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Old 30-October-2007, 02:57 PM
Burt Burt is offline
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Join Date: Jul 2006
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Default The Observable Universe %

Quote:
Originally Posted by Steve Limpus View Post
I was really excited to hear Pamela say that the observable universe is thought to be three or four percent of the entire universe; ... If Pamela says its three or four percent that's good enough for me. Does anyone know *how* we figured out that percentage?
Hi Steve. The closest answer that I found is that cosmologists think that the minimum size of the total universe is some 133 billion light years radius. This gives a volume of around 10 billion billion cubic light years. The observable universe has a present radius of about 46 billion light years, giving a volume of about 400 thousand billion cubic light years. The observable volume is then about 4% of the whole.

One must remember though, that the observations are also compatible with an infinitely large universe, which makes the observable portion, well, zero %?
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