All Questions
Tagged with optics general-relativity
28
questions
-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
0
answers
80
views
Critical angle in General Relativity
Analogies between optical propagation in different refractive media and the effect of gravity in light geodesics are well established. But in optics one can have total internal reflection if certain ...
- 14.5k
7
votes
2
answers
2k
views
How do we know that bending of light around stars is due to bending of space-time and not diffraction?
One question that popped up during the studies of special and general relativity (which I am forced to take unfortunately) is the following:
How do we know that this is due to the bending of space-...
- 649
0
votes
1
answer
104
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Effects of the sun on Einstein's prediction of gravitational bending of light
From what I understood, $1.75''$ was the predicted value derived by Einstein.
Is it possible that light from the star, at the time of solar eclipse, can also be bent somehow by the solar particles ...
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
1
vote
1
answer
42
views
Black holes in a denser media
In Crown Glass, the speed of light is 1.52 times the speed of light in vacuum. Consider the following hypothetical situation:
Hypothetical Situation
If a black hole is surrounded by a giant crown ...
- 359
4
votes
2
answers
421
views
Seeing one's back on the event horizon
If we would hypothetically be exactly on the event horizon, we should see our own back, because of the circular motion of photons on the event horizon, right?
But what would be the image size, or $-$ ...
- 991
9
votes
1
answer
311
views
does the beam of a laser have 'throw'?
I was thinking about Einstein's train and platform experiment and was wondering if a beam of light experiences throw? Let me explain, if I take a water hose and point it straight out and then swing ...
- 93
8
votes
1
answer
344
views
Book on optics in curved space-time
As evidenced from my earlier questions on vision and curved space, I am struggling a little bit with visual perception in curved space-time.
I would like a book recommendation on optics and vision in ...
2
votes
2
answers
563
views
Does gravitational lensing violate Fermat's Principle that light must travel in straight lines?
Does bending of light due to warping of space violate Fermat's Principle or is it that in the principle light goes in a straight line with respect to space (taking space as the reference) and in ...
- 3,905
3
votes
2
answers
312
views
Gravitational distortion of an object's diameter, at a distance,
Does the curvature of space-time cause objects to look smaller than they really are? What is the relationship between the optical distortion and the mass of the objects?
- 31
11
votes
3
answers
2k
views
Liouville's theorem and gravitationally deflected lightpaths
It is customary in gravitational lensing problems, to project both the background source and the deflecting mass (e.g. a background quasar, and a foreground galaxy acting as a lens) in a plane.
Then, ...
- 3,755
43
votes
5
answers
15k
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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