Magnification of distant glaxies by intervening galaxies

[chicopee]

Recently, an article on the web appeared about the magnification of very old galaxies from intervening galaxies, so my question is the light from these very old galaxies bending around the perimeter of these closer galaxies or is the light going thru these closer galaxies, or it both.

 

[IRstuff]

Mostly going around. Einstein's general theory of relativity describes the refraction of light traveling across a gravity well, such as might be around a large galaxy. Usually, the light density of a galaxy is too high to see much through it. We are in a relatively low density part of our galaxy, so we're able to see outside. Were we closer to the center of the galaxy, our night sight would be too bright to see much else.

TTFN
faq731-376

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[chicopee]

Your post makes sense, thanks.

 

[IRstuff]

An interesting fallout of General Relativity is the relativistic time dilation experienced by our GPS satellites. The rubidium clocks used by GPS are so accurate that they need to be corrected for time dilation effect predicted by relativity:

http://en.wikipedia.org/wiki/Error_...sitioning_System#Calculation_of_time_dilation

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[chicopee]

I did not think that GPS satellites travelled that fast for time dilation effect by after reading Wikipedia's article on time dilation, I am convinced. I'll have to dig up my old textbook(at least 50 years old) on modern physics and refresh my memory .