All Questions
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6 views
What causes force on a body in gravitationally curved space time?
take the example of earth sun system. The earth is said to orbit around sun because the sun bends the space time around it .
Now if by some means we stop earth in its path such that its at rest with ...
2
votes
0answers
11 views
Is particle superposition reflected in the particle's gravitational footprint?
Recently, I have heard of extensions of the double slit experiment that propose to use a bacterium as the particle. I've also heard that the double slit experiment, in principle, would still show an ...
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0answers
20 views
Why we can't conserve light? [duplicate]
All I made up in my mind about light beeing a wave traveling at vertain speed, made me thing of it like something we could store in tehory.
So I would assume if I had a box where the inside is made ...
2
votes
1answer
14 views
First integral of the Kepler problem
Consider the motions of a bounded particle which is under the influence of the
gravitional interaction of a second particle fixed at the origin
$$
\ddot q = -\nabla V(q)
$$
where $V(q) = - \frac{\mu}...
0
votes
1answer
21 views
If the universe were not expanding, there literally would be no difference between night and day. Why?
Refer the title. If a galaxy is far enough away, its speed will exceed that of light. Its light will never reach us at all. Many astronomers today seriously
believe that if the universe were not ...
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0answers
15 views
What is the physical meaning of Lie dragging?
Wikipedia's article on torsion includes the following excerpt:
Suppose that an observer is moving along a geodesic, and carries with herself a system of rigid straight measuring rods (a coordinate ...
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0answers
11 views
A body with a mass $ m $ is moving without friction on a rim of a carousel that has a radius $ R $.
A question :
A body with a mass $ m $ is moving without friction on a rim of a carousel that has a radius $ R $. A carousel is rotating with an angular speed $ \omega (t) = Ae^{-\alpha t} $ ; $ A,\...
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0answers
3 views
Why traction vector depends on surface(section) orientration?
Need help with stress tensors. Every book says that traction vector at a point P depends on orientation of surface cutting this point. But as far as I know traction is defined in this way: Traction is ...
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0answers
11 views
Total resistance of this circuit?
So this is the circuit I can't solve please tell me which resistances I should take in series and which as parallel?
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0answers
5 views
Can gravitational lensing be canceled by another lensing effect, such that looks like there is no object behind the lenses?
As I understand, gravitational lensing allows to "see" objects behind lenses. But, is it possible that a combined effect make invisible an object behind, say, stars or galaxies?
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1answer
6 views
What balances the weight of a horizontally rotating object?
When an object is made to rotate in a horizontal circle:
Why does the angle between the plane of rotation and the horizontal decrease if the speed of rotation increases?
What force balances the ...
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0answers
10 views
Is there a limit to how much energy an electron can have?
If so what happens after the electron exceeds this limit? or maybe this limit is the dangerously close to the speed of light hence all the energy from the known universe combine would not be enough? ...
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0answers
12 views
Projection of trajectory from phase space on to the real space
which is the best way to project the trajectory of a particle from phase space on to real space. Let's make an example: let's consider a particle in a central potential. We know that the Lagrangian (...
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0answers
13 views
Levitating money trick - why is it stable?
This video shows a magician levitating a dollar bill using static electricity. Why is the bill stable? According to Earnshaw's theorem, no distribution of charges in an electrostatic potential ...
0
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0answers
5 views
Are “electromagnetic harvesters” viable for energy generation?
I saw this video of a 13 year old where he states that he converts wave-based energy into an electric charge and uses it to run a string of LED lights. He's not the first one to look into doing this, ...
