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Message from discussion A positive cosmological constant
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Phillip Helbig---undress to reply  
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 More options May 4 2012, 3:54 am
Newsgroups: sci.physics.research
From: hel...@astro.multiCLOTHESvax.de (Phillip Helbig---undress to reply)
Date: Fri, 4 May 2012 09:54:15 +0200 (CEST)
Local: Fri, May 4 2012 3:54 am
Subject: Re: A positive cosmological constant
In article
<ab7eccc2-5132-40d7-a353-b1222d36f...@l15g2000vbv.googlegroups.com>,
"Anon E. Mouse" <agall...@gmail.com> writes:

> I referenced the paper cited above and quote the abstract here;
> "The Cosmological Spacetime
> Fulvio Melia, Majd Abdelqader
> (Submitted on 30 Jul 2009)

>     We present here the transformations required to recast the
> Robertson-Walker metric and Friedmann-Robertson-Walker equations in
> terms of observer-dependent coordinates for several commonly assumed
> cosmologies. The overriding motivation is the derivation of explicit
> expressions for the radius R_h of our cosmic horizon in terms of
> measurable quantities for each of the cases we consider. We show that
> the cosmological time dt diverges for any finite interval ds
> associated with a process at R -> R_h, which therefore represents a
> physical limit to our observations. This is a key component required
> for a complete interpretation of the data, particularly as they
> pertain to the nature of dark energy. With these results, we affirm
> the conclusion drawn in our earlier work that the identification of
> dark energy as a cosmological constant does not appear to be
> consistent with the data. "

Please read recent papers by Geraint Lewis.  That's an uncommon
combination of names; he is the only astronomer in the world with that
name, so it should be easy to find him at arXiv.  He also blogs at
Cosmic Horizons.  It's a low-traffic blog so you can easily read
everything.  He also discusses his own recent work there.  Recently,
together with a Dutch colleague, he wrote a paper criticizing some
recent work (not sure if it is the above paper) claiming that strange
things happen at the Hubble radius, and shows that the claim is false.  
I agree.  As he notes, there have been no open questions regarding
cosmic horizons for at least more than 40 years.  There is a classic
paper by Wolfgang Rindler which is THE paper to read if one is
interested in these things.  He didn't write that many papers in the
1950s so you should be able to find it at ADS (where you can access the
full text in PDF or GIF format).  Also, you absolutely have to read
Stabell and Refsdal's paper on the classification of cosmological models
and the companion paper by Refsdal, Stabell and de Lange which
calculates various quantities for various cosmologies.  In particular,
they explicitly calculate all the various types of horizons for a wide
range of cosmological models, and plot them in the cosmological
parameters space.  Anything which disagrees with this is simply wrong.
(Note that before Rindler's paper there was real confusion of the
concepts and also confusion in the nomenclature.)  These two papers can
also be found at ADS.  Just search for "Stabell, R."; these are among
his oldest papers.

> Thus the inclusion of a positive cosmological constant added in 1917
> alters a founding postulate of the relativity principle as given in
> 1915. It is the second of only three postulates that is altered. The
> second postulate as given and translated states roughly, no mass can
> move faster than c. The amended necessary to include a postive
> cosmological constant would be, no mass moving faster than c can be
> directly observed, or as an affirmative statement, only mass moving
> with a relative velocity less than c may be directly observed.

Even without the cosmological constant, cosmological velocities can be
greater than C.  Check out Edward Harrison's classic textbook on
cosmology.

> Mass/energy has been left behind our local group. Mass energy has
> escaped our local group and expansion of space-time over time
> increases apparent velocities in a manner inconsistent with Newtonian
> mechanics alone.

The local groups is  well within the horizon.

> The relative velocity of the masses and charges of the prions of the
> nucleus are moving with a relative velocity greater than c in the
> laboratory frame of reference and this is the fundamental cause of our
> inability to directly observe sub-atomic particles, which is why we
> use inference instead of direct observation.

There is no evidence of this.  Also, what is "direct"?  Various types of
electron microscopes essentially observe individual atoms.

 
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