Ebook: Statistical Physics and the Atomic Theory of Matter from Boyle and Newton to Landau and Onsager

Daniel Bernoulli in l 738 and John Hcrapath in 1820 did produce
essentially correct theories, both of which were ignored. Why? First, there
were many competing theories, and before the existence of atoms was
established the notion of random motions and coUisions determining
natural phenomena was ri dicu led. The first incorrect theory was due to
Newton. He showed that a static gas consisting of particles interacting with
an inverse distance force !aw leads to Boyle's law, PV= const. It was
widely assumed that Newton proved that a gas consists of interacting static
particles, although Newton himself never claimed this. Brush points out the
irony of Newton's work delaying progress in the theory of gases by showing
(from a Newton manuscript published only in 1965) that Newton
essentia lly calculated a proper kinetic gas pressure in his unusual
derivation of centrifugal rorce. He calculated the force due to impacts (not
action at a distance) of a point mass bouncing around in a sphere. Brush
states "Newton should have discovered the kinetic theory of gases."
Although the book is written at a level which can be understood by
undergraduates, it is full of such wonderful tales and insights, many of
which arc probably unknown even to experts in statistical mecha ni cs.
The kinetic theory ra n into further competition when infrared
radiation was disco•·ered and it was thought that a wave theory of heat was
needed. Of course, today wc would say that light is a form of energy which
can be converted into heat. More competition came from the caloric
theory, which treated heat as a substance. This theory was prcdomincnt in
lhecarly 1800'sandgaveusmuchofourterminologysuehasca!oriesand
latent heat
Finally the work of Clausius, Maxwell, and Bohiman succeeded in
demonstrating the val idity of the kinetic theory of gases. However, Brush
recounts how Maxwell began by attacking this theory. Maxwell's
calculations showed that viscosity would be independent of density, which
was contrary to published experimental results. Eventually, Maxwell's
prediction was borne out by his own more exact experiments.
Brush hasadmira!ly succeeded in giving the reader a proper historical
perspective of the advancement of science by not only discussing the
canonical path to understanding but by also following many of the
fascinatingdcadends. Theintcrplay between theory and experiment is also
stressed and the reader gets a good sense of the confusion in a field before
the key experiment is performed or key concept is developed.
Qucstionsofirreversibilityarisc from the kinetic theory and this is the
topic of the second .chapter; the well-known >1ory of the development of
quantum theory is given in the third chapter. The fourth chapter, in part,
tells the rascinating story of how the quantum mechanical calculations of
the ionization of an atom and the introduction of quantum statistics led to
a revolution in the understanding of stellar atmospheres and stellar
evo lution. Here Brush misses the opportunity to cite the delightful paper of
Dirac in History of Twentieth Ce111ury Physics, Varenna Summer School
(Academic Press, New York, !977), which gives a personal aaount of the
invention of Fermi-Dirac statistics.
Chapter Four also gives an exceptionally lucid account of theories of
Landau, London, Tisza, and Feynmann on superfluidity. Brush writes
about helium II that the discovery of its extremely low viscosity was reported
in the same issue of Namre by Kapitza and by J. F. Allen and A. D
Misener. Kapitza had the dramatic flair to call the phenomenon .. superfluidity"
and his work is better remembered.
Chapter Five gives a good historical survey of the advances in
understanding interatomic forces, and Chapter Six follows the development
of the physics of phase transitions. An emphasis is placed on the Ising
model which was suggested by Lcn7. to Ising as a Ph. D. project. Brush
could have pointed out the parallel with the Potts model which was
suggcstedby Dombinasimilarmanner.
Brush's history is anything but dull.