Quantum theory & the premises of Kalam cosmological argument

[ZackMartin]

OK Juice, here is the post I promised you. This thread is only to address the question of whether quantum theory contains counterexamples to the principle "Everything that begins to exist has a cause", which is the first premise of the Kalam Cosmological Argument (KCA)

Claim: "Virtual particles begin to exist, but do not have a cause". If this claim is true, we have a counterexample to the principle.

Juice responds: "Virtual particles begin to exist, but they do have a cause - they are caused by the quantum vacuum" (I hope I have described your view correctly)

I say: First of all we need to define "causation". And the problem here is that different people define "causation" in different ways. But Juice says he is willing to let me define it as I wish, so I will share my definition of causation. Next I will attempt to apply this definition to virtual particles in quantum physics.

Causation: Firstly, we need to appreciate that causation is the opposite of irreducible chance. Determinism is the opposite of indeterminism. If an event happened without a cause, then nothing that came before it in time would be relevant to its happening, and even if we knew perfectly the entire history of the universe before it, then that knowledge would enable us to predict nothing about this uncaused event. It would be an event which occurred by pure, irreducible, chance. By contrast, if the event is caused, then the properties of whatever caused are relevant to its properties, and in principle we can predict the event accurately based on its cause.

Chance: We need to understand the difference between reducible and irreducible chance. Many complex systems behave in a seemingly random manner; but their random behaviour is compatible with them being completely deterministic. Very often, chance is simply causes too complex for us to comprehend. This is the kind of chance which classical physics deals with. If a container contains a billion gas molecules, bouncing into each other constantly, their movements could be perfectly deterministic; but their motions are so complex, and impossible to us to predict in practice, that they appear to us random. So there is chance here, but chance fundamentally reducible to cause. But quantum physics, according to many interpretations of it, introduces a different type of chance - irreducible chance, not reducible to causation.

So, let me share my rough definition of causation: A causes B if, perfect knowledge of every fact about A, would enable us to predict B precisely. Let's add the elements, that B can't be part of A, and that A must wholly precede B. I think we can make this more formal using the mathematical concept of Kolmogorov complexity. The conditional Kolmogorov complexity K(x|y) is the length of the shortest program that produces x as output given y as input. The unconditional Kolmogorov complexity K(x) is equal to K(x|λ), where λ is the empty string.

If we have perfect knowledge of A, we can reduce that knowledge to a bit string a that describes A; likewise a bit string b that describes B. Now comparing the conditional Kolmogorov complexity K(b|a) to the unconditional Kolmogorov complexity K(b) - if A causes B, K(b|a) will be a lot smaller than K(b), while if A does not cause B, K(b|a) will be roughly equal to K(b). In other words, K(b|a)/K(b) is close to zero if A causes B, and close to unity if A does not cause B, and in-between (if there are other causes of B than A, or if B is partially but not fully due to irreducible chance.) Now, maybe you can see some technical problems with this definition (I can); I think those problems have solutions - but to avoid too many digressions, for now I'm going to pretend I don't see them unless you happen to bring them up. The gist of the idea - that we can define causation as a mathematical relation between bodies of information - is more important here than if the formula is exactly right.

Now consider the claim that "Virtual particles arising in a pure quantum vacuum are uncaused". This is asserting, that whichever A you choose, whether it be the entire history of the universe prior to B, or some subset thereof, it will not help you in any way predict B; knowledge of A does not help you predict anything about B, hence A does not cause B. Whereas, your claim that "Virtual particles are caused by the quantum vacuum in which they arise", is asserting that somehow knowledge of that vacuum would enable us to accurately predict the properties of the virtual particles that arose.

If hidden variable theory is false, then the claim "The quantum vacuum causes virtual particles" is false, and the claim "Virtual particles begin to exist without a cause" is true.

The question is, as a matter of physics, which position is more correct? Well, if the hidden variables interpretation is true, then there is no irreducible chance, reality is ultimately deterministic, and hence virtual particles really are caused by the vacuum state beforehand, even if it be a hidden state. However, given most other interpretations of quantum theory, virtual particles really are the products of irreducible chance, and no amount of information of the state of the vacuum beforehand will enable us to predict them.

Which interpretation is correct? No one claims to really know; however, the majority of physicists don't accept the hidden variables (Bohm) interpretation. For example, see this paper, in an informal poll only 8% of physicists agreed with Bohm. While this poll is rather unscientific, everyone says the same thing - hidden variables is a distinctly minority view in contemporary physics. They have at least some decent factual reasons for this belief - it's questionable how scientific hidden variables are, unless someone can devise an experiment which demonstrates these hidden variable's existence (in which case they wouldn't be entirely "hidden" any more) - while maybe someone will some day, so far no one has managed to come up with such an experiment. Secondly, experimental demonstration of the EPR paradox poses problems for many hidden variables theories, although it doesn't rule out all of them, has lead many physicists to believe that hidden variable theories are less likely.

So I would say, virtual particles are a counterexample to KCA if (1) my theory of causation is correct, (2) hidden variable theory is false. Based on the collective judgement of contemporary physics, (2) is probably true - hidden variable theories are probably false. So unless there is something major wrong with my theory of causation, virtual particles are a counterexample to KCA.

[MaxVel]

This might be a completely irrelevant question, but:

If we take away the quantum vacuum is it still possible for virtual particles to begin to exist?

[magellan004]

So, let me share my rough definition of causation: A causes B if, perfect knowledge of every fact about A, would enable us to predict B precisely.

I agree with the above.

The question is, as a matter of physics, which position is more correct?

Indications are that what we see as chance today becomes determined tomorrow through more knowledge . For example if we knew everything about say, the weather systems, then there would be no chance in predicting weather. We could determine tomorrow's weather. As far as I know we never find that a previous 'cause' turns out to be replaced by 'Just a matter of chance'. So I don't think we need to use polls of physicists. The record shows random chance is a label used for things that have a presently unknown cause. And no 'random cause' can be scientifically confirmed.

So I would say that it's reasonable to view the Quantum vacuum as an unknown but non-random 'space'. And therefore products of the quantum vacuum can be predicted.

(I have noticed your explanation of various things and I really like the way you go through everything thoughtfully.)

Magellan

[shunyadragon]

I agree with the above.


Indications are that what we see as chance today becomes determined tomorrow through more knowledge . For example if we knew everything about say, the weather systems, then there would be no chance in predicting weather. We could determine tomorrow's weather. As far as I know we never find that a previous 'cause' turns out to be replaced by 'Just a matter of chance'. So I don't think we need to use polls of physicists. The record shows random chance is a label used for things that have a presently unknown cause. And no 'random cause' can be scientifically confirmed.

So I would say that it's reasonable to view the Quantum vacuum as an unknown but non-random 'space'. And therefore products of the quantum vacuum can be predicted.

(I have noticed your explanation of various things and I really like the way you go through everything thoughtfully.)

Magellan

I am puzzled by your use of the word 'chance' in this post. It needs more explanation, and is likely more akin to the layman's view of random, which does not make much sense in science.. The reason why weather is difficult to predict is that determining variables of weather are numerous, and computer chaos fractal models are what are used today to make weather predictions, which are much much better than used even 30 to 40 years ago. Since divergent alternates in weather prediction increase with time, weather forecasting becomes limited as the time factor increases.

[magellan004]

I am puzzled by your use of the word 'chance' in this post. It needs more explanation, and is likely more akin to the layman's view of random, which does not make much sense in science.. The reason why weather is difficult to predict is that determining variables of weather are numerous, and computer chaos fractal models are what are used today to make weather predictions, which are much much better than used even 30 to 40 years ago. Since divergent alternates in weather prediction increase with time, weather forecasting becomes limited as the time factor increases.

In Post 1 Zack was addressing this issue: 1. "Virtual particles begin to exist, but do not have a cause". 2. ' "Virtual particles begin to exist, but they do have a cause - they are caused by the quantum vacuum"
As I understood it - he was saying (basically) that if a thing happens by chance then it does not have a cause. No matter how much information we had, we could never predict that outcome.

Firstly, we need to appreciate that causation is the opposite of irreducible chance. Determinism is the opposite of indeterminism. If an event happened without a cause, then nothing that came before it in time would be relevant to its happening, and even if we knew perfectly the entire history of the universe before it, then that knowledge would enable us to predict nothing about this uncaused event. It would be an event which occurred by pure, irreducible, chance. By contrast, if the event is caused, then the properties of whatever caused are relevant to its properties, and in principle we can predict the event accurately based on its cause.

Using ' layman's' terms (as you say) - if things pop out of the quantum vacuum at random, then it does not make much sense in science. That's all I was saying.

Magellan

[shunyadragon]

[QUOTE=magellan004;3404035]In Post 1 Zack was addressing this issue: 1. "Virtual particles begin to exist, but do not have a cause". 2. ' "Virtual particles begin to exist, but they do have a cause - they are caused by the quantum vacuum"

I believe cause is misused here. Virtual particles appear in the quantum vacuum, I do not believe it is considered tha cause, only the medium for Virtual particles.

The following gives some idea, but it is too brief. You need to do further reading . . .

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

The concept of virtual particles arises in the perturbation theory of quantum field theory, an approximation scheme in which interactions (in essence, forces) between real particles are calculated in terms of exchanges of virtual particles. Any process involving virtual particles admits a schematic representation known as a Feynman diagram, which facilitates the understanding of calculations.

© source where applicable

It may be described that virtual particles are a result of the physical nature of the zero-state field in the Quantum Vacuum. There is no known 'cause for virtual properties.

As I understood it - he was saying (basically) that if a thing happens by chance then it does not have a cause. No matter how much information we had, we could never predict that outcome.

Whether something is the result of chance (?) or not has nothing to do with 'cause,' which in this case is unknown.

Using ' layman's' terms (as you say) - if things pop out of the quantum vacuum at random, then it does not make much sense in science. That's all I was saying.

Magellan

No, Virtual particles definitely do make sense in science. There is no known contradiction here to scientific theories and hypotheses. There is simply no known specific cause to the existence of virtual particles.

Yes, the randomness that is observed in the behavior of Virtual particles is one of the few known observances of true randomness in nature, but it is a predictable behavior of virtual particles. We do not have virtual particles behaving differently.

Chance and the use of random in layman's language really do not have a parallel in science.

'Random' in science may be used to describe the occurance of events where the more than one result or outcome may have equal probability. In our macro world these 'random events' do not show random results, but show fractal pattern based on chaos theory, and the outcome is constrained by the laws of nature and the environment. Basically this randomness has a predictable pattern.

[ZackMartin]

If we take away the quantum vacuum is it still possible for virtual particles to begin to exist?

I'm not sure how we can answer that. What does it mean to "take away the quantum vacuum"? What are you proposing would exist in its place?

[robertb]

I'm not sure how we can answer that. What does it mean to "take away the quantum vacuum"? What are you proposing would exist in its place?

A philosophical nothing.

[ZackMartin]

Indications are that what we see as chance today becomes determined tomorrow through more knowledge . For example if we knew everything about say, the weather systems, then there would be no chance in predicting weather. We could determine tomorrow's weather.

Yet impossible in practice, and probably always will be, due to the sensitivity to initial conditions in chaotic systems. Weather prediction is the classic field of application of chaos theory - in fact, much of chaos theory started out in research into computerised weather prediction.

As far as I know we never find that a previous 'cause' turns out to be replaced by 'Just a matter of chance'. So I don't think we need to use polls of physicists. The record shows random chance is a label used for things that have a presently unknown cause. And no 'random cause' can be scientifically confirmed.

So I would say that it's reasonable to view the Quantum vacuum as an unknown but non-random 'space'. And therefore products of the quantum vacuum can be predicted.

So, you are an advocate of hidden variable theories. Yet most physicists disagree with you. Thought about why?

One reason is Bell's theorem, which has at least partially been experimentally verified. Bell's theorem doesn't completely rule out hidden variable theories, but it largely rules out local ones. The most well-known hidden variable theory is Bohm's, which is explicitly non-local.

All our experience in physics so far indicates that the laws of physics are local - i.e. information cannot travel faster than the speed of light in a vacuum. Yet, Bohm's theory violates that experience.

So it comes down to what you want to give up - Bell's theorem says you must give up at least one of fundamental determinism, locality, or counterfactual definiteness. You don't want to sacrifice determinism, but Bell's theorem then forces you to sacrifice one of the others instead - and our collective experience teaches us the other two as much as it does determinism. Most physicists feel that of the three, they'd rather give up determinism than locality or counterfactual definiteness. Bohm decides to give up locality and keep determinism. (Although technically, one could keep both determinism and locality by giving up counterfactual definiteness, this is for now a purely theoretical possibility - no one has proposed an actual theory having that property, and most physicists think it rather unlikely anyone will ever succeed in doing so.)

[ZackMartin]

A philosophical nothing.

I'm not sure if that idea is even coherent. I tend to think it isn't. I'm not sure how we can determine whether it is coherent or not, either.

[ZackMartin]

I am puzzled by your use of the word 'chance' in this post. It needs more explanation, and is likely more akin to the layman's view of random, which does not make much sense in science.. The reason why weather is difficult to predict is that determining variables of weather are numerous, and computer chaos fractal models are what are used today to make weather predictions, which are much much better than used even 30 to 40 years ago. Since divergent alternates in weather prediction increase with time, weather forecasting becomes limited as the time factor increases.

It's the difference between the pseudorandom and the truly random. The digits of pi are not truly random, they are only pseudorandom - there is a procedure to calculate them. Consider the digits of one of Chaitin's constants (minus the finite computable prefix) - we can prove that there is no procedure to calculate them. Chaitin's constants are closer to true randomness than PI is. Reducible chance is pseudorandomness, but irreducible chance is true randomness.

[MaxVel]

I'm not sure how we can answer that. What does it mean to "take away the quantum vacuum"? What are you proposing would exist in its place?

Well, let me put it another way, then.

Is the existence of virtual particles contingent on anything?


(A following question would be 'Is the Quantum vacuum contingent?')

[ZackMartin]

Yes, the randomness that is observed in the behavior of Virtual particles is one of the few known observances of true randomness in nature, but it is a predictable behavior of virtual particles. We do not have virtual particles behaving differently.

The randomness of virtual particles is predictable, but the precise form that randomness takes is not.

Chance and the use of random in layman's language really do not have a parallel in science.

I'm not using words in a "layman's" sense. In the layman's sense, there is no distinction between reducible and irreducible chance. In the philosophy of physics, there is.

'Random' in science may be used to describe the occurance of events where the more than one result or outcome may have equal probability. In our macro world these 'random events' do not show random results, but show fractal pattern based on chaos theory, and the outcome is constrained by the laws of nature and the environment. Basically this randomness has a predictable pattern.

A truly random number can still have predictable components. Take one of Chaitin's constants, let us call that C. Now write down C as an infinite binary string. Now, change every second bit to 0. Now you have a number with a partly predictable pattern, but it is still an uncomputable number, and hence still truly random.

[ZackMartin]

s the existence of virtual particles contingent on anything?


(A following question would be 'Is the Quantum vacuum contingent?')

An interesting question - but how to answer it? What exactly does "contingent" mean? Now that's an interesting philosophical question.

The most common answer seems to be possible worlds - X is contingent if there exists a possible world in which X is false. (Leaving aside the difficult question of what if anything a "possible world" is, exactly.)

So, is there a possible world in which virtual particles don't exist?

I'm not sure how we can even begin to answer that question. One person might say "No", another could say "Yes", and we have no clear way of determining who is right.

So I'm inclined to think your question is unanswerable.

[robertb]

I'm not sure if that idea is even coherent. I tend to think it isn't. I'm not sure how we can determine whether it is coherent or not, either.

Indeed. That is the question which lies beyond the proverbial horizon, I suppose.

The reason for my quip was to cut to the chase, as this is usually where these types of discussions end up.

In principle, it seems that even though we may conceive of an absolute nothing, that this fact alone does not immediately mean that such a situation is actually possible in reality. In other words a basic state of energy may be the absolute bottom turtle after all.