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XPost: sci.physics.relativity, alt.astronomy, sci.physics
XPost: sci.math
From: r.peter.webbbbb@gmail.com
"Koobee Wublee" wrote in message
news:eb17e124-ac05-4ec3-9df6-34456f85bb7f@qq9g2000pbb.googlegroups.com...
On Jun 21, 9:41 pm, Tom Roberts wrote:
> Astronomers observe a very strong correlation between the distance to an
> object and its velocity away from us -- the further away an object is, the
> faster (statistically) it is receding from us. That specific CORRELATION
> is the
> signature of expansion, not just some "average".
What Tom calls “very strong correlation” is actually based on the
following three assumptions. If any one of the assumptions is not
true, that “very strong correlation” will easily break down.
** Chandrasekhar limit – This term was derived based on the exploding
pressure of simple electron degeneracy model and the imploding
pressure of classical Newtonian law of gravity. We know Newtonian law
of gravity deviates from reality at extremities. So, this quantity
becomes questionable.
___________________________________________
No, the Chandeskhar limit has nothing to do with it. Or rather very little.
The expansion of the Universe has been measured using white dwarfs and
supernova. But these are only two of many "standard candles" that have been
used. The measurement of the expansion of the Universe does not require
Chandrasekhar's limit to be correct. Indeed Chandrasekhar's limit was
dioscovered well *after* Hubble determined the rate of expansion of the
Universe, and Hubble nowhere used Chandeskhar's limit which was unknown at
the time.
** Definition of luminosity – This was defined as a procedure to
measure what the luminosity is, and this is not a trivial matter. The
time span in this measurement calls out to span several weeks. After
all, energy = Planck’s constant * frequency.
____________________________________________________
Luminosity is well defined. You can google it if you don't know what it
means.
** Hubble expansion – This was observed by Hubble back in the late
1920’s. The technology back then only allowed him to go to 500k
parsecs at best. Extrapolating the linear expansion from the observed
several 100k parsecs to several mega and more parsecs calls out for
justification.
_____________________________________________
Absolute garbage. You should look up what a "parsec" is. There is *no*
expansion of the Universe on observational scales of 500k parsecs. And nor
did Hubble find any, or claim that thgey exist. Yopu clearly don't know what
a parsec is, don't know the scale of the Universe, and don't know what
Hubble discovered.
If the above two assumptions were indeed valid, the
universe expansion rate that follows a square root function (instead
of Hubble’s linear) where at nearby distances it appears to be linear
as Hubble had observed could easily conclude a no accelerated
expansion of the universe, and the sanity of the first law of
thermodynamics can be retained to allow many engineers to wipe away
the sweats.
____________________________________________
Or, you could be crank who knows zero physics. Perhaps you should plot
redshift against distance and show us it is a square root function (which of
course its not).
Gee, Tom. As an experimental physicist, why do you choose to close
your eyes on questioning the experimental methods that concludes an
accelerated expansion of the universe?
_______________________________________________
Perhaps if you identify where you think they are wrong, rather than claiming
that they are?
> The basic way to observe the cosmological
> expansion of the universe,
Tom, you should know by now that there is no basic way to observe the
cosmological expansion of the universe.
__________________________________________
Wrong. You do it by measuring red shift of distant objects. Why don't you at
least google some of these terms to see what they actually mean before
posting total crap?
--- SoupGate-Win32 v1.05
* Origin: you cannot sedate... all the things you hate (1:229/2)
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