All Questions
23
questions
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=...
0
votes
2
answers
124
views
Does gravity affects electromagnetic waves? Or electromagnetism affects gravity?
I'm confused about the relationship of electromagnetism and gravity, or are they even related?
It has been said the electromagnetic field produces a gravitational field, and so, there is no gravity if ...
2
votes
2
answers
387
views
Is there a relation between spacetime curvature and radiation?
To my understanding, the curvature of spacetime is determined by the stress-energy tensor.
I was wondering if we could calculate some of those components using radiation.
Is it possible that objects ...
-3
votes
3
answers
229
views
Why is light not affected by gravity?
If a rocket needs to go to mars, it needs to go through a specific trajectory. But i can see the sun straight where it is, so light does not obey gravity?
15
votes
2
answers
1k
views
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, $...
1
vote
2
answers
191
views
Does it take work to bend light?
We all know that light always travels in a straight line. Would it not then stand to reason that changing the path of light requires energy? If so, would this not violate Newton's laws of motion if ...
7
votes
2
answers
483
views
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 ...
2
votes
0
answers
438
views
Paradox of radiation of charged particles in a gravitational field
"Paradox of radiation of charged particles in a gravitational field" - Wikipedia ( Paper by a guy I forget the same of)
On wikipedia (reliable ikr), there is a paradox occuring between ...
11
votes
3
answers
2k
views
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 ...
3
votes
6
answers
922
views
Does light’s deflection by a gravitational well vary depending on frequency or other properties of the wave?
I’m curious if the magnitude of the displacement of light by a gravity well is variable to any property of the photons (frequency, polarization, etc).
0
votes
2
answers
179
views
Is the Light REALLY bent?
I've learned that always, the light go straight. The as Einstein's gravitation therory, the light can be bent in bented space-I mean, curved space.
Actullay, I think that if we in the space which ...
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 ...
3
votes
0
answers
130
views
Consequences of a stable geon
What would be the consequences be of a stable geon? What similiarity, if any, would it have to a naked singularity? What would a stable geon potentially look like, and what would the immediate ...
1
vote
1
answer
278
views
'Hovering' light rays on the edge of a black hole
According to Prof. Hawking, light rays will 'hover' on the edge of a black hole. If this is true, and the light 'stops' on the edge, how can the electric/magnetic fields which, constitute the light, ...
1
vote
3
answers
2k
views
Why can't light escape a blackhole? [duplicate]
Gravity attracts objects which have mass right. We know that light is massless so why does a black hole's gravity attract light?