Sagittarius A-Star's latest activity
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Sagittarius A-Star reacted to Demystifier's post in the thread Graduate Six Textbook Mistakes in Quantum Field Theory with
Informative.
I joined this forum soon after writing this paper, so this is how I have chosen my name. :smile: -
Sagittarius A-Star reacted to SiennaTheGr8's post in the thread High School Lorentz Transformation of Electric & Magnetic Fields Visualized with
Like.
I've made some more improvements to this app, including: Made the two-column desktop layout more convenient: the visualization remains... -
Sagittarius A-Star reacted to Vincf's post in the thread High School Confusion about one of Maxwell's equations with Like.
In the reference frame attached to the magnets, the electric field has a conservative circulation, and therefore: $$ \oint \mathbf{E}...
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Sagittarius A-Star replied to the thread High School Confusion about one of Maxwell's equations.Yes. But ##\Phi_B = \int \int_\Sigma {\vec B \cdot d\vec S}## changes over time, because the angle between the magnetic field and the...
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Sagittarius A-Star reacted to FactChecker's post in the thread High School Confusion about one of Maxwell's equations with Like.
This is about the amount of magnetic flux going through the open loop of the rotating wire. That is changing as the wire rotates. With...
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Sagittarius A-Star replied to the thread Undergrad Why is the Lorentz Force always perpendicular to velocity?.For geometric intuition: In Geometric Algebra, the electromagnetic bivector can be written in the following way as the sum of a...
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Sagittarius A-Star reacted to Dale's post in the thread Undergrad Why is gravity a fictitious force? with Informative.
Sure, that is a matter of definitions and categories. Nevertheless, the tidal force is the physical part of gravity, the part that does...
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Sagittarius A-Star replied to the thread Undergrad Why is gravity a fictitious force?.I think in GR tidal gravity, it just has to be small enough and insensitive enough.
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Sagittarius A-Star replied to the thread Undergrad Why is gravity a fictitious force?.Is it a matter of adoption of a definition, what a true force is? I think a true force can be measured with an accelerometer.
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Sagittarius A-Star replied to the thread Undergrad Why is gravity a fictitious force?.Why? I think a true force creates a deviation from the geodesic.
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Sagittarius A-Star replied to the thread Undergrad Why is gravity a fictitious force?.I don't think so. If for example an asteroid breaks in tidal gravity, the related forces are electrical forces between parts of it.
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Sagittarius A-Star reacted to SiennaTheGr8's post in the thread Undergrad Why is the Lorentz Force always perpendicular to velocity? with Informative.
As an interesting(?) aside, we can "pick out" the magnetic force for a particular observer in a manifestly covariant way (I know this...
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Sagittarius A-Star replied to the thread Help with problem in MIT open course general relativity.This video shows, how to use ##\LaTeX## in MS word.
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Sagittarius A-Star replied to the thread Help with problem in MIT open course general relativity.This is not a full solution for problem (3b), but maybe a useful hint. When I substitute the RHS of (3b) into (3a), the two...
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Sagittarius A-Star reacted to PeterDonis's post in the thread Help with problem in MIT open course general relativity with Like.
I think there's a subtlety here. ##U## is the 4-velocity of an observer at rest in the chosen frame. A charge at rest in the same frame...