From: Emlyn O'regan (oregan.emlyn@healthsolve.com.au)
Date: Thu Aug 15 2002 - 01:49:12 MDT
When people talk about space expanding, do they merely mean that all the
atoms in the universe are moving away from the center? Or is it something
funkier than that? Anyone got a good url where the physics impaired can get
an explanation?
Emlyn
> -----Original Message-----
> From: Anders Sandberg [mailto:asa@nada.kth.se]
> Sent: Thursday, 15 August 2002 16:51
> To: extropians@extropy.org
> Subject: Re: Nature Article
>
>
> On Thu, Aug 15, 2002 at 04:31:15PM +0930, Emlyn O'regan wrote:
> >
> > See, this is where I haven't been paying attention to
> physics. If space
> > itself can expand, rather than the things in it merely
> getting further from
> > each other, how can we perceive that?
>
> Image that you are looking at a pulsar emitting regular
> flashes. If the
> pulsar is moving away from you at a constant speed you will just see
> regular flashes (due to relativity at another frequency than
> the pulsar
> is flashing in its rest frame). But if space between you and
> the pulsar
> is growing, then it will grow while the light is traveling through it,
> and this will make the flashes appear to come later and later - there
> would be a decrease in frequency over time as seen by you. A
> sufficiently fast space expansion would lead to a Zenon-like effect
> where the distance the light had yet to travel remains constant or
> grows, making it never reach you.
>
>
>
>
> --
> --------------------------------------------------------------
> ---------
> Anders Sandberg Towards
> Ascension!
> asa@nada.kth.se
http://www.nada.kth.se/~asa/
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