in astronomy it is proved that universe we wre seeing is light years?

Question

away and hence represents events of past. is it possible to
"see" ourselves several million light years away ?if so how do we prove it is "we"

Answer 1

what "we" are you talking about? you mean "us" as in the earth?

impossible. earth and the sun don't travel the speed of light so light years don't refer to the objects, just their light. and the light is dispersed in all directions, away from the source, not in circles and back around to our little eye balls


unless we stick a huge mirror 500,000 light years away from us, so we could look back at us 1,000,000 years later.
we'de be lucky to even catch a half a dozen photons of our reflection in a mirror that far away.

or travel back in time
http://www.youtube.com/watch?v=GHC8z6ULs18

Answer 2

While it's theoretically possible there are some practical issues such as devising a suitable optical instrument with the resolution required to see an individual person at a great distance of say a light second yet alone light day or even week distant.

The second problem is getting to a point in space where we can see 'ourselves' as this would require faster than light travel and that while not entirely impossibe under the mankind current understanding of physics is likely to be a practical impossiblity.

Answer 3

If you can place a mirror millions of light years away from Earth, it is possible to bounce a light beam with your image on it and have it bounce back to Earth. However, you won't be around to see it. A light year is the distance light travels in a year. If the mirror is placed at one million light years away from Earth, it would take two million years for light to make the round trip. So our decendants, assuming the human race could survive two million years, would see your image.

Answer 4

I'm sure a few stray photons reflect off of the Earth, go out into space and encounter such gravitational wells that they eventually end up heading back to Earth a second time, many many years later. That would be an extreme exception though. You would need a whole lot of photons, still arranged in their proper sequence to "see" any of Earths past.

Answer 5

We don't use the word "proof" in experimental science. Experiment doesn't ever prove anything; it merely lends support.

That being said, yes, the observable universe is definitely many billions of light years across.

No, we cannot see ourselves millions of light years away because we are not there. We are here.