🚀 go-pugleaf

On Dec 2, 06:23, srwen...@verizon.net wrote in sci.physics.relativity:
> Hi, I'm a layman with an interest in physics.  I just read an
> interesting report on Physics News Update (focus.aps.org) concerning
> unresolved questions in reconciling thermodynamics with special
> relativity.  In particular it seems that there is no agreement on how
> temperature would transform between inertial observers.  Apparently,
> Planck and Einstein were of the opinion that moving observers would
> find temperature reduced, but other physicists thought the reverse
> would be true.  And the question is still causing confusion.
>
> If I recall correctly from my intro physics course, the temperature of
> a gas is just (proportional to) the statistical variance of the speeds
> of the atoms.  Do I have this right?  I also recall that the
> distribution of speeds (actually, velocities) is normal (Gaussian).
> (Actually, contrary to what our teachers told us, the distribution can
> not be strictly normal, since the speeds of the atoms must be less
> than the speed of light but the normal distribution is unbounded).
> So, what would be the distribution of velocities perceived by a moving
> observer?  I would think we could get an answer by using the formula
> for the relativistic addition of velocities.  Consider first those
> atoms moving most rapidly in the opposite direction to the moving
> observer; the formula would compress the range of those velocities to
> keep them all less than the speed of light.  Now consider those atoms
> moving more rapidly than the observer, and in his direction; in this
> case the moving observer would measure a wider range of speeds than
> would a stationary observer, since the atoms would not be pushing up
> against the universal speed limit in his frame.  So, we end up with a
> skewed distribution as measured by the moving observer that is tighter
> on one end and looser on the other, compared to the symmetric
> distribution measured by the stationary observer.  Is the variance
> (temperature) increased or decreased?  Hasn't anyone actually done
> this calculation?  Why is it so hard?  Or, do I have it all wrong.

"Classical" thermodynamics is idiotic enough so applying Einstein's
relativity to it could not make it more idiotic. Jos Uffink is
recognized, even within the Establishment, as the greatest expert
dealing with the foundations of thermodynamics:

http://philsci-archive.pitt.edu/archive/00000313/
Jos Uffink: "The Second Law made its appearance in physics around
1850, but a half century later it was already surrounded by so much
confusion that the British Association for the Advancement of Science
decided to appoint a special committee with the task of providing
clarity about the meaning of this law. However, its final report
(Bryan 1891) did not settle the issue. Half a century later, the
physicist/philosopher Bridgman still complained that there are almost
as many formulations of the second law as there have been discussions
of it (Bridgman 1941, p. 116). And even today, the Second Law remains
so obscure that it continues to attract new efforts at clarification.
A recent example is the work of Lieb and Yngvason (1999)......The
historian of science and mathematician Truesdell made a detailed study
of the historical development of thermodynamics in the period
1822-1854. He characterises the theory, even in its present state, as
'a dismal swamp of obscurity' (1980, p. 6) and 'a prime example to
show that physicists are not exempt from the madness of crowds' (ibid.
p. 8).......Clausius' verbal statement of the second law makes no
sense.... All that remains is a Mosaic prohibition ; a century of
philosophers and journalists have acclaimed this commandment ; a
century of mathematicians have shuddered and averted their eyes from
the unclean.....Seven times in the past thirty years have I tried to
follow the argument Clausius offers....and seven times has it blanked
and gravelled me.... I cannot explain what I cannot understand....This
summary leads to the question whether it is fruitful to see
irreversibility or time-asymmetry as the essence of the second law. Is
it not more straightforward, in view of the unargued statements of
Kelvin, the bold claims of Clausius and the strained attempts of
Planck, to give up this idea? I believe that Ehrenfest-Afanassjewa was
right in her verdict that the discussion about the arrow of time as
expressed in the second law of the thermodynamics is actually a RED
HERRING."

Note that two things would never undergo a critical discussion in
Einstein zombie world: the second law of thermodynamics and Einstein's
second postulate. If you wish to criticize them, you should go to
another world.

Pentcho Valev
pvalev@yahoo.com