Is Randomness Real or Just Complex Predictability?

[Pythagorean]

Russ and DrRocket,

I finally found a thread in which ZapperZ and sA responded in more a more coherent way than the previous example.

My interpretation is this:

0) firstly, philosophical determinism and scientific determinism are two different things (just like the problem with "random").

1) QM is scientifically deterministic. The conditions are determined by the state of the system. Different systems will exhibit different behaviors. This is determinism.

2) No physicist will comment on whether the system is philosophically deterministic, because each philosopher (untrained in either the formalism or experimental experience with quantum systems) has their own preconceptions about what deterministic means.

But here's the thread for you to draw your own conclusions:

https://www.physicsforums.com/archive/index.php/t-16253.html

 

[DrRocket]

Russ and DrRocket,

I finally found a thread in which ZapperZ and sA responded in more a more coherent way than the previous example.

My interpretation is this:

0) firstly, philosophical determinism and scientific determinism are two different things (just like the problem with "random").

1) QM is completely scientifically deterministic. The conditions are determined by the state of the system. Different systems will exhibit different behaviors. This is determinism!

2) No physicist will comment on whether the system is philosophically deterministic, because each philosopher (untrained in either the formalism or experimental experience with quantum systems) has their own preconceptions about what deterministic means.

I agree with 0 and 2.

QM is not detereministic. Is it stochastic. In fact the lack of determinism of QM is one of the major stumbling blocks in unifying general relativity with quantum theories.

What is true about QM is that the evolution of the state function is deterministic. At the elementary level that is the implication of the Schrodinger equation.

However, the state function does not determine the events of the system but only the probabilities associated with the various possible outcomes. What is evolving deterministically is a set of probability measures, which is what the state function represents.

The outcome of quantum experiments varies, even with identical conditions. It varies according to the probabilities predicted by the state function for whatever observables are of interest. That is obviously not deterministic. It is in fact the ony example in nature of which I am aware in which probability is fundamenatal and not just an ad hoc model used due to ignorance of the details of the physics.

The fact that macroscopic physics appears to be deterministic is not the issue. This transition from the quantum mechanical to the classical is only partially understood, and is usually explained in terms of "collapse of the wave function" in the Copenhagen interpretation and is also studied under the name of "quantum decoherence" in other circles. It may well be just a manifestation of the law of large numbers, and in my opinion that is most likely the case.

There are also some research avenues being pursued that attempt to find a deterministic model that would still yield the observed quantum effects. This despite the most common interpretation of Bell's theorem which is that hidden variable theories are not viable. The thought there is that the assumptions of Bell's theorem may be erroneous. There are relatively few physicists who are willing to entertain this idea, but among them are Gerardus 'tHooft and there is not a better theorist, particularly with regard to quantum theories, on this planet. Whether this pans out or not is anyone's guess. However, the very existence of this line of inquiry illustrates the stochastic nature of quantum theories.

At the most fundamental level quantum theory is quite obviously stochastic. That is a dead nuts certainty. Any contrary opinion is just plain wrong. Any contrary theoretical approach to mainstream quantum field theories is speculative.

It occurs to me that you may be comingling the notions of "causa"l and "determinism". While the fact that quantum mechanics is not deterministic is clear, the question of causality is not. Causality is not so clear precisely because quantum theory is stochastic. I would agree that physicists are reluctant to address this question, and I am in that camp myself.

 

[Pythagorean]

I agree with 0 and 2.

QM is not detereministic. Is it stochastic. In fact the lack of determinism of QM is one of the major stumbling blocks in unifying general relativity with quantum theories.

What is true about QM is that the evolution of the state function is deterministic. At the elementary level that is the implication of the Schrodinger equation.

However, the state function does not determine the events of the system but only the probabilities associated with the various possible outcomes. What is evolving deterministically is a set of probability measures, which is what the state function represents.

The outcome of quantum experiments varies, even with identical conditions. It varies according to the probabilities predicted by the state function for whatever observables are of interest. That is obviously not deterministic. It is in fact the ony example in nature of which I am aware in which probability is fundamenatal and not just an ad hoc model used due to ignorance of the details of the physics.

The fact that macroscopic physics appears to be deterministic is not the issue. This transition from the quantum mechanical to the classical is only partially understood, and is usually explained in terms of "collapse of the wave function" in the Copenhagen interpretation and is also studied under the name of "quantum decoherence" in other circles. It may well be just a manifestation of the law of large numbers, and in my opinion that is most likely the case.

There are also some research avenues being pursued that attempt to find a deterministic model that would still yield the observed quantum effects. This despite the most common interpretation of Bell's theorem which is that hidden variable theories are not viable. The thought there is that the assumptions of Bell's theorem may be erroneous. There are relatively few physicists who are willing to entertain this idea, but among them are Gerardus 'tHooft and there is not a better theorist, particularly with regard to quantum theories, on this planet. Whether this pans out or not is anyone's guess. However, the very existence of this line of inquiry illustrates the stochastic nature of quantum theories.

At the most fundamental level quantum theory is quite obviously stochastic. That is a dead nuts certainty. Any contrary opinion is just plain wrong. Any contrary theoretical approach to mainstream quantum field theories is speculative.

It occurs to me that you may be comingling the notions of "causa"l and "determinism". While the fact that quantum mechanics is not deterministic is clear, the question of causality is not. Causality is not so clear precisely because quantum theory is stochastic. I would agree that physicists are reluctant to address this question, and I am in that camp myself.

I changed 1) to remove "completely" but you were too quick, so you caught my absolute thinking (which was an error). I think we agree now, even on 1).

The miscommunication comes from determinism, I think. You may have been interpreting my use of the word determinism as similar to the religious notion of determinism, which has roots in "predeterminism" which would say something like "all events are already determined".

But this is not what I'm saying. 1), Scientific determinism refers to the ability to write laws about something, and for them to be more or less true. i.e. we can determine things about the universe. It's not exhaustive, like the religious definition, all outcomes are not predetermined.

Let's look at the tunneling microscope example. This is useful to us. Let's say we set up a finite potential well of some shape such that each electron in a stream has a 5% chance of tunneling. Then we know for every million electrons we drive through it, 50k of them will tunnel. We have determined something about the system that we can exploit and manipulate. There is obviously a chain of causality here, somehow, even though it evades our intuition.

 

[DrRocket]

But this is not what I'm saying. 1), Scientific determinism refers to the ability to write laws about something, and for them to be more or less true. i.e. we can determine things about the universe. It's not exhaustive, like the religious definition, all outcomes are not predetermined.

If that is your definition then Ok, but that is not how the term is used in science.

The scientific defintion of determinism is actually like the religious definition. It does back to Newtonian mechanics and the observation of LaPlace that were one to have complete knowledge of the state of the universe at any particular point in time then all future events are predicted by applicatoin of Newton's laws of motion. Newtonian mechanics is deterministic. So is general relativity. Quantum mechanics is not deterministic.

 

[Pythagorean]

I think they're quite different. Scientific determinism, or causal determinism is about a causal chain. Were getting into ontology vs epistemology at this point. We can only speculate about the causality so far. We can't 'determine' some things about causality with QM but this is not what causal determination is about. You've given your interpretation, for instance, that reality is fundentally numbers? I think? CI uses wave collapse, but there's no concrete physical mechanism for it, so it avoids a discussion on causality.

Anyway, I don't think determinism has changed with QM so much as we've had to change the definition of causality, which affects the definition of causal determinism, since the classical view is insufficient. I also assume QM will eventually be 1up'd, and the underlying reality will be better understood with time and discovery. This is how paradoxes are solved!

Anyway, my question is how does a probabilistic basis undermine causality?

 

[Pythagorean]

Here's an interesting journalism read based on an interview with experimentalists, Conway and Kochen:

http://www.sciencenews.org/view/generic/id/35391/title/Do_subatomic_particles_have_free_will%3F

That makes compelling arguments for non-determinism. There are comments from determinists as well.

 

[unusualname]

DrRocket has the most appealing argument in this thread, for me.

Obviously we can't know for certain whether random exists, but we need it for free-will, so I'm betting random exists, and at a granularity that evolution could make use of, so at (molecular) particle level (not sub-planckian etc).

It's not so friggin bad you know

 

[SW VandeCarr]

To believe in the truly random is to believe in the supernatural. By definition the supernatural is "beyond natural law".

You can make some mathematically justified statements about an infinite 'truly' random sequence that you can't justify for other infinite sequences. For example: A truly random infinite sequence of digits must contain every finite digit sequence.

The proof is straightforward: For any arbitrarily large finite digit sequence within an infinite random digit sequence, the probability of some finite ordered sequence of n digits is $$10^{-n}$$. No matter how large n is, the probability can never be zero. Therefore, any finite sequence that is possible in an infinite random sequence must occur.

By definition, this cannot be said of any infinite digit sequence that is not truly random.

EDIT:You may not consider some mathematical concepts to be "real" or justified (for example, if you are a strict constructivist) , but to say such concepts are "supernatural" is nonsense.

 

[JoeDawg]

Anyway, I don't think determinism has changed with QM so much as we've had to change the definition of causality, which affects the definition of causal determinism, since the classical view is insufficient. I also assume QM will eventually be 1up'd, and the underlying reality will be better understood with time and discovery.

I agree with this. I think conceptually it follows like this:

Newtonian Mechanics->Causation->Determinism->Freewill

The further along you get the less well understood.
Unfortunately, its even worse in terms of modern physics.
We don't really have an understanding of what is described by QM.

Quantum Mechanics->(entanglement??)
Cosmic Mechanics->(dark matter,dark energy?)

I don't think you can really draw much of anything in the way of conclusions about free will from either of these, because they just aren't working on the same level, both in relation to scale and conceptually.

When Newton described gravity he was accused of describing 'action at a distance', because no one understood how an object could affect another one without being in the same region of space. Until Einstein it was all just observation and math... no theory.

 

[unusualname]

By an "event with no cause" I mean one that has no preceding event with which it can be unambiguously mathematically linked.

This is not so difficult to imagine, eg at a space-time singularity, what comes out the other side has no preceding event associated with it in this sense.

If you get non-continuous phenomena or singularities, then the usual causal model's can't apply.

So quantum events might just be the outcomes of plank scale black holes evaporating and their associated singularity, or something similar.

Random just requires a singularity in the mathematical model, certainly nothing supernatural.

 

[GeorgCantor]

There is nothing fundamentally wrong with 'Supernatural', because there is no 'natural' explanation as to why there is something rather than nothing. Everyone is entitled to his/her own beliefs on these questions. People seldomly appreciate what to exist or to be means.

 

[wuliheron]

There is nothing fundamentally wrong with 'Supernatural', because there is no 'natural' explanation as to why there is something rather than nothing.

I'd add that merely defining something as a "singularity" does not mean ipso facto that it is not supernatural. Thus far there is absolutely no proof whatsoever that infinity exists in nature much less singularities and, personally, I can't imagine how one might go about proving their existence.

In his famous Scientific American article on how black holes evaporate Stephen Hawking noted that a black hole could spontaneously emit a color TV or the complete works of Proust just by virtue of how random it is. One person might describe such an event as merely random, while another might describe it as supernatural and both could be correct. To assert that this can only occur with a singularity neither defines singularities as "natural" nor their products.

 

[SMERSH]

Interesting discussion. A few thoughts.

By "random" I assume the definition of an event or events without a "cause" to such an event.

I think if there exists ANY such "random" events without cause then logical induction implies the idea that ANY imaginable (or unimaginable) event is not only possible, but must occur - the genie is effectively out of the bottle so to speak and everything collapses.

Let's imagine a universe ( A type universe ) in which everything has a cause (random does not exist). The "phase space" or possible states of such a universe is effectively "closed", there are certain states of such a universe that are simply impossible because the chain of events could not possibly lead to such a state.

Let's now imagine a universe ( B type universe ) in which NOT everything has a cause, there truly is a "wiggle" room somewhere for some event or events to occur outside of the chain of causality. Immediately, I think this creates an open "phase space" of possible states since such uncaused events can trigger an ever larger chain reaction of larger events that dramatically alter the state of the universe into an infinite vareity of possible states - anything is possible in such a universe.

Not only will random events in such a B type universe by definition be "outside" any framework of laws in this universe (since they are uncaused), but these events could then in turn cause a chain of events such that whatever laws exist in the B type universe are inconsistent.

For example in the B universe A causes B causes C by some given law in universe type B. Random event D occurs which prevents A from causing B. All of a sudden the causal chain in this universe is broken - that means the law of that universe is broken or inconsistent.

For any given law in a B type universe, the same scenario would exist as stated in the prior paragraph so such a B type universe would have NO universal laws - and randomness seems to take over everything in such a universe by inductive logic - like some kind of virus.

Is such a B type universe even possible and logically coherent? Perhaps Einstein had a point when he difficulty with such a universe when he said "God does not play dice"... this idea seems to lead to total chaos.

 

[unusualname]

There is nothing fundamentally wrong with 'Supernatural', because there is no 'natural' explanation as to why there is something rather than nothing. Everyone is entitled to his/her own beliefs on these questions. People seldomly appreciate what to exist or to be means.

By "supernatural" I usually assume people mean stuff that can't ever be explained by physics/mathematics.

Since random can come out the other end of a black-hole singularity it doesn't need to be "supernatural".

I'm only suggesting that quantum mechanics can have a truly random nature without huge leaps of imagination into the "supernatural", though obviously Planck-scale black holes evaporating is a wildly speculative guess.

 

[Pythagorean]

I'd add that merely defining something as a "singularity" does not mean ipso facto that it is not supernatural. Thus far there is absolutely no proof whatsoever that infinity exists in nature much less singularities and, personally, I can't imagine how one might go about proving their existence.

In his famous Scientific American article on how black holes evaporate Stephen Hawking noted that a black hole could spontaneously emit a color TV or the complete works of Proust just by virtue of how random it is. One person might describe such an event as merely random, while another might describe it as supernatural and both could be correct. To assert that this can only occur with a singularity neither defines singularities as "natural" nor their products.

Well, I agree with you in the ideal case, but I think "singularities" in physics are already taken to be ideals. So a real singularity will just involve really big numbers (i.e. a large amount of mass in a small amount of space). Not necissarily an inifinite amount of mass existing in 0 space.

But I agree, infinite doesn't seem to exist in nature.

 

[Pinu7]

John Baez would answer the OP with 'yes.' His argument (the Bayesian interpretation) can be found here: http://math.ucr.edu/home/baez/bayes.html

Personally, I believe the opposite since an empirical description of the universe need no notion of 'pure randomness.' All of it is statistical.

 

[unusualname]

I'd add that merely defining something as a "singularity" does not mean ipso facto that it is not supernatural. Thus far there is absolutely no proof whatsoever that infinity exists in nature much less singularities and, personally, I can't imagine how one might go about proving their existence.

Singularities are not a big deal, they just occur in certain mathematical models. If we describe the world by mathematics then we should accept singularities, and that what comes out the other side can not be causally related to what preceded it.

Of course, you may not believe mathematics can describe the world, but that's up to you.

 

[GeorgCantor]

But I agree, infinite doesn't seem to exist in nature.

Einstein disagrees with you:

"Only two things are infinite - the universe and human stupidity, and I'm not sure about the former.

 

[GeorgCantor]

Singularities are not a big deal, they just occur in certain mathematical models.

They are not?? Quantum gravity is a piece of cake for you?

If we describe the world by mathematics then we should accept singularities, and that what comes out the other side can not be causally related to what preceded it.

What is it that 'comes out the other side'? And what is "the other side"?

If you were alluding to the term 'Hawking radiation', it's still just a hypothesis/guess.

 

[unusualname]

They are not?? Quantum gravity is a piece of cake for you?

No, of course not, we haven't worked out how to deal with singularities yet, what I mean is their occurrence is natural in our mathematical models, there's nothing "supernatural" in explaining their occurrence

What is it that 'comes out the other side'? And what is "the other side"?

If you were alluding to the term 'Hawking radiation', it's still just a hypothesis/guess.

What comes out the other side is a new event unrelated mathematically to anything that preceded it, hence it's random.

I have no idea how to explain the possible selection mechanism this "new event" will undertake, other than to say it is "random". Something I do believe is that human consciousness allows for influencing the "selection" of certain quantum events, which allows us free-will, but I don't want to sound like a crank by expounding any further, thanks.

 

[apeiron]

Is such a B type universe even possible and logically coherent? Perhaps Einstein had a point when he difficulty with such a universe when he said "God does not play dice"... this idea seems to lead to total chaos.

This is why I would take a different approach (the Peircean approach) postulating that reality is fundamentally free, but self-organises through the development of global constraints.

So anything could happen (there is this essential spontaneity where things can happen without cause). But then all this free action must lead to some kind of interaction. One kind of random fluctuation will have an impact on all the others. And out of this mutual interaction must arise some global state. This global state will then have a downwards causal effect - it will act as a constraining context, actively limiting the free fluctuations.

So reality is both fundamentally free (spontaneous) and yet this in turn must produce self-organising constraints that in fact fundamentally limit the expression of this freedom.

Sounds like QM and decoherence to me. And it gives us back what we can recognise as both the random and determined - local limited fluctuations and globally classical organisation.

 

[GeorgCantor]

No, of course not, we haven't worked out how to deal with singularities yet, what I mean is their occurrence is natural in our mathematical models, there's nothing "supernatural" in explaining their occurrence.

Right now i believe there are at least 1000 gifted phd's and Nobel Prize winners working day and night to remove this most 'natural' occurence in the mathematics.

What comes out the other side is a new event unrelated mathematically to anything that preceded it, hence it's random.

There is no other side. Hollywood movies suck.

 

[wuliheron]

Well, I agree with you in the ideal case, but I think "singularities" in physics are already taken to be ideals. So a real singularity will just involve really big numbers (i.e. a large amount of mass in a small amount of space). Not necissarily an inifinite amount of mass existing in 0 space.

But I agree, infinite doesn't seem to exist in nature.

In either case, what occurs is that the laws of nature as we know them break down. You could argue that some other laws may still apply, but that is entirely speculative and still doesn't mean that those laws actually apply in our universe. Thus, at the very least, we can still say it is supernatural within the context that it does not follow the laws of nature in our universe.

Singularities are not a big deal, they just occur in certain mathematical models. If we describe the world by mathematics then we should accept singularities, and that what comes out the other side can not be causally related to what preceded it.

Of course, you may not believe mathematics can describe the world, but that's up to you.

The issue isn't just whether the world can be described by mathematics, but exactly what mathematics describe the world and which don't. That infinity is a useful concept goes without saying, but the question remains as to whether or not it represents reality.

 

[unusualname]

Right now i believe there are at least 1000 gifted phd's and Nobel Prize winners working day and night to remove this most 'natural' occurence in the mathematics.

I think that's not quite accurate, what people are trying to do is accommodate singularities in their models.

Perhaps we really should embrace them since they give us a mechanism for random in QM, and the appealing argument that, since our consciousness might actually be a quantum system, we then (uniquely in the universe) can influence the selection mechanism

The issue isn't just whether the world can be described by mathematics, but exactly what mathematics describe the world and which don't. That infinity is a useful concept goes without saying, but the question remains as to whether or not it represents reality.

If you are non-spiritual then I think you will have to accept that mathematics can fully describe the universe and if singularities are predicted then singularities are what we have.

 

[wuliheron]

If you are non-spiritual then I think you will have to accept that mathematics can fully describe the universe and if singularities are predicted then singularities are what we have.

No, it is quite easy to merely take the pragmatic stance without having to invoke spirituality much less any unsubtantiated metaphysical beliefs in mathematics. For me it is a moot point whether or not either one is true. What matters is merely whether they are useful.

 

[unusualname]

No, it is quite easy to merely take the pragmatic stance without having to invoke spirituality much less any unsubtantiated metaphysical beliefs in mathematics. For me it is a moot point whether or not either one is true. What matters is merely whether they are useful.

well, at some stage you have to explain free-will, I've done it with a possible mathematical model, how do you explain it?

 

[wuliheron]

well, at some stage you have to explain free-will, I've done it with a possible mathematical model, how do you explain it?

I wasn't aware that freewill demanded explanation.

Again, what matters is if the concept is useful and everything else takes a backseat to that simple fact of life. Thus it becomes possible to view everything in relative terms: language, quanta, freewill, or whatever without contradiction and, in the end, it is nature who plays the role of ultimate arbiter as to what is useful.

 

[unusualname]

I wasn't aware that freewill demanded explanation.

Again, what matters is if the concept is useful and everything else takes a backseat to that simple fact of life. Thus it becomes possible to view everything in relative terms: language, quanta, freewill, or whatever without contradiction and, in the end, it is nature who plays the role of ultimate arbiter as to what is useful.

It certainly does demand an explanation, which boils down to, how random events might exist and how we might be able to influence them.

Well, singularities explain how they might exist, and then the fact that if we actually are a (quantum) system in which the random events occur we might be able to "choose" them. ie That's what we are - a product of evolution which allows us to choose what happens to this post-singularity event after a Planck-scale black-hole collapses.

You can argue that all particles have "free-will" with this explanation but they, boringly, just do it "randomly", we have a complex emergent system out of which our desires etc arise.

 

[wuliheron]

It certainly does demand an explanation, which boils down to, how random events might exist and how we might be able to influence them.

Why does freewill demand explanation? I see no compelling reason to explain freewill anymore than I might feel compelled to find out why my TV remote died. I might spend a million dollars isolating the cause, or I can simply buy a new one. Either way the end result is the same: I buy a new remote and move on.

 

[unusualname]

Why does freewill demand explanation? I see no compelling reason to explain freewill anymore than I might feel compelled to find out why my TV remote died. I might spend a million dollars isolating the cause, or I can simply buy a new one. Either way the end result is the same: I buy a new remote and move on.

It depends how concerned you are with understanding the human condition.

I believe mathematics can fully describe us, but that doesn't have to imply determinism. Not only have you got the possibility of the causal chain going through a singularity you also have the possibility that there are transitions from lower dimensions to higher dimensions in the dynamics of microscopic phenomena. At the boundary where the higher dimensions become available you have new degrees of freedom which need not have any causal mechanism which depends on the preceding lower dimensional event.

This is the philosophy section so I guess it's ok to hand-wave like this, I obviously haven't got a detailed scientific model, but with the current state of affairs in Physics all sorts of exotic models look possible

Statistical physics can explain the large scale determinism of the universe even if the microscopic particles are behaving randomly, a single particle has no mechanism to invoke "free-will" and "choose" its behaviour, but if you actually are the particle or a more complex system consisting of many particles then it seems reasonable that you might be able to influence the random selection of events.

In any case, if random doesn't exist then we have super-determinism, and that implies that everything is pretty pointless.

We don't know if random exists, but I rather hope it does, and it can be fully consistent with a mathematical model of the universe without invoking the "supernatural"

 

[wuliheron]

It depends how concerned you are with understanding the human condition.

Then it is not freewill that demands explanation but, instead, merely some people that demand an explanation for personal reasons.

In any case, if random doesn't exist then we have super-determinism, and that implies that everything is pretty pointless.

We don't know if random exists, but I rather hope it does, and it can be fully consistent with a mathematical model of the universe without invoking the "supernatural"

Another possibility is that the issue is simply beyond human comprehension or, at least, beyond science or does not follow the principle of the excluded middle in any classical sense. Using nature to study nature is one thing, while using nature to establish the ultimate "nature-of-nature" is another and any results obtained are suspect.

 

[unusualname]

Another possibility is that the issue is simply beyond human comprehension or, at least, beyond science or does not follow the principle of the excluded middle in any classical sense. Using nature to study nature is one thing, while using nature to establish the ultimate "nature-of-nature" is another and any results obtained are suspect.

It is not beyond human comprehension any more than understanding why one event can determine another, we simply allow that also, there are events that aren't determined because the mathematical model doesn't allow for them to be determined by what preceded.

 

[jostpuur]

wuliheron has very slippery discussion style.

Instead of responding to any single comment in this thread, people should take a look at earlier posts and try to see if the discussions seems to have any direction in it.

 

[wuliheron]

wuliheron has very slippery discussion style.

Instead of responding to any single comment in this thread, people should take a look at earlier posts and try to see if the discussions seems to have any direction in it.

Slippery or merely supportive of your views?