All Questions
Tagged with gravity electromagnetic-radiation
58
questions
3
votes
1
answer
115
views
Accelerating masses lose energy?
If I understand this correctly, accelerating charges lose energy in the form of EM waves because they change the electric and magnetic fields, which "costs" energy. Does that mean that accelerating ...
- 812
0
votes
3
answers
276
views
Why does gravitational lensing bend light rather than absorbing it?
I've read that gravitational lensing bends the light; I am a little confused about black holes and why lensing produces different results. Black holes absorb light whereas lensing should have also ...
- 111
1
vote
2
answers
225
views
Has anyone checked whether the speed of light $c$ varies according to gravitation?
My physics is fairly basic, but I hope someone can answer without being too rude.
A transparent medium such as water or glass refracts light and also reduces its speed, so I was wondering whether ...
- 111
3
votes
2
answers
436
views
Do electromagnetic fields gravitate?
It's well known that electromagnetic fields contains energy but do they gravitate?
When we talk about the composition of the universe it's now accepted that the 74% is dark energy, the 22% is dark ...
- 905
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
1
vote
1
answer
131
views
Slow light and gravitational lensing
It has been proposed that the Sun's gravitational lens be used to observe distant objects, but according to relativity a spacecraft would need to be 550 AU away in order to take advantage of the ...
- 13
2
votes
2
answers
914
views
Does gravity affect radiation incident on the planet?
Just curious ...
Known facts:
When outside the atmosphere levels of radiation are higher
Typically such radiation is CBR, Solar Radiation
Question:
If the matter of the atmosphere and ...
- 4,723
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
1
vote
1
answer
2k
views
Can electromagnetic radiation (i.e. photons) produce gravity? [duplicate]
I don't want to play with physical laws in a frivolous way.
Assuming that the nature of matter and energy is the same, can a high density of highly energetic photons produce a gravity force?
We do ...
- 1,334
3
votes
1
answer
304
views
Does a magnetic field have gravity?
Re-reading https://physics.stackexchange.com/a/33156/5265; I find myself thinking if light, being EM in the humanly visible spectrum, may possess gravity - does a magnetic field also possess gravity?
- 4,723
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
-2
votes
1
answer
564
views
future light cones and light paths
I understand that an event, in a four dimensional space-time, produces a light cone. As time increases the cones gets larger on either side of the event (past and future). For example the if the sun ...
- 159
6
votes
4
answers
3k
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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