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From: nather@utastro.UUCP (Ed Nather)
Newsgroups: net.astro.expert
Subject: Re: The Universe
Message-ID: <276@utastro.UUCP>
Date: Mon, 24-Jun-85 10:27:32 EDT
Article-I.D.: utastro.276
Posted: Mon Jun 24 10:27:32 1985
Date-Received: Sun, 30-Jun-85 01:13:40 EDT
References: <2649@tekig.UUCP>
Organization: U. Texas, Astronomy, Austin, TX
Lines: 56

> The article in yesterdays Oregonian (from the Chicago Tribune News Service)
> about Stephen Hawking's talks in Chicago, left me with several questions.
> 
> 	1)    "One of the revolutionary consequences of the
> 		inflationary universe model is that there may be
> 		more than one universe; there may be an infinite
> 		number of universes."
> 
> I take it that the inflationary universe is the balloon example that was
> given here within the last couple of months.  

No, that was a two-dimensional analogy of the "current" (Hot Big Bang) model.

> But why and how can there
> be more than one universe?

Well, on the other hand, why not?  None of the current speculations (oops --
I mean, theories) provides any way to detect their existence, or allow
communication, or whatever.  A really *neat* theory, in the view of modern
cosmologists, in one that CAN NEVER BE TESTED by observation; as such, it is
immune to disproof.  Of such things is tenure made ...

> 	2)	 "Some funny things will happen when the universe
> 		begins to collapse.  The direction of time will be
> 		reversed and the past will become the future..."

Hardly.  The "past" is fixed in concrete, while the future is probabilistic,
according to current physics.  That's unlikely to change -- unless we were
to go from an uncertain past into a pre-determined future ... ulp ... maybe
we should leave it alone ...

> 		  "An observer on a space ship in the recollapsing
> 		would see things going in reverse, from disorder to
> 		order..."
> 
> Somehow it seems that even if/when the universe begins to collapse, we
> will still be going "forward" in time, regardless of whether things are
> going from order to disorder or disorder to order.??
> Max Guernsey

I'm sure you're right.  The whole business of the "laws of thermodynamics"
is in interpretive quicksand, in my view.  The "laws" were derived from a
tiny time-slice of a vast, evolving universe, and are expected to be valid
under all possible evolutions.  Maybe, but I doubt it.  Like the inverse
square law of gravity, which breaks down at very tiny distances (the nifty
"singularity" of mathematical description) we're likely to find the "laws
of thermodynamics" become invalid, and need "correction" when we get too
far from the environment in which they were derived.

The sky *will* get bright at night, though, just before the end ...

-- 
Ed Nather
Astronony Dept, U of Texas @ Austin
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