Re: The size of the universe <= 14E+9 light years

On Sat, 29 Sep 2007 11:59:17 -0000, Friar Broccoli <EliasRK@xxxxxxxxx>
posted:

On Sep 29, 12:35 am, catHORME...@xxxxxxxxxxxxxxx (Don Cates) wrote:
On Sat, 29 Sep 2007 01:15:26 -0000, Friar Broccoli <Elia...@xxxxxxxxx>
posted:



On Sep 27, 1:19 pm, Jack Dominey <l...@xxxxxx> wrote:
In <1190653524.104789.89...@xxxxxxxxxxxxxxxxxxxxxxxxxxx>, Ken Denny

<k...@xxxxxxxxxxxx> wrote:
Therefore no two points in the
universe can be more than 14E+9 light years apart.

Take a look athttp://en.wikipedia.org/wiki/Universe#Size
andhttp://en.wikipedia.org/wiki/Observable_universe#Misconceptions.

I was impressed by the following comment from the article:

"Those galaxies are now about 46 billion light-years from us, but at
the time the light was emitted, that matter was only about 40 million
light-years away from the matter that would eventually become the
Earth. See comoving coordinates."

If that is correct then the universe has been expanding at a rate
that is effectively well over 99% the speed of light. I must admit
to some skepticism.

I'm curious how you calculate a 'rate of expansion' from within the
thing that is expanding. Can you show me your calculations?

Part of the statement was:

... at the time the light was emitted, that matter was only about
40 million light-years away ...

So if the universe had not been expanding it would have taken
40,000,000 years for the light to reach "earth". It actually
took say 12,000,000,000 years, which is 300 times "too long".
So the EFFECTIVE (I used the word "effectively") rate of
expansion looks like 99.66% that of light.

In reflecting further, that apparent rate is so close to C that
I began wondering if C might be a property of the space-time in
which it propagates.

I'm afraid I didn't word my concern very well.
If you are looking at something at the edge of the observable
universe, then it must, by definition, have an apparent velocity away
from us at C. If you pick something closer then the apparent velocity
away from us is less than C. In neither case is it a metric of
expansion rate. An expansion rate would be a change of volume with
time, not a velocity.
--
Don Cates ("he's a cunning rascal" - PN)

.

Relevant Pages

  • Re: The size of the universe <= 14E+9 light years
    ... universe can be more than 14E+9 light years apart. ... the time the light was emitted, that matter was only about 40 million ... light-years away from the matter that would eventually become the ... expansion looks like 99.66% that of light. ...
    (talk.origins)
  • Re: The size of the universe <= 14E+9 light years
    ... the time the light was emitted, that matter was only about 40 million ... light-years away from the matter that would eventually become the ... So if the universe had not been expanding it would have taken ...
    (talk.origins)
  • Re: The size of the universe <= 14E+9 light years
    ... "Those galaxies are now about 46 billion light-years from us, ... the time the light was emitted, that matter was only about 40 million ... If that is correct then the universe has been expanding at a rate ... Friar Broccoli ...
    (talk.origins)
  • Re: The size of the universe <= 14E+9 light years
    ... "Those galaxies are now about 46 billion light-years from us, ... the time the light was emitted, that matter was only about 40 million ... If that is correct then the universe has been expanding at a rate ...
    (talk.origins)
  • Re: Dont like the truth? Lie.
    ... A Quintessential Introduction to Dark Energy ... "Most of the energy in the universe is not gravitationally attractive. ... We are probably the last generation to have been taught that gravity ... Visible matter comes nowhere close to closing the Universe. ...
    (sci.space.policy)