Thermodynamics and The Universe

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And that Feynman quote that you like to cite doesn't mean what you think it mean

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Just to clarify this, since buz keeps throwing around this quote as if it supports his position,: Feynman wasn't saying that quantum mechanics wasn't the most accurate description of the world we have.When he said he doesn't understand it, he was referring to the fact that he doesn't understand how the world can be that way (not that it is that way). He was expressing a sense of awe and confusion at the way the world is. This awe and confusion wasn't rooted in the fact that we don't understand; it's rooted in the fact that we understand it all too well.As crash keeps saying, explain the two slits experiments without referring to some sort of quantum mechanical interpretation. The experiment and results are so simple that the explanation will have to be counterintuitive.

Just a question from the sideline...you write: is the "cannot" too strong? According to the probabalistic interpretation of entropy, isn't it just very likely that the system will remain in a state of maximum entropy (by definition)? There's still a chance (Vanishingly small as it may be) that entropy will decrease, right?

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I can only guess that you're referring to thermodynamics origins with Boltzmann and his statistical approach. This is a kind of micro view of thermodynamics that I'm not that familiar with, I'm more familiar with a higher level view. Statistical approaches always have probabilistic error bars, but even at higher levels of abstraction we still have error bars, so even if we've measured some system to have maximal entropy, we could never be certain that was the case. Like absolute zero, maximal entropy is probably a state we'll never achieve in any practical terms.

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I am referring to the Boltzmann view, I should have been more explicit.For example, take the simple case of a box with white gas molecules on one side and black on the other seperated by a partition. Once you remove the partition, the gas becomes homogenous. The statistical approach basically says "there are more ways to be disordered" so that is the most likely state the gas will be in. Or, to flip it around, the state that a system is most likely to be in is defined as "most disordered." The view also says that given enough time it is possible for the gas to once again separate since it's just more probable that is will be in a state of homogeneity.I'm positive you've heard this before, but that is the angle I was looking at your statement from.

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That's about the best definition for "disordered" that I've seen. I would, though, say that the macroscopic state that is produced by the largest set of microscopic states is the most disordered.

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Pedantry gratefully accepted.