0
votes
1answer
39 views

Gravitational lensing of massless photons

I recently got a more complete proof of photons having no mass. (I knew it before, but now I really know it.) But now, I'm curious how gravitational lensing can occur without a mass to act on. I have ...
0
votes
3answers
135 views

Is light slower when traveling inside a gravity field?

This question is not about phase velocity changed which causes refraction, but about the real time itself being slower by the gravity of any object (from general relativity). If so, would this mean ...
2
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1answer
150 views

Calculating a Deflection of Light Integral from Einstein's 1907 paper on Gravity and Light

$\frac{1}{c^2}\int_{\theta=-\pi/2}^{\theta=\pi/2} \frac{kM}{r^2}cos\theta ds=2\frac{kM}{c^2\Delta}$ An observation: $\cos\theta=\frac{\Delta}{r}$
4
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3answers
601 views

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 ...