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To: count-your-change; Alamo-Girl
The accounting for starlight from far distant stars with an explanation that says, if I understand it, that the stars are old but the light from them is young to us.

So the further out we see, the further back in time we're looking. And what information about the beginning is that showing us?

http://en.wikipedia.org/wiki/Observable_universe

The age of the universe is about 13.7 billion years, but due to the expansion of space we are now observing objects that are now considerably farther away than a static 13.7 billion light-years distance. The edge of the observable universe is now located about 46.5 billion light-years away.

Estimates of the matter content of the observable universe indicate that it contains on the order of 10 [to the 80th] atoms. The vast majority of the energy density is contributed by dark matter and dark energy.

38 posted on 01/24/2009 5:15:17 AM PST by metmom (Welfare was never meant to be a career choice.)
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To: metmom

One thing it tells us is that there was a beginning, not an easy concept for some, I guess. Another is that if the farthest objects are 13 billion years old we can’t really say much about their condition at this moment seeing they’ve had 13 billion years to change or not.


40 posted on 01/24/2009 7:59:12 AM PST by count-your-change (You don't have be brilliant, not being stupid is enough.)
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To: metmom; count-your-change; betty boop; Suzie-Q; GodGunsGuts
There are a few things often overlooked in "age of the universe" debates on this forum.

First, that space/time itself expands. Thus a photon sent out when a star was just a billion light years away may not reach us until ten billion lights later. The photon traveled at the speed of light. For it, no time elapsed (null path.) But it took longer to get here because space/time itself expanded. In the inflationary phase of this universe, space/time itself expanded faster than the speed of light.

Second, that the rules which apply to relative velocities in special relativity - e.g. that relative velocities cannot increase past the speed of light - do not apply to relative velocities in comoving coordinates. If you could engineer a space vehicle which folds four dimensional space/time and tunnels from one side to the other and move through it, you would be traveling faster than the speed of light without violating the speed limit.


42 posted on 01/24/2009 10:16:52 AM PST by Alamo-Girl
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