Can we prove that the universe is finite or infinite?

Question

If I say that the universe is finite, how can you say with certain that I am wrong?

First you have to define "universe" – TryTryAgain Mar 29 '12 at 22:42 — TryTryAgain, Mar 29 '12 at 22:42

score 3 · Answer 1 · answered Mar 29 '12 at 18:04

George Gamow tried to explain the origin of the Elements Georges Lemaître's theory of the expansion of the Universe. He proposed a ball of neutrons exploding as the Big Bang,nucleocosmogenesis. http://en.wikipedia.org/wiki/George_Gamow Alpher and Robert Herman predicted that the afterglow of the big bang would have cooled down after billions of years, filling the universe with a radiation 5 degrees above absolute zero. Alpher and Herman's prediction in support of the big bang was not substantiated until 1964, when Arno Penzias and Robert Wilson made the accidental discovery, for which they were awarded the Nobel Prize in Physics in 1978.The universe was once very hot and dense, and the photons and baryons formed a plasma. As the universe expanded and cooled, the radiation (photons) decoupled from the matter. The radiation cooled and is now at 2.73 Kelvin. http://aether.lbl.gov/cmb.html

This is amazing conformation of the Big Bang & the finite nature of time & space. — , Mar 29 '12 at 18:06
@Brian Goulet--Not necessarily: If the universe is "local" (i.e., causally-separated from others in a multiverse), time & space could've had a past-eternal origin, and several cosmological models (including Aguirre & Gratton's 2002 "Steady-state eternal inflation", Nikodem Poplawski's 2010 "Cosmology with torsion", and 2020 Nobel Prize winner Roger Penrose's 2010 "Cyclic conformal cosmology") provide falsifiable (i.e., scientifically valid) premises for such a possibility. Preprints describing those models are freely available: Penrose's has had some observational validation. — Edouard, Mar 27 '22 at 11:01

score 0 · Accepted Answer · answered Mar 20 '12 at 11:42

0

Due to General Relativity the universe started 13.7GYr ago. It was finite then and since there was no phase of infinite expansion, it is still finite.

answered Mar 20 '12 at 11:42

draks ...

982

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Where is your proof that it was finite then? Current measurements of the curvature of space indicate that it's flat; and a flat universe has to be infinite. – Dan Is Fiddling By Firelight Mar 21 '12 at 13:48
@DanNeely Was it flat back then too? – draks ... Mar 21 '12 at 14:14
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@DanNeely Indications are not proof. – uSeRnAmEhAhAhAhAhA Feb 20 '14 at 16:49
@deletethisaccount A model is not a proof either... – anderstood Oct 21 '15 at 21:09
lies
– Arman Armenpress Dec 17 '20 at 10:19

score -2 · Answer 3 · answered Apr 02 '12 at 01:28

-2

If the universe is infinite, there would be an infinite amount of stars in it, therefore there will be no night and we have to sleep in Sunglasses.

answered Apr 02 '12 at 01:28

whitefleaCH

153

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not necessarily. the universe could be a fractal. en.m.wikipedia.org/wiki/Olbers'_paradox – Jus12 Apr 02 '12 at 13:35
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What you're describing is Olber's paradox. It requires the universe to be infinite in both volume and prior duration. A finite volume or a finite age will both render it null and void. http://en.wikipedia.org/wiki/Olbers%27_paradox – Dan Is Fiddling By Firelight Apr 02 '12 at 17:35
This reminds me of Aristotle's proof that vacuum does not exist... (otherwise moving my hand would give it an infinite velocity...) – anderstood Oct 21 '15 at 21:11

Can we prove that the universe is finite or infinite?

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