All Questions
Tagged with optics general-relativity
6
questions
43
votes
5
answers
15k
views
How does gravitational lensing account for Einstein's Cross?
Einstein's Cross has been attributed to gravitational lensing. However, most examples of gravitational lensing are crescents known as Einstein's rings. I can easily understand the rings and crescents, ...
- 6,044
1
vote
1
answer
808
views
Treating gravitational lensing as index of refraction
In Einstein's theory of gravity, an electromagnetic wave passing near a massive object is bent from its rectilinear path. We may regard this bending equivalently as due to a medium of refractive index ...
- 1,116
-3
votes
5
answers
411
views
What causes a single photon to divert its trajectory?
If a single photon passes close enough to a star, the gravity will diverts its trajectory. What causes a photon to divert its trajectory as it passes a sharp edge or the boundary of two mediums?
- 4,083
3
votes
1
answer
212
views
Does the index of refraction of the sun's corona and solar wind contribute to the bending of light
It's not hard to imagine that the sun's corona and surrounding solar winds have an optical density that can affect the index of refraction near the surface of the sun and bend light in these regions. ...
- 2,270
3
votes
2
answers
2k
views
Why do we know that light must follow a geodesic?
THE CONTEXT:
Some context to my question: Einstein once posed the thought experiment of a man falling inside a closed box. Just before the box was dropped, a photon was fired horizontally moving from ...
- 1,087
2
votes
1
answer
282
views
Do gravitational lenses act as prisms?
Light creates gravity, and the greater the light's frequency, the greater this gravitational effect is. It stands to reason then that light of different colors would react slightly differently to ...
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