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From: ethan@utastro.UUCP (Ethan Vishniac)
Newsgroups: net.physics
Subject: Re: Bang! or not?
Message-ID: <394@utastro.UUCP>
Date: Sat, 20-Jul-85 17:57:39 EDT
Article-I.D.: utastro.394
Posted: Sat Jul 20 17:57:39 1985
Date-Received: Sun, 21-Jul-85 23:06:17 EDT
References: <371@kontron.UUCP>
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Organization: U. Texas, Astronomy, Austin, TX
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> Does anybody know the current status of the Big Bang vs Steady State
> controversy? I know that as of a few years ago, most research took the
> big bang as an operational theory, but a lot of researchers didn't.
> 
The Big Bang is the overwhelming winner in terms of verifiable 
predictions (like the relationship between the microwave background
and the primordial abundances of elements.  I suppose it is possible
that the Big Bang is a "local" event in some sense and the larger universe
(which would have to be unobservably large) is steady state, but the
equilibrium state of the universe might not be to your liking.
If your question is meant as an opinion poll then I should say that the
number of agnostics on this topic is small, but not zero, and the number
of researchers who actively believe some competing theory is *very* small.

> I left off at the point that people were discussing the possibility
> that the red-shift observed in the spectra from distant objects may not
> be due to doppler effects, but from the cumulative gravitational effect
> on photons from the billions and billions of atoms they come close to
> during the trip. (Also that the massive red-shift observed from quasars
> may be caused when the photons climb out of a massive gravity well.)

Passing a concentration of matter does not necessarily cause any *net*
redshift.  After all the photon will blueshift as it approaches a concentration
and redshift as it leaves.  Any net effect will be due to the universe
changing (expanding) while this is going on.

The evidence that quasars are at their apparent distance includes

   1)  Nearby quasars are surrounded by a halo of light that looks just like
       the outer parts of a galaxy.  In other words quasars look like a
       very bright source of radiation embedded in a more or less ordinary
       galaxy at the apparent redshift.

   2)  Individual nearby quasars are frequently found in clusters of galaxies
       with the same redshift whose individual members look like galaxies
       should look at the apparent distance of the quasar.

   3)  A handful of quasars show multiple images due to gravitational lensing
       by closer galaxies.  These lense are understandable *only* if quasars
       are at their apparent distances.

There are probably other arguments,but these are the ones that have impressed
me the most.
> 
> ===============================================
> | Steve McIntosh, Kontron electronics, Irvine |
> ===============================================
> "Science Fiction - sticks to your mind, not to your hand!"

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-- 

"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