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Hi, I am a string theorist and a publicist.


Mar
15
comment Retrodiction in Quantum Mechanics
Just imagine any single example to see that what you write is just pure nonsense. For example, take a healthy man and try to calculate the probability that he suffered from cancer but was cured from it. What do you think is the probability? How do you make your procedure? For example, you may do repeated experiments with men, and storing them in Fukushima reactor, to make sure they will catch cancer. Some of them will be cured, and the probability you were asked to measure will turn out to be 100% because all your healthy men will be cancer survivors.
Mar
15
comment Retrodiction in Quantum Mechanics
However, the proportion of the repetitions in which the initial state of the experiment will satisfy a property will depend not only on the final states in the experiments but also on their initial states, and by very definition, you don't know which initial states you should use to end up with the final state. What you write makes no sense whatsoever.
Mar
15
comment Retrodiction in Quantum Mechanics
Dear Peter, concerning your updated version: it's not just Copenhagen interpretation that makes retrodictions only possible probabilistically (more precisely, dependent on subjective priors). Just take any question that could be retrodicted and calculate the probability that the answer is Yes using any interpretation of QM you may think of. If the probability is required to differ from 0% and 100%, you will fail. Just like it's not possible to retrodict with certainty, because events' irreversibility, it's also not possible to retrodict probabilities with values that are sharply well-defined.
Mar
15
comment Why does amount of protons define how matter is?
Right: short, clear, correct. The chemical and material properties of the material is only given by the arrangements of electrons and those are only influenced by the electric fields which only depend on the number of protons. So chemical, biological, and "mechanical" properties of the material only depend on the number of protons - that's why we use the same word e.g. "uranium" for isotopes with the same Z. The number of neutrons only matters for nuclear properties and processes.
Mar
15
comment In superluminal phase velocities, what is it that is traveling faster than light?
Great answer, or at least I would give the same one. ;-) +1
Mar
15
revised Retrodiction in Quantum Mechanics
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Mar
15
comment Retrodiction in Quantum Mechanics
This is just completely silly, Peter. Retrodictions - and whether they can be quantitative and objective - surely don't depend on interpretations of quantum mechanics. If this were the case, one could also claim that e.g. dinosaurs have never lived on Earth according to Shor's interpretation of quantum mechanics, or whatever of this kind.
Mar
15
revised Retrodiction in Quantum Mechanics
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Mar
15
revised Retrodiction in Quantum Mechanics
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Mar
15
answered Retrodiction in Quantum Mechanics
Mar
15
comment What Would be the Experimental Signature of Composite Leptons?
Dear dmckee, that's nice but imagine, just for the sake of an argument, that a member of CMS says during a press conference at some point in 2011 that the CMS has collected evidence of lepton compositeness. What do you think that they would have to have seen in order to make similar surprising statements? ... I didn't quite understand why the deviations you mention - their very being - would be characteristic of lepton compositeness as opposed to any new physics.
Mar
15
comment What Would be the Experimental Signature of Composite Leptons?
Great question, (future?) Dr Brannen. Let's see how the answers match the quality. :-) BTW the top-antitop asymmetry could be a sign, too - assuming that the up-quark and top-quark share something in their composite setup.
Mar
14
answered Why didn't Newton have a cosmological constant
Mar
14
answered Why does energy in earthquake waves seem to go up with the three halves power?
Mar
14
comment refractive index of air in dependence of temperature
If you really need it, see e.g. this 1967 paper by James Owens, opticsinfobase.org/abstract.cfm?uri=ao-6-1-51 - But clearly, the refractive index depends not only on the temperature but also on pressure, composition, and strictly speaking also the wavelength of the light. It is naive to think that there is any "exact" function because what you're asking is a very messy problem depending on the definition of "air" (composition), "light" (frequency), and many other things. Clearly, the density of the molecules will matter a lot, but other things will matter, too.
Mar
14
revised Shape of the Higgs branching ratio to ZZ
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Mar
14
revised Evidence for black hole event horizons
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Mar
14
comment Evidence for black hole event horizons
No, finbot, this argument about disappearing energy doesn't really "assume" general relativity: it pretty much proves one of its consequences, namely the event horizons. Moreover, GR is clearly valid. A major interpretation of the question is how to distinguish objects with horizons with those without horizons assuming the existing knowledge about physics - which surely includes the insights of GR. If you pretend that random pillars of physics are unknown, then you may prevent people from making arguments, indeed. But that wasn't really the case here.
Mar
14
revised What is the difference between thermal and infrared imaging?
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Mar
14
answered What is the difference between thermal and infrared imaging?