Free Republic
Browse · Search
News/Activism
Topics · Post Article

To: Physicist
So space itself is most likely infinite, only the particles that lie within it, like stars and planets are finite, approximately 13 to 15 billion light years away?? So if a galaxy lies 100 or more billion light years away, despite the distance with our technology of today we would still be able to detect it?
141 posted on 04/25/2002 6:48:50 AM PDT by Reaganwuzthebest
[ Post Reply | Private Reply | To 139 | View Replies ]


To: Reaganwuzthebest
We may never be able to detect it. If the universe (defined not as all the matter we can travel to, but all the matter that exists) is infinite in extent, then--except for our local bubble--all of it is receding from us faster than the speed of light. We can never reach it, and its light can never reach us.

That's not to say that we can now see everything we could eventually see, if we last long enough. Some galaxies that are just beyond our current horizon will eventually be visible; we can't see them now because (as far as we can see in our reference frame) they haven't formed, yet. We can in principle watch the process of star and galaxy formation in the early universe, as the universe evolves. As the universe expands, however, the recession velocity of the earliest observable universe increases, and time dilation dictates that it evolve ever more slowly, as the velocity asymptotically approaches the speed of light. That puts a strict outer limit on the matter we'll ever be able to see.

146 posted on 04/25/2002 7:05:34 AM PDT by Physicist
[ Post Reply | Private Reply | To 141 | View Replies ]

Free Republic
Browse · Search
News/Activism
Topics · Post Article


FreeRepublic, LLC, PO BOX 9771, FRESNO, CA 93794
FreeRepublic.com is powered by software copyright 2000-2008 John Robinson