2
$\begingroup$

From our planet we can only see so far on any direction.

If a galaxy farther out than ours had a planet would its view extend beyond our measurements?

$\endgroup$
1
$\begingroup$

Yes, exactly. Because the universe is only 13.7 billion years old, light from a certain radius doesn't have enough time to reach you. Since light is travelling towards you at the same speed in all directions, and cosmological expansion is uniform in all directions, your observable universe is a sphere in which you sit at the center. So, for a distant galaxy, this sphere would, just like ours, have a radius of 46 billion light years. Since they're far away, this encompasses different regions of the universe.

$\endgroup$
  • $\begingroup$ Since there is no possibility of recording the other observations how can we be certain that there view would not just stop at our current boundry? $\endgroup$ – Argus Sep 5 '12 at 22:53

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.