[Fis] Re: miscellanea / temperature / symmetry

Dear FIS colleagues,

Trying to answer to Michel's neat observation ("Ask to people what is
temperature and what is entropy: most will claim that they know what is
temperature, but little people will claim that they know what is
entropy..."), I have been lead to some freak conclusions. Here they are:

Formally, the relationship between entropy and temperature would not look
so much entangled. Like in other transformations of energy (electrical,
chemical, mechanical), we handle the heat phenomenology by way of two
coupled magnitudes: an extensive one (entropy) and an intensive one
(temperature). Seemingly, we easily agree on what the
temperature or 'intensity' is (energy per degree of freedom) and how to
unambiguously measure it, while the 'extension' magnitude (the 'mass',
'volume', or 'charge') to which it should apply indeed looks arcane.

But I think it might be exactly the opposite!

If we look into our sensibility working, it just provides us with the
'warmer' and 'cooler' sensation (caught into a logarithmic framework,
Weber-Fechner law). We can compare the 'warmths' of our body and the
environment precisely due to entropy change of the molecular
mechano-sensitive variety of ionic channels that detect
membrane-stretching; while the regular scale of Kelvin, Celsius, etc.,
becomes a sensorial arcane. Temperature cannot be felt in itself, except by
our recourse to the gradients occurring within the coupled extensive
magnitude of entropy.

Thus, the 'visual' measurement of temperature achieved during the
scientific and industrial revolution by way of thermometers is not so
direct and natural, in spite of our familiar scientific catechism. The way
entropy was conceptualized later on--the spurious introduction of
'disorder'-- and further historical confusions throughout statistical
mechanics misguided interpretations, Maxwell demon, cosmic 'entropy death',
Shannon's info, etc., have conflated the 'mystery' around entropy almost
as a central part of our scientific curriculum.

If the above is cogent (!), at fis we should also take the challenge of
proposing scientific interpretations of thermodynamic entropy at a pair
with its sensorial clarity and immediateness.

best

Pedro

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Received on Mon Apr 26 12:28:40 2004