Quantum Physics and "Theory and History"

[Paul]

You’re trying to disproove an epistemological/meta-quantum physics proposition by pointing out the results of some experiment. But, of course you need an epistemological theory to interpret any experiment in the first place. So first you need to point out which opposing theory is correct, and than explain how the experiment fits your theory, but not his.

You don’t need any theory to see the interference pattern, and therefore know that the “billiard ball” theory is incorrect. I didn’t say anything about what is correct.

Besides, the double slit experiment is done with light, not electrons.

Nonsense. You can do it with any “particle” you like: electrons, protons, split peas…

[z1235]

The debate about whether or not reality is “deterministic” becomes meaningless the moment we realize that our very definition of “deterministic” is constrained by our limited knowledge and perception. Stephen’s last sentence presented this splendidly:

@Stephen

The randomness/uncertainty is a feature of our state of knowledge, and not of the universe.

Z.

[Merlin]

Z, can you truly conceive of a non-deterministic world? I certainly can’t. It would seem to be a Burridan’s Ass world, not a place where things actually happen.

[z1235]

Merlin, I am fully in the “deterministic” camp. Fundamental limits to our knowledge, reason, logic, perception, and measurement may place permanent boundaries to our ability to explain (hence, needing the crutches of “uncertainty”) but that doesn’t mean that phenomena aren’t inherently explainable. Of course, I can’t prove this. I consider it as an axiom – my aesthetic intuition that this may be one of the infinite unprovable truths around us.

With my previous post I wanted to emphasize that the very meaning of the terms we’re debating is bound by our limitations mentioned above.

Z.

[JAlanKatz]

Well, I guess I’ll comment here. I’m not a physicist, nor have I read the chapter. I am a logician who has studied the more philosophical side of the questions, though. First, what Merlin describes here sounds exactly like the pilot wave interpretation, which is my preferred interpretation. Yes, this interpretation reifies probability and has particles (real particles, not things that are particles and waves, which is why I like it) behaving non-deterministically, but it actually has an answer for why the loss of determinism does not boil up to the surface. In essence, if I own a casino, it is possible to know within a very tiny margin the amount of money I will pay out and take in over a year as a fraction of total bets. It is impossible to know this for a minute, very hard for an hour, and difficult for a day. The individual events are (from our perspective in this case, in reality in physics) probabilistic, while the summation is not.

Now, what I’d expect Mises to say about physics is that non-determinism on the basic level is irrelevant to us, because our minds cannot make sense of probabilistic behavior. Thus, any such behavior does not enter into human action. That is, epistemologically there is no “real probability” even if metaphysically there is. But like I said, I haven’t read that section.

I have to take exception to most of what was said here about chaos/complexity theory. Chaos theory does not hold that these systems are non-deterministic, just that we cannot make predictions about them. In the famous Lorenz case, the story proceeds on the (questionable) assumption that there is a real function that takes as input the past and predicts the weather the next day, and illustrates that even on that assumption, we cannot make good predictions: the inputs are real numbers, and we round them off; the process is iterative (daily) and so small changes in early values lead to huge changes in final outcomes - so rounding to 3 places gives entirely different answers than rounding to 4 places, invalidating our predictions.

[I_Ryan]

@Merlin

Free will does not require determinism. I can choose freely a path which’s end I cannot know, as for example I’d be doing if willingly downing my plane on a desert island. For all I know, there is no determinism in an action which’s effects are unknown, and yet I can make the decision to embark on it.

Sure, choice without knowledge of effect would be hard, but again not impossible. So there can be, and indeed there is, a major debate between free will and determinism.

If you were to choose to “down[… your] plane on a desert island”, you would believe that the effects of doing that would be better than the effects of doing something else. If you choose, with your “free will”, to do something, you believe that the effects of doing that would be better than the effects of doing something else. I wasn’t saying anything else.

[Azure]

Free will does not require determinism. I can choose freely a path which’s end I cannot know, as for example I’d be doing if willingly downing my plane on a desert island. For all I know, there is no determinism in an action which’s effects are unknown, and yet I can make the decision to embark on it.

Sure, choice without knowledge of effect would be hard, but again not impossible. So there can be, and indeed there is, a major debate between free will and determinism.

If you (completely) did not understand cause and effect, that would mean no action you perform could reliably bring about any desired end. Sure you could still act but such action would not be purposeful. Our actions are purposeful because we understand causality and always act under the implicit assumption that things happen for a reason, and it is possible to use this knowledge to change the world to our advantage.

[Merlin]

Guys, I know that would be a totally strange, and even not fully conceivable scenario, but the question I pose is: “ Even if the world was not deterministic and/or we could not understand anything about the deterministic chain of events, would we still act freely or would some strange entity act for us?”

Bringing about the desired end is not the test of free will, but of successful (‘rational’ post facto) action. So again, even in a state of mind induced by LSD, where determinism is hardly a rule (although one could make the argument that even that world is still deterministic at a very, very subconscious level) I am again acting freely, though from what I suspect would be the point of view of Mises, totally randomly.

[Azure]

It depends on how you define free will. Most define “free” actions as being the result of purposeful decision, while “unfree” actions are the things your body just does like breathe. As I’ve explained before, in order for an action to be purposeful the individual in question must assume causality. So if the man in question does not understand causality, then his actions are not “free” ones.

[scineram]

@Merlin

It appears that we cannot know the quantum world directly. Clearing the “uncertainty” inherent in the system isn’t necessarily a matter of figuring out how to better locate a sub-atomic particle or how to better track it. It could just be that our ideas of “time” and “space” that we are so used to just don’t apply as well in the world of QP. It might be other, possibly inconceiveable phenomena that drives causality here.

As long as its deterministic its fine. When people pretend that subatomic particles are not deterministic but probabilistic, this just seems a plain surrender of reason.

What seems is just ignoring what is already quite clear. Some it is indeed just interpretation and semantics, but you really cannot do all the measurements and predictions you want.

[z1235]

@scineram

Some it is indeed just interpretation and semantics, but you really cannot do all the measurements and predictions you want.

A deterministic reality is not inconsistent with our inability to determine it as such.

[Caley_McKibbin]

Scientists that do experiments with a hypothesis will 100% of the time interpret the results as verifying the hypothesis regardless of whether it is accurate. They wouldn’t want their lab shut down and funding revoked after it didn’t pan out.

[Azure]

Scientists that do experiments with a hypothesis will 100% of the time interpret the results as verifying the hypothesis regardless of whether it is accurate. They wouldn’t want their lab shut down and funding revoked after it didn’t pan out.

If this were true, then why would anyone pay to have research done at all?

[Merlin]

http://www.toptenz.net/top-10-most-famous-thought-experiments.php

Check out no.2. That’s hard core Copenhagen, and that’s why it makes no sense to have different rules for ‘macro’ and ‘micro’,.

[Caley_McKibbin]

If this were true, then why would anyone pay to have research done at all?

This being true does not exclude the possibility of getting results. You are a born sucker if you as the financier of something don’t have a planned way to determine whether you are getting bang for your buck. Politicians don’t give a rat’s ass. It isn’t their money.

[Azure]

This being true does not exclude the possibility of getting results. You are a born sucker if you as the financier of something don’t have a planned way to determine whether you are getting bang for your buck.

If, 100% of the time, experimenters came with the conclusion of their hypothesis being verified, then why even perform the experiment at all? If there is no possibility of something different happening then acting is fruitless.

[Caley_McKibbin]

Good question. Ask an experimenter. I’m being cheeky when I say 100%, but I can’t recall a contrary example.

[Epicurus_Ibn_Kalhoun]

@Merlin

I haven’t gone to chapter 5, but Mises tacked QP in the introduction and from what I know of QP, I must say it makes little sense.

All the time Mises is saying that there is at all times a single causal chain of events, of which even human though is part, and that this chain drives the physical world. Than he goes on to state that, even QP can fit inside this framework. Now, QP says, among other BS, that from the same initial state and the same impulses, a system can develop in several ways! That is a clear breach of the causality principle. Bur Mises here tries to salvage QP by saying that QP does not hold that causality does not exist, but that instead of every cause bringing about an effect, what happens is that every cause brings about a probability distribution of effects.

This seems a poor makeshift to me: saying that if I hit the same ball in exactly the same way, 50% of the time it will go right, and 50% left is again a breach of the causality principle. Perhaps it would have been better to just say that QP is just a makeshift set of pseudo rules that seem to work right now, and will be replaced with actual science once we get to know the subatomic world better.