Re: Where is the center of the universe?

From	dvus <dven1@adelphia.net>
Newsgroups	alt.astronomy, sci.physics, sci.physics.relativity
Subject	Re: Where is the center of the universe?
Date	2015-11-24 17:07 -0500
Message-ID	<dbk5cvF2onvU1@mid.individual.net> (permalink)
References	<54D7D8B6.20A9@ix.netcom.com> <QOSdnfQd_95ZnkXJnZ2dnUU7-L-dnZ2d@giganews.com> <SvydnRLtaes8LdLLnZ2dnUU7-KudnZ2d@giganews.com> <dbb3o2FnqgdU1@mid.individual.net> <mrWdnaImztaC2c7LnZ2dnUU7_82dnZ2d@giganews.com>

Cross-posted to 3 groups.

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On 11/23/2015 11:51 AM, Tom Roberts wrote:
> On 11/21/15 11/21/15 - 5:43 AM, dvus wrote:
>> If there is no "center" of the Universe then
>> it would seem that it would have to be infinite in size.
>
> No. An infinite 3-d space that is not uniform can have a center, and any
> uniform closed 3-d space will have no center.
>
>      "Closed" is a topological term. Loosely, it means of finite
>      size and having no boundary. For instance, the 2-D surface
>      of a sphere, CONSIDERING ONLY THE SURFACE -- there is no
>      "edge" to fall off (which would be a boundary)....
>
>
>> Yet we are told the BB
>> happened just under 13.75 light-years ago.
>
> You have misread. That should be 13.75 billion years ago.
>
>
>> How could it be infinite if it
>> originated a finite time ago?
>
> You are conflating different aspects of the geometry. It is quite
> possible for the 3-d space of constant time to be infinite, yet there is
> nothing (i.e. no part of the manifold) preceding the big bang. That is,
> an infinite space can arise out of the big bang singularity -- such
> singularities can be inscrutable.
>
>
>> Additionally, I have read numerous articles that purport that
>> cosmologists are
>> now able to see galaxies that formed a short time after the BB. What
>> will they
>> see when they are able to see beyond those earliest galaxies?
>
> Earlier than those galaxies is "recombination" -- the time when the
> temperature of the universe cooled enough to permit atoms to form.
> Before that time there were so many free charged particles the light
> could not propagate any significant distance. Light that existed at that
> time can propagate to our telescopes, and has been redshifted so much it
> is now known as the cosmic microwave background radiation (CMBR). The
> CMBR is quite visible as microwave radiation with a current temperature
> of 2.7 K; it is observed to be isotropic to within about 1 part in 10,000.
>
>      Measurements of the CMBR have become incredibly detailed and
>      are key aspects of testing cosmological models.
>
>
>> Also, I constantly see diagrams supposedly of the entire Universe
>> shaped kind of
>> like a football. (why it isn't round I don't know) Those diagrams
>> don't indicate
>> the Universe is infinite or they would have to be be infinitely big.
>
> You are confusing different models, thinking they are the same; they
> aren't.
>
> The long axis of the "football" is TIME. The other two dimensions are
> space, and one spatial dimension is suppressed (to make visualization in
> 3-d possible). Such diagrams apply to models of the universe in which
> there is a "big crunch" -- a time-reversed version of the big bang where
> everything is compressed to infinite density and the universe ends in a
> singularity. In these models space is finite (and spherical [#]).
>
>      [#] But it is NOT the interior of a sphere (which obviously
>      has a boundary). Rather it is topologically the 3-sphere S^3,
>      which has no boundary. Here "spherical" means "having the
>      symmetry SO(3)", not "looking like a ball".
>
>
>> Then I read about theories of the "multiverse" composed of many bubble
>> Universes
>> surrounding ours. How can you surround an infinite Universe?
>
> By using other dimensions. Or by not having a spatially-infinite
> universe (see above).
>
>
>> I try to read everything I can get my hands on about this subject but
>> I still
>> can't seem to wrap my mind around the seemingly contradictory facts I
>> see here
>> and elsewhere. [...]
>
> See Ned Wright's cosmology tutorial; it is the best intro I know.
>      http://www.astro.ucla.edu/~wright/cosmolog.htm

It seems as though no one can say what the "shape" of the Universe 
really is, all these mathematical terms don't describe it in a way a 
person can visualize. If someone said we lived on the surface of a 
sphere of some determinate size I could visualize that, or if they said 
it was a fairly homogenous sphere we lived inside of, I could visualize 
that. But all I see are explanations of a Universe that's "bounded" or 
"not bounded" without an explanation of just what the heck that really 
means. I suppose if you live in a Universe which you consider has no 
"outside" it's tough to give its shape except in mathematical terms.

I'd even prefer it if someone said "we have no idea" rather than these 
murky non-explanations.

-- 
dvus

Thread

Re: Where is the center of the universe? Sam Wormley <swormley1@gmail.com> - 2015-11-20 17:45 -0600
  Re: Where is the center of the universe? The Starmaker <starmaker@ix.netcom.com> - 2015-11-20 23:48 -0800
    Re: Where is the center of the universe? Poutnik <poutnik4nntp@gmail.com> - 2015-11-21 10:27 +0100
      Re: Where is the center of the universe? benj <none@gmail.com> - 2015-11-21 05:13 -0500
        Re: Where is the center of the universe? Poutnik <poutnik4nntp@gmail.com> - 2015-11-21 12:57 +0100
          Re: Where is the center of the universe? benj <none@gmail.com> - 2015-11-21 13:44 -0500
            Re: Where is the center of the universe? Poutnik <poutnik4nntp@gmail.com> - 2015-11-21 20:01 +0100
              Re: Where is the center of the universe? benj <none@gmail.com> - 2015-11-21 14:17 -0500
            Re: Where is the center of the universe? Poutnik <poutnik4nntp@gmail.com> - 2015-11-21 20:01 +0100
              Re: Where is the center of the universe? benj <none@gmail.com> - 2015-11-21 14:22 -0500
    Re: Where is the center of the universe? Sam Wormley <swormley1@gmail.com> - 2015-11-21 08:05 -0600
      Re: Where is the center of the universe? benj <none@gmail.com> - 2015-11-21 13:48 -0500
        Re: Where is the center of the universe? Tom Roberts <tjroberts137@sbcglobal.net> - 2015-11-23 10:21 -0600
          Re: Where is the center of the universe? Maciej Woźniak <mlwozniak@wp.pl> - 2015-11-23 17:34 +0100
          Re: Where is the center of the universe? The Starmaker <starmaker@ix.netcom.com> - 2015-11-23 11:31 -0800
            Re: Where is the center of the universe? rickman <gnuarm@gmail.com> - 2015-11-23 15:54 -0500
              Re: Where is the center of the universe? The Starmaker <starmaker@ix.netcom.com> - 2015-11-23 13:43 -0800
                Re: Where is the center of the universe? rickman <gnuarm@gmail.com> - 2015-11-23 16:49 -0500
                Re: Where is the center of the universe? The Starmaker <starmaker@ix.netcom.com> - 2015-11-23 16:17 -0800
              Re: Where is the center of the universe? dvus <dven1@adelphia.net> - 2015-11-24 16:52 -0500
                Re: Where is the center of the universe? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2015-11-24 22:24 +0000
    Re: Where is the center of the universe? Saul Levy <saullevy1@cox.net> - 2015-11-21 07:13 -0700
      Re: Where is the center of the universe? "Notroll2015" <notroll2015@charter.net> - 2015-11-21 12:48 -0600
        Re: Where is the center of the universe? Saul Levy <saullevy1@cox.net> - 2015-11-21 14:10 -0700
  Re: Where is the center of the universe? dvus <dven1@adelphia.net> - 2015-11-21 06:43 -0500
    Re: There's nothing special about the start of "the big bang". benj <none@gmail.com> - 2015-11-21 13:45 -0500
      Re: There's nothing special about the start of "the big bang". "Notroll2015" <notroll2015@charter.net> - 2015-11-21 12:51 -0600
      Re: There's nothing special about the start of "the big bang". Edward Stansfield <stansfield5REM6@linuxmail.org> - 2015-11-21 14:11 -0500
    Re: Where is the center of the universe? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2015-11-21 20:37 +0000
      Re: Where is the center of the universe? The Starmaker <starmaker@ix.netcom.com> - 2015-11-21 21:06 -0800
        Re: Where is the center of the universe? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2015-11-22 11:43 +0000
          Re: Where is the center of the universe? benj <none@gmail.com> - 2015-11-22 09:01 -0500
            Re: Where is the center of the universe? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2015-11-22 14:59 +0000
          Re: Where is the center of the universe? The Starmaker <starmaker@ix.netcom.com> - 2015-11-22 14:02 -0800
            Re: Where is the center of the universe? Sam Wormley <swormley1@gmail.com> - 2015-11-22 16:32 -0600
        Re: Where is the center of the universe? Saul Levy <saullevy1@cox.net> - 2015-11-22 07:18 -0700
    Re: Where is the center of the universe? Tom Roberts <tjroberts137@sbcglobal.net> - 2015-11-23 10:51 -0600
      Re: Where is the center of the universe? Arc Michael <abookoflife@yahoo.com> - 2015-11-24 13:57 -0800
      Re: Where is the center of the universe? dvus <dven1@adelphia.net> - 2015-11-24 17:07 -0500
        Re: Where is the center of the universe? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2015-11-24 22:48 +0000
          Re: Where is the center of the universe? Arc Michael <abookoflife@yahoo.com> - 2015-11-24 17:01 -0800
            Re: Where is the center of the universe? Saul Levy <saullevy1@cox.net> - 2015-11-25 01:20 -0700
              Re: Where is the center of the universe? Arc Michael <abookoflife@yahoo.com> - 2015-11-25 10:51 -0800
                Re: Where is the center of the universe? Saul Levy <saullevy1@cox.net> - 2015-12-03 18:13 -0700
          Re: Where is the center of the universe? The Starmaker <starmaker@ix.netcom.com> - 2015-11-24 21:47 -0800
            Re: Where is the center of the universe? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2015-11-25 10:32 +0000
              Re: Where is the center of the universe? The Starmaker <starmaker@ix.netcom.com> - 2015-11-25 09:47 -0800
                Re: Where is the center of the universe? The Starmaker <starmaker@ix.netcom.com> - 2015-11-25 21:36 -0800
                Re: Where is the center of the universe? The Starmaker <starmaker@ix.netcom.com> - 2015-11-26 14:22 -0800
                Re: Where is the center of the universe? The Starmaker <starmaker@ix.netcom.com> - 2015-11-26 14:27 -0800
                Re: Where is the center of the universe? Saul Levy <saullevy1@cox.net> - 2015-11-26 15:39 -0700
                Re: Where is the center of the universe? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2015-11-27 00:48 +0000
                Re: Where is the center of the universe? The Starmaker <starmaker@ix.netcom.com> - 2015-11-26 17:34 -0800
                Re: Where is the center of the universe? The Starmaker <starmaker@ix.netcom.com> - 2015-12-01 21:52 -0800
                Re: Where is the center of the universe? Saul Levy <saullevy1@cox.net> - 2015-12-02 09:49 -0700
        Re: Where is the center of the universe? Tom Roberts <tjroberts137@sbcglobal.net> - 2015-11-25 09:59 -0600
          Re: Where is the center of the universe? benj <none@gmail.com> - 2015-11-25 11:16 -0500
            Re: Where is the center of the universe? Tom Roberts <tjroberts137@sbcglobal.net> - 2015-11-25 11:02 -0600
              Re: Where is the center of the universe? Maciej Woźniak <mlwozniak@wp.pl> - 2015-11-25 18:47 +0100
              Re: Where is the center of the universe? The Starmaker <starmaker@ix.netcom.com> - 2015-11-25 10:06 -0800
                Re: Where is the center of the universe? Arc Michael <abookoflife@yahoo.com> - 2015-11-25 10:52 -0800
                Re: Where is the center of the universe? Sam Wormley <swormley1@gmail.com> - 2015-11-25 14:04 -0600
                Re: Where is the center of the universe? Arc Michael <abookoflife@yahoo.com> - 2015-11-25 12:38 -0800
                Re: Where is the center of the universe? Saul Levy <saullevy1@cox.net> - 2015-11-25 14:23 -0700
                Re: Where is the center of the universe? "Notroll2015" <notroll2015@charter.net> - 2015-11-25 15:51 -0600
                Re: Where is the center of the universe? Saul Levy <saullevy1@cox.net> - 2015-11-29 12:40 -0700
          Re: Where is the center of the universe? Maciej Woźniak <mlwozniak@wp.pl> - 2015-11-25 17:50 +0100
          Re: Where is the center of the universe? The Starmaker <starmaker@ix.netcom.com> - 2015-11-25 10:01 -0800
            Re: Where is the center of the universe? Sam Wormley <swormley1@gmail.com> - 2015-11-25 14:05 -0600
              Re: Where is the center of the universe? The Starmaker <starmaker@ix.netcom.com> - 2015-11-25 12:42 -0800

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