Open/Closed Universe

Twink (
Tue, 25 Nov 1997 19:31:43 -0500 (EST)

>At 17:18:46 Tue, 25 Nov 1997 +1100 (EST) Bradley Graham Weslake
<> wrote:
>>>>There are a multitude of other observed phenomena which align
>>>>well with the theory of a closed universe, as well as theoretical
>>>>reasons for believing that such a case is probable.
>>> Doesn't this contradict your initial statement?
>>No it does not. In the first instance I said that *observations* tend at
>>this stage to support an open universe. In the second instance I said
>>that there are many *theoretical* reasons for believing a closed
>>universe is probable.

Don't want to nitpick too much, but your statement was "There are a
multitude of other observed phenomena which align[sic] well with the
theory of a closed universe, as well as theoretical reasons for believing
that such a case is probable." (The statement this contradicts is your
qualified admission that "...I agree that current observations tend to
suggest an open universe...") The first part of that sentence seems
to me to translate into there being _evidence_ for a closed universe.
What is this evidence? And why would there be good theoretical
reasons if somewhere the theory did not match up with some facts?

It appears the universe is open, but I'm interested in why, if it does,
do some still maintain otherwise. What reasons do they have? And
are these reasons valid and tractable? In the interim, we might do
well to discuss/try to understand the idea of an open, globally
hyperbolic universe -- rather than be shackled to the current
Standard model, which might become obsolete.

One, but by no means the only, model of an open universe is that
of David Layzer. But even if his model is found to be faulty, any
good theory of cosmology should be able to account for the fact
that the universe has a lot less mass than would needed to close
it -- given current observations.

Please do not take the above to mean that I think science is
ruthlessly empirically driven. It is not -- at least, not in the
fashion pure empiricists would have us believe. Instead, I
think it rest not on accumulating evidence, but on
explaining/integrating wider fields of evidence. (This is
why, to try to add something to the quantum physics
debate, classical mechanics has been superseded. Post-
classical theories (QM, QFT, QED, QCD, ST, GT, etc.) are
able to explain more with less: more facts with less ad hoc

An aside: What are the probabilities and how are they
measured in this area?


Daniel Ust