Re: how big is the universe?

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"Ed Gibbs" <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]
> I think when they say "infinite" they mean just that - goes on forever
> and ever without end.

And there is actually some logic to this, that the universe may be infinite
in the common sense? I can see it as a philosophical speculation, but can it
be derived from a scientific model? I'm non scientist, so I'm not arguing
against- actually, I find the idea fascinating- but I'm trying to get a
grasp on what it means, scientifically. Since the universe was once very
small, and as it grew, it must have been finite- how does something go from
being finite to infinite? Or, does the model say that it was infinite from
the beginning, and what does that really mean? I've read some speculation
that our big bang was something that occured withing some bigger framework,
which perhaps is infinite, so in that sense, I can sort of "get it".



>
> That is distinctly different from very, very large - which implies
> that it is finite, though possibly so large that it appears for all
> intents and purposes to be infinite.

Either way, it's mind blowing- to think of all the stuff out there, that if
knew about it we'd be shocked. We need to somehow, eventually, learn about
what's out there, otherwise we are very provincial indeed. (I don't like the
word "indeed", but sometimes I use it when I'm in awe. <G>)


>
> There are also finite but unbounded - a universe that could be very,
> very large (not infinite) but has no edge - say a 4 dimensional sphere
> that you can go around to come back to where you started, as you can
> on the surface of the earth.

OK, I can get that one- that's easy by comparison.



>
> Then there are things like perpetual inflation, which posits that our
> very, very large big bang universe is one of an enormous and
> constantly growing (though quite possibly finite) number of big bang
> universes.
>
> And then there are the really crazy theories...;-)

No doubt if our civilization continues for centuries, each generation will
push the envelope, each discovering more amazing stuff than the last. I find
this to be wonderful, the bigger and more outrageous the better- from a
philosophical point of view.

Now, if only somewhere out there is some civilization that has been around
for millions of years, which has done a "Comparative Study of Evolution on a
Galactic Scale" and the follow up "Compartive Study of Civilizations on a
Galactic Scale". Then of course, an even more advanced civilization will do
a compartive study across galaxies. And, somewhere out there is the most
advanced, the smartest, of all that may have a deep understanding of the
universe on a scale larger than their respective "visible universe". My
theory, from a dummy's point of view, is that when we have a better
understanding of dark matter and dark energy, somehow there is a lot of
infomation contained therein, that could tell us a lot about a big chunk of
the universe, maybe beyond "the edge" of the visible universe- such as the
"large scale structure" too big for us to see- structures so big that from
within any given "visible universe" you could see only a small part of it.


>
> Ed Gibbs
>
> Joe Zorzin <[EMAIL PROTECTED]> wrote in message
news:<[EMAIL PROTECTED]>...
> > When astronomers use the term "infinite" in this context, what do they
mean?