Saturday, October 27, 2007

Reading Cosmology

I don't really understand the equations, but I think I get the gist. Einstein was one switched-on fellow. His insights go way beyond what he is famous for. Seems he also laid the groundwork for modern cosmology by postulating that the universe is homogenous and isotropic. That means that on a large enough scale, it has uniform density and no direction. If this is true, the universe is a bound but expanding surface. Like the surface of a balloon that expands as you blow it up but remains a sphere. Observations, by Hubble and others since, confirm that the universe is homogenous and isotropic. Einstein apparently reasoned that it would be absurd for the universe to -- in my words, not his -- be doing any "work," i.e. to have a non-uniform density (what would keep it or make it non-uniform but "work") or to be "going anywhere" (moving where?). Physics is confirming his cosmological constant and an accelerating expansion. He spent the last years of his life working on a unified theory that may be worth taking a closer look at.

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