Gravitational Lensing Q: Angle Deflection Sun/Earth?

Macrobe
Messages
12
Reaction score
0
I have a simple question about gravitational lensing around our sun: is the angle of deflection 1.75" arcseconds the angle of deflection as the light goes past the sun, or the angle of deflection when it is received here on earth?
 
Physics news on Phys.org
I can't find it on that, though it is an interesting read. Very informative.
 
Macrobe said:
I can't find it on that, though it is an interesting read. Very informative.
I don't understand your question. The angle is defined relative to an undeflected ray, so it is the same angle everywhere.
 
Oh...yeah...duh. If you'll pardon the colloquialism, I had a brain fart. My apologies.
 

Thread 'I don't see how a black hole's event horizon can be crossed'

OK, so this has bugged me for a while about the equivalence principle and the black hole information paradox. If black holes "evaporate" via Hawking radiation, then they cannot exist forever. So, from my external perspective, watching the person fall in, they slow down, freeze, and redshift to "nothing," but never cross the event horizon. Does the equivalence principle say my perspective is valid? If it does, is it possible that that person really never crossed the event horizon? The...
View full post »

Thread 'Synchronizing clocks in an inertial frame if light is anisotropic'

ASSUMPTIONS 1. Two identical clocks A and B in the same inertial frame are stationary relative to each other a fixed distance L apart. Time passes at the same rate for both. 2. Both clocks are able to send/receive light signals and to write/read the send/receive times into signals. 3. The speed of light is anisotropic. METHOD 1. At time t[A1] and time t[B1], clock A sends a light signal to clock B. The clock B time is unknown to A. 2. Clock B receives the signal from A at time t[B2] and...
View full post »

Thread 'Is the variation of the metric ##\delta g_{\mu\nu}## a tensor?'

From $$0 = \delta(g^{\alpha\mu}g_{\mu\nu}) = g^{\alpha\mu} \delta g_{\mu\nu} + g_{\mu\nu} \delta g^{\alpha\mu}$$ we have $$g^{\alpha\mu} \delta g_{\mu\nu} = -g_{\mu\nu} \delta g^{\alpha\mu} \,\, . $$ Multiply both sides by ##g_{\alpha\beta}## to get $$\delta g_{\beta\nu} = -g_{\alpha\beta} g_{\mu\nu} \delta g^{\alpha\mu} \qquad(*)$$ (This is Dirac's eq. (26.9) in "GTR".) On the other hand, the variation ##\delta g^{\alpha\mu} = \bar{g}^{\alpha\mu} - g^{\alpha\mu}## should be a tensor...
View full post »

Similar threads

I With gravitational lensing, which way is down?
Replies
24
Views
610
B Eddington Exp vs Newton: Comparing Starlight Deflection
Replies
6
Views
2K
B Black hole electromagnetic spectrum
Replies
4
Views
2K
I Absolute meaning of spatial deviaton angle of light around the sun
Replies
2
Views
892
A Gravitational Bending of Light: Equation for Photon Trajectory in Strong Fields
Replies
9
Views
2K
I Doubts about the relativistic description of electrical interactions
Replies
2
Views
1K
B How quickly does the Earth feel the effects of a halved Sun's mass?
Replies
38
Views
3K
B Gravitational potential energy, a thought experiment
3
Replies
125
Views
6K
Gravitational lensing and the speed of light
Replies
13
Views
4K
B Gravitational Waves: A Question on Earth's Magnitude & Frequency
Replies
24
Views
2K

Hot Threads

Recent Insights

Back
Top