Dale's latest activity
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Dale reacted to Kostik's post in the thread A A global energy conservation law in general relativity with
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Please see the derivation below that, if the metric is time-independent, then the integral over a sufficiently large 4D spacetime region... -
Dale replied to the thread Being bad at Physics.So how did you react to this discovery? Did you assign yourself additional problems to solve and spend big chunks of free time working...
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Dale reacted to PeroK's post in the thread I Does a Sensor interact with atoms in the double slit experiment? with Like.
I agree with the first part. Not the second. Superposition is a key property of quantum systems. A particle in QM is described by a...
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Dale replied to the thread A How do you convert the Pound–Rebka redshift into time variation?.Just multiply it by 1 second. So ##\rm{-5.13 \ 10^{-15}} = \rm{-5.13 \ fs/s}##
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Work done on moving object during short time ##\delta t## is $$\mathbf{F}\cdot\mathbf{v}\delta t$$ During time ##[t_1, t_2]##...
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Dale replied to the thread I Energy of Electromagnetic Waves in Destructive Interference.Certainly. But this has nothing whatsoever to do with conservation of energy. You could also arrange lenses so that the center had a low...
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Dale replied to the thread B Work done when moving an object.The difference between displacement and velocity in this context is the difference between work and power. For work $$dW=\vec F \cdot...
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Get an app like https://phyphox.org/ which lets you get the raw accelerometer data. While holding my phone at rest with my phone...
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Dale replied to the thread I Freefall and gravity.That can be determined with an accelerometer. Edit: I see I am late to respond
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Dale replied to the thread I Energy of Electromagnetic Waves in Destructive Interference.No. The preceding two questions have nothing to do with the conservation of energy.
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Dale replied to the thread I Shwartzschild coordinate system.They are different manifolds so there is not a coordinate transform between them. Of course locally you can always find coordinates that...
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Dale reacted to pervect's post in the thread I How to calculate basis vectors from metric tensor (as a matrix)? with Like.
A recap of what others said. If one defines coordinates on a manifold, (to be more formal, one might talk about a coordinat chart), one...
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Dale replied to the thread I How to calculate basis vectors from metric tensor (as a matrix)?.If you can write the matrix above then you have already chosen a basis. The obvious basis is $$ \begin{bmatrix} 1 & 0 \\ 0 & 0...
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Dale replied to the thread I How to calculate basis vectors from metric tensor (as a matrix)?.I don’t understand the question. Basis vectors are not things that are derived. They are things that are chosen. What do you mean by...
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Dale reacted to PeroK's post in the thread I Shape of wave function (probability distribution) of a single photon with Like.
A single photon doesn't have a position-space wave-function. Basic QM is explicitly non-relativistic, so does not describe light.