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Old 23-September-2005, 12:45 AM
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cran cran is offline
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In short:
- the darkness of the night sky (not possible if the universe is infinite).
- ToSeek

It is possible, and astronomy proves that all the time... to differentiate 'light' from 'darkness' requires a minimum number of photons from source per unit time, per unit area of light receptor - for an infinite universe to appear as 'light' would also require an infinite time for reception ... longer time exposures by very high resolution receptors are finding more sources of light in what previously appeared to be 'dark' blank spaces...

The other two are based on plausible (though not necessarily unique) interpretations of observations...


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But what evidence is there that is explained by big bang theory, but not that one? Surely there must be some.
- uniqueuponhim

It is central to the theory, and is based upon observations of apparent expansion, in turn based upon observation and measurement of redshift.

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Second, how are scientists able to look back and determine exactly what was going on as little as 10^-44(I think) seconds after the big bang happened? How are they able to deduce this, and how are they able to be certain that those deductions are accurate?

This is a matter of producing models based on the appearances and our current understanding of physics.
- Q. uniqueuponhim; A. ToSeek

I think it's 10^-43 seconds (Planck era), and it's based on quantum-related theory and lab experiments.

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So in other words, nobody really knows, but we think it's the latter? What observations are there which point to the latter one being true?
- uniqueuponhim

The interpretation of the sum of all large-scale astronomical observations... and yes, nobody really knows - that's what makes science fun

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...at what distance from the universe(and by universe here, I mean the collection of matter which comprises it, not the space it encompasses) would it become just a star-like point to the naked eye, and how far from the universe would you have to be for it to be too faint to see at all with the naked eye?
- uniqueuponhim

That would depend upon whether one can define a limit to the matter of the universe - a year or so back, some workers announced a diameter of ~78GLy, if that's any help... from there, you need someone with reasonable skills in trig to answer your question.
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"I don't know...I'm making it up as I go along!" ...Dr I. Jones

"...and your wise men don't know how it fee-e-e-eels...
to be thick as a brick..." J. Tull

"Nature abhors perfection... cats abhor a vacuum!"

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