The difference between uncertainty due to ignorance and uncertainty due to the information not existing may be interesting. Perhaps it can be moved into the article somehow. Perhaps into another article.
The text says that Aspect's experiment "confirmed the Copenhagen interpretation", which might be interpreted to mean that it disconfirmed the many-worlds interpretation or some others, when it did nothing of the sort. It merely confirmed that it is impossible to speak about the outcome of a measurement that isn't in fact made. Both interpretations of what that means are consistent with experiment, as are other interpretations (like "Decoherence"). --LDC
Good point, I'll fix it. Do you know anything about decoherence? --Axel
Decoherence isn't an interpretation in and of itself, it simply explains how the different parts of a wave function can disentangle themselves. You still need them to either disappear (Copenhagen) or persist (many-worlds).
For what it's worth, I've found that whenever professional physicists have an opinion on the matter, they tend to find the (unfortunately-named) many-worlds interpretation more convincing. Consensus has been growing especially in the past two decades, which was when all this decoherence and entanglement stuff was worked out. Certainly, I haven't met a single serious proponent of the CI. Thus, I think simply calling the Copenhagen Interpretation "mainstream" is misleading. -- CYD
- And also the final nail in the coffin by Chaitin; his mathematical proof that the universe can never be proved unpredictable (let alone random) by any scientific process (making "non-determinism" an inherently unscientific assumption).
This sounds interesting. Can you write more about it? The Anome
He proved that there is a number K such that if you're given a sequence of numbers longer than K, it is impossible for you to prove the non-existence of an algorithm that compresses that sequence.
- See algorithmic information theory. The theorem talks about formal proofs in axiomatic systems and does not really constitute a "nail in the coffin" of any physical theory. AxelBoldt
- And what do you believe a physical theory is if not an axiomatic system? I concede that the axioms of physical theories are unknown and only vaguely guessed at until long after the physical theory has been worked out. But I have a hard time imagining a theoretician saying the axioms do not exist, or that they cannot be rigorously formulated after sufficient, tedious, effort by legions of mathematicians.
- For example, most people believe that Feynman's path integral formalism has a rigorous formulation. It's just that 50 years of effort looking for one weren't quite enough.
- If Chaitin's result is not the nail in the coffin of Copenhagen, that's only because most people aren't aware of the result. -- ark
So given a sequence of facts, observations or measurements about the world, when the sequence gets sufficiently long, it is impossible for you to ever prove that it is random; that patterns in the data do not exist.
http://www.mathpages.com/rr/s9-08/9-08.htm talks about this. It also talks about Bell's theorem in general, explaining in detail what it means, what motivated it, and its fatal limitations. -- ark
The major overhaul of 24.* introduced a much worse version and was reverted. Specifically:
- It claimed that the Copenhagen interpretation holds as second axiom "the wave function is not real". This is not an axiom of the theory, never expressed in that form by Bohr et al., but rather a criticism by proponents of other interpretations.
- It claimed that the first axiom, namely that the wave function contains everything there is to know about the system, is unremarkable. In fact, this was the most controversial statement of Copenhagen, because it explicitly rejected hidden variable theories. It is still to this day most surprising to laymen.
Several other similar distortions throughout the article, it was not worth my while to correct each individually. AxelBoldt, Friday, June 7, 2002
Just great. The article is misleading and completely useless now.
It doesn't matter who expressed "the wave function is not real", it is an essential FEATURE of the theory. That's why it was in there. What you want, what you have now, is a "description" of the theory that's completely one-sided. It's "defined" exactly how the proponents want it defined. It's not descriptive, it's propagandistic. So you have a highly POV article. Bravo. Useless.
Axel, you're not a layman so don't you fucking dare speak about what laymen find surprising. If you show a wave to a layman and then tell them that it has "no absolute position" they won't find that surprising at all.
- No they won't. And if it were the situation that things had no absolute positions, we could all describe things as waves and be done with it. The trouble isn't that things have "no absolute position". The problem is that things sometimes *do* have "absolute positions" and sometimes they don't.
And like I said, repeatedly ad nauseum, the hidden variables are COMPLETELY IRRELEVANT nowadays except for people who think in terms of 19th century physics. Nobody who knows anything about quantum mechanics expects this. So the comparison is bullshit. If you want to put in hidden variables as a historical detail, then make a separate HISTORY section. But you don't because physicists are fucking useless at history.
- Hidden variables are important because most layman when they first contact QM, assume that everything can be explained by a hidden variable theory. The hidden variable model is the most simple, natural, and inituitive model of quantum mechanics, and its important to recognize why it doesn't work. You yourself have proposed a model of QM which is a hidden variable theory.
I give up. Unless it's recognized that the entries are for laymen and that they should have ultimate control over what's in them, the whole physics section is completely fucking useless.
Btw, you reverted because you don't want to justify anything and you're too fucking lazy. Admit it that way, there's nothing nice or noble about what you're doing! -- Ark
- Personal attacks and insults are an inappropriate use of talk pages Ark and are a violation of policy. There is no way in hell you are going to convince anyone you are right when you use such language. Axel, nor anyone else for that matter, deserves to be called “fucking lazy” for trying to contribute in the best way they know how. Axel in particular, has been an immense asset to the project – especially with the mathematics and physics articles. I would not consider this to be, in any way, lazy -- let alone fucking lazy. Please stop these personal attacks. --maveric149, Friday, June 7, 2002
Well, I've stopped watching the physics pages and if nobody talks about me, I'm ignoring them completely. Physicists (actually physics students) are the most arrogant sons of bitches in the universe. Axel thinks his judgement of what laymen think about physics is better than what a layman tells him. What do you think that makes him?
Oh, and "the best way they know how" simply isn't good enough. Laypeople are better served left to themselves on physics if the only thing physicists can give are meaningless disconnected tidbits you can find in any popular article, let alone book on modern physics! Because they don't want to provide any more than that, they are fucking lazy. Willfully destroying the work of anyone who tries to provide more than that goes beyond being fucking lazy. -- Ark
I added something about Copenhagen vs. many-worlds. One of misconceptions that Ark seemed to have in particle physics talk was that the dispute (at this point) is something other than aesthetics. Most cosmologists like many worlds over Copenhagen. They might prefer classical music over rock music or like carrots over brocolli. As things stand right all, it's a matter of personal preference. (But that's likely to change in the next decade or so.)
The other misconception Ark seems to have is the "unremarkableness" of the first axiom. It's *that* axiom that is really weird. Getting back to Chatin's theorem that Ark asserts means you can't prove that universe is random. What Ark seems to be saying is that Chatin's showed that you can't prove that there aren't some hidden variables underneath that are controlling things. It's the first axiom that says that this isn't the case. And while you can't show that there aren't hidden variables, you can show and what has been shown as that if there are hidden variables, it means that every particle in the universe is communicating with ever other particle in the universe instaneousenously (which is Bohms interpretation). --RoadRunner
What particle physicists think and what cosmologists think are very different matters. I don't give a damn what particle physicists think. For THEM it might be a matter of aesthetics, not for cosmologists!
First, cosmologists don't hold to logical positivism. So "aesthetics" is about the most important thing there is!
Second, do you know to what length cosmologists will hold go to to preserve conservation of information?
They'll postulate baby universes spawning out of black holes, precisely as garbage dumps for that information. They'll even postulate alter dimensions if they have to.
- I believe that I know more cosmologists than you do, and neither of your assertions is correct. --RoadRunner
What Ark seems to be saying is that Chatin's showed that you can't prove that there aren't some hidden variables underneath that are controlling things.
If you have a question of me, ask me damnit. As a matter of fact, that's NOT what I think. I think it means that if you have a choice between a deterministic and a non-deterministic interpretation (such as between many-worlds and copenhagen) then you're forced to choose for many-worlds. And if you only have a non-deterministic theory, then you're forced to junk it as completely unsatisfactory and be left with nothing at all.
- Then what does Chatin have to do with any of this?
It's a popular game among physicists called "the layman is stupid" which you're engaging in. Obviously, you have nothing constructive to say to laypeople, despite your protestations yesterday. Ark, Friday, June 7, 2002