All Questions
Tagged with gravity electromagnetic-radiation
58
questions
21
votes
2
answers
2k
views
Gravitational slingshot of light using a black hole/massive object
Wikipedia has this page on gravity assists using planets. In some cases this effect was used to accelerate the spacecraft to a higher velocity. This diagram shows this in a very oversimplified manner. ...
- 4,023
15
votes
2
answers
1k
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Is there a gravitational analogue of a classical Rutherford-atom?
In a Rutherford-atom, the electron classically emits EM radiation on an average rate of,
$$
-\frac{dE}{dt}=\frac {\omega^4 e^2 R_0^2}{3c^3(4π\epsilon_0)}
$$
Where $\omega$ is the angular frequency, $...
- 421
15
votes
3
answers
616
views
Can the question of a gravitationally accelerated charge radiation be tested experimentally?
I know that the question of radiation from a gravitationally accelerated charge has been discussed extensively at Does a charged particle accelerating in a gravitational field radiate?. Yet the ...
- 166
11
votes
3
answers
2k
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Can light cause gravity? [duplicate]
We know the following:
Two masses are attracted to one another, as represented by Newtonian gravity
$F = \frac{GMm}{R^{2}}$
Light is massless and bends in the curvature of space-time which can be ...
- 540
9
votes
3
answers
2k
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Why is it hard to detect a black hole
I've read in some texts that we can't directly observe a black hole in space because not even light can escape from its gravity. Some of the indirect observational methods mentioned are, gravitational ...
- 359
8
votes
1
answer
373
views
Can light gravitationally affect itself?
Consider a electromagnetic wave in a vacuum. From my understanding of general relativity,
The wave has momentum, and thus generates a gravitational field in all directions.
The gravitational field ...
- 235
7
votes
1
answer
747
views
Can gravity radiate?
In electromagnetism, when a charge accelerates, it emits radiation. We know this because we can write the retarded potentials, apply $\vec E=- \nabla V-\frac{\partial \vec{A}}{\partial t}$ and $\vec B=...
- 1,616
7
votes
2
answers
483
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Do gravitational waves travel always in a straight line (along a geodesic) like EM waves?
There are a lot of questions and answers on this site about light traveling in straight lines in vacuum (following a geodesic). And there are a lot about both EM and gravitational waves traveling at ...
- 29k
6
votes
4
answers
3k
views
Gravitational lensing or cloud refraction?
My current understanding of gravitational lensing follows
When a star or other massive body passes between us and another star, the phenomenon
generally labeled 'gravitational lensing' occurs. The ...
- 171
5
votes
2
answers
890
views
Are photons affected by Earth's gravity? [duplicate]
Just wondering if the Earth's gravity affects the photons? We can obviously think about equivalent mass of photons by using de broglie relation and then use it to calculate force of gravitational ...
- 691
5
votes
1
answer
350
views
Is the number of wavelengths of light spanning a distance invariant with respect to spacetime distortion?
I was recently asked by a friend how the expansion of spacetime affects photons. I gave him what I feel is a satisfactory general response, but it got me wondering how, exactly to calculate this ...
- 4,973
5
votes
2
answers
395
views
Light dispersion in gravitational theories
GR predicts no Ricci curvature in vacuum (or at least when we can ignore the cosmological constant). Would theories that violate this lead to observable light dispersion in solar system tests of ...
- 175
4
votes
1
answer
1k
views
What is the effect of gravity on gamma rays?
I read an article about a Gamma Ray burst linked to a black hole. How does high gravity fields affect gamma rays?
- 119
4
votes
1
answer
388
views
Is there an Abraham-Lorentz force for Gravity?
The Abraham-Lorentz force in Electromagnetism is the recoil a charge experiences as it accelerates due to own emission of radiation.
The Newtonian theory of gravity is identical to that of ...
- 596
4
votes
2
answers
293
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Why does General Relativity predict more light deflection than Netwonian Physics?
If one looks at the limit as light's mass approaches zero, Newtonian Physics predicts a deflection of light (this can be seen by the fact that all objects are accelerate the same due to gravity.) ...
- 2,172