The Universe: Open or Closed?

Twink (
Sat, 22 Nov 1997 19:59:53 -0500 (EST)

At 12:28 AM 11/23/97 +0100, Anders Sandberg <> wrote:
>> I question the question. Perhaps the universe is open, hyperbolic and
>> infinite in extent. If so, then the search for the missing mass is like
>> trying to find caloric or measure the Earth's movement against the
>> aether.
>It would still be missing, since it is detected (or rather, a
>discrepance is detected) by the rotation curves of galaxies.

Yes, but...

>cosmological density doesn't come into the question directly, although
>many scientists no doubt hope the missing mass sets omega=1.

even accounting for that leaves the amount of mass needed under current
estimates between one tenth and one hundredth that need to "close" the
universe -- i.e., give it global positive curvature. I've talked to a few
of mine who have backgrounds in the field, and they agree. They believe
that the cosmologists who subscribe to positive curvature are far from
proving their case. I suspect other motives at work -- such as intuition:
an open, infinite and everexpanding universe is not neat and simple like
a finite, closed one that bounces back and forth.

Daniel Ust