stars

[tejolson]

I don't want to sound like I know more than I actually know. I did that on the last two questions I asked. I know nothing, but that doesn't seem to stop me from thinking about this stuff. So since E = mc2, would that mean that light can be moved like mass? Lets say there is a star at one end of the galaxy and we see it in the sky. That same star is still shining and the galaxy is moving. About a billion years later it's in another part of the galaxy. Only it's much closer. So, can we see this same star twice in two different parts of the sky? And another question, can photons take the scenic route by being pulled this way and that around the galaxy? Can that sun be no where near where we think it is. Can the stars we see in the sky be doubles, tripples, or even be that same star seen more than a thousand times?

 

[MeteorWayne]

Stars don't move fast enough for us to see it's light more than once; in fact nothing with mass can move as fast as light.

The deflection of light caused by stars within a galaxy is to small to see the image more than once.

However, the mass of an entire galaxy or galaxy cluster can be sufficient to act as a lens to galaxies further away, in which case the background galaxy is distorted in shape, magnified, or can be seen in multiple images.

See this link:

http://imagine.gsfc.nasa.gov/docs/featu ... _lens.html

Wayne

 

[neilsox]

MeteorWayne likely answered the intent of the question, however microlensing does occur, and will be observed more often as resolution improves. Double images appear frequently, typically a second of arc apart. When (and if) 0.01 seconds of arc can be resolved, perhaps half of the stars will be a double image, at least rarely and briefly, and occasionally = one of the pair will be micro lensed again making three images which we can observe. Microlensing occurs because of strong gravity fields. Neil