PREFACE
This work sets forth a theory which is speculative in
nature, there being no verifying experiments. It is based
on the idea of the reversibility of everything in time; that is,
that every type of process has its time-image, a corresponding
process which is its exact reverse with respect to time. This
accounts for all physical laws but one, namely, the second
law of thermodynamics. This law has been found in the
nineteenth century to be a source of a great deal of difficulty.
The eminent physicist, Clerk-Maxwell, in the middle of the
nineteenth century, while giving a proof of that law, admitted
that reversals are possible by imagining a "sorting demon"
who could sort out the smaller particles, and separate the
slower ones from the faster ones. This second law of
thermodynamics brought in the idea of energy-level, of
unavailable energy (or "entropy" as it was called by Clausius)
which was constantly increasing.
In the theory herein set forth, we suppose that reversals
of the second law are a regular phenomenon, and identify them
with what is generally known as life. This changes the idea of
unavailable energy into that of a reserve fund of energy, used
only by life, and created by non-living forces.
This is in accordance with some recent discoveries. The
late Prof. William James has discovered in the domain of
mental phenomena what he calls "reserve energy," which later
investigation has shown to be present to a more limited extent
in all biological phenomena. It remained a mystery, however,
where this energy came from, and the theory of reserve energy
as set forth in this work suggests a possible explanation of
these phenomena.
In relation to the universe as a whole, the theory herein
set forth represents the idea of what is known as cyclical
change. This idea is a very old one, being found among the
philosophers of the Ionian school, and reappearing at later
periods from time to time. On the other hand, the generally
accepted theory of the second law of thermodynamics
represents a different philosophical tendency, the tendency
that considers changes once made as irreparable. Aristotle's
philosophy is a good example of that tendency in ancient
times, but it has appeared more recently, especially in
Spencer's theory of evolution, which, it is interesting to note,
is hardly more than a statement of the second law of
thermodynamics in philosophical terms.
Since the manuscript was completed my attention was
attracted by a quotation from a lecture by the great scientist,
Lord Kelvin, in which a theory is suggested which is very
similar to mine in its general outlines; Lord Kelvin, however,
does not work out the theory. He suggests that life works
through a reversal of the second law of thermodynamics;
and that living organisms, especially animal life, actually act
the part of Clerk-Maxwell's "sorting demon." Lord Kelvin,
however, regards this as an indication of some suspension
of the ordinary physical laws, instead of seeking for the
explanation in these physical laws themselves.
To quote Lord Kelvin's own words: "It is conceivable
that animal life might have the attribute of using the heat
of surrounding matter, at its natural temperature, as a
source of energy for mechanical effect . . . The influence
of animal or vegetable life on matter is infinitely beyond
the range of any scientific enquiry hitherto entered on.
Its power of directing the motions of moving particles,
in the demonstrated daily miracle of our human free-will,
and in the growth of generation after generation of plants
from a single seed, are infinitely different from any possible
result of the fortuitous concurrence of atoms."
[To be continued]
At first I hesitated to publish my theory of the reversibility
of the universe; but I was encouraged on discovering the
quotation from Lord Kelvin above mentioned; so that now,
knowing that this is not the first time that it has been suggested
that life is a reversal of the second law of thermodynamics, I
have decided to publish the work and give my theory to the
world, to be accepted or rejected, as the case may be.
WILLIAM JAMES SIDIS
January 6, 1920.