From: Jeff L Jones (jeff@spoonless.net)
Date: Fri Aug 24 2007 - 21:30:39 MDT
On 8/24/07, Matt Mahoney <matmahoney@yahoo.com> wrote:
> We observe galaxies not only receding, but accelerating away. We postulate a
> mysterious "dark energy", a sort of negative gravity, inconsistent with
> general relativity.
I don't know about the rest of the stuff you wrote (regarding black
holes), but dark energy is certainly consistent with GR. In fact, it
was a basic part of GR from the very beginning. Einstein called it
the "cosmological constant" which he originally thought was negative,
since he believed in a static universe. After Hubble discovered it
was actually expanding, Einstein removed the dark energy calling it
his "greatest blunder" and setting it back to zero (for no other
reason than simplicity--by Occam's razor). Now we've measured that
it's very close to zero, but actually positive. (This is the most
common interpretation--it's also possible that it could be something
more than just a cosmological constant, such as quintessence, but if
so it's not that different and still entirely consistent with GR.)
Jeff
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