Trending questions
244,127 questions
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origin of energy stored in an electric field
I've understood that in a device like a capacitor the energy stored in the electric field between the plates corresponds to the work done by an external source in charging it, so similarly an electric ...
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Apparent pressure difference between two points at same elevation in a siphon
Consider the following diagram of a siphon (from wikipedia):
I am concerned with finding the pressure difference between points B and C, using Bernoulli's theorem. Liquid is incompressible, all flow ...
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Supersymmetric Hamiltonian for particle on a line with internal degrees of freedom
I was going through David Tong's Supersymmetric Quantum Mechanics
https://www.damtp.cam.ac.uk/user/tong/susy/susyqm.pdf
On page 8, (1.7), is the expression for the Hamiltonian correct? When I ...
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The Æther, the speed of light and gravity [closed]
I've been thinking about several things lately, and one of them is the Æther, because when people say that electromagnetic waves don't need to be propagated by a medium, I immediately see that they're ...
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Could other theories account for the presence of Cosmic Microwave Background (other than a Big Bang)? [closed]
Some scientists say CMB is "proof" of the Big Bang event, as no other source accounts for its presence (that I know of). However, I can think of a few things that seem to do so:
Over a long ...
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Infinitely many coserved currents in a free QFT
In a (1+1)-D integrable quantum field theory (e.g. the sine-Gordon model), there is a tower of infinitely many conserved currents with increasing spins. During a scattering, the existence of such a ...
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Does gravitational information travel through a black hole or around a black hole?
I would like to know if information can travel through black holes. If a mass falls into a black hole will the radius grow via information traveling along the event horizon or through the black hole?
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Spacetime curvature and light deflection [closed]
Could you tell me if this reasoning is correct?
Radius of curvature in spacetime caused by the Sun 338421512319 meters
Radius (physical) of the Sun 696340000 meters
338421512319/696340000 = 486
The ...
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Path integral formulation for selective paths in an energy shell $\delta(H(x,t)-E)$
Path integral formulation for selective paths in an energy shell $\delta(H(x,t)-E).$
I'm looking for a detailed calculation of this constrain condition.
All the publication I have access to didn't ...
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Does the value of the gravitational constant change due to dark matter?
Dark matter possess its own gravity. So doesn't it would mean that we will obtain different values of gravitational constant by doing experiments at different places?
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Problem book in quantum mechanics [duplicate]
Can someone recommend problem book in quantum mechanics ? Without theory (or only as reference), with many problems/exercises.
(not Flügge)
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Why does a mosquito net block the breeze?
When my window is fully open, I can feel the breeze from outside. But when I put on my mosquito net, the breeze gets blocked almost completely. Why does mosquito net block the breeze, even though its ...
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Is white light a bunch of photons or a messy electromagnetic wave or both?
I'm a layperson so I hope you'll excuse my naivete. I have this notion that white light is made of many different frequencies. When I think about them being photons I can imagine them all bunched up ...
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Statistical mechanics and the distribution of phases of oscillation
Imagine an elliptical region of phase space $\{(q,p)\in \mathbb{R}^2:p^2/2m + kq^2/2=E\}$ of constant energy $E$ for a 1D harmonic oscillator. Since all points on the ellipse have the same energy, ...
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Why integral curves of a null vector must be null geodesics?
In many General Relativity literature, the following question takes as a very obvious fact but I don't understand why or how it holds.
Why integral curves of a null vector on a null hypersurface is ...
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