WASHINGTON -- Scientists say the explosion of a star halfway across the universe was so huge it set a record for the most distant object that could be seen on Earth by the naked eye.
"lily" said How do they know it was halfway across?
'Redshift'. The further something is away from us, the faster it moves away, causing the light it emits to be 'shifted' toward the 'slow' (red) end of the spectrum. Seeing how far the light from a star has 'red shifted' is a pretty accurate measure of it's distance.
We don't know if the universe is finite or infinite. They take the calculated age of the universe and the distance back in time where the event occurred and compre the two. The result was about half the age of the universe, thus halfway across.
"lily" said So we've determined the universe isn't really infinite?
The universe may be infinite, or it may be expanding as matter fills it. We just don't know.
We have measured the age (and size), given redshift, at about 13.7 billion years. What lies beyond that, we can't say.
If the Universe is infinite, there is the theory that other universes have existed and been present, somewhere - but they were so far away from us that their presence has not be detected.
Hence 50% or halfway.
(Remember light bends in space.)
How do they know it was halfway across?
'Redshift'. The further something is away from us, the faster it moves away, causing the light it emits to be 'shifted' toward the 'slow' (red) end of the spectrum. Seeing how far the light from a star has 'red shifted' is a pretty accurate measure of it's distance.
You see!!! This is all the result of Global Warming!!!!!!
So in essence this really happened 7.5 billion years ago. Thats cool. Someone correct me if I am wrong
So we've determined the universe isn't really infinite?
The universe may be infinite, or it may be expanding as matter fills it. We just don't know.
We have measured the age (and size), given redshift, at about 13.7 billion years. What lies beyond that, we can't say.
If the Universe is infinite, there is the theory that other universes have existed and been present, somewhere - but they were so far away from us that their presence has not be detected.
"The aging star, in a previously unknown galaxy, exploded in a gamma ray burst 7.5 billion light years away."
So in essence this really happened 7.5 billion years ago. Thats cool. Someone correct me if I am wrong
Quite correct. Since we see light from stars, and light travels at a (more or less