerable number of degrees of freedom. A tornado moving across a plain seems to have a lot of "choice".

And then a complex system, like something that is living/mindful, can actually construct its own boundary conditions, or non-holonomic constraints. It has both the continuing supply of local degrees of freedom that a dissipative structure enjoys, and the capacity to choose how to dispose of them (according to anticipatory goals).

It is this ability to construct global constraints (as through the epistemic cut/semiotics, in the form of genes or words, but also membranes, pores and other forms of physical constraint) that is the "trick" ordinary physics does not see, but which is basic to biophysics.

So there is in fact well-worked out theory that explains what we observe. But only biologists seem to learn about it.

Although it would be worth reading Schroedinger's "What is Life?" as he showed how physicists naively believe in "order from order", whereas reality was about "order from disorder". Even a clock is a harnessing of entropy (the mechanism is a form, an organisation, that constrains the release of the energy in a coiled spring to do work for a purpose).

In the same way, an experimenter can construct the boundary conditions that constrain a state of quantum potential. The wavefunction is then that part of the system which the experimenter has "determined". And the probabilities the wavefunction contain are the degrees of freedom that still remain.

An act of observation is then the imposition of yet further constraints that "collapse the wavefunction" by yet further reducing the systems' degrees of freedom. The indeterminate becomes increasingly determined. Or rather increasingly constrained towards some single definite state.