Wednesday, 9 May 2012

Olbers' Paradox

This states that if the universe was infinitely large, there would be a star along every possible line of sight and the sky would at all times be uniformly as bright as the sun. (Day and night; no dark bits!)

This argument presupposes that an infinitely large universe would contain an infinite number of bright objects. That is not necessarily the case.

According to currently prevailing theories, the universe is expanding at an increasing rate due to SPACE expanding. The total mass/energy in the universe has been estimated and is therefore finite. It is not believed to be increasing in mass/energy. Rather the total mass/energy density is decreasing.

Were the "finite" universe, as we see it today, to expand infinitely, in space terms, there would be no increase in the number of bright objects, and the sky would appear pretty much as it does today, albeit with some moving about. In fact, I believe (as many do) that it will become dimmer.

We would then have an infinite universe without a star on every possible line of sight.
Hence Olbers' paradox would appear to be flawed.

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