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Calorimetry is alive and well


However, I do believe
that there is justification in teaching calorimetry as an outmoded
concept that has historical significance and has helped science progress.


In its modern usage, 'calorimetry' has *nothing*
to do with 'caloric' the non-existant substance (except etymologically).

Quite true. Calorimetry - heating something and watching what
happens to the temperature - is still alive and well in solid state
physics, as well as in chemistry. The specific heat of a material, as
well as latent heats from _any_ phase transition provide valuable
insights into materials.

For example, when a material is cooled and undergoes a phase change
from non-superconducting to superconducting, the specific heat changes
in a way that clearly indicates that it has become superconducting.
The specific heat of a piece of glass can even tell you if it was
cooled slowly or quenched rapidly!


* I say 'usually' because I believe that there are more complicated set ups
in use these days. A search on the WWW brought up pages on things like
'differential scanning calorimetry', whatever that is.

FYI:
Think of differential scanning calorimetry as two simultaneous
calorimetry experiments. A know quantity of a known material (like
Al2O3 or quartz) is heated at a constant rate. A second material to be
studied is simultaneously heated at the same rate. As the heat is
applied, the temperatures increases (hence "scanning"). The difference
between the temperatures of the two objects (hence "differential") is
related to their specific heats (hence "calorimetry"). If the specific
heat of the first is known, the second can be easily determined. This
is particularly useful at either high or low temperatures, where it is
hard to thermally isolate the sample from its surroundings

Tim


----------------------
Timothy J. Folkerts email: tim.folkerts@valpo.edu
Department of Physics phone: 219-465-2134
Valparaiso University
Valparaiso, IN 46383