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| Laboratory test of curvature redshift | 29 Mar 2010 15:48 GMT | 2 |
[[Mod. note -- Most discussion of the author's theory would likely violate the newsgroup charter's prohibition on "excessively speculative" theories, so followups should be by E-mail to the poster (which I have set to be the default) unless you genuinely believe that you
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| Two questions about quantum momentum and position | 25 Mar 2010 04:24 GMT | 13 |
1) It is well known that the inner product of position and momentum eigenvectors: <x|p> = exp[i pq] (1) Is there some simplified expression for the outer product:
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| Geodesics | 22 Mar 2010 16:28 GMT | 1 |
====== Moderator's note ================================= Relativistic bicycles? I wonder, how fast you want to make them ;-)) SCNR, HvH. ==============================================================
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| R. Feynman left a puzzle. | 21 Mar 2010 09:35 GMT | 5 |
Suppose a single photon polarized by a polaroid set at the angle 30 arrives at a polaroid at the angle zero – as in Fig. 11-3 [1]. Quantum mechanics tells us, the photon, as a whole, will get through 3/4 of the time, and 1/4 of the time it will heat the polaroid by being
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| Motion Molehill | 20 Mar 2010 02:27 GMT | 2 |
By "motion molehill" I mean a hypothetical version of motionmountain.net aimed more or less at third grade level. That thought occurred to me after reading (and contributing a little to) a 362-post (currently) thread in a private newsgroup hierarchy (panix.questions) about teaching
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| Time dilation and constant velocity vs. acceleration | 19 Mar 2010 17:33 GMT | 19 |
I'm doing some individual study about GR and have this basic question. In the Twins Paradox, the twin who stays fixed ages more than the twin who travels and then comes back. My question is this: is it the acceration of the travelling twin that causes the dilation, or does
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| Question on a diffusion equation | 13 Mar 2010 18:12 GMT | 1 |
I have a complicated diffusion equation with various slowly changing time dependent parameters. Does anyone know if there is an analogue of the adiabatic approximation that would apply
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| Operator identity | 10 Mar 2010 19:45 GMT | 2 |
I have a one dimensional quantum mechanics problem where x is the coordinate operator and p the momentum operator (so [x,p]=i).
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| Questions About Nuclear Radii | 10 Mar 2010 19:45 GMT | 11 |
In the case of atoms, there is a rough correlation that gives the radius for different n values: R ~ n^2 a, where a = the Bohr radius. Atoms can range in size by a factor of at least 300^2, and radiation from huge Rydberg atoms with n ~ 300 has been observed in space.
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| proof of the exclusion principle | 10 Mar 2010 19:18 GMT | 1 |
I have read this on wikipedia about the exclusion principle, without any reference: "In relativistic quantum field theory, the Pauli principle follows from applying a rotation operator in imaginary time to particles of
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| Two errors and a (glaring?) oversight in A. Zee's Path intergal presentation? | 04 Mar 2010 19:52 GMT | 6 |
In his development of the path integral at: http://jayryablon.files.wordpress.com/2009/12/sakurai-and-zee.pdf professor A. Zee has two errata which he has corrected at: http://www.kitp.ucsb.edu/~zee/nuts.html. One is a missing factor of
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| The Big Bang & Variable Light Speed | 04 Mar 2010 10:26 GMT | 74 |
The Big Bang & Variable Light Speed I'm going to offer an interesting perspective on the FW cosmology -- a different take that brings to light (pun intended) what's hiding in plain sight.
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| Does the Lie Product formula work for infinite-dimensional operators? | 04 Mar 2010 10:26 GMT | 4 |
Please take a look at http://en.wikipedia.org/wiki/Lie_product_formula. Would this formula, which is stated to apply to NxN matrices, also apply to an infinite-dimensioned operator / matrix? Why or why not? Thanks,
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| How Do I Tell if a constant reall Is? | 04 Mar 2010 09:32 GMT | 10 |
Consider a metric for a 2-dimensional manifold in the form: ds^2 =dt^2 - dx^2/ c^2 How can I tell PHYSICALLY whether c is a constant or is some non - constant function.
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| The Twin Paradox and the derivation of proper time... | 02 Mar 2010 23:35 GMT | 3 |
I am reading Luminet's paper titled "Time, Topology and the Twin Paradox" available at: http://arxiv.org/ftp/arxiv/papers/0910/0910.5847.pdf The author is deriving the equation for proper time and compares
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