Arguments Against Superdeterminism [Archive]

ueit

Aug1-09, 10:53 AM

I think Superdeterminism invites the "Supernatural". There is similar talk in the philosophy forum, so i'll copy-paste what i stated there:

"A purely deterministic "mind" as a determinite consequence of a brain in a determinite universe requires the Supernatural. If we do not have free will, who willfully created my celluar phone, if it was not the will of the engineers at Nokia? Whose will was that? Who created the LHC collider and the beer i've just opened? How could any of those things exist if "we" did not willfully created them? Who did?"

What is the difference between a cell phone and a rock at a fundamental level? There are the same type of particles following the same physical laws. The question "Who created the LHC collider...", and all other, are loaded, they presuppose the necessity of an entity with free will. My answer is that, all objects (including a cell phone and a rock) appear in the same way, through interactions between the same type of particles following the same physical laws. I have seen no evidence for the contrary. If you know of such evidence I'd like to see it.

A difference only exists at the macroscopic level because some objects have significance for us. To make an analogy, do you think there is any fundamental difference between a group of stars resembling a lion or a fish and any other random group of stars?

What is supernatural about a cell phone?

WaveJumper

Aug1-09, 11:51 AM

What is the difference between a cell phone and a rock at a fundamental level? There are the same type of particles following the same physical laws. The question "Who created the LHC collider...", and all other, are loaded, they presuppose the necessity of an entity with free will. My answer is that, all objects (including a cell phone and a rock) appear in the same way, through interactions between the same type of particles following the same physical laws. I have seen no evidence for the contrary. If you know of such evidence I'd like to see it. A difference only exists at the macroscopic level because some objects have significance for us.

Thought provoking theory, really. True but incomplete IMO. It does not even begin to address the reason for the illusory existence of a classical world(even if it makes sense only to us). And why is there the illusion of "us", superdeterminism cannot explain this and neither can QM. A purely quantum picture of the universe cannot explain everything that we've found to exist, because a large ensemble of particles do not always behave in the same way as the individual ones that comprise them. Hence a TOE is supposed to account for both the quantum and the classical level of bahaviour.

To make an analogy, do you think there is any fundamental difference between a group of stars resembling a lion or a fish and any other random group of stars?

Yes of course. If the group that resembles the lion begins to collectively behave like a Lion and starts hunting for zebras made up of other stars(i.e. the atoms of the stars that are considered to be a lion move intentionally all the way to the atoms that comprise zebras).
The classical level exists even if it's just a shadow and it needs an explanation. Without free-will this explanation screams "Supernatural".

What is supernatural about a cell phone?

The idea of a cell phone in a superdeterministic universe with no free will or some form of higher intelligence is mind-bending.

ueit

Aug1-09, 01:58 PM

Thought provoking theory, really. True but incomplete IMO. It does not even begin to address the reason for the illusory existence of a classical world(even if it makes sense only to us). And why is there the illusion of "us", superdeterminism cannot explain this and neither can QM.

I see no evidence that the human brain does not obey QM. IMHO there is only a computational problem. I doubt that QM is even required as I don't buy Penrose's theory about microtubules. AFAIK the brain is fully into the classical regime. What is your evidence that the brain somehow eludes QM? Also, this is not an argument against SD as SD is supposed to explain why QM works as it does.

A purely quantum picture of the universe cannot explain everything that we've found to exist, because a large ensemble of particles do not always behave in the same way as the individual ones that comprise them.

Of course, the behaviour of a composite object is different from the behaviour of its parts. However, in theory you can calculate the evolution of a complex object if you know its constituents. It is a computational problem.

Hence a TOE is supposed to account for both the quantum and the classical level of bahaviour.

Sure, as long as the computational power permits it.

Yes of course. If the group that resembles the lion begins to collectively behave like a Lion and starts hunting for zebras made up of other stars(i.e. the atoms of the stars that are considered to be a lion move intentionally all the way to the atoms that comprise zebras).

Well, this is another type of lion. One that doesn't hunt.:biggrin:

The classical level exists even if it's just a shadow and it needs an explanation. Without free-will this explanation screams "Supernatural".

I failed to see how the classical world requires "free-will" in order to be explained. Again do you have some evidence for this assertion? To be a little constructive, animals are genetically programmed to react in certain ways. You do not need "free-will" to explain their behaviour.

The idea of a cell phone in a superdeterministic universe with no free will or some form of higher intelligence is mind-bending.

Sorry, but this is not an argument at all.

WaveJumper

Aug1-09, 04:10 PM

I failed to see how the classical world requires "free-will" in order to be explained.

I am putting great efforts into seeing the world as you see it and my head is spinning. What is "we" in this "universe" of yours? Your theory does not answer the question - if everything is an illusion, what causes it? Or is the existence of illusion also an illusion? I assume you see the classical world as a movie embedded in dumb quantum fields, where fields interact to produce the illusion of self. If this is so, what makes us try and explain this weird reality(why would a robot try and explain itself if it didn't have free will or wasn't programmed to do so?

Again do you have some evidence for this assertion? To be a little constructive, animals are genetically programmed to react in certain ways.

Yes, right!!! Genetically programmed is the right term for your vision of the universe. If there is no randomness, even the theory of evolution must abandon the idea of random mutations. If they are not random, i think you know where that leads...

You do not need "free-will" to explain their behaviour.

Why are we explaining anything in a superdeterministic universe at all? Was the Big Bang preprogrammed so that our shadow classical reality would appear out of quantum fields interactions, where we would have the illusion of asking questions about our illusiory existence? How is this supposed to work without a creator? Simply put, what causes the appearance of existence of cell phones in superdeterministic universes? What could explain our personal subjective experience of reality? Some event in the past? What is this event?

How do you explain the fact that you don't have free will, yet you've come to realise that you never had free will? Was this event(the realisation) pre-programmmed?

ThomasT

Aug1-09, 05:33 PM

In the context of Bell's Theorem, a superdeterministic theory would negate the statistical independence between the source generating the entangled particles and the detectors.
It's not clear to me what you mean by this.

Considering a simple optical Bell setup (emitter, two polarizing filters, and two photon detectors), I assume that you mean "the source generating the entangled particles" to refer to the polarizers.

There's a predictable relationship between joint polarizer settings and joint detection rates -- and the pairing process produces statistical dependence between the sets of separately accumulated detection attributes.

What statistical independence are you referring to?

... superdeterminism (SD) is seldom even mentioned as a possibility and usually dismissed. I would like to see a clear statement of the arguments against SD and see how founded they are.As far as I can tell, the term, superdeterminism, is semantically equivalent to the term, determinism.

All of physical science, whether one is searching for dynamical rules/laws specific to an emergent regime/scale or fundamental to and pervading everything, is based on the assumption of determinism.

Unfortunately, by itself, it doesn't explain anything.

Or am I completely missing your point?

What might superdeterminism, or absolute determinism, etc. refer to that determinism doesn't already refer to?

DrChinese

Aug1-09, 09:18 PM

In the context of Bell's Theorem, a superdeterministic theory would negate the statistical independence between the source generating the entangled particles and the detectors. IMHO there is nothing absurd about this. There are plenty of examples in physics where the motion of two distant objects presents correlations (this includes all objects that are accompanied by long-range fields).

Nevertheless, superdeterminism (SD) is seldom even mentioned as a possibility and usually dismissed. I would like to see a clear statement of the arguments against SD and see how founded they are.

SD is not science anymore than belief in God is.

Unless of course you postulate a specific theory which shows how different forces - let's say the weak and the electromagnetic - have heretofor unknown connections. Let's say we use radioactive decay to make the decision to set polarizar settings in a Bell test in which the detectors are separated (sufficiently that they are outside of each other's light cones). The superdeterministic theory will require that the decay be coordinated so that the results can be properly correlated per Malus. That's a tall order! Ditto for any possible selection mechanism. You need all experimental apparati - regardless of setup - to conspire.

So where is the science here?

ThomasT

Aug2-09, 12:01 AM

John Bell on the BBC:

There is a way to escape the inference of superluminal speeds and spooky action at a distance. But it (Superdeterminism) involves absolute determinism in the universe, the complete absence of free will. Suppose the world is super-deterministic, with not just inanimate nature running on behind-the-scenes clockwork, but with our behavior, including our belief that we are free to choose to do one experiment rather than another, absolutely predetermined, including the "decision" by the experimenter to carry out one set of measurements rather than another, the difficulty disappears. There is no need for a faster than light signal to tell particle A what measurement has been carried out on particle B, because the universe, including particle A, already "knows" what that measurement, and its outcome, will be.

The only alternative to quantum probabilities, superpositions of states, collapse of the wave function, and spooky action at a distance, is that everything is superdetermined. For me it is a dilemma. I think it is a deep dilemma, and the resolution of it will not be trivial; it will require a substantial change in the way we look at things.

From this I think it's clear that superdeterminism, absolute determinism, universal determinism and determinism are synonymous.

How does the assumption of determinism, which underlies physical science anyway, obviate the assumption of nonlocality?

How is determinism an alternative to quantum probability, quantum superposition, and quantum state vector reduction?

Descartz2000

Aug3-09, 01:16 AM

I think if Superdeterminism could possibly be a loophole, I think it should be looked at more closely, if only as a way around FTL communication. In certain respects it makes sense: why should the experimenter (or any human for that matter) be free or separate from which he/her came. I mean don't we develop and make our way in the world through our biology, genetic make-up, physiology, bio-physics, evolution of brain, etc... If true, then it seems our behavior is a result of all of these variables as well. Where exactly does the human brain separate itself from all of these factors, and become "free" to conduct whatever set up he chooses in experiments. Some of the Eastern religions take on this Superdeterminism approach to understanding the world. If nothing else, it should at least be considered and discussed.

Fra

Aug3-09, 02:17 AM

ueit

Aug3-09, 02:26 AM

I am putting great efforts into seeing the world as you see it and my head is spinning. What is "we" in this "universe" of yours?

We are large groups of (mainly) quarks and electrons.

Your theory does not answer the question - if everything is an illusion, what causes it? Or is the existence of illusion also an illusion? I assume you see the classical world as a movie embedded in dumb quantum fields, where fields interact to produce the illusion of self. If this is so, what makes us try and explain this weird reality(why would a robot try and explain itself if it didn't have free will or wasn't programmed to do so?

I didn't say that "everything is an illusion". How exactly our brain works is not a QM question. On the other hand I have seen no evidence that the brain should deserve a different treatment than any other object.

We try to explain the world around us because we are genetically programmed to do so (it enhances survival).

Yes, right!!! Genetically programmed is the right term for your vision of the universe. If there is no randomness, even the theory of evolution must abandon the idea of random mutations. If they are not random, i think you know where that leads...

Evolution does not require that mutations are fundamentally random (unpredictable in principle). The term "random mutation" refers to our lack of knowledge regarding the exact conditions at the time that mutation occurred. So there is no conflict between a deterministic universe and evolution.

Why are we explaining anything in a superdeterministic universe at all? Was the Big Bang preprogrammed so that our shadow classical reality would appear out of quantum fields interactions, where we would have the illusion of asking questions about our illusiory existence? How is this supposed to work without a creator? Simply put, what causes the appearance of existence of cell phones in superdeterministic universes? What could explain our personal subjective experience of reality? Some event in the past? What is this event?

Those questions can be also put in a probabilistic universe. The fact that some quantum events might be unpredictable do not explain any of your above questions therefore I think they have no relevance to our topic. Give me a good account of how "our personal subjective experience of reality" appears in a universe that is not superedetrministic.

How do you explain the fact that you don't have free will, yet you've come to realise that you never had free will? Was this event(the realisation) pre-programmmed?

The existent evidence pointed me into that direction. I don't think it was "pre-programmed". It could be predicted by someone with infinite knowledge but this is different.

ueit

Aug3-09, 02:54 AM

It's not clear to me what you mean by this.

Considering a simple optical Bell setup (emitter, two polarizing filters, and two photon detectors), I assume that you mean "the source generating the entangled particles" to refer to the polarizers.

No, I refer to the emitter (PDC crystal for example). Bell's theorem requires that the properties of the entangled particles (say spin) do not depend on the state of the detectors. A superdeterministic theory would deny this. As an example, assume that the emission is "stimulated" by a field coming from the detectors and the spin of the entangled particles is related to the value of this field. But because the evolution is deterministic, this field uniquely determines the future state of the detectors, therefore the spin of the entangled particles and the detector settings at the time of detection are not independent variables.

As far as I can tell, the term, superdeterminism, is semantically equivalent to the term, determinism.

I agree. I use the term (invented by Bell, I think) in order to point out that a separation between the system and observer is not possible. Such a separation might be possible in certain deterministic theories.

All of physical science, whether one is searching for dynamical rules/laws specific to an emergent regime/scale or fundamental to and pervading everything, is based on the assumption of determinism.

I also agree.

Unfortunately, by itself, it doesn't explain anything.

Or am I completely missing your point?

It can explain a lot of things. Correlations that are supposed to appear as a result of non-local effects can be explained by a past common cause + deterministic evolution. A probabilistic theory wouldn't allow for that.

What might superdeterminism, or absolute determinism, etc. refer to that determinism doesn't already refer to?

See above.

ueit

Aug3-09, 03:09 AM

SD is not science anymore than belief in God is.

Unless of course you postulate a specific theory which shows how different forces - let's say the weak and the electromagnetic - have heretofor unknown connections. Let's say we use radioactive decay to make the decision to set polarizar settings in a Bell test in which the detectors are separated (sufficiently that they are outside of each other's light cones). The superdeterministic theory will require that the decay be coordinated so that the results can be properly correlated per Malus. That's a tall order! Ditto for any possible selection mechanism. You need all experimental apparati - regardless of setup - to conspire.

So where is the science here?

The separation of the weak and electromagnetic forces is AFAIK not believed to be fundamental anymore. A Nobel price has been given for contribution to the unification of the two forces (see the Wiki article for "Electroweak interaction"). So your comments are about 30 years outdated. If you agree that string theory is science (not a belief in a god) then you would also agree that, at a fundamental level all known physics is based on a single object, a string, and a unique set of laws. Seen from this perspective there is realy not much of a difference between different types of experimental setups (computer random generators, brains, radioactive decay, etc). If the time evolution of a string is deterministic then all known objects have a predictable behavior as well, regardless of their macroscopic appearance.

About the "conspiracy" accusations you should also claim that the energy conservation principle is not scientiffic because it applies to all systems (involving any known forces or mixtures of them).

ueit

Aug3-09, 03:21 AM

To me, the question is not wether I can 100% disproove determinism or superdeterminism - I can't, the question is what predictive advantages does it give us?

As I see it, the determinism attemps are more motivated by secret desires to restore more realism. But I do not see any motivation for this from the point of view of scientific inquiry.

Deterministic hidden variable theories are a class of theories that has not been explored. They might lead to a better understanding of QM, possibly to new experimental predictions.

I only see disadvantages since it's encourages to a particular realistic type of reasoning, that I personally find inhibiting. /Fredrik

I think the science as we know it exists because of this "inhibiting type of reasoning". I see no disadvantage in restoring a well mathematical defined, deterministic and local theory at a fundamental level.

Fra

Aug3-09, 04:41 AM

If you have the motivation to explore that, I see no good reason why you shouldn't of course. But to me, searching for deterministic and realist type theories isn't consistent with my own view of the serching process which isn't deductive, but I am open for changing my mind whenever convincing evidence is at hand, like always.

/Fredrik

Demystifier

Aug3-09, 05:59 AM

Either
a) humans do not have free will, or
b) humans are not completely described by the known (either classical or quantum) physical laws.
Period.

Personally, I vote for physical laws.

Fra

Aug3-09, 07:00 AM

I don't quite see a clean connection between the question of free will of humans and the structure of physical law.

My only opinions is that a human is just as much a physical system as is an atom. The difference is the complexity, there is no divine distinction anywhere.

What does it even mean from the point of view of measurement, wether object A has "free will"?

The only sensible interpretaiton I can come up with is that free refers to "not constrained by the knowledge of the observer". In that case, free will seems to be related to unpredictability of the outside, as in "freedom of action", or "unpredictable action".

If that's not what's mean, then what does it mean?

I think we need a measure, or interaction scheme, from which to infere with some degree of certainty that object A has free will or not, otherwise it seems to be mainly some philosophy of mind, rather than philosophy of science or physics.

/Fredrik

Demystifier

Aug3-09, 08:44 AM

What does it even mean from the point of view of measurement, wether object A has "free will"?

The only sensible interpretaiton I can come up with is that free refers to "not constrained by the knowledge of the observer". In that case, free will seems to be related to unpredictability of the outside, as in "freedom of action", or "unpredictable action".

By your definition, free will is not an objective property of an object, because it is defined by knowledge of some observer. Two observers may disagree on whether object A has or has not free will. But in my language, only an objective property is a property. For example, beauty of an object is not a property of an object. So, with your definition of free will, the free will does not exist, just as beauty does not exist.

I know, you will say that not only beauty and free will are subjective, but that EVERYTHING is subjective. Well, as you know, I do not agree with such a radical attitude. Nevertheless, if I would accept that everything is subjective (which indeed might be the case), then, in my language, nothing exists (except me, which brings us to the Descartes "Cogito ergo sum", but that's not science any more).

DrChinese

Aug3-09, 08:49 AM

The separation of the weak and electromagnetic forces is AFAIK not believed to be fundamental anymore. A Nobel price has been given for contribution to the unification of the two forces (see the Wiki article for "Electroweak interaction"). So your comments are about 30 years outdated.

Absurd, this is 100% backwards. Precisely because of what we know about these forces, the kind of SD you describe is RULED OUT. They don't conspire to support Bell test results.

Fra

Aug3-09, 09:02 AM

I know, you will say that not only beauty and free will are subjective, but that EVERYTHING is subjective. Well, as you know, I do not agree with such a radical attitude.

You predicted my response quite well :biggrin: Yes I know you don't agree. I'm still fascinated by theyour apparently solid view.

Nevertheless, if I would accept that everything is subjective (which indeed might be the case), then, in my language, nothing exists (except me, which brings us to the Descartes "Cogito ergo sum", but that's not science any more).

To me the fact that "everything is subjective", does not mean that I think everything is arbitrary or out of control, far from it. To me there is only a difference of degrees of subjectivity. Objectivity is when alot of subjects are tuned and then there is an effective objectivity. This is what is the case with the laws of physics for example as we currently know them. Objectivity is emergent as subjective views interact, what takes place is a kind of negotiation. My quest, is to understand and describe the process which has produced the remarkable stability without any reference to external realist type objectivity.

I probably mentioned before but I think our disagreements trace all the way down to our view of science as well.

The fact that there is no deductive description of the scientific method, doesn't mean that there is no sufficiently good inductive type of inference.

/Fredrik

ueit

Aug3-09, 10:34 AM

Absurd, this is 100% backwards. Precisely because of what we know about these forces, the kind of SD you describe is RULED OUT.

This is pure circular reasoning. We do not know what mechanism, if any, stays at the basis of quantum interactions (be it EM, weak or strong). This is what we are debating, remember? By the same reasoning you would say that BM must be rejected because the current description of the weak and EM fields does not include a non-local force.

If you accept, for the sake of the argument, that radioactive decay is a deterministic process then it must be related to the particle configuration of the nucleus. But the configuration of the nucleus is a configuration of charged particles (quarks) and this configuration is in principle predictable.

They don't conspire to support Bell test results.

Prove it!

Demystifier

Aug3-09, 10:52 AM

. Objectivity is when alot of subjects are tuned and then there is an effective objectivity. This is what is the case with the laws of physics for example as we currently know them. Objectivity is emergent as subjective views interact, what takes place is a kind of negotiation.

This corresponds to my option b), because it means that current physical laws are not completely correct, but only to "some degree".

I probably mentioned before but I think our disagreements trace all the way down to our view of science as well.

Yes, that's true.

Doc Al

Aug3-09, 10:54 AM

Prove it!
Right back at you! Your entire argument seems to be that "it's possible" that the configuration of things at the Big Bang were arranged so that the seemingly "free" choice of polarizer settings in a Bell experiment are somehow pre-arranged (despite efforts to "randomize" them) just to preserve the expected correlations. While I certainly don't believe that the choice of polarizer settings for Alice and Bob are "free" in any ultimate (contra-causal) sense, until you produce a real physical explanation as to why those choices are not at least proximately "free" (and thus statistically independent), the claim is rather empty.

Fra

Aug3-09, 11:10 AM

This corresponds to my option b), because it means that current physical laws are not completely correct, but only to "some degree".

Yes you might put it like that. I partially might buy option b - the the difference is that I don't what is has to do with free will or no free will. I argee to some of your standpoints and criticts on QM, but for completely different reasons I think.

When you say the laws aren't correct, I think you imply that there are some other laws that ARE exactly correct, in some objective way - right?

I do not think that. The phrase incorrect is not what I would use, I would just say that we have inferred the laws we have for a good reason, but this inference process is still ongoing and so the laws are still evolving and this process is not predictable to me, all we can do is "play the game".

I try to study the evolving rules of this game. Even IF there was some objective laws like you think, we don't get around the at hand problem is howto FIND those laws, is still a GAME. It's the game of science, and what is the structure of that game? In particular how do we describe the origin of hypothesis withing Poppers scheme? Popper ignored this.

From my point of view, your standpoint is like a vision of a scientific result, but without similarly scientific strategy on howto get there. This is how I see realist structures - it's some specific set of information - that is introduced without prior inference process. It sometimes bysteps the critical reasoning.

Well I'm probaly as stubbron in my radical solipsism as you are with deterministic realism :wink:

/Fredrik

Tac-Tics

Aug3-09, 12:32 PM

Doesn't this belong on the philosophy board?

Free will is a total cop out. Randomness is useful, but it's still a cop out. The true interpretation of QM is almost certainly beyond the limits of science to deduce.

Count Iblis

Aug3-09, 12:43 PM

Right back at you! Your entire argument seems to be that "it's possible" that the configuration of things at the Big Bang were arranged so that the seemingly "free" choice of polarizer settings in a Bell experiment are somehow pre-arranged (despite efforts to "randomize" them) just to preserve the expected correlations. While I certainly don't believe that the choice of polarizer settings for Alice and Bob are "free" in any ultimate (contra-causal) sense, until you produce a real physical explanation as to why those choices are not at least proximately "free" (and thus statistically independent), the claim is rather empty.

The correlations themselves are not a problem. It is the way the correlations depends on some "free parameters", like the settings of the polarizers that seems to imply a contradiction with local deterministic theories.

It is not clear to me why these violations of Bell's inequality cannot also be interpreted to imply that no counterfactual choice of one of the polarizers exists that would not affect the outcome of the measurement at the other polarizer, despite the theory being locally deterministic. A present state in which the setting of a polarizer is different would, under inverse time evolution, have to evolve back to some other low entropy initial state of the universe.

This means that there are always nonlocal correlations in the present state, as the present state has a far larger entropy than the initial state (assuming that there is a one to one mapping from the set of initial states to the set of present states). Choosing a different present macrostate is then no problem, but choosing a different present microstate that one could specify by taking the original microstate and then specify only a few changes (a few bits of information), looks impossible to me.

DrChinese

Aug3-09, 01:16 PM

This is pure circular reasoning. We do not know what mechanism, if any, stays at the basis of quantum interactions (be it EM, weak or strong). This is what we are debating, remember? By the same reasoning you would say that BM must be rejected because the current description of the weak and EM fields does not include a non-local force.

If you accept, for the sake of the argument, that radioactive decay is a deterministic process then it must be related to the particle configuration of the nucleus. But the configuration of the nucleus is a configuration of charged particles (quarks) and this configuration is in principle predictable.

You are arguing both sides of the same argument! Either a) electroweak theory is accurate, and there is no room for SD in it currently; or b) SD is completely outside our current Physics.

I pointed out that a) contradicts your hypothesis. So clearly SD is outside of what we know. That makes it 100% as speculative as the existence of God, so where is the science in any of this?

Yes, we all know that every physical theory we currently have - relativity, QM, evolution, the big bang, etc. could be a giant SD illusion intended to trick us all into believing we know something about the universe around us. And this is similar to those who say God created the Earth 4000 years ago and placed the fossil record there - and so that evidence should be disregarded.

Well, I and most others will not so easily ignore the repeatable evidence that local realism (of which you are a proponent) must be dropped per Bell's Theorem. It is clear to me that if you can get someone to agree in SD, then you can also get that person to also agree that Bell is wrong. But SD is not science and Bell is.

compton

Aug3-09, 04:56 PM

I don't quite see a clean connection between the question of free will of humans and the structure of physical law.

In order to believe that physical determinism poses a threat to free will, you also have to believe that laws of nature are equivalent to inviolable prescriptions. Although proponents of such a view may not consciously believe in a Prescriber, they still persevere with the view that laws of nature 'are' prescriptions.

However, if one adopts a view that natural laws are descriptive, the problem of free will disappears. In this view, all the choices made by concious beings are not forced upon them by the laws of nature. Rather, Indeed, it is the reverse. The laws of nature are the true descriptions of the world. For example, although it is true that you cannot 'violate' a law of nature, it is not because laws of nature 'force' you to behave as such, but because the laws are true descriptions of what we do or have done.

The truthfulness of a propositions is determined by nature. The reverse is not true and amounts to the modal fallacy of reasoning.

On the other hand, it is not possible to toss out determinism and still maintain a consistent concept of physical law whether your view is descriptive or prescriptive.

ThomasT

Aug4-09, 01:18 AM

It can explain a lot of things. Correlations that are supposed to appear as a result of non-local effects can be explained by a past common cause + deterministic evolution. A probabilistic theory wouldn't allow for that.There's no compelling reason to assume nonlocality. It remains a possibility. That's all.

The mere assumption of determinism doesn't tell us how things are happening, and it doesn't obviate probabilistic theories.

Deterministic hidden variable theories are a class of theories that has not been explored. They might lead to a better understanding of QM, possibly to new experimental predictions.They've been, and are still being, explored. Together, lhv and nlhv theories constitute the entire class of deterministic hidden variable theories. Lhv models of entangled states are ruled out, but for reasons that don't imply anything about the underlying reality. Nlhv models of entangled states are allowed, but there are good reasons to believe that they don't actually describe reality. And, afaik, neither of these has revealed anything about standard qm that wasn't already apparent from standard qm.

denisv

Aug4-09, 01:46 AM

In order to believe that physical determinism poses a threat to free will, you also have to believe that laws of nature are equivalent to inviolable prescriptions. Although proponents of such a view may not consciously believe in a Prescriber, they still persevere with the view that laws of nature 'are' prescriptions.

However, if one adopts a view that natural laws are descriptive, the problem of free will disappears. In this view, all the choices made by concious beings are not forced upon them by the laws of nature. Rather, Indeed, it is the reverse. The laws of nature are the true descriptions of the world. For example, although it is true that you cannot 'violate' a law of nature, it is not because laws of nature 'force' you to behave as such, but because the laws are true descriptions of what we do or have done.
So, inviolable prescriptions vs. inviolable descriptions, the objective difference being...?

Fra

Aug4-09, 02:45 AM

So, inviolable prescriptions vs. inviolable descriptions, the objective difference being...?

I didn't get comptons point either.

Here is another personal view of this.

IMHO, the whole motivation for physical law is neither invioable prescriptions nor inv. descriptions. It's used in predictive strategies, inferred from nature by evolutionary processes. The utility of a rule to infere the future from the current, is justified with a context where sometime depends on this rule, and there can be variation and selection.

Thus the justification of any rule of inference, is that it does in fact exists in nature since this rule has a self-preserving trait. This doesn't mean that bad inferences are banned, it's just that they not like make it through the competition.

So my view of physical law, is that it is a rule for helping inference of the future, given the present, and thus rule has been formed in the past. It is manifested in the microstructure of matter around us. The laws of physics are IMHO mplicit in the makeup of matter. Thus, the microstructure and interaction properties of matter ENCODE physically, a view of law. If you consider this matter indefinitely stable in all ways, then so ar the laws. But if the evolving material content is not in equilibrium, then the encoded laws are still evolving IMO.

Thus to me, a law is effectively a state, but due to information capacity constraints, there is no embedding state space. So we can not apply ordinary statistics to these states. Only a evolving logic like in biology would work.

The information capacity constraint, is the exploit I imagine to turn this into predctions. If you ponder how possibly encodable distinguishable laws scale with the complexit of matter, then the _observable_ (ie. inferrable) laws of physics are bound to get simpler (ie. unification).

That might provide a somewhat unique starting point, and then see how new laws emerge as the "symmetry" if we call it that is broken by the observers growing larger and larger.

/Fredrik

WaveJumper

Aug4-09, 03:33 AM

We are large groups of (mainly) quarks and electrons.

No, that's a rather narrow and misleading view. Life is an emergent property of quarks and electrons. There is very Big difference between a dead person and an alive person, though they are made up of the same quarks and electrons.

I didn't say that "everything is an illusion".

Without free-will, everything is an illusion.

How exactly our brain works is not a QM question. On the other hand I have seen no evidence that the brain should deserve a different treatment than any other object.

Why didn't you say consciousness instead of brain? Brain is not consciousness, though they are obviously related.

We try to explain the world around us because we are genetically programmed to do so (it enhances survival).

This explanation, along with all explanations of anything are completely senseless in a superdeterministic universe.

Evolution does not require that mutations are fundamentally random (unpredictable in principle). The term "random mutation" refers to our lack of knowledge regarding the exact conditions at the time that mutation occurred. So there is no conflict between a deterministic universe and evolution.

True, but if you posit that everything is a consequence of a pre-determined configuration of exteremely low entropy at the Big Bang, it raises more questions than it answers.

Those questions can be also put in a probabilistic universe. The fact that some quantum events might be unpredictable do not explain any of your above questions therefore I think they have no relevance to our topic. Give me a good account of how "our personal subjective experience of reality" appears in a universe that is not superedetrministic.

How about "Free will(and Life) is an emergent property in our universe, because there are infinite number of universes".

The existent evidence pointed me into that direction. I don't think it was "pre-programmed". It could be predicted by someone with infinite knowledge but this is different.

I think your idea is radical(that's generelly a good thing when applied to reality), but it degrades science, understanding, knowledge and logic and as such is absurd. If free will is an illusion, how is your theory not another illusion/delusion?

Demystifier

Aug4-09, 04:07 AM

Well I'm probaly as stubbron in my radical solipsism as you are with deterministic realism :wink:

Well, I wouldn't call myself stubborn, but yes, that is my preferred viewpoint, especially the realism. :wink:

ueit

Aug4-09, 07:05 AM

Right back at you! Your entire argument seems to be that "it's possible" that the configuration of things at the Big Bang were arranged so that the seemingly "free" choice of polarizer settings in a Bell experiment are somehow pre-arranged (despite efforts to "randomize" them) just to preserve the expected correlations. While I certainly don't believe that the choice of polarizer settings for Alice and Bob are "free" in any ultimate (contra-causal) sense, until you produce a real physical explanation as to why those choices are not at least proximately "free" (and thus statistically independent), the claim is rather empty.

The way a SD theory might explain entanglement has nothing to do with a specific configuration at the Big-Bang. The correlations are not a result of fine-tuning of the original conditions but a result of source-detector interaction. The mechanism is as follows:

1. The detector is described by some particle configuration (it doesn't matter what, no conspirational fine-tuning required).
2. Each particle has an associated classical-like local field. This field is not one of the known fields (EM, weak, etc.) but those fields are assumed to arise as an effective description of the assumed fundamental field. This field has also infinite range so that it can communicate the particle configuration anywhere, at light speed.
3. A particle is only emitted when the detectors' field has a certain, "favorable", value, corresponding to a certain detector configuration.
4. The properties of the emitted particle is a function of the above field.

The result of the above proposed mechanism, both the properties of the emitted particle (spin for example), and the future detector configuration depend on the detector's configuration in the past, therefore they cannot be assumed to be statistical independent, hence the possible violation of Bell's inequalities by a local theory.

octelcogopod

Aug4-09, 07:32 AM

The only problem I can see that could argue against superdeterminism is consciousness.
If we were talking about anything else in the world I would have no problem believing that they were all things controlled by the quantum forces.
I do however see a gap between quarks and electrons, and qualia.
So far there has been no way to bridge the mental with the physical, and if you think about it, it becomes increasingly harder to do so.
This is not a question about free will (although it's related) but rather how the subjective conscious states can emerge from physical matter and energy.
You can measure and scrutinize the brain all you want, but never are you able to capture the actual subjective experience.
And the only way to do so seems to be to translate neuron relations into known subjective states, if we were able to know every possible neuron configuration. But even in that scenario the magical property of the consciousness is gone.

Consciousness is not just a property of the brain, it is a property of the senses, and the environment around those senses perceive.
But if superdeterminism was true, we should be able to pick up this experience directly in the brain, because the brain would have to be the carrier of all such information.
There's also the free will question of course. If superdeterminism is true, how can we make a choice? No matter on what level the choice is, I can choose to pick up the apple or not, so that would mean deterministic events would control all my emotions and thoughts, but how could I be aware then? Am I really aware?

ueit

Aug4-09, 07:33 AM

You are arguing both sides of the same argument! Either a) electroweak theory is accurate, and there is no room for SD in it currently; or b) SD is completely outside our current Physics.

I pointed out that a) contradicts your hypothesis. So clearly SD is outside of what we know. That makes it 100% as speculative as the existence of God, so where is the science in any of this?

1. Please substantiate your first statement (a). Where exactly did you provide evidence for your assertion that electroweak theory is incompatible with SD ?

DrChinese

Aug4-09, 02:58 PM

1. Please substantiate your first statement (a). Where exactly did you provide evidence for your assertion that electroweak theory is incompatible with SD ?

Read any of the Weinberg/Salaam work and follow-on work, and you will see that there is no mention of a superdeterministic mechanism. Yet there would need to be for there to be a violation of Bell Inequalities when the angle setting is determined by radioactive decay (i.e. randomly as far as we know). The mechanism you propose (which is not really a specific proposal at all) requires that either the electromagnetic properties are "right" for emission, which requires that the source knows the detector settings in advance. But they won't be selected until AFTER the photon pair is in flight.

I really must point out that anyone can postulate a non-falsifiable hypothesis (which is completely useless in all respects) regarding any existing physical theory. Hey, maybe oranges are really tiny solar systems but they simply act like edible fruit due to superdeterminism!

Why don't you own up to the true purpose of your question, which I believe is to find a back-handed way to keep local realism in play? If you were serious about superdeterminism per se, you would start by looking for evidence IN FAVOR of SD (of course there is none currently) rather than asking for evidence AGAINST (as you have done).

Doc Al

Aug4-09, 04:01 PM

The way a SD theory might explain entanglement has nothing to do with a specific configuration at the Big-Bang. The correlations are not a result of fine-tuning of the original conditions but a result of source-detector interaction. The mechanism is as follows:

1. The detector is described by some particle configuration (it doesn't matter what, no conspirational fine-tuning required).
2. Each particle has an associated classical-like local field. This field is not one of the known fields (EM, weak, etc.) but those fields are assumed to arise as an effective description of the assumed fundamental field. This field has also infinite range so that it can communicate the particle configuration anywhere, at light speed.
3. A particle is only emitted when the detectors' field has a certain, "favorable", value, corresponding to a certain detector configuration.
4. The properties of the emitted particle is a function of the above field.

The result of the above proposed mechanism, both the properties of the emitted particle (spin for example), and the future detector configuration depend on the detector's configuration in the past, therefore they cannot be assumed to be statistical independent, hence the possible violation of Bell's inequalities by a local theory.
(1) I see no justification in your model for your statement that future detector positions depend on past detector positions. I don't see anything in your model that prevents detector positions from being chosen "randomly", determined perhaps by the polarization of some cosmic microwave background photon.

(2) If I understand your model properly, it satisfies Bell's locality conditions and thus cannot agree with experiment in all situations. Even if the "field" from the detector communicates with and influences the emission of the particles, the actual detector positions can be randomly chosen at the very last instant (as in double delayed choice experiments) just before the already-emitted particles reach the detectors.

ThomasT

Aug4-09, 05:49 PM

The way a SD theory might explain entanglement has nothing to do with a specific configuration at the Big-Bang. The correlations are not a result of fine-tuning of the original conditions but a result of source-detector interaction.The correlation is between the angular difference of the crossed polarizers and the rate of joint detection. The detectors placed after the polarizers are always both set the same. The polarizer settings are varied. So, I assume that by detector you mean polarizer.

Keeping that in mind:

The mechanism is as follows:

1. The detector is described by some particle configuration (it doesn't matter what, no conspirational fine-tuning required).
2. Each particle has an associated classical-like local field. This field is not one of the known fields (EM, weak, etc.) but those fields are assumed to arise as an effective description of the assumed fundamental field. This field has also infinite range so that it can communicate the particle configuration anywhere, at light speed.
3. A particle is only emitted when the detectors' field has a certain, "favorable", value, corresponding to a certain detector configuration.What about when the polarizer settings are varied while the particles are in flight?
4. The properties of the emitted particle is a function of the above field. If this were true, then wouldn't it be possible to predict the sequences (and not just the rates) of both individual and joint detections?

The result of the above proposed mechanism, both the properties of the emitted particle (spin for example), and the future detector configuration depend on the detector's configuration in the past, therefore they cannot be assumed to be statistical independent ...They're dependent due to the pairing process, which is based on the assumption that the polarizers are analyzing the same (or a related) property wrt any given pair of detection attributes. The problem is that it's unknown where the relationship between the entangled particles is produced. The standard assumption is that it's happening via the emission process, and that everything is happening according to the principle of locality via transmissions less than or equal to c. But the precise qualitative charactaristics of the emitted disturbances is unknown. So, standard qm can't give a realist, or explicitly local, account. However, from optics, and the conservation laws, and the known statistical dependencies, etc., standard qm gives an accurate statistical account of the joint state in a nonfactorable form -- which doesn't rule out the possibilities of locality, or nonlocality, or ftl transmissions. And, locality and light speed limit remain the defacto standard assumptions.
... hence the possible violation of Bell's inequalities by a local theory.I think that the Aspect experiment with time-varying analyzers, as well as the demonstrated independence between polarizer orientation and individual detection in every Bell experiment, make your proposal unacceptable.

ueit

Aug5-09, 04:55 AM

No, that's a rather narrow and misleading view. Life is an emergent property of quarks and electrons. There is very Big difference between a dead person and an alive person, though they are made up of the same quarks and electrons.

The "big" difference boils down to a difference in the particle configuration, nothing else. Do you have evidence for the existence of something else?

Without free-will, everything is an illusion.

I don't see how this follows.

Why didn't you say consciousness instead of brain? Brain is not consciousness, though they are obviously related.

Consciousness is an emergent, macroscopic property of the particle configuration of the brain. It has no relevance at fundamental level.

This explanation, along with all explanations of anything are completely senseless in a superdeterministic universe.

How is a fundamentally probabilistic universe different in this aspect?

True, but if you posit that everything is a consequence of a pre-determined configuration of exteremely low entropy at the Big Bang, it raises more questions than it answers.

Those questions being...?

How about "Free will(and Life) is an emergent property in our universe, because there are infinite number of universes".

I do not see how this answers what I've asked you:

"Give me a good account of how "our personal subjective experience of reality" appears in a universe that is not superedetrministic."?

How does the number of universes change anything?

I think your idea is radical(that's generelly a good thing when applied to reality), but it degrades science, understanding, knowledge and logic and as such is absurd. If free will is an illusion, how is your theory not another illusion/delusion?

Free will is an assumption we make, not an empirical observation. The fact that this particular assumption is wrong does not imply that our direct observations are delusional.

ueit

Aug6-09, 05:25 AM

Read any of the Weinberg/Salaam work and follow-on work, and you will see that there is no mention of a superdeterministic mechanism. Yet there would need to be for there to be a violation of Bell Inequalities when the angle setting is determined by radioactive decay (i.e. randomly as far as we know). The mechanism you propose (which is not really a specific proposal at all) requires that either the electromagnetic properties are "right" for emission, which requires that the source knows the detector settings in advance. But they won't be selected until AFTER the photon pair is in flight.

Look, tell me which of the following assumptions you find incompatible with the papers you refer to:

1. Each particle (electron, quark, neutrino, etc.) has a well defined trajectory.
2. Each particle is accompanied by an infinite range, local field.
3. The trajectory of each particle is determined by the structure of this field.

I really must point out that anyone can postulate a non-falsifiable hypothesis (which is completely useless in all respects) regarding any existing physical theory. Hey, maybe oranges are really tiny solar systems but they simply act like edible fruit due to superdeterminism!

SD refers to a class of possible theories (like the class of non-local theories like BM or GRW), it is not a unique theory. Therefore it is too soon to say if those theories are falsifiable or not. I see no a-priori reason to assert that they are not. I see no relevance of your "orange" analogy to SD. SD does not claim that we are deluded. Our observations are correct. SD only imposes some additional constraints on what experimental results are possible to be observed.

Why don't you own up to the true purpose of your question, which I believe is to find a back-handed way to keep local realism in play? If you were serious about superdeterminism per se, you would start by looking for evidence IN FAVOR of SD (of course there is none currently) rather than asking for evidence AGAINST (as you have done).

SD is usually dismissed because of various reasons ('t Hooft is an exception). For now I want to evaluate how strong the arguments against the idea are. Also, I do find EPR experiments as pointing towards SD because the other explanations are very close to a belief in god as you have mentioned (non-locality, unfalsifiable many worlds, etc). While SD may seem counter-intuitive it doesn't contradict (at least in an obvious way) no well established scientific result.

WaveJumper

Aug6-09, 04:02 PM

The "big" difference boils down to a difference in the particle configuration, nothing else. Do you have evidence for the existence of something else?

I think you have misunderstood my statement. I said that a particluar particle configuration does not mean a living entity. This same configuration can also mean a dead entity(person, animal, etc.). It's not only the configuration that is at play, in fact it's the configuration that causes the emergence of a totally New phenomenon - that of Life. It's still a mistery what it really is that causes a particluar dumb quantum particles configuration to "come alive". Your guess that this emergent phenomenon is a deterministic process is a speculative unfalsifiable guess.

I don't see how this follows.

If every event in the universe is pre-determined by an awful long chain of reactions(incl. your free will), how can we ever know anything for sure? There may be no universe at all, how would we tell if a deterministic process isn't causing us hallucinations of an objectively existent universe? We can't say anything with certainty about anything. We can only say - "A deterministic process is causing/forcing us to believe there is A, B or C".

Consciousness is an emergent, macroscopic property of the particle configuration of the brain. It has no relevance at fundamental level.

What do you mean by "fundamental level"? There are good arguments to believe that at the most fundamental level, something and nothing are one and the same and that all known concepts from our experience are squeezed into non-existence.

How is a fundamentally probabilistic universe different in this aspect?

True randomness(whatever that is) is a pre-requisite for probabalistic genetic occurences. I don't think our observations point to there being a particlular chain of events in the past that lead to particular genetic mutations.

Those questions being...?

If you are putting forward the Simulation Argument, do say so. I find it rather thought provoking and i think it makes much more sense than a "bare" superdeterministic universe that has no first cause. If you had said from the onset that that's what you believe, i think your worldview would have met even more recognition(but maybe that's just me).

I do not see how this answers what I've asked you:

"Give me a good account of how "our personal subjective experience of reality" appears in a universe that is not superedetrministic."?

True Randomness in the quantum vacuum. Wait infinity. Infinity is a long time. Vacuum fluctuations come and go, constantly creating particle-antiparticle pairs. Occasionally whole atoms are created. emember, you have infinity on your side. After 10^5678 "years" - there goes BOOM, a giant quantum fluctuation gives birth to a whole universe like ours(Bolzmann brains). This of course pre-supposes the existence of a spacelike medium. It sounds somewhat abstract, but what we perceive as reality is already abstract enough.

How does the number of universes change anything?

It's the existence of true randomness that counts. Infinite universes, or infinite random quantum fluctuations(some of which create whole atoms and are theorised to be able to create even universes) all rely on randomness as a pre-requsite.

Free will is an assumption we make, not an empirical observation.

How can we make the assumption that we have free-will if we don't have the free-will to make assumptions? This is circular reasoning, not much different than the liar's paradox - The liar said - "I am a liar".

Generally speaking, it sounds like you have the virtual reality argument in mind. If it is so, i have nothing against it, as i see reasons to believe that this might be plausible.

The fact that this particular assumption is wrong does not imply that our direct observations are delusional.

How are we not delusional? We believe we are making our own choices, we believe we live our own lives in our own ways, we believe we are not "pre-programmed" cause-effect robots. How is this not a delusion in a Superdeterministic universe?

I am surprised you didn't invoke the block view of the universe(as per GR) and its all-at-once existence of past, present and future. You could make a strong case on determinism there.

ThomasT

Aug7-09, 03:42 PM

ueit, I'm still not sure what the distinguishing characteristics of a superdeterministic theory are.

Anyway, here's a good article by Ghirardi for those who haven't read it:

http://plato.stanford.edu/entries/qm-collapse/

SW VandeCarr

Aug7-09, 07:13 PM

If arguments against SD are wanted, it seems one the most obvious is that it negates the concepts of entropy and information. SD would imply the entropy of any system anywhere at any time is zero since there is never any objective uncertainty as to a system's state or evolution. Then we are dealing with subjective uncertainty only. However subjective uncertainty would also be predetermined, as our "subjective" state is also a function of a system with zero entropy. (Note: I'm using 'subjective' and 'objective' as if there were a fundamental difference. However,I agree with others here that our notion of 'objectivity' is related to issues of consistency and clarity of descriptions).

EDIT: What happens to "the arrow of time" if thermodynamic entropy is always zero?

ueit

Aug8-09, 08:07 AM

The correlation is between the angular difference of the crossed polarizers and the rate of joint detection. The detectors placed after the polarizers are always both set the same. The polarizer settings are varied. So, I assume that by detector you mean polarizer.

By "detector" I mean the device or group of devices that measure the spin. It might be polarizer + photon detector, or a Stern-Gerlach device or something else. What is important is that the "detector" also includes whatever is used to change its orientation (be it an electric engine, a human, a monkey pressing a button, etc.). Everything that has a contribution to the decision regarding the measurement axis is included in the generic name of "detector".

What about when the polarizer settings are varied while the particles are in flight?

As I have said, "a particle is only emitted when the detectors' field has a certain, "favorable", value, corresponding to a certain detector configuration." Because the evolution of the detector is deterministic, its future orientation is "fixed". The "change" while the particle is in flight is nothing but the detector's deterministic evolution which is "known" by the particle since emission. In other words, you cannot "fool" the particle. The particle "knows" what will happen because it knows the value of the field in the past + deterministic evolution law.

If this were true, then wouldn't it be possible to predict the sequences (and not just the rates) of both individual and joint detections?

Sure, but only if you know the exact value of the field at particle's place.

I think that the Aspect experiment with time-varying analyzers, as well as the demonstrated independence between polarizer orientation and individual detection in every Bell experiment, make your proposal unacceptable.

It doesn't, see above.

ueit

Aug8-09, 08:28 AM

ueit, I'm still not sure what the distinguishing characteristics of a superdeterministic theory are.

See my answer above.

Anyway, here's a good article by Ghirardi for those who haven't read it:

http://plato.stanford.edu/entries/qm-collapse/

Thanks!

Doc Al

Aug8-09, 08:46 AM

ueit

Aug8-09, 08:58 AM

Including the polarization of the cosmic microwave background photon that was used to "choose" the detector setting, right?

Right.

So basically the emitter knows the state of the entire universe and thus certainly can predict the detector settings at any future time and choose to emit or not emit particles accordingly.

Indeed.

Good one! Of course the detector is no dummy--it also knows the state of the entire universe and can predict the behavior of the emitter and act accordingly. (I assume the behavior of the emitter is just as deterministic as is that of the detector.)

Sure, but as we are not interested in the particles emitted from detectors I've let them out.

All I see is some vague handwaving that somehow everything works out in the end. Where is the physics?

Can you show that there is something inconsistent in the above assumptions? Can you show mathematically that such a behavior is not possible? If you can, it is great. Rejecting a possible mechanism is good science. But maybe, such a mechanism works and leads to testable predictions (for example one may find out that only a small class of fields lead to predictions that are consistent with QM).

Doc Al

Aug8-09, 09:10 AM

Can you show that there is something inconsistent in the above assumptions? Can you show mathematically that such a behavior is not possible? If you can, it is great. Rejecting a possible mechanism is good science. But maybe, such a mechanism works and leads to testable predictions (for example one may find out that only a small class of fields lead to predictions that are consistent with QM).
I stated up front that it's "possible" (meaning: not immediately self-contradictory), as I think Bell did as well. So what? It's also "possible" that you (and all of PF) are just a figment of my imagination.

You have not provided or described any mechanism. What experiment would you propose to falsify your proposed "mechanism"? To get anywhere, you need a specific physical mechanism.

ueit

Aug8-09, 09:41 AM

I stated up front that it's "possible" (meaning: not immediately self-contradictory), as I think Bell did as well. So what? It's also "possible" that you (and all of PF) are just a figment of my imagination.

You have not provided or described any mechanism. What experiment would you propose to falsify your proposed "mechanism"? To get anywhere, you need a specific physical mechanism.

In order to falsify the mechanism one should propose a clear mathematical structure. I am not able to propose it. But if you want a "cheap" example of a SD theory just take Bohm's interpretation, as it is, and replace in the equation the instantaneous, "present" particle distribution with a past distribution so that locality is observed. The "present" distribution is then "predicted" by the particle from the past one.

It would be more interesting to find a formulation that is not such obviously ad-hoc, but for the time being I was only interested if there are well formulated arguments against SD.

ueit

Aug8-09, 09:59 AM

SW VandeCarr

Aug9-09, 12:51 AM

Are you saying that a classical gas, composed of molecules with strict deterministic behavior would not obey the laws of thermodynamics?

I'm making a reductio ad absurdum argument. If SD is true, then all events occur with probability one. If you plug p=1 into the Shannon equation (which differs from the Boltzmann entropy equation only by the choice of the constant) you get zero entropy. A block universe under SD (as I understand SD) is completely defined at all space-time points. Therefore its entropy would be zero everywhere all the time. The universe exists in just one possible state.

http://en.wikipedia.org/wiki/Boltzmann_entropy

EDIT:http://en.wikipedia.org/wiki/Entropy_(statistical_thermodynamics)

I'm posting these links, not because I don't think most people on this thread know what I'm talking about, but because some might not, and I just want to be specific regarding what I'm talking about.

Count Iblis

Aug9-09, 09:15 AM

I'm making a reductio ad absurdum argument. If SD is true, then all events occur with probability one. If you plug p=1 into the Shannon equation (which differs from the Boltzmann entropy equation only by the choice of the constant) you get zero entropy. A block universe under SD (as I understand SD) is completely defined at all space-time points. Therefore its entropy would be zero everywhere all the time. The universe exists in just one possible state.

http://en.wikipedia.org/wiki/Boltzmann_entropy

This is the fine grained entropy, not the coarse grained entropy used in thermodynamics. The fine grained entropy is always zero, even in "ordinary physics".

SW VandeCarr

Aug9-09, 12:50 PM

This is the fine grained entropy, not the coarse grained entropy used in thermodynamics. The fine grained entropy is always zero, even in "ordinary physics".

Just a short response for now. What kind of entropy does the equation I cited (S_{B}) describe? If it's the "fine grained" entropy and it's always zero, what good is it?

ThomasT

Aug9-09, 03:58 PM

By "detector" I mean the device or group of devices that measure the spin. It might be polarizer + photon detector, or a Stern-Gerlach device or something else. What is important is that the "detector" also includes whatever is used to change its orientation (be it an electric engine, a human, a monkey pressing a button, etc.). Everything that has a contribution to the decision regarding the measurement axis is included in the generic name of "detector".Using the standard referents for emitter, polarizer, and detector, in a simple optical Bell test setup involving emitter, 2 polarizers, and 2 detectors it's pretty easy to demonstrate that the polarizer settings aren't determined by the detector settings, or by the emitter, or by anything else in the design protocol except "whatever is used to change" the polarizer settings.

It's been demonstrated that the method that's used to change the polarizer settings, and whether it's a randomized process or not, isn't important wrt joint detection rate. What is important is the settings that are associated with the detection attributes via the pairing process -- not how the settings themselves were generated.

As I have said, "a particle is only emitted when the detectors' field has a certain, "favorable", value, corresponding to a certain detector configuration." Because the evolution of the detector is deterministic, its future orientation is "fixed". The "change" while the particle is in flight is nothing but the detector's deterministic evolution which is "known" by the particle since emission. In other words, you cannot "fool" the particle. The particle "knows" what will happen because it knows the value of the field in the past + deterministic evolution law.It's already well established that detector orientations don't trigger emissions -- and changing the settings while the emissions are in flight has no observable effect on the correlations. If you want to say that these in-flight changes are having some (hidden) effect, then either there are some sort of nonlocal hidden variable(s) involved, or, as you suggest, there's some sort of heretofor unknown, and undetectable, local field that's determining the correlations. Your suggestion seems as contrived as the nonlocal models -- as well as somewhat incoherent wrt what's already known (ie., wrt working models). Anyway, flesh out the details of it, submit it to the appropriate forum, and maybe somebody who knows more than I do will agree with your approach.

I still don't know what the distinguishing characteristics of a superdeterministic theory are. Can you give a general definition of superdeterminism that differentiates it from determinism? If not, then you're OP is just asking for (conclusive or definitive) arguments against the assumption of determinism. There aren't any. So, the assumption that the deep reality of Nature is deterministic remains the defacto standard assumption underlying all physical science. It isn't mentioned simply because it doesn't have to be. It's generally taken for granted -- not dismissed.

SW VandeCarr

Aug9-09, 04:21 PM

I still don't know what the distinguishing characteristics of a superdeterministic theory are. Can you give a general definition of superdeterminism that differentiates it from determinism? If not, then you're OP is just asking for (conclusive or definitive) arguments against the assumption of determinism. There aren't any. So, the assumption that the deep reality of Nature is deterministic remains the defacto standard assumption underlying all physical science. It isn't mentioned simply because it doesn't have to be. It's generally taken for granted -- not dismissed.

I don't know how SD is defined either. Perhaps you can address my concerns stated in post 53. I'm basing my argument on Boltzmann entropy.

ThomasT

Aug10-09, 11:08 PM

I don't know how SD is defined either. Perhaps you can address my concerns stated in post 53. I'm basing my argument on Boltzmann entropy.Since we're not sure exactly what ueit means by superdeterminism, lets assume for the moment that it's just an emphatic form of the term determinism (equivalent to saying that Nature is absolutely deterministic or really really deterministic, which is equivalent to the standard meaning of determinism).

If arguments against SD are wanted, it seems one the most obvious is that it negates the concepts of entropy and information.Determinism is an assumption about the underlying nature of the reality that we observe. It's a given as far as physical science's search for fundamental, as well as emergent, dynamical laws.

It isn't obvious to me, and I don't understandl, how the assumption of determinism "negates the concepts of entropy and information".

As I've mentioned, afaik, there are no (and I don't think there can be any) definitive or conclusive arguments against determinism. Entropy might be irrelevant for this, and our information seems to support the assumption of determinism.

Maybe I just don't understand your argument. So, if you could lay it out, step by step, that might help.

ueit

Aug11-09, 04:08 AM

I don't know how SD is defined either. Perhaps you can address my concerns stated in post 53. I'm basing my argument on Boltzmann entropy.

As ThomasT says, there is no difference between superdeterminism and determinism. However, classical deterministic theories can work with free, external parameters because either there is no long-range field (billiard balls) either the field vanishes with distance (classical EM and gravitational fields). The distinctive characteristic of SD (as I propose it) is that such a separation observer-observed is not possible because the interaction between distant particles never becomes negligible. It is a quantitative, not qualitative difference. The closest analogous would be a system (galaxy) of black holes in general relativity. In order to model the trajectory of one BH you need to know the distribution of all other BH-s.

Regarding your argument, AFAIK a reversible system has a constant entropy. If our universe is SD then it has a constant entropy. However we cannot measure the entropy of the universe, only of a part of it. But this part is not reversible because the interactions with the environment are not taken into account, therefore the entropy may increase.

SW VandeCarr

Aug11-09, 04:30 AM

Maybe I just don't understand your argument. So, if you could lay it out, step by step, that might help.

The basic argument is fairly straightforward. Entropy, both in the Shannon IT context and in the Gibbs thermodynamic context, is a logarithmic function of probabilities The Gibbs entropy equation:

S=-k\sum_{i}p_{i}lnp_{i}

The probabilities are based on the number of states in which a system can exist. For example a sequence of ten fair coin tosses has 1024 possible states, each state having an equal probability of 1/1024. In thermodynamics, we're talking about the macrostate of a system as a composition of N microstates. The model of the evolution of a thermodynamic system is a Markov process involving the transition probabilities from one state to another.

Given this background, if you assume SD, I'm arguing that there is just one state in which a system can exist at any point in time. The whole notion of a probability becomes irrelevant as an objective concept. Entropy is a function of the number of possible states in which a system can exist. If there is only one state, entropy is equal to zero. Moreover, since the evolution of a system is strictly determined, there is no Markov process.

In the coin toss example, the ten toss sequence is predetermined. There is only one possible outcome before the coin is actually tossed. At best we an only talk about subjective entropy: that is, our uncertainty as to the outcome. This is what SD says. Now, if you take this one step further and ask what subjective uncertainty actually is, it's a state of a system, the system being our brain and the state of knowledge represented in the brain. That's my reductio ad absurdum. We only imagine there are multiple possible outcomes. In reality (under SD) there is only one possible outcome and probabilities have no objective meaning. How can we talk about the entropy of the universe increasing when there is no objective entropy?

SW VandeCarr

Aug11-09, 05:03 AM

As ThomasT says, there is no difference between superdeterminism and determinism.

Regarding your argument, AFAIK a reversible system has a constant entropy. If our universe is SD then it has a constant entropy. However we cannot measure the entropy of the universe, only of a part of it. But this part is not reversible because the interactions with the environment are not taken into account, therefore the entropy may increase.

I saw your post after I posted my last post quoting ThomasT. If you concede that the entropy of the universe is constant under SD, what does that say about the Second Law? As far as local environments, I'm not sure your argument rescues the Second Law. Local entropy may increase, decrease, or remain constant with the background of a constant entropy universe. In any case, entropy is imaginary if there are no objective probabilities. IMHO, you can have SD or the Second Law, but not both.

Count Iblis

Aug11-09, 09:42 AM

Just a short response for now. What kind of entropy does the equation I cited (S_{B}) describe? If it's the "fine grained" entropy and it's always zero, what good is it?

That formula is completely general and can describe any kind of enetropy. To get the entropy we use in practice, you always have to use a coarse graining procedure to define the probabilities.

If you have a given number number of molecules in a given volume and you would exactly specify the energy of the system, then there is only one quantum state the system vcan be in. So, what you do is you explicitely specify some small energy uncertainty delta E and then count the number of microstates that are within that small energy nterval. Then, the fundamental assumption being that all these microstates are equally likely, yields the Boltzmann formula:

S = k Log(Omega)

where Omega is the number of microstates.

Check out this rigorous derivation of (http://en.wikipedia.org/wiki/Fundamental_thermodynamic_relation#Derivation_from _first_principles)

dS = dQ/T

from S = k Log(Omega)

to see the importance of specifying the delta E.

So, in the end we arrive at:

dS = dE/T + X dx/T

where X is the generalized force and x and external parameter. And for a reversible change we have dE + X dx = dQ

WaveJumper

Aug11-09, 04:34 PM

In order to falsify the mechanism one should propose a clear mathematical structure. I am not able to propose it. But if you want a "cheap" example of a SD theory just take Bohm's interpretation, as it is, and replace in the equation the instantaneous, "present" particle distribution with a past distribution so that locality is observed. The "present" distribution is then "predicted" by the particle from the past one.

It would be more interesting to find a formulation that is not such obviously ad-hoc, but for the time being I was only interested if there are well formulated arguments against SD.

Lets push your model a bit deeper and see if it survives. We know from QCD, that more than 99% of all mass of matter is concentrated in the nuclei and the mass of quarks only adds up to a few percent. The rest of the mass(>96%) comes from virtual gluons that randomly pop into existence and disappear again from the quantum vacuum. The Higgs field is theorised to make up the other few percent and give mass to quarks and electrons through virtual Higgs bosons, and it is thought to derive its energy from the quantum vacuum too. So it appears we are very close to having evidence that all of physical matter in space-time emerges from timeless and spaceless planck scale through random quantum fluctuations. This may resolve the biggest of all questions - "Why is there something instead of nothing?" through adjustments to both how we view "something" and how we view "nothing". But one could wonder - are quantum fluctuations really random if they have the ability to create such immense volumes of information at our macro scale(the whole structure of reality as we see it)? Only infinity and the notion that given infinity, everything that can occur will occur in the quantum vacuum can provide a somewhat coherent explanation. What's your opinion?

SW VandeCarr

Aug12-09, 05:36 AM

That formula is completely general and can describe any kind of enetropy. To get the entropy we use in practice, you always have to use a coarse graining procedure to define the probabilities.

Thanks for clarifying that. Given that the Gibbs formula is good for both fine and coarse grained entropy, it would seem that SD would restrict the Second Law to specific experiments at most, but that the Second Law is not a universal principle. Therefore, with SD, we cannot explain the arrow of time in terms of the Second Law, nor can we justify entropy as an objective concept. (see my previous posts.) SD may even mean that we have to give up the idea of randomness at all scales, even random quantum fluctuations at Planck scales.

ThomasT

Aug12-09, 02:52 PM

SW VandeCarr, it seems to me that probabilistic descriptions and the concepts of entropy and information are independent from the assumption of determinism.

It's assumed that the underlying evolution of any physical system is deterministic. This assumption is objective in the sense that, and insofar as, it's inferrable from the development of dynamical laws and principles that correspond with the objective data.

However, the assumption of determinism doesn't inform us about the details of the underlying (real) state or evolution of any physical system. Even though it's assumed that any physical system can be in only one (real) state at any given time, those (real) states are generally unknown and the behavior of observable objects is increasingly upredictable as the dependence of the behavior on unknown factors increases. So, probabilistic descriptions are often necessary, and their use doesn't contradict the underlying assumption of determinism.

You wrote:
We only imagine there are multiple possible outcomes. In reality (under SD) there is only one possible outcome and probabilities have no objective meaning.If the underlying states and dynamics were known, then probabilistic descriptions would be obviated. But they aren't.

However, this doesn't mean that probabilistic descriptions aren't objective. It isn't our imaginations that tell us that the tossed coin is going to come up either heads or tails.

How can we talk about the entropy of the universe increasing when there is no objective entropy?I don't know quite how to think about the entropy of the universe. Is there a definitive statement about the entropy of the universe? I've seen several different values given, none of which are 0.

In any case, entropy is connected with the dissipation of energy and the arrow of time -- the archetypal example of which is the radiative arrow. Drop a pebble into a smooth pool of water. The evolution of the wavefront is deterministic, isn't it?

I don't think your argument is why ueit's proposal should be rejected. There are other reasons, not the least of which is the notion of fields whose strength doesn't diminish with distance.

ThomasT

Aug12-09, 03:07 PM

Therefore, with SD, we cannot explain the arrow of time in terms of the Second Law, nor can we justify entropy as an objective concept. (see my previous posts.) SD may even mean that we have to give up the idea of randomness at all scales, even random quantum fluctuations at Planck scales.The Second Law doesn't explain the arrow of time. It's just a generalization of it. Since observations are so far in agreement with it, it's kept.

Entropy, in its many forms, is very much an objective concept insofar as it depends on measurements.

The assumption of determinism isn't at odds with randomness. Randomness refers to unpredictability. We use words like random and spontaneous when we can't specify causal antecedents. This doesn't mean that there aren't any.

SW VandeCarr

Aug12-09, 10:06 PM

However, this doesn't mean that probabilistic descriptions aren't objective. It isn't our imaginations that tell us that the tossed coin is going to come up either heads or tails.

I don't know quite how to think about the entropy of the universe. Is there a definitive statement about the entropy of the universe? I've seen several different values given, none of which are 0.

The entropy of the universe, whatever it might be, is definitely not 0. ueit has already agreed that SD implies a constant entropy for the universe and if the universe is in just one possible spacetime state (block universe), all events occur with a real probability of one, which yields zero when plugged into the Gibbs equation for entropy. This is an argument against SD.

Regarding probabilities, if the uncertainty is due only to a lack of complete information, the probabilities are not objective. They would be objective only if we assume that nature is fundamentally probabilistic and true randomness actually exists.

ThomasT

Aug12-09, 10:56 PM

ueit has already agreed that SD implies a constant entropy for the universe ... He's also agreed that SD is synonymous with standard determinism. There's a better name for what he's proposing, which I'll suggest to him. Anyway, determinism doesn't imply a constant entropy.

... and if the universe is in just one possible spacetime state (block universe), all events occur with a real probability of one, which yields zero when plugged into the Gibbs equation for entropy. This is an argument against SD.I don't think the block universe model should be taken literally, as a realistic representation. The universe is assumed to be in one possible, transitory, spatial configuration at any given time wrt evolutionary (deterministic), presentist models.

Saying that all events occur with a real probability of one is meaningless. Probabilities are applicable before, not after, the facts of observation.

Regarding probabilities, if the uncertainty is due only to a lack of complete information, the probabilities are not objective.If we had complete information we wouldn't need probabilities. What is non objective about the observation that a tossed coin will come up either heads or tails?

They would be objective only if we assumed that nature was fundamentally probabilistic and true randomness actually existed.No. Probabilities are objective when they're based on observable possibilities. Randomness refers to our observations, not the deep reality of Nature. True randomness does exist. There are lots of things that we really can't predict. :smile:

Why would we assume that Nature is fundamentally probabilistic when there are so many reasons to believe that it isn't?

SW VandeCarr

Aug12-09, 11:18 PM

Why would we assume that Nature is fundamentally probabilistic when there are so many reasons to believe that it isn't?

I'm not assuming anything. I don't know. I'm saying if....then. Given determinism, the future is as well determined as the past. We just don't know for certain what it will be. Therefore, it's our uncertainty that probabilities quantify.

ThomasT

Aug13-09, 02:17 AM

I'm not assuming anything. I don't know. I'm saying if....then. Given determinism, the future is as well determined as the past. We just don't know for certain what it will be. Therefore, it's our uncertainty that probabilities quantify.Yes, it's our uncertanties that probabilities quantfy. We assume an underlying determinism (for many good reasons). But we don't know the details of that underlying determinism. Hence, the need for probabilistic descriptiions.

ueit asks for arguments against determinism. Afaik, there aren't any -- at least no definitive ones. And, as far as I can tell from this thread you haven't given any.

But, ueit's proposed explanation for Bell-type correlations is problematic for reasons that I've given.

So, where are we?

SW VandeCarr

Aug13-09, 11:46 AM

Yes, it's our uncertanties that probabilities quantfy. We assume an underlying determinism (for many good reasons). But we don't know the details of that underlying determinism. Hence, the need for probabilistic descriptiions.

ueit asks for arguments against determinism. Afaik, there aren't any -- at least no definitive ones. And, as far as I can tell from this thread you haven't given any.

But, ueit's proposed explanation for Bell-type correlations is problematic for reasons that I've given.

So, where are we?

I think you're trying to have it both ways. First, just to be clear, we need to quantify uncertainty. Uncertainty is a function of a probability: U=4(p(1-p)) where 4 just scales the measure to the interval [0,1]. It's clear uncertainty is maximal when p=0.5 and 0 when p=0
or p=1.

Now you've already agreed that probability measures our uncertainty. What does our uncertainty have to do with nature? Someone tosses a fair coin behind a curtain. The coin is tossed but you don't see it. For the "tosser" uncertainty is 0. For you, it's 1.

Now we have deterministic theories that are not time dependent. The laws of physics are presumed to hold in the future just as in the past. The charge of an electron does not change with time. If we have determinism (D), it's clear that any outcome of a time dependent process is also entirely predictable in principle. That means randomness is only a reflection of our current state of knowledge. If you could have perfect information as to some future time dependent outcome, you have U=0. This corresponds to p=1 or p=0. This is what I meant when I said that under D, with perfect information, future events occur with a real probability 1 (or 0). In effect under D, we don't have probabilities in nature. We only have our uncertainty about nature.

ThomasT

Aug13-09, 01:59 PM

I think you're trying to have it both ways.Trying to have what both ways?

First, just to be clear, we need to quantify uncertainty. Uncertainty is a function of a probability: U=4(p(1-p)) where 4 just scales the measure to the interval [0,1]. It's clear uncertainty is maximal when p=0.5 and 0 when p=0 or p=1. The probability already quantifies the uncertainty, doesn't it?

Now you've already agreed that probability measures our uncertainty.I agreed that probabilities are quantitative expressions of our uncertainties.

What does our uncertainty have to do with nature?That's what I was wondering when you said ...
They (probabilities) would be objective only if we assume that nature is fundamentally probabilistic and true randomness actually exists. ... and I pointed out that probabilities are objective when they're based on observable possibilities, and that randomness refers to our observations, not the underlying reality.

Someone tosses a fair coin behind a curtain. The coin is tossed but you don't see it. For the "tosser" uncertainty is 0. For you, it's 1.OK.

Now we have deterministic theories that are not time dependent. The laws of physics are presumed to hold in the future just as in the past. The charge of an electron does not change with time. If we have determinism (D), it's clear that any outcome of a time dependent process is also entirely predictable in principle.OK, until we get to quantum stuff where that pesky quantum of action becomes significant.

That means randomness is only a reflection of our current state of knowledge.I agree.

If you could have perfect information as to some future time dependent outcome, you have U=0. This corresponds to p=1 or p=0. This is what I meant when I said that under D, with perfect information, future events occur with a real probability 1 (or 0).Of course, an event either has occured or it hasn't.

In effect under D, we don't have probabilities in nature. We only have our uncertainty about nature.Ok, so I guess we agree on this. So far, wrt ueit's OP we don't have any good argument(s) against the assumption of determinism.

What about a field associated with filtering-measuring devices in optical Bell tests, whose strength doesn't diminish with distance, and whose values determine or trigger emissions? (Lets call it the Ueit Field.) Any arguments against that?

kote

Aug13-09, 02:58 PM

So far, wrt ueit's OP we don't have any good argument(s) against the assumption of determinism.

Classical objective causation, the newtonian billiard-ball style particle collision causation, has been disproven by quantum mechanical experiments. Historically, this conception of classical physical causation is what was meant by determinism in nature. If that's what we mean now (but I don't think it is) then the conversation is over.

Quantum mechanics also suggests that there are forces in the universe that are inherently unknowable. We can only directly measure the location of a particle on our detector, we can't directly measure the quantum forces that caused it to end up at that specific location instead of another. If this aspect of QM is true, then deterministic natural laws, if they exist, are inherently unknowable themselves (and you can further argue whether or not an unfalsifiable physical construct can in principle be considered to exist at all).

Of course, the problem of induction already disallows for proof of physical determinism.

Spinoza and others have argued that physical determinism is rationally guaranteed by the laws of logic. Arguments from logic are the only type that have any hope of proving determinism in nature.

On a practical level it is necessary to assume determinism in nature, and on a macro level things seem to be pretty deterministic. However, on the quantum level where this causation is supposed to be taking place, we have absolutely no idea how anything actually works. We cannot visualize any sort of causation on the quantum level, and we cannot come close to predicting any results.

An assumption of determinism stems from a macroscopic point of view that presupposes a quantum-scale mechanism for physical causation. However, when you actually look at the quantum level, no evidence for any such mechanism can be found, and it has been argued that no such mechanism could exist at all.

SW VandeCarr

Aug13-09, 03:13 PM

The probability already quantifies the uncertainty, doesn't it?

Not really. You approach certainty as as you move toward p=0 or p=1 from p=0.5. Uncertainty is maximal at p=0.5 Look at the equation.

OK, until we get to quantum stuff where that pesky quantum of action becomes significant.

Well, D doesn't exclude anything. It would seem you're going to have to accept hidden variables if you want D or settle for a universe that is truly random at it's smallest scales. That's what I mean by trying to having it both ways.

What about a field associated with filtering-measuring devices in optical Bell tests, whose strength doesn't diminish with distance, and whose values determine or trigger emissions? (Lets call it the Ueit Field.) Any arguments against that?

I'm not a physicist and I don't feel I'm qualified to venture an opinion on that. I feel I am qualified enough in statistics and probability to venture an opinion in this area (in a frequentist or Bayesian sense) both in the methods and the limitations of these methods.
I did just offer a tentative opinion re hidden variables. You can tell me whether I'm correct or not

kote

Aug13-09, 03:19 PM

Oh, right, this thread is on superdeterminism, not determinism :).

As for superdeterminism... the only way it can be logically explained is if one of your causes is superfluous. Superdeterminism is: A and B each independently caused C.

So, what caused C? Answer: A or B, take your pick.

Logically this is impossible unless A and B are actually the same thing but are being described two separate ways. In essence, superdeterminism is just straight determinism with the addition of superfluous 2nd order explanations.

Mental activity is often ascribed such 2nd order explanatory power over physical events. But the fact that physical events (assuming we have deterministic natural laws) can be explained entirely in physical terms doesn't prove that logic is being violated and superdeterminism is right, it just proves that mental activity at some level must be reducible to physical activity (ie our brains).

Bottom line: superdeterminism violates logic. It's logically impossible in its true sense. Additionally, 2nd order explanations from properties emergent on 1st order explanations are interesting, but they don't solve any problems in basic physics, which is only concerned with 1st order causation.

SW VandeCarr

Aug13-09, 03:31 PM

Oh, right, this thread is on superdeterminism, not determinism :).

The OP has agreed (as per ThomasT) that SD and D are the same.

ThomasT

Aug13-09, 03:53 PM

You approach certainty as as you move toward p=0 or p=1 from p=0.5. Uncertainty is maximal at p=0.5.That seems pretty quantitative to me. :smile: Your equation just quantifies it in a different way.

Well, D doesn't exclude anything. It would seem you're going to have to accept hidden variables if you want D or settle for a universe that is truly random at it's smallest scales. That's what I mean by trying to having it both ways.Yes, of course, the presumed existence of hidden variables comes with the assumption of determinism. I don't think anybody would deny that hidden variables exist.

Assuming determinism, then randomness exists only at the instrumental level, the level of our sensory apprehension.

ThomasT

Aug13-09, 04:00 PM

kote

Aug13-09, 04:20 PM

Is this the standard definition of superdeterminism?

It's slightly more nuanced, but basically, yes. Superdeterminism is a second level of causation on top of one cause per effect causation. It is not necessarily true that the second level is reducible to the first level in any of its individual parts, but as a system, the second level of explanation (cause) emerges fully from the first level. Additionally, in superdeterminism, the first order explanation is always necessary and sufficient on its own.

For example, you may not find the sensation of pain anywhere in the micro level atomic world, but the sensation of pain may still emerge as a unique property from the correct systemic arrangement of atoms in my brain along with corresponding atomic impulses in my nerves etc.

This second order of properties that emerges from the first order properties of the atoms can be used in causal statements. "The pain caused me to pull my hand back from the fire." This, however, is a "super-" cause, emerging from the first order cause (or explanation) involving atoms bumping into each other according to the laws of nature at the micro level.

Edit: Now that I think about it, I may have put a little too much interpretation in my explanation. Superdeterminism just means events can have more than one immediate and sufficient cause. However, I think it's pretty trivial to conclude that this is logically impossible unless all causes are in essence the same, in which case you get what I just described.

ThomasT

Aug13-09, 05:10 PM

It's slightly more nuanced, but basically, yes. Superdeterminism is a second level of causation on top of one cause per effect causation. It is not necessarily true that the second level is reducible to the first level in any of its individual parts, but as a system, the second level of explanation (cause) emerges fully from the first level. Additionally, in superdeterminism, the first order explanation is always necessary and sufficient on its own.

For example, you may not find the sensation of pain anywhere in the micro level atomic world, but the sensation of pain may still emerge as a unique property from the correct systemic arrangement of atoms in my brain along with corresponding atomic impulses in my nerves etc.

This second order of properties that emerges from the first order properties of the atoms can be used in causal statements. "The pain caused me to pull my hand back from the fire." This, however, is a "super-" cause, emerging from the first order cause (or explanation) involving atoms bumping into each other according to the laws of nature at the micro level.

Edit: Now that I think about it, I may have put a little too much interpretation in my explanation. Superdeterminism just means events can have more than one immediate and sufficient cause. However, I think it's pretty trivial to conclude that this is logically impossible unless all causes are in essence the same, in which case you get what I just described.

So superdeterminism just refers to the principles and laws governing higher order physical regimes?

kote

Aug13-09, 05:20 PM

So superdeterminism just refers to the principles and laws governing higher order physical regimes?

It doesn't necessarily have to do with the physical realm at all. Perhaps everything is in our minds and mental causes and effects are basic to reality. We can even talk about causation in a made up universe with its own rules. Superdeterminism is about logical laws of causation. It's a mode of explanation positing overcausation.

Superdeterminism: One effect can have multiple immediate and sufficient causes.

...but read above for some of how this can and can't work :)

ThomasT

Aug13-09, 11:05 PM

kote, I think you've lost me, so I'm going to go back to your post #73 (on determinism) and work my way to your last post on superdeterminism, nitpicking as I go.

Classical objective causation, the newtonian billiard-ball style particle collision causation, has been disproven by quantum mechanical experiments.Not disproven, but supplanted by qm wrt certain applications. Classical physics is used in a wide variety of applications. Sometimes, in semi-classical accounts, part of a system is treated classically and the other part quantum mechanically.

Historically, this conception of classical physical causation is what was meant by determinism in nature. If that's what we mean now (but I don't think it is) then the conversation is over.I think that's pretty much what's meant -- along the lines of an underlying deterministic wave mechanics. But the conversation isn't over, because this view is reinforced by qm and experiments, not disproven.

Quantum mechanics also suggests that there are forces in the universe that are inherently unknowable. We can only directly measure the location of a particle on our detector, we can't directly measure the quantum forces that caused it to end up at that specific location instead of another. If this aspect of QM is true, then deterministic natural laws, if they exist, are inherently unknowable themselves (and you can further argue whether or not an unfalsifiable physical construct can in principle be considered to exist at all).Yes, quantum theory, at least wrt the standard interpretation, does place limits on what we can know or unambiguously, objectively say about our universe. The assumption of determinism is just that, an assumption. It's based on what we do know about our universe. It places limits on the observations that might result from certain antecedent conditions. It's falsifiable in the sense that if something fantastically different from what we expect vis induction were to be observed, then our current notion of causal determinism would have to be trashed.

Of course, the problem of induction already disallows for proof of physical determinism.Yes, it can't be proven. Just reinforced by observations. Our windows on the underlying reality of our universe are small and very foggy. However, what is known suggests that the deep reality is deterministic and locally causal.

Induction is justified by its continued practical utility. A general understanding for why induction works at all begins with assumption of determinism.

On a practical level it is necessary to assume determinism in nature, and on a macro level things seem to be pretty deterministic. However, on the quantum level where this causation is supposed to be taking place, we have absolutely no idea how anything actually works. We cannot visualize any sort of causation on the quantum level, and we cannot come close to predicting any results.It's almost that bleak, but maybe not quite. There's some idea of how some things work. There are indications that the deep reality of our universe is essentially wave mechanical. But try efficiently modelling some process or other exclusively in those terms.

An assumption of determinism stems from a macroscopic point of view that presupposes a quantum-scale mechanism for physical causation.Ok.

However, when you actually look at the quantum level, no evidence for any such mechanism can be found, and it has been argued that no such mechanism could exist at all.As you indicated earlier, we can't actually look at the quantum level, but the assumption of determinism is kept because there is evidence that there are quantum-scale mechanisms for physical causation.

JoeDawg

Aug14-09, 02:54 AM

Induction is justified by its continued practical utility.

That's 'justifying' induction via induction. Using induction may be practical, even unavoidable, but that sort of 'justification' reduces to a common-sense circular argument, nothing more. And common sense is notoriously unreliable.

Induction is only useful when it works, and its actually a classic example of an 'unjustified' assumption. Nothing wrong with that really, but it places limits on its utility.

ThomasT

Aug14-09, 02:57 AM

kote, before I begin nitpicking again, let me ask -- are you saying that superdeterminism refers to the fact that there are different levels of explanation, ie., either in terms of underlying dynamics or in terms of phenomena which emerge from those underlying dynamics?

That's what you seem to be saying by "superdeterminism: one effect can have multiple immediate and sufficient causes", and in your elaboration on that.

Or, are you saying that the higher order explanation might be referred to as superdeterministic?

If either, I don't think that that's what ueit meant to convey in using the term.

In essence, superdeterminism is just straight determinism with the addition of superfluous 2nd order explanations. A higher order explanation isn't necessarily superfluous, though it might, in a certain sense, be considered as such if there exists a viable lower order explanation for the same phenomenon.

In most cases, we have presumably higher order explanations in lieu of discovering lower order explanations that are presumed to exist vis the assumption of an underlying deterministic dynamics.

Anyway, since there are multiple levels of explanation, your statement above would seem to reduce to superdeterminism = determinism. Which is the conclusion we came to earlier in this thread. In other words, the term superdeterminism is superfluous.

ThomasT

Aug14-09, 04:33 AM

That's 'justifying' induction via induction. Using induction may be practical, even unavoidable, but that sort of 'justification' reduces to a common-sense circular argument, nothing more.We can begin to try to understand the deep reason for why induction works by positing that the underlying reality of our universe is causally deterministic, but that's just a vague precursor to a detailed answer to the question in terms of fundamental dynamics.

The fact that we continue to behave inductively can, at the level of our behavior, be understood as being due to the fact that it usually works.

And common sense is notoriously unreliable.If it were that unreliable, it wouldn't be common.

Induction is only useful when it works ... It usually does work.

... and its actually a classic example of an 'unjustified' assumption. Nothing wrong with that really, but it places limits on its utility.We can treat induction as an assumption, or as a method of reasoning, but it's more generally a basic behavioral characteristic. We behave inductively. It's part of our common behavioral heritage, our common sense.

Hippasos

Aug14-09, 04:55 AM

If it were that unreliable, it wouldn't be common.

Either unreliable or (not?) so often used...

JoeDawg

Aug14-09, 06:23 AM

The fact that we continue to behave inductively can, at the level of our behavior, be understood as being due to the fact that it usually works.

worked, in the past.

Induction reasons from observed to unobserved.
You are reasoning from observed instances, in the past, where induction worked, to as yet unobserved instances in the future.
You're using induction to justify your belief in induction.

We can treat induction as an assumption, or as a method of reasoning, but it's more generally a basic behavioral characteristic. We behave inductively. It's part of our common behavioral heritage, our common sense.
Sure, we behave irrationally all the time.
Using induction involves an unjustified assumption.
That doesn't mean, once we make the assumption we can't proceed rationally.
As Hume said, induction is mere habit.

We can, of course, use it rationally, but we can't justify its usage.

ueit

Aug14-09, 08:51 AM

Using the standard referents for emitter, polarizer, and detector, in a simple optical Bell test setup involving emitter, 2 polarizers, and 2 detectors it's pretty easy to demonstrate that the polarizer settings aren't determined by the detector settings, or by the emitter, or by anything else in the design protocol except "whatever is used to change" the polarizer settings.

That may be true if you only look at the macroscopic description of the detector/emitter/etc. We do not know if the motion of particles in these objects exert an influence on the motion of particles in other objects because we only have a statistical description. The individual trajectories might be correlated even if the average force between macroscopic objects remains null.

It's been demonstrated that the method that's used to change the polarizer settings, and whether it's a randomized process or not, isn't important wrt joint detection rate. What is important is the settings that are associated with the detection attributes via the pairing process -- not how the settings themselves were generated.

I agree but this is irrelevant. Nothing has been demonstrated regarding the individual results obtained.

It's already well established that detector orientations don't trigger emissions

How?

-- and changing the settings while the emissions are in flight has no observable effect on the correlations.

I wouldn't expect that anyway.

If you want to say that these in-flight changes are having some (hidden) effect, then either there are some sort of nonlocal hidden variable(s) involved, or, as you suggest, there's some sort of heretofor unknown, and undetectable, local field that's determining the correlations. Your suggestion seems as contrived as the nonlocal models -- as well as somewhat incoherent wrt what's already known (ie., wrt working models).

The field is the "hidden variable", together with particles' positions, so, in this sense, is not known. However, if this field determines particles' motions it has to appear, on a statistical level as the EM, weak, color field. The question is if such a field can be formulated. Unfortunately I cannot do it myself as I don't have the required skills but I wonder if it could be achieved, or it is mathematically impossible. Now, in the absence of a mathematical formulation it is premature to say that it must be contrived, or that the hypothesis is not falsifiable.

I still don't know what the distinguishing characteristics of a superdeterministic theory are. Can you give a general definition of superdeterminism that differentiates it from determinism? If not, then you're OP is just asking for (conclusive or definitive) arguments against the assumption of determinism. There aren't any. So, the assumption that the deep reality of Nature is deterministic remains the defacto standard assumption underlying all physical science. It isn't mentioned simply because it doesn't have to be. It's generally taken for granted -- not dismissed.

What I am interested is local determinism, as non-local determinism is clearly possible (Bohm's interpretation). There are many voices that say that it has been ruled out by EPR experiments. I am interested in seeing if any strong arguments can be put forward against the use of SD loophole (denying the statistical independence between emitter and detector) to reestablish local deterministic theories as a reasonable research object.

kote

Aug14-09, 09:47 AM

What I am interested is local determinism, as non-local determinism is clearly possible (Bohm's interpretation). There are many voices that say that it has been ruled out by EPR experiments. I am interested in seeing if any strong arguments can be put forward against the use of SD loophole (denying the statistical independence between emitter and detector) to reestablish local deterministic theories as a reasonable research object.

ueit,

Statistics are calculated mathematically from individual measurements. They are aggregate observations about likelihoods. Determinism deals with absolute rational causation. It would be an inductive fallacy to say that statistics can tell us anything about the basic mechanisms of natural causation.

Linguistically, we may use statistics as 2nd order explanations in statements of cause and effect, but it is understood that statistical explanations never represent true causation. If determinism exists, there must necessarily be some independent, sufficient, underlying cause - some mechanism of causation.

Because of the problem of induction, no irreducible superdeterministic explanation can prove anything about the first order causes and effects that basic physics is concerned with.

The very concept of locality necessarily implies classical, billiard-ball style, momentum transfer causation. The experiments of quantum mechanics have conclusively falsified this model.

kote

Aug14-09, 10:03 AM

Not disproven, but supplanted by qm wrt certain applications. Classical physics is used in a wide variety of applications. Sometimes, in semi-classical accounts, part of a system is treated classically and the other part quantum mechanically.

ThomasT, I can treat my sister as if she's my aunt. That doesn't make it true :). Local causation stemming from real classical particles and waves has been falsified by experiments. EPRB type experiments are particularly illustrative of this fact.

Yes, it can't be proven. Just reinforced by observations. Our windows on the underlying reality of our universe are small and very foggy. However, what is known suggests that the deep reality is deterministic and locally causal.

If there is evidence of deep reality being deterministic, I would like to know what it is :). As for the universe being locally deterministic, this has been proven impossible. See above.

Induction is justified by its continued practical utility. A general understanding for why induction works at all begins with assumption of determinism.

So we're supporting determinism by assuming determinism?

As you indicated earlier, we can't actually look at the quantum level, but the assumption of determinism is kept because there is evidence that there are quantum-scale mechanisms for physical causation.

If the evidence is inductive, then since you claim induction relies on an assumption of determinism itself, there is no evidence at all. I'm not denying the idea that there could be evidence for basic determinism, but the only evidence I've seen proposed here so far has been ethical. It has been assumptions about what we should believe and what's practical, rather than what we can know or what's true.

kote

Aug14-09, 10:14 AM

A higher order explanation isn't necessarily superfluous, though it might, in a certain sense, be considered as such if there exists a viable lower order explanation for the same phenomenon.

ThomasT,

If there is no viable lower order explanation then by definition you aren't dealing with a higher order explanation. Higher order explanations, as such, are not necessary, and unless they are reducible to first order explanations, they cannot be sufficient either.

Basically, they aren't true causes (or explanations) at all.

ThomasT

Aug14-09, 05:01 PM

What I am interested is local determinism, as non-local determinism is clearly possible (Bohm's interpretation). There are many voices that say that it has been ruled out by EPR experiments.Lhv formalisms of quantum entangled states are ruled out -- not the possible existence of lhv's. As things stand now, there's no conclusive argument for either locality or nonlocality in Nature. But the available physical evidence suggests that Nature behaves deterministically according to the principle of local causation.

I am interested in seeing if any strong arguments can be put forward against the use of SD loophole (denying the statistical independence between emitter and detector) to reestablish local deterministic theories as a reasonable research object.You've already agreed that the method of changing the polarizer settings, as well as whether or not they're changed while the emissions are in flight, incident on the polarizers, is irrelevant to the rate of joint detection.

The reason that Bell inequalities are violated has to do with the formal requirements due to the assumption of locality. This formal requirement also entails statistical independence of the accumulated data sets at A and B. But entanglement experiments are designed and executed to produce statistical dependence vis the pairing process.

There's no way around this unless you devise a model that can actually predict individual detections.

Or you could reason your way around the difficulty by noticing that the hidden variable (ie., the specific quality of the emission that might cause enough of it to be transmitted by the polarizer to register a detection) is irrelevant wrt the rate of joint detection (the only thing that matters wrt joint detection is the relationship, presumably produced via simultaneous emission, between the two opposite-moving disturbances) . Thus preserving the idea that the correlations are due to local interactions/transmissions, while at the same time modelling the joint state in a nonseparable form. Of course, then you wouldn't have an explicitly local, explicitly hidden variable model, but rather something along the lines of standard qm.

SW VandeCarr

Aug14-09, 06:38 PM

Yes, of course, the presumed existence of hidden variables comes with the assumption of determinism. I don't think anybody would deny that hidden variables exist.

Well, if you assume D then you must be including local hidden variables. Therefore you're rejecting both Bell's Theorem and the Heisenberg uncertainty principle. Moreover, I guess quantum fluctuations at the Planck scale could not be random either.

My reductio ad absurdum argument was based on thermodynamics which at the theoretical level is based on probabilities. If a system can only exist in one possible state and only transit into one other possible state, there is no Markov process. All states exist with p=1 or p=0. (past. present, and future). Under D, probabilities can only reflect our uncertainty. If you plug 0 or 1 into the Gibbs equation, you get positive infinity or 0. Any values in between (under D) are merely reflections of our uncertainty. Yet we can actually measure finite non zero values of entropy in experiments (defined as Q/T or heat/temp). Such results cannot be only reflections of our uncertainty. Remember, there is no statistical independence under D.

None of this either proves or disproves D. I don't think it can be done. It seems to be essentially a metaphysical issue. However, it seems to me (I'm not a physicist) like you have give up a lot to assume D at all scales.

ThomasT

Aug14-09, 10:13 PM

Well, if you assume D then you must be including local hidden variables. Therefore you're rejecting both Bell's Theorem and the Heisenberg uncertainty principle. Moreover, I guess quantum fluctuations at the Planck scale could not be random either.Yes, I'm including local hidden variables. Bell's analysis has to do with the formal requirements of lhv models of entangled states, not with what might or might not exist in an underlying quantum reality. The HUP has to do with the relationship between measurements on canonically conjugate variables. The product of the statistical spreads is equal to or greater than Planck's constant. Quantum fluctuations come from an application of the HUP. None of this tells us whether or not there is an underlying quantum reality. I would suppose that most everybody believes there is. It also doesn't tell us whether Nature is local or nonlocal. So, the standard assumption is that it's local.

None of this either proves or disproves D. I don't think it can be done.I agree.

It seems to be essentially a metaphysical issue.I suppose so, but not entirely insofar as metaphysical constructions can be evaluated wrt our observations of Nature. And I don't think that one has to give up anything that's accepted as standard mainstream physical science to believe in a locally deterministic underlying reality.

ThomasT

Aug14-09, 11:11 PM

Local causation stemming from real classical particles and waves has been falsified by experiments. EPRB type experiments are particularly illustrative of this fact.These are formal issues. Not matters of fact about what is or isn't true about an underlying reality.

If there is evidence of deep reality being deterministic, I would like to know what it is :).It's all around you. Order and predictability is the rule in physical science, not the exception. The deterministic nature of things is apparent on many levels, even wrt quantum experimental phenomena. Some things are impossible to predict, but, in general, things are not observed to happen independently of antecedent events. The most recent past (the present) is only slightly different from 1 second before. Take a movie of any physical process that you can visually track and look at it frame by frame.

There isn't any compelling reason to believe that there aren't any fundamental deterministic dynamics governing the evolution of our universe, or that the dynamics of waves in media is essentially different wrt any scale of behavior. In fact, quantum theory incorporates lots of classical concepts and analogs.

As for the universe being locally deterministic, this has been proven impossible.This is just wrong. Where did you get this from?

Anyway, maybe you should start a new thread here in the philosophy forum on induction and/or determinism. I wouldn't mind discussing it further, but I don't think we're helping ueit wrt the thread topic.

SW VandeCarr

Aug15-09, 05:33 AM

=ThomasT;I suppose so, but not entirely insofar as metaphysical constructions can be evaluated wrt our observations of Nature. And I don't think that one has to give up anything that's accepted as standard mainstream physical science to believe in a locally deterministic underlying reality.

I think we may have to give up more if we want D. You didn't address my thermodynamic argument. Entropy is indeed a measure of our uncertainty regarding the state of a system. We already agreed that our uncertainty has nothing to do with nature. Yet how is it that we can measure entropy as the relation Q/T? The following shows how we can derive the direct measure of entropy from first principles (courtesy of Count Iblis):

http://en.wikipedia.org/wiki/Fundamental_thermodynamic_relation#Derivation_from _first_principles

The assumption behind this derivation is that the position and momentum of each of N particles (atoms or molecules) in a gas are uncorrelated (statistically independent). However D doesn't allow for statistical independence. Under D the position and momentum of each particle at any point in time is predetermined. Therefore there is full correlation of the momenta of all the particles.

What is actually happening when the experimenter heats the gas and observes a change in the Q/T relation (entropy increases)? Under D the whole experiment is a predetermined scenario with the actions of the experimenter included. The experimenter didn't decide to heat the gas or even set up the experiment. The experimenter had no choice. She or he is an actor following the deterministic script. Everything is correlated with everything else with measure one. There really is no cause and effect. There is only a the predetermined succession of states. Therefore you're going to have to give up the usual (strong) form of causality where we can perform experimental interventions to test causality (if you want D).

Causality is not defined in mathematics or logic. It's usually defined operationally where, given A is the necessary, sufficient and sole cause of B, if you remove A, then B cannot occur. Well under D we cannot remove A unless it was predetermined that p(B)=0. At best, we can have a weak causality where we observe a succession of states that are inevitable.

ueit

Aug15-09, 08:45 AM

ueit,

Statistics are calculated mathematically from individual measurements. They are aggregate observations about likelihoods. Determinism deals with absolute rational causation. It would be an inductive fallacy to say that statistics can tell us anything about the basic mechanisms of natural causation.

There is no fallacy here. One may ask what deterministic models could fit the statistical data. If you are lucky you may falsify some of them and find the "true" one. There is no guarantee of success but there is no fallacy either.

Linguistically, we may use statistics as 2nd order explanations in statements of cause and effect, but it is understood that statistical explanations never represent true causation. If determinism exists, there must necessarily be some independent, sufficient, underlying cause - some mechanism of causation.

I don't understand the meaning of "independent" cause. Independent from what? Most probable, the "cause" is just the state of the universe in the past.

Because of the problem of induction, no irreducible superdeterministic explanation can prove anything about the first order causes and effects that basic physics is concerned with.

No absolute proof is possible in science and I do not see any problem with that. Finding a SD mechanism behind QM could lead to new physics and I find this interesting.

The very concept of locality necessarily implies classical, billiard-ball style, momentum transfer causation. The experiments of quantum mechanics have conclusively falsified this model.

This is false. General relativity or classical electrodynamics are local theories, yet they are not based on the billiard-ball concept but on fields.

ueit

Aug15-09, 09:25 AM

Lhv formalisms of quantum entangled states are ruled out -- not the possible existence of lhv's. As things stand now, there's no conclusive argument for either locality or nonlocality in Nature. But the available physical evidence suggests that Nature behaves deterministically according to the principle of local causation.

You've already agreed that the method of changing the polarizer settings, as well as whether or not they're changed while the emissions are in flight, incident on the polarizers, is irrelevant to the rate of joint detection.

The reason that Bell inequalities are violated has to do with the formal requirements due to the assumption of locality. This formal requirement also entails statistical independence of the accumulated data sets at A and B. But entanglement experiments are designed and executed to produce statistical dependence vis the pairing process.

There's no way around this unless you devise a model that can actually predict individual detections.

Or you could reason your way around the difficulty by noticing that the hidden variable (ie., the specific quality of the emission that might cause enough of it to be transmitted by the polarizer to register a detection) is irrelevant wrt the rate of joint detection (the only thing that matters wrt joint detection is the relationship, presumably produced via simultaneous emission, between the two opposite-moving disturbances) . Thus preserving the idea that the correlations are due to local interactions/transmissions, while at the same time modelling the joint state in a nonseparable form. Of course, then you wouldn't have an explicitly local, explicitly hidden variable model, but rather something along the lines of standard qm.

I think I should better explain what I think it does happen in an EPR experiment.

1. At source location, the field is a function of the detectors' state. Because the model is local this information is "old". If the detectors are at 1 ly away, then the source "knows" the detectors' state as it was 1 year in the past.

2. From this available information and the deterministic evolution law the source "computes" the future state of the detectors when the particles arrive there.

3. The actual spin of the particles is set at the moment of emission and does not change on flight.

4. The correlations are a direct result of the way the source "chooses" the spins of the entangled particles. It so happens that this "choice" follows Malus's law.

In conclusion, changing the detectors before detection has no relevance on the experimental results because these changes are taken into account when the source "decides" the particles' spin. Bell's inequality is based on the assumption that the hidden variable that determines the particle spin is not related to the way the detectors are positioned. The above model denies this. Both the position of the detector and the spin of the particle are a direct result of the past field configuration.

ueit

Aug15-09, 09:33 AM

The assumption behind this derivation is that the position and momentum of each of N particles (atoms or molecules) in a gas are uncorrelated (statistically independent). However D doesn't allow for statistical independence. Under D the position and momentum of each particle at any point in time is predetermined. Therefore there is full correlation of the momenta of all the particles.

The trajectory of the particle is a function of the field produced by all other particles in the universe, therefore D does not require a strong correlation between the particles included in the experiment. Also I do not see the relevance of predetermination to the issue of statistical independence. The digits of Pi are strictly determined, yet no correlation exists between them. What you need for the entropy law to work is not absolute randomness but pseudorandomness.

SW VandeCarr

Aug15-09, 03:54 PM

The trajectory of the particle is a function of the field produced by all other particles in the universe, therefore D does not require a strong correlation between the particles included in the experiment. Also I do not see the relevance of predetermination to the issue of statistical independence. The digits of Pi are strictly determined, yet no correlation exists between them. What you need for the entropy law to work is not absolute randomness but pseudorandomness.

Correlation is the degree of correspondence between two random variables. There are no random variables involved in the computation of pi.

Under D, probabilities only reflect our uncertainty. They have nothing to do with nature (as distinct from ourselves). Statistical independence is an assumption based on our uncertainty. Ten fair coin tosses are assumed to be statistically independent based on our uncertainty of the outcome. We imagine there are 1024 possible outcomes, Under D there is only one possible outcome and if we had perfect information we could know that outcome.

Under D, not only is the past invariant, but the future is also invariant. If we had perfect information the future would be as predictable as the past is "predictable". It's widely accepted that completed events have no information value (ie p=1) and that information only exists under conditions of our uncertainty.

I agree that with pseudorandomness the thermodynamic laws work, but only because of our uncertainty given we lack the perfect information which could be available (in principle) under D.

EDIT: When correlation (R^{2}) is unity, it is no longer probabilistic in that no particles move independently of any other. Under D all particle positions and momenta are predetermined. If a full description of particle/field states is in principle knowable in the past, it is knowable in future under D.

ThomasT

Aug20-09, 03:32 PM

What is actually happening when the experimenter heats the gas and observes a change in the Q/T relation (entropy increases)? Under D the whole experiment is a predetermined scenario with the actions of the experimenter included. The experimenter didn't decide to heat the gas or even set up the experiment. The experimenter had no choice. She or he is an actor following the deterministic script. Everything is correlated with everything else with measure one. There really is no cause and effect. There is only a the predetermined succession of states. Therefore you're going to have to give up the usual (strong) form of causality where we can perform experimental interventions to test causality (if you want D).

Causality is not defined in mathematics or logic. It's usually defined operationally where, given A is the necessary, sufficient and sole cause of B, if you remove A, then B cannot occur. Well under D we cannot remove A unless it was predetermined that p(B)=0. At best, we can have a weak causality where we observe a succession of states that are inevitable.The assumption of determinism and the application of probabilities are independent considerations.

I wouldn't separate causality into strong and weak types. We observe invariant relationships, or predictable event chains, or, as you say, "a succession of states that are inevitable". Cause and effect are evident at the macroscopic scale.

Determinism is the assumption that there are fundamental dynamical rules governing the evolution of any physical state or spatial configuration. We already agreed that it can't be disproven.

The distinguishing characteristic of ueit's proposal isn't that it's deterministic. What sets it apart is that it involves an infinite field of nondiminishing strength centered on polarizer or other filtration/detection devices and/or device combinations and propagating info at c to emission devices thereby determining the time and type of emission, etc., etc. So far, it doesn't make much sense to me.

We already have a way of looking at these experiments which allows for an implicit, if not explicit, local causal view.

Anyway, his main question about arguments against the assumption of determinism has been answered, and I thought we agreed on this -- there aren't any good ones.

SW VandeCarr

Aug20-09, 04:04 PM

Anyway, his main question about arguments against the assumption of determinism has been answered, and I thought we agreed on this -- there aren't any good ones.

Of course you can't disprove or really even argue against metaphysical assumptions (except with other metaphysical assumptions). Nature appears effectively deterministic at macro-scales if we disregard human intervention and human activity in general. At quantum scales, it remains to be proven that hidden variables exist. (Afaik, there is no real evidence for hidden variables).Therefore strict (as opposed to effective) determinism remains a matter of taste. In any case, to the extent that science uses probabilistic reasoning, science is not based de facto on strict determinism. Thermodynamics is based almost entirely on probabilistic reasoning. Quantum mechanics is deterministic only insofar as probabilities are determined and confirmed by experiment.

(Note: I'm using "effective determinism" in terms of what we actually observe within the limits of measurement, and "strict determinism" as a philosophical paradigm.)

ThomasT

Aug20-09, 09:31 PM

At quantum scales, it remains to be proven that hidden variables exist. (Afaik, there is no real evidence for hidden variables).I think everybody should believe that hidden variables exist, ie., that there are deeper levels of reality than our sensory faculties reveal to us. The evidence is electrical, magnetic, gravitational, etc., phenomena.

Whether local hidden variable mathematical formulations of certain experimental preparations are possible is another thing altogether. This was addressed by Bell.

Ueit is interested in lhv models. Bell says we're not going to have them for quantum entangled states, and so far nobody has found a way around his argument.

WaveJumper

Aug21-09, 05:46 PM

Anyway, his main question about arguments against the assumption of determinism has been answered, and I thought we agreed on this -- there aren't any good ones.

That's right, but how is it different to the idea that we are living in the Matrix and if no good arguments can be put forward against it, is that a model of the universe that you think should even be considered by science?

ThomasT

Aug21-09, 09:26 PM

That's right, but how is it different to the idea that we are living in the Matrix and if no good arguments can be put forward against it, is that a model of the universe that you think should even be considered by science?One difference is that there are some good reasons to believe in determinism. It seems that our universe is evolving in a somewhat predictable way. There are many particular examples of deterministic evolution on various scales. This suggests some pervading fundamental dynamic(s). So, physics makes that assumption.

We might be in some sort of Matrix. But there's no particular reason to think that we are. The question is, does our shared, objective reality seem more deterministic the more we learn about it?

kote

Aug21-09, 09:34 PM

The question is, does our shared, objective reality seem more deterministic the more we learn about it?

Well I think if you're looking at it that way the answer is very clearly "no" :smile:. QM had to go screw things up with the Copenhagen Interpretation giving up on deterministic objective reality completely. No one questioned it with Newton.

Since you mentioned it, it looks more and more like the world could be discrete, suggesting a structure with limits on its basic numerical accuracy - very Matrix-like.

I don't think science can tell us anything about the issue though. Hume covered that pretty well in my opinion. I do think the assumption of determinism is a rational extension of logic that needs to be made for the world to be intelligible for us.

ThomasT

Aug21-09, 10:04 PM

Well I think if you're looking at it that way the answer is very clearly "no" :smile:. QM had to go screw things up with the Copenhagen Interpretation giving up on deterministic objective reality completely.The CI tells us that the quantum of action and the requirements for objective communication place limits on what we can say about Nature. This has nothing to do with the assumption of determinism, which is a rational extension of what we do observe wrt the evolution of systems on various scales.

Since you mentioned it, it looks more and more like the world could be discrete, suggesting a structure with limits on its basic numerical accuracy - very Matrix-like.The more I learn, the more it seems to me that the world is a fundamentally seamless complex of interacting waveforms in a hierarchy of media. The metaphysical extension of quantization isn't discreteness per se, but rather resonances, harmonics, etc.

But maybe I don't understand what you're getting at here.

I don't think science can tell us anything about the issue though. Hume covered that pretty well in my opinion. I do think the assumption of determinism is a rational extension of logic that needs to be made for the world to be intelligible for us.Science is how we most objectively observe the world and least ambiguously communicate those observations. It wouldn't make much sense for us to talk about the world in any way other than how it seems to us to be evolving -- which is deterministically.

ThomasT

Aug21-09, 10:47 PM

1. At source location, the field is a function of the detectors' state. Because the model is local this information is "old". If the detectors are at 1 ly away, then the source "knows" the detectors' state as it was 1 year in the past.Ok, lets say the setup is A <1ly> E <1ly> B. The emission part of a series of runs begins and ends before the filters/detectors at A and B are even built. After all of the emissions that might possibly be detected in the experiment have been in transit for, say, 10 months, then the experimenters at A and B build their ends and put the stuff in place.

If they've set things up correctly, then when the data sets at A and B are properly paired and correlated with the appropriate angular differences, then you'll see something closely approximating a cos^2 Theta dependency (Malus Law).

But the filters'/detectors' state couldn't have had anything to do with the emission values because the filters/detectors didn't even exist until all of the emissions were already more than 3/4 of the way to the filters/detectors.

2. From this available information and the deterministic evolution law the source "computes" the future state of the detectors when the particles arrive there.But, in the above scenario, the source couldn't have the necessary information, even nonlocally, because there were no filters/detectors to generate a field until long after all of the emissions originated.

Yet the joint results would approximate a Malus Law dependency between angular difference and rate of coincidental detection.

ueit

Aug25-09, 09:10 AM

Ok, lets say the setup is A <1ly> E <1ly> B. The emission part of a series of runs begins and ends before the filters/detectors at A and B are even built. After all of the emissions that might possibly be detected in the experiment have been in transit for, say, 10 months, then the experimenters at A and B build their ends and put the stuff in place.

If they've set things up correctly, then when the data sets at A and B are properly paired and correlated with the appropriate angular differences, then you'll see something closely approximating a cos^2 Theta dependency (Malus Law).

But the filters'/detectors' state couldn't have had anything to do with the emission values because the filters/detectors didn't even exist until all of the emissions were already more than 3/4 of the way to the filters/detectors.

The particles that the detectors are made of existed in one form or another since the big-bang as energy conservation precludes one to bring "new" matter into existence. The field that carries the information about the detectors is centered around each particle of the detector, and also exists since big-bang. This information transfer takes place at the level of fundamental particles not only when an object takes the macroscopic form of a detector.

But, in the above scenario, the source couldn't have the necessary information, even nonlocally, because there were no filters/detectors to generate a field until long after all of the emissions originated.

Yet the joint results would approximate a Malus Law dependency between angular difference and rate of coincidental detection.

See above.

junglebeast

Aug25-09, 10:18 AM

I pointed out that a) contradicts your hypothesis. So clearly SD is outside of what we know. That makes it 100% as speculative as the existence of God, so where is the science in any of this?

All our macroscopic evidence provides us an apparently deterministic view of the world. Current theory asks us to consider this as a mere coincidence that is not always true...but SD is an alternative that reconciles both the quantum experiments as well as our notion that the world is apparently deterministic. Therefore it has more evidence imo (albeit an inconclusive amount)..

ThomasT

Aug25-09, 11:17 AM

The particles that the detectors are made of existed in one form or another since the big-bang as energy conservation precludes one to bring "new" matter into existence. The field that carries the information about the detectors is centered around each particle of the detector, and also exists since big-bang. This information transfer takes place at the level of fundamental particles not only when an object takes the macroscopic form of a detector.This isn't testable. It amounts to saying that god did it. We agreed that superdeterminism is synonymous with determinism, and that there's good reason to assume that Nature is fundamentally deterministic and that it obeys the principle of locality. But this doesn't inform us about the specific mechanisms wrt which processes evolve.

It's been shown that lhv formulations are incompatible with quantum entangled states, and that this doesn't imply that nonlocality is a fact of nature -- but only that the formal requirements rule out an explicitly local realistic account.

Count Iblis

Aug25-09, 11:54 AM

See also here:

http://arxiv.org/abs/0908.3408

ueit

Aug26-09, 08:25 AM

This isn't testable. It amounts to saying that god did it.

Once a mathematical formulation for such a field is found (if it exists) we can say if the theory is testable or not. On the other hand this is no different from classical fields. They have existed since the big-bang. If not, please tell me when a certain object acquired mass and started to feel the gravitational field?

It's been shown that lhv formulations are incompatible with quantum entangled states

Where?

ThomasT

Aug26-09, 01:33 PM

Once a mathematical formulation for such a field is found (if it exists) we can say if the theory is testable or not. On the other hand this is no different from classical fields. They have existed since the big-bang. If not, please tell me when a certain object acquired mass and started to feel the gravitational field?What field? What theory? You say that emission is a function of filter/detector settings. But it obviously isn't, so then you say that this ability of the filter/detector to precipitate emission exists in the ethereal field or the particles that will eventually become the filter/detector. So, I ask you, what's wrong with this?

You're talking about a field that doesn't exist, surrounding objects that don't exist, affecting a process from which they're spacelike separated vis local transmissions/interactions. This isn't good spitballing.

We've already discussed that there are reasons to believe that quantum entanglement is due, exclusively, to local transmissions/interactions. This is what I believe.

However, the problem, if one absolutely must have an explicitly local realist description of entanglement, is in finding a way to express locality in a way that's formally compatible with the required nonseparability (nonfactorability) -- which is due to the required statistical dependence between the separately accumulated data sets, produced by the data pairing process -- of entangled states

ueit

Aug27-09, 06:49 AM

What field? What theory? You say that emission is a function of filter/detector settings. But it obviously isn't, so then you say that this ability of the filter/detector to precipitate emission exists in the ethereal field or the particles that will eventually become the filter/detector. So, I ask you, what's wrong with this?

You're talking about a field that doesn't exist, surrounding objects that don't exist, affecting a process from which they're spacelike separated vis local transmissions/interactions. This isn't good spitballing.

Let's just assume that the field is the classical EM field. We have a electron source and two detectors. From now on, forget their macroscopic appearance, think of them as large groups of quarks and electrons, quark-electron "galaxies", if you want. Now calculate the resultant field (coming from each particle in the three "galaxies") around the location of the source. At certain times the force acting on an electron becomes large enough that the electron starts to move. You select then only those electrons that will be "captured" by the detector-galaxies. This is the type of theory I propose. Tell me what do you think it is wrong about it.

ThomasT

Aug27-09, 02:01 PM

Let's just assume that the field is the classical EM field. We have a electron source and two detectors. From now on, forget their macroscopic appearance, think of them as large groups of quarks and electrons, quark-electron "galaxies", if you want. Now calculate the resultant field (coming from each particle in the three "galaxies") around the location of the source. At certain times the force acting on an electron becomes large enough that the electron starts to move. You select then only those electrons that will be "captured" by the detector-galaxies. This is the type of theory I propose. Tell me what do you think it is wrong about it.In our latest example, there was only one "galaxy", the emitter, wrt which some sort of emission producing field effect could be associated. There could be no no "quark-electron galaxies" associated with filters/detectors at the time of emission, because there were no filters/detectors at the time of emission.

I can almost envision what you're saying. But it's much to vague to be of any use. And anyway, imho, Nature doesn't work that way.

I think the evidence is pretty compelling that the assumption of parameter independence is a good one. The inequalities are being violated because the assumption of outcome independence is necessarily contradicted by the design and execution of Bell tests. So, what you need if you want a viable realistic description that is explicitly local, is a formal locality condition that doesn't include outcome independence.

WaveJumper

Aug30-09, 02:33 AM

So if we roll back the universe 13.7 billion years, does everyone believe that if we have the same 'configuration' of energy states in the singularity, 13.7 billion years later we'd have the absolutely same universe where i would again be typing this post?

Blenton

Aug30-09, 03:08 AM

I do.

WaveJumper

Aug30-09, 06:08 AM

I do.

One weird consequence of such a belief is that the single source of all deterministic reality obviously wants to fool us about its true nature, by implanting in the deterministic sequence of events conflicting concepts of false gods - Jesus, Mohammed, Buddha, etc., the 6-day creation, the 6000 year old Earth, etc. Essentially, according to the deterministic model of the universe, god is not very different from a Nigerian scammer(the fraudulent emails being manifested by holy books).

Descartz2000

Aug31-09, 02:11 AM

One weird consequence of such a belief is that the single source of all deterministic reality obviously wants to fool us about its true nature, by implanting in the deterministic sequence of events conflicting concepts of false gods - Jesus, Mohammed, Buddha, etc., the 6-day creation, the 6000 year old Earth, etc. Essentially, according to the deterministic model of the universe, god is not very different from a Nigerian scammer(the fraudulent emails being manifested by holy books).

I think if there is any kind of consistent logic in the Universe, then 'yes' I believe if re-run and the conditions and configurations were identical, the Universe would lead me to this very spot, sitting here typing. If not, then it seems obvious we live in a world without consistency and the various configurations in the Universe throughout time and their relationships and interactions with each other do not correlate to macro scale phenomena. If the outcome could be different, and let's say I did not exist as a result, or I was washing my car instead of typing at this moment, all of this points to a world where conditions, variables, configurations, and relationships do not consistently correlate with macro scale outcomes.