Is free will compatible with the probabilistic nature of QM?

[out of whack]

If your actions are DETERMINED they are not free, if RANDOM they are not willed... so the concept of freewill is an oxymoron term from the get go...

Absolutely. This should be the start and the end of the cogitation, regardless of QM or other considerations. A lucid examination of free will should include the realization that both terms are mutually exclusive: decisions are either free or willed, they cannot be both. The end.

 

[K.J.Healey]

That is logically true.

However, QM claims much more than that. It claims that the probabilities are not uncertain, but deterministic. So as long as QM claims to be complete by using deterministic probabilities, it cannot allow for philosophical free will. That is if you are willing to be logical about it.

So you're saying that since the probabilities of a state of an event is deterministic(though the result cannot be determined without observation), there's no free will? I don't get it? Why couldn't the "freedom of choice" comes in how you measure said event, or whether or not you choose to measure it.

 

[jiohdi]

So you're saying that since the probabilities of a state of an event is deterministic(though the result cannot be determined without observation), there's no free will? I don't get it? Why couldn't the "freedom of choice" comes in how you measure said event, or whether or not you choose to measure it.

the question becomes, what CAUSED you to make the measurement? some DETERMINED force, or some RANDOM one...what else?

 

[Jonny_trigonometry]

Some people argue that QM is complete because if there were deterministic hidden variables behind QM, then the determinism would not allow free will.
However, such an argument for completeness of QM is completely meaningless for the following reason: If QM is complete, then fundamental laws of nature are purely probabilistic and physical events are fundamentally random. Fundamental randomness does NOT allow free will. For example, if there are 50:50 chances for two different behaviors of a human, then the human cannot decide to behave allways in the same way.

Thus, everyone who believes in free will should reject completeness of QM!

But what if the hidden variable is consciousness?

 

[Demystifier]

But what if the hidden variable is consciousness?

In that case, QM is not complete.

 

[Demystifier]

So you're saying that since the probabilities of a state of an event is deterministic(though the result cannot be determined without observation), there's no free will? I don't get it? Why couldn't the "freedom of choice" comes in how you measure said event, or whether or not you choose to measure it.

If you can freely chose to measure something, then this freedom is not described by QM. If there is something not described by QM, then QM is not complete. Period.

 

[musicheck]

I think this question has already been answered by the mathematician John Conway's "Free Will Theorem." It states, in his provocative wording, "If experimenters have free will, then so do elementary particles." Given that I personally find it rather odd to give elementary particles such regard, I think the natural thing to do is throw out free will, not QM.

 

[Demystifier]

I agree with you.

 

[ZapperZ]

I think this question has already been answered by the mathematician John Conway's "Free Will Theorem." It states, in his provocative wording, "If experimenters have free will, then so do elementary particles."

But this isn't supported by our physical evidence. Elementary particles can exhibit entanglement and superpositions. Experimenters do not. I know that I can't be in 2 places at once even though I wish many times that I could. So extrapolating the properties of one into the realm of another isn't necessary valid.

That assumption also ignores an important effect - emergent phenomena.

Zz.

 

[Burnsys]

I don't think we have to go to the Quantum level to discuss free will, there are several classic experiments that says we don't have free will, at least we don't have "Conscious free well", if free will exist at the unconscious level, then how much of it is Free?

 

[Demystifier]

But this isn't supported by our physical evidence. Elementary particles can exhibit entanglement and superpositions. Experimenters do not. I know that I can't be in 2 places at once even though I wish many times that I could. So extrapolating the properties of one into the realm of another isn't necessary valid.

That assumption also ignores an important effect - emergent phenomena.

If the theory called QM is correct, than, in principle, you CAN be in a superposition and/or entangled with something else. The problem is that it is difficult to achieve this in practice, due to decoherence (caused by the interaction with the environment).

Emergent phenomena are only apparent (not true) phenomena. For example, classical deterministic chaos appears random, but the true dynamics is deterministic. Similarly, emergent free will would not be true free will.

 

[ZapperZ]

If the theory called QM is correct, than, in principle, you CAN be in a superposition and/or entangled with something else. The problem is that it is difficult to achieve this in practice, due to decoherence (caused by the interaction with the environment).

But we still do not have the evidence that the decoherence causes a smooth "crossover" or a "phase transition" between two very distinct and different worlds - classical and quantum. You go from some system that is classically deterministic to something in which such a thing is not available.

So no, I would put those as two separate system. My point here is that because of such distinct differences, and the fact that we do not have any mechanism and evidence yet that shows a clear connection between the two, then simply extrapolating one into the other isn't a valid exercise.

Emergent phenomena are only apparent (not true) phenomena. For example, classical deterministic chaos appears random, but the true dynamics is deterministic. Similarly, emergent free will would not be true free will.

Whether it is "true" or not, it is still there. Superconductivity is an emergent phenomena, and it is as "true" (Carver Mead would argue it is the "truest" of any physical phenomena) as any. And it certainly would not appear if you simply look at the individual constituents. Again, the point here being that if you simply look at the reductionist viewpoint and think that one can simply extrapolate such a thing via adding level of complexities, then one would still miss phenomena such as superconductivity, because there is no evidence to show that one can derive such a thing based on looking at the individual interactions - just ask the poor students of Bob Laughlin.

Zz.

 

[Demystifier]

B Again, the point here being that if you simply look at the reductionist viewpoint and think that one can simply extrapolate such a thing via adding level of complexities, then one would still miss phenomena such as superconductivity, because there is no evidence to show that one can derive such a thing based on looking at the individual interactions - just ask the poor students of Bob Laughlin.

I think that the example of superconductivity is misleading because it involves unnecessary mystification. To avoid it, let me use a common sense example: a house. You can miss the phenomenon of house if you think only about its constituents - the bricks - as individual objects.
After all, a microscopic theory of superconductivity also exists, doesn't it?

 

[ZapperZ]

I think that the example of superconductivity is misleading because it involves unnecessary mystification. To avoid it, let me use a common sense example: a house. You can miss the phenomenon of house if you think only about its constituents - the bricks - as individual objects.
After all, a microscopic theory of superconductivity also exists, doesn't it?

No. The BCS theory starts with the many-body ground state. That is what Bob Laughlin tried to do (read his Nobel Prize speech) with his graduate student - make them derive superconductivity by looking at it one particle at a time and adding more and more of them. It is just isn't there.

Furthermore, to counter your argument on the "fundamentality" of such a thing, there have been plenty of arguments (certainly from Laughlin, Phil Anderson, and David Pines) that our measurements themselves are emergent. We have to couple things that we are measuring with classical systems involving a gazillion interactions and degrees of freedom. So the world that we know of today is verified via such a process, and thereby, inherently emergent. In fact, if the Higgs is ever discovered, that clearly indicates that mass is an emergent phenomenon!

Similar arguments can be made connecting fractional charges/quantum hall effect in condensed matter with the fractional charges of quarks.

But again, the point I'm trying to make is that just because one set of "rules" work in one scale or one regime, this does not automatically means that it is valid to extrapolate or apply such a rule in another regime. Quantum rules simply makes no sense to be applied at the classical scale, not because of the "size", but because of decoherence and a number of other yet-undiscovered factors. Such non-extrapolation observation can be clearly seen across phase transitions as well, so this isn't just restricted to quantum-classical regimes. One simply can't put on blinders and assumes automatically that one set of rules and behavior is valid everywhere.

It is why when postmodernists tried to apply quantum and relativistic laws into political, economic, and social systems, they all resulted in absurdity.

Zz.

 

[Demystifier]

Well, I must admit that I do not know much about solid state physics, so I cannot respond appropriately. Still, it is hard to me to believe that it is not known how to derive superconductivity by starting from first microscopic principles. Maybe I should ask a question on the solid-state subforum.

 

[ZapperZ]

The only "microscopic" theory of superconductivity that is widely accepted in the BCS theory. You can easily look at its derivation from First Principles from the paper itself and satisfy yourself on its many-body starting point.

Zz.

 

[Quatl]

Free will is a topic with a lot of meat on it and there are many ways I'd like to slice it up. However I'll try to restrict this to aspects that are more relevant to this post.

There is a philosophical definition of truth which I've often heard scientists use that I think applies here. Usually the way it is stated is different but my phrasing is that "A proposition contains truth within a given context, to the extent that it is useful." I've often heard that a given theory or hypothesis is "good" because it makes useful predictions for example. There are many ideas that have been "true" in this sense historicaly, that have later been pushed aside to one degree or another when a "better" theory came along.

For example Newtonian gravity was "replaced" by relativity. Einstein's version is considered to be more useful, and thus more true or accurate. The same flow is apparent in the historical progression that led to QM. Is QM "complete"? It's difficult to say (my personal hope is that it is but then I'd like a million dollars too and I'm not willing to go through the work required to get that either.) What is not really debatable is that QM is useful.

However, trying to predict the outcome of human behavior with either classical or quantum mechanics isn't going to get you very far. This doesn't imply that the mind is non-physical per say, but rather that mechanics isn't the most useful set of principles to use in that realm.

I feel that Free will is a useful "truth", in that it apears to explain human behavior more accuratly than other concepts.

However free will is certainly not facilitated by randomness (I think the QM -> FW crowd is inserting a soul into the cracks without realizing it) Free will implies that a person makes decisions based on rules, and evidence. In this sense Free will is a deterministic theory anyway.

Consider that a perfect intellect with access to perfect information will always make the same decision in the same circumstance. This does not imply that the entity has no choice, rather it is the result of making a "good" decision. While free will implies that the entity could make another choice, the less "good" choice wouldn't make sense. That is that one could decide to light themselves on fire just to prove that they can make such a choice.

This also implies that a perfect Free Entity will behave (to the extent that it is able and interested) in a predictable fashion more or less. However humans while they may have free will, do not have perfect knowledge. Still most human behavior ends up withen fairly narow bounds. For a given situation, most folks will behave in one of a finite set of ways.

It is I think in principle sensible to say that one could develop a theory that would statistically predict the outcome of a human interaction, if the initial conditions were known in detail. Such a theory would not be able to predict a specific person's response however as the Human's internal processes are hidden from us. Rather you could say something like "a given human in situation X has a probability distribution of Y"

I think it's interesting that QM has exactly the same problem ;) And for basically the same reason.