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Strange

Entry 382, on 2006-08-18 at 13:54:01 (Rating 1, Science)

In my last blog entry I listed 13 things that, according to New Scientist, don't make sense. The second thing which doesn't make sense is the horizon problem. This states that the observable Universe (28 billion light years in diameter) is so uniform (it is similar density, temperature, etc on a large scale in all directions) that we cannot explain it. No force or phenomenon could travel faster than light to result in this uniformity over that distance because the Universe is only 14 billion years old.

The theory of inflation solves this problem (along with a few others) but we don't really know why inflation would have happened. Essentially inflation theory states that the Universe expanded really quickly just after the big bang. When I say really quickly I mean *really* quickly: by a factor of 100 quadrillion quadrillion in one billion quadrillionth of a second!

In many ways this whole idea is unprecedented elsewhere in science, but until we have a theory of quantum gravity we probably can't really understand what's happening. My intuition says we will find this theory is a good model, but what really happened will be better explained in different terms - sort of like Newtonian gravity is a good model but not strictly correct.

Recent space probes have found anisotropy in the microwave background which is consistent with inflation, so I think cosmologists are on the right track. Maybe the reality of this is like Haldane said: The Universe is not only stranger than we imagine, it is stranger than we can imagine.

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