Sagittarius A-Star's latest activity
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Sagittarius A-Star replied to the thread Graduate What Exactly Is The Physical Content Of Maxwell's Equations?.Addition: Geometric Algebra can also be applied to curved spacetime. I did not yet have a closer look to this. Source... -
Sagittarius A-Star reacted to weirdoguy's post in the thread Graduate What Exactly Is The Physical Content Of Maxwell's Equations? with
Like.
May or may not. Differential geometry is my specialisation within mathematical physics, and when I tried to study geometric algebra it... -
Sagittarius A-Star reacted to FactChecker's post in the thread Graduate What Exactly Is The Physical Content Of Maxwell's Equations? with Like.
IMHO, as a casual amateur, geometric algebra (and geometric calculus) goes a long way to demystifying the subject. Unfortunately, it...
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Sagittarius A-Star replied to the thread Graduate What Exactly Is The Physical Content Of Maxwell's Equations?.What also may help for understanding the EM field is to use Geometric Algebra, applied to 4D-spacetime. The wedge product ##\wedge##...
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Sagittarius A-Star replied to the thread Graduate About the definition of Born rigidity.With ##\gamma=1/\sqrt{1-\omega^2r^2/c^2}## ##dA = \gamma r dr d\phi## The proper area is ##A(R)= 2\pi \int_0^R \gamma r \, dr= {2 \pi...
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Sagittarius A-Star replied to the thread Graduate About the definition of Born rigidity.The circumference will be measured in the non-Euclidean geometry of the rotating disk as ##U=\gamma 2\pi R## with...
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Sagittarius A-Star replied to the thread Graduate About the definition of Born rigidity.I think for clarificaion one should distinguish between one-way- and two-way speeds. For applying the LT for a segment of the rim of...
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Sagittarius A-Star reacted to A.T.'s post in the thread Graduate About the definition of Born rigidity with Like.
Yes, this is the flaw in the reasoning. The usual length contraction factor is isotropic: It depends only on the speed, not on the...
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Sagittarius A-Star replied to the thread Graduate About the definition of Born rigidity.Regarding "But here the static rulers in O_r should be twice as long": This is only true, if you apply the standard Lorentz...
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Sagittarius A-Star replied to the thread Undergrad Small question about constantly accelerating charges.According to Wolfgang Rindler, the EP cannot be applied to the "paradox" of an accerated charge, because it's field is not local. An...
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Sagittarius A-Star replied to the thread Graduate Can a causal or time-like structure emerge without assuming a metric?.Maybe this helps: https://www.wolframphysics.org/technical-introduction/potential-relation-to-physics/time-and-spacetime/ via...
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Sagittarius A-Star replied to the thread Undergrad Photons & Time: t=0 What?.For example: If you send a light pulse from Earth to Alpha Centauri, then the spacetime-interval between the emition-event on Earth and...
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Sagittarius A-Star reacted to DaveC426913's post in the thread Undergrad Photons & Time: t=0 What? with
Agree.
That would be a commute of 30 minutes! Less than it takes me on a busy Monday. -
Sagittarius A-Star replied to the thread Undergrad Photons & Time: t=0 What?.For example: The distance from Earth to Alpha Centauri is 4.367 LY. If you travel with 99.99999999 % light speed (relative to Earth) to...
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Sagittarius A-Star replied to the thread Graduate Can a causal or time-like structure emerge without assuming a metric?.Maybe that helps: Source: https://en.wikipedia.org/wiki/CPT_symmetry#Derivation_of_the_CPT_theorem
