Recent content by AlephClo

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    I How time dilation is a permanent change and length contraction not?

    I now have a better understanding. Thank you all
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    I How time dilation is a permanent change and length contraction not?

    I am confused. 1) I assume with are discussing SR effect only here. 2) In the first paragraph you say will always measure the same whatever their history. While in the second paragraph, if one clock move apart (I add: as part of its history) they may well show different elapsed times. 3) What...
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    I How time dilation is a permanent change and length contraction not?

    Comparing high precision atomic clocks, one flying in a airplane and one on the ground had demonstrated permanent time dilation presumably due to special relativity (speed) and/or general relativity (gravity) . While similar experiment with a ruler would demonstrate length contraction only...
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    How is the Coriolis generalized potential obtained

    The Coriolis potential last term of (42) is obtained by integration through r and R from last term of (40). I do not understand why we do not need to integrate through v as well, since the Coriolis force depends on v? Homework Equations Equation (41) is wrong I think, L must be replaced by...
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    I How to derive Nielsen equation from Lagrange equation?

    I have done couple hours of research and tried to derive it myself. The best that I found is this, but I do not understand where the commutator come from. It does not seem to be the Poisson braket commutator applied to T either (A,B) = AB-BA . Nor that I understand where the (2) relationship...
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    I How to derive Nielsen equation from Lagrange equation?

    How to derive Nielsen equation from Lagrange equation
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    I Understanding ISSS from Minkowski Space to Poincaré Group

    Thank you very much PeterDonis and Stangerep. I do have MTW and I am in the process to go through it entirely, in conjuction with Schutz and Carroll. I looked at MTW and Ballentine and think I will be able to understand spin. I went through Gravity & Light Winter School by F Schuller both...
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    I Understanding ISSS from Minkowski Space to Poincaré Group

    The fermions spin +- 1⁄2, +- 3⁄2 etc; I understand is a the fourth symmetry of spacetime CPT, and it is derived⁄established from Poincaré and Lorentz groups. I want to unserstand the rational that supports that. Thank youy for your time and patience. AlephClo
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    I Understanding ISSS from Minkowski Space to Poincaré Group

    Maybe you can get an idea from what I have read, but it is in french (my mother-tongue) http://dhenriet.perso.centrale-marseille.fr/states/Siteloic/Accueil_files/EA.pdf I can perform a google translate if you wish. Thank you AlephClo
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    I Understanding ISSS from Minkowski Space to Poincaré Group

    I try to understand where the intrinsic spin symmetry of spacetime (ISSS) is established. I read articles but still do not understand how to put together all the information to make a clear picture of where ISSS comes from. Minkowski space - Lorentz group O(1,3) - Covering SO(1,3) with SL(2)c -...
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    A Physical meaning of open set on manifold

    Rubi, I have read the topolgical definition of neighborhoods and its equivalence to open sets, and this clarifies my question about physical meaning open sets. I will further read on Do Carmo. Robphy, You opened a new area of interest that I will explore. Merci to both of you. AlephClo
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    A Physical meaning of open set on manifold

    i) The definition of continuity that is used is: The map F: M into N is continuous if for all V that belongs to Powersets(N) the preimage,f(V) is an open in Powersets(M). M and N are sets on which the differentiable manifolds are built. ii) The particular application is General Relativity, if...
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    A Physical meaning of open set on manifold

    I understand the definition of continuity on a manifold based on open sets. I was questionning myself about what is the corresponding physical meaning of an open set of a manifold (M, Power-set-of-M, Atlas). Is it a simple (maybe simplest) assumption in order to define mathematically continuity...
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    I Riemannian Metric Invariance

    Very clear. Thank you very much Andrewkirk
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