Re: Accelerating Expansion of the Universe

George Murphy (gmurphy@raex.com)
Tue, 29 Dec 1998 07:58:01 -0500

RDehaan237@aol.com wrote:
..................
> "A positive cosmological constant it seems, though this finding is in
> conflict with other lines of evidence. Frank Tipler pointed me to
> studies which suggest that until we measure distances accurately out to
> ~ z = 3, then local motions will probably distort the apparent value of
> Hubble's "constant". That'll take some doing yet."

A little hermeneutic of suspicion: The announced result, _if_ it holds up,
would wreck Tipler's "physics of immortality".
.............................

> "What does it mean for the Universe, is more to the point? Never ending
> expansion and separation of all non-bound systems... a very lonely
> Universe in the distant future. All non-bound masses will disappear over
> each other's c-boundary. Maybe. That's if the lambda factor is
> well-behaved. In the far future it may reverse and bring it all back to
> a Big Crunch. There's no theoretical way of knowing what the long term
> behaviour of lambda will be. It's a vacuum energy phenomenon and that's
> something physics still has a poor grasp on."

Lambda may be entirely a vacuum energy phenomenon - if you come at the issue
from a particle physicist/quantum field theorist position. If you approach it from
the geometrically-minded general relativist's position, lambda may be a fundamental
feature of the laws of physics - e.g., to _define_ a metric in terms of curvature in the
sort of affine theory which Schroedinger explored.

........................................
George L. Murphy
gmurphy@raex.com
http://web.raex.com/~gmurphy/