Joe Fitzsimons
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 Jan 23 comment Does decoherence need non-determinism? I've posted an updated answer to answer the question as I now understand it. Jan 23 revised Does decoherence need non-determinism? added 2571 characters in body; added 1 characters in body Jan 23 comment Does decoherence need non-determinism? @WIMP: Can you please revise the question to make it clear exactly what you are asking? It's currently not clear either from the question or subsequent comments. Jan 23 comment Does decoherence need non-determinism? You need to rephrase your question if both myself and Matt have misunderstood your intention. Are you now asking if you can deterministically collapse to a particular eigenstate? The answer to that is no, because it violates linearity. Jan 23 comment Does decoherence need non-determinism? @WIMP: The first line of my answer reads: "if by deterministic you mean possessing a local hidden variable interpretation". Certainly global hidden variables can be made to work, but then they always can. Jan 23 comment Can gravitational potential energy be released in a fire? @Sklivvz: If the entire mass of the fuel did remain at the top, then you would be correct. However, this is not presumably not the case. When you burn something, in most cases you are converting a significant proportion of the mass to gas. Jan 23 comment Why does a ballerina speed up when she pulls in her arms? @Sklivvz: I have no objections to the new form, and have removed my downvote. Jan 23 comment Can gravitational potential energy be released in a fire? @Sklivvz: Yes, it does. However, it is in a subtle way: The gas produced falls into equilibrium, so this heat is not caused by the combustion reaction, but at a later stage. Jan 23 comment The origin of the value of speed of light in vacuum It doesn't have to be 1, you can pick any non-zero value. Jan 23 comment The origin of the value of speed of light in vacuum +1 for pointing out the only sane choice of units (none!). Jan 23 comment The origin of the value of speed of light in vacuum @Johannes: That is not the point at all. The way units are defined in terms of setting specific values to physical constants doesn't mean those constants can't change. The consequence is simply that a better measurement of the speed of light means that my apartment is a different size in those units. This clearly does not mean c or $\mu_0$ or $\epsilon_0$ are fixed, simply that their measurement in SI units is. This is a quirk of the choice of units, not something fundamental. Jan 23 comment The origin of the value of speed of light in vacuum @Johannes: that's not true. Their value in SI units is defined, but that is because they are used to define the units. It's not the same thing at all. Jan 23 comment The origin of the value of speed of light in vacuum @Johannes: All three are measurable quantities, so you are free to define any one in terms of the other two. Jan 23 comment Double slit experiment near event horizon @Columbia: you clearly aren't violating it, as the linearity of quantum mechanics is preserved. The theorem is a simple consequence of linearity. Jan 23 comment Why does a ballerina speed up when she pulls in her arms? @Sklivvz: you referred to how hard she pulled in her arms. That is clearly a reference to force. If you remove or correct that paragraph, I'll remove my downvote. Jan 23 comment Can gravitational potential energy be released in a fire? @Sklivvz: of course you don't see an effect if you model the whole atmosphere without gravity (which is what you are doing here), but that model does not reflect reality. Jan 23 answered The origin of the value of speed of light in vacuum Jan 22 comment Can gravitational potential energy be released in a fire? @Georg: I'm afraid I'm one of those too, but I'd like to think I'm still ok on thermo and statistical mechanics. Jan 22 comment Can gravitational potential energy be released in a fire? (By here I mean in the answers to this question, not this specific answer) Jan 22 comment Why does a ballerina speed up when she pulls in her arms? @Carl: Exactly, it's the work done that counts, not the profile of force used.