Quantum Mechanics - Schools of interpretation

[Ginkgo]

Tell me what's wrong with this interpretation:

I have two dice in a can and am rattling them around just before throwing them down on the table. The possible outcomes are 2 through 12 dots showing as the future observation, when the dice come to rest on the table, with various probabilities. Conceptually, there is a distribution of possible outcomes associated with my rattling can -- a "wave" function (probability distribution) of outcomes that "collapses" when I throw the dice onto the table and the dice settle down and stop moving.

Theoretically we could use the physics of mechanics to predict the outcome, if we knew all of the relevant data about the dice and can (their physical properties) and the forces involved in the shaking and rattling of the can. But this is impossible, so we build a probability model based on the assumption of equally probable (1/6) outcomes for the individual dice and the laws of probability for compound events. Of course, a physical die is not perfectly balanced, etc, but barring badly lopsided dice, the wave function describing all possible outcomes is usually good enough, assuming one or more of the dice don't get lost from a wild throw-down.

Mike, I don't think there is anything wrong with this provided that we accept live in a completely deterministic universe. In other words, the laws of probability are not really probable because we cannot take into account all of the relevant factors. Things just appear to be probable. If we could somehow calculate all of the variables involved then we would discover that all events of the past and all the events into the future were and are determined by the laws of physics.

The only problem with this is that most interpretations of quantum mechanics refutes these ideas.

[Mike Strand]

Thanks, Ginkgo.

At one point, Einstein said "God doesn't play dice with the universe". I don't know if this was his final opinion, but it suggests that he believed in deterministic physics. It suggests that models based on probability theory are used in quantum theory, like it is in throwing dice, because we don't know all of the influencing factors involved -- either what they are or what their values are, etc.

My impression is that virtually all present quantum theorists reject this idea. But this rejection may be hubristic. Who is to say that human beings are even capable of listing all of the causal factors, let alone pin them down enough to make predictions? With the recent validation of the Higgs particle, I get the impression that quantum theorists are saying there's nothing more to discover. Hmmm .... where in past history has that attitude been expressed and found to be in error?

The dice example is, I think, revealing. It reflects an everyday situation with familiar types of factors that influence the outcome of the throw, and yet it's impossible to predict the outcome of a single throw. This is why a probability model is used to approximate what's going on with the dice and to make predictions about average outcomes and the distribution of outcomes -- but never an individual outcome.

So the dice analogy is possibly a portent: That at the subatomic scale there are forces and factors involved that we currently cannot pin down. Luckily, we can use a probability model to predict average outcomes and the distribution of outcomes. However, this doesn't mean that such factors will never be discovered, even if, as in the dice example, we won't be able to know them well enough to make predictions of individual outcomes.

[Ginkgo]

Thanks, Ginkgo.

At one point, Einstein said "God doesn't play dice with the universe". I don't know if this was his final opinion, but it suggests that he believed in deterministic physics. It suggests that models based on probability theory are used in quantum theory, like it is in throwing dice, because we don't know all of the influencing factors involved -- either what they are or what their values are, etc.

My impression is that virtually all present quantum theorists reject this idea. But this rejection may be hubristic. Who is to say that human beings are even capable of listing all of the causal factors, let alone pin them down enough to make predictions? With the recent validation of the Higgs particle, I get the impression that quantum theorists are saying there's nothing more to discover. Hmmm .... where in past history has that attitude been expressed and found to be in error?

The dice example is, I think, revealing. It reflects an everyday situation with familiar types of factors that influence the outcome of the throw, and yet it's impossible to predict the outcome of a single throw. This is why a probability model is used to approximate what's going on with the dice and to make predictions about average outcomes and the distribution of outcomes -- but never an individual outcome.

So the dice analogy is possibly a portent: That at the subatomic scale there are forces and factors involved that we currently cannot pin down. Luckily, we can use a probability model to predict average outcomes and the distribution of outcomes. However, this doesn't mean that such factors will never be discovered, even if, as in the dice example, we won't be able to know them well enough to make predictions of individual outcomes.

Hi Mike,

I think you are right. Einstein had a real philosophical objection to quantum mechanics so he proposed a hidden variable theory. Bell's inequality pretty much put an end to the hidden variable debate.

I also think your dice analogy at the end of your post is a very good one. When I see these types of comments I often think about the Schrodinger equation and its attempt to unify quantum mechanics and classical physics. I think the equation does this very well except for the fact that it says nothing in terms of individual observations. In other words, when we see probability turn into an actual event.

[Mike Strand]

Again, I appreciate your reply and comments, Ginkgo.

I've studied Bell's Inequality and its implications, and I confess I don't really understand it. Any light you can shed on it would be appreciated. Your comment about its eliminating the idea of hidden variables, however, challenges me to try again. I hate to think I have to try to advance my understanding of math and physics, though, in order to do this.

[jackles]

Before the dice are thrown the meaning of the result of the dice throw is already known ie good bad or neutral.so its the way that meaning of the result fits in with the general meaning of the event that produces the exact right out come for the dice roll.the result of the dice throw comes down to meaning in the event relative to existance.the store of meaning imformation in the event is on going into to future existance in existance.

[Ginkgo]

Before the dice are thrown the meaning of the result of the dice throw is already known ie good bad or neutral.so its the way that meaning of the result fits in with the general meaning of the event that produces the exact right out come for the dice roll.the result of the dice throw comes down to meaning in the event relative to existance.

If the results of the dice are know I am wondering, known to whom? You didn't actually say.

[jackles]

The meaning of the out come is known by the looker.if theres a reason for throwing them.if theres no reason theres no meaning.so its the stored meaning in the event that causes the reason for meaning of the dice roll outcome.as in dna.

[Ginkgo]

The meaning of the out come is known by the looker.if theres a reason for throwing them.if theres no reason theres no meaning.so its the stored meaning in the event that causes the reason for meaning of the dice roll outcome.as in dna.

I think you are arguing for some type of hard determinism here. This also has implications for free will as well.

[jackles]

Viewer and object are a singular presentation in existance.

[Ginkgo]

Again, I appreciate your reply and comments, Ginkgo.

I've studied Bell's Inequality and its implications, and I confess I don't really understand it. Any light you can shed on it would be appreciated. Your comment about its eliminating the idea of hidden variables, however, challenges me to try again. I hate to think I have to try to advance my understanding of math and physics, though, in order to do this.

I'm sure your understanding would be better than mine.

I found this and it might help. I think it would be possible to formulate the information into a Venn diagram. This may help as well.

http://www.upscale.utoronto.ca/PVB/Harr ... eorem.html

[Mike Strand]

Many thanks, Ginkgo! Your reference looks great, and I think I'll be studying it for awhile. For me, Bell's Theorem and its implications are the main challenge to a better understanding of quantum physics. I appreciate the time you've taken to refer me to this material.

Here's a reference I tried to study before, without much success. If you haven't seen it, it may be of some use to you:

http://plato.stanford.edu/entries/bell-theorem/

[jackles]

What i get from a quik read on bells theorum is that the future cannot be predicted from the passed.the future state of a partical cannot be predicted from a present state store.there is no present state store.the actualisation is always fresh in the present tense.not comming from a store in the past tense.is this correct.if this is correct it would mean existance as a presentation doesnt store its self in a tense like way but actualises only for the observation.

[Ginkgo]

What i get from a quik read on bells theorum is that the future cannot be predicted from the passed.the future state of a partical cannot be predicted from a present state store.there is no present state store.the actualisation is always fresh in the present tense.not comming from a store in the past tense.is this correct.if this is correct it would mean existance as a presentation doesnt store its self in a tense like way but actualises only for the observation.

I don't think Bell's theorem has a lot to say about the future being predicted from the past. I think it works like this

Two particles are generated from a single source. They are separated by a small distance at first but the distance increases.However, the distance apart is irrelevant. They can be meters apart or light years apart, it makes no difference. The theory is that both were generated in a single moment in time and both are entangled.Entanglement means that both particles are in constant 'communication' with each other. One particle knows what the other particle is doing instantaneously.This violates Einsteins theory of relativity.

Einstein couldn't accept this and wanted to claim that these two particles are not in immediate 'communication' with each other but contain hidden variables or a type of DNA (for want of a better explanation). So what one particle does the other is programmed to do . In other words, their histories are in some way identical and as such they are played out.

Bell's theory attempts to demonstrate that there are no hidden variables, but in fact quantum process is random and therefore unpredictable. Bell demonstrates this by way of of a probability experiment. Basically,to cut a long story short the finding suggest that if hidden variables were an actually then we would expect the test results to show 55% or more probability( not a real figure but it will do) in favour of hidden variables. As we all know if we were to toss a coin enough times then we would expect the heads/tail ratio to be close to 50%. The more toss the closer to 50%. Again to cut a long story short, repeated experiments so far have shown that there are no hidden variables. The quantum process is random, just like a coin toss.

[jackles]

Thanks for that answer ginkgo .so what your saying is the result is randomly convienient to 50- 50 .so 50-50 expresses the event.or existance express the event convienient to 50-50 out come.

[Ginkgo]

Thanks for that answer ginkgo .so what your saying is the result is randomly convienient to 50- 50 .so 50-50 expresses the event.or existance express the event convienient to 50-50 out come.

This is a very difficult question for me to answer. Perhaps it would be easier for someone with more knowledge than myself. However, having said that I think it might be worth exploring the question through the many-worlds interpretation. As you know there are a number of interpretations. The many-worlds is not the one I think is correct, but I thin k it will help answer the question.

Imagine you and I are arguing as to how is going down the street to get the newspaper. We decide to toss a coin in order to decide who goes to get the paper. One the coin lands one of us is committed to getting the paper. In the many-worlds interpretation you go and get the paper, while in the parallel world I go and get the paper. The coin toss was a 50/50 probability with only two possible outcomes when the coin actually landed on the floor. In one world you go and get the paper and in another world I go and get the paper. We now exist in different universes.

So the 50/50 interpretation( if you want to call it that) is convenient for the classical physicists because it does away with the problem of the the observer determining the outcomes of an advent. The outcomes of a 50/50 events exist in separate worlds, never to interact with each other again.