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From: myers@bnl.UUCP (Eric Myers)
Newsgroups: net.astro.expert
Subject: Re: Where's the center of the universe?
Message-ID: <122@bnl.UUCP>
Date: Thu, 23-May-85 14:01:12 EDT
Article-I.D.: bnl.122
Posted: Thu May 23 14:01:12 1985
Date-Received: Thu, 30-May-85 03:30:31 EDT
References: <1544@amdahl.UUCP> <117@utastro.UUCP>
Distribution: net
Organization: Brookhaven National Lab. Upton, N.Y.
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> > If the Universe is expanding from a common point, where is that
> > point?  In particular, in what area of our sky is the direction
> > of this point?
> > -- 
> > Gordon A. Moffett               ...!{ihnp4,cbosgd,sun}!amdahl!gam
> 
> The universe is expanding, but the center of expansion is not uniquely
> defined.  The idealized models of the universe (Friedman models) are
> spherically symmetric around any arbitrary point.
> 
> "Don't argue with a fool.      Ethan Vishniac
>  Borrow his money."            {charm,ut-sally,ut-ngp,noao}!utastro!ethan
>                                Department of Astronomy
>                                University of Texas

   One way to think of it is this:  Blow up a balloon.  If you lived on
the surface you'd see everything moving away from everything else, and
you could say that your universe was expanding.  But there is no center
about which this expansion takes place. [The inside of the balloon doesn't
count -- it isn't a part of your universe if you live on the surface of
the balloon.]


-- 
Eric Myers,  Physics Dept., Brookhaven National Laboratory, Lon Guyland, NY
             myers@bnl.arpa / myers@bnl.bitnet / philabs!sbcs!bnl!myers