Science in Christian Perspective
One more time...
General Evolution and the Second Law of Thermodynamics
J. A. CRAMER
Department of Physics,
Wheaton College Wheaton, Illinois
The idea that the General Theory of Evolution and the Second Law of Thermodynamics are mutually contradictory is an error based on the failure to recognize that the Second Law allows parts of the universe to decrease entropy (increase order) while requiring that the total amount of disorder in the universe must always increase. Thus the Second Law cannot be used against Evolution, although the distinctly different argument from mathematical improbability is legitimate.
Wilder-Smith
The idea that the Theory of Evolution defies the Second Law of Thermodynamics
appears to be making an impression in some circles. I do not know the
full history
of the idea, but I first encountered it as an excerpt from A. E. Wilder-Smith's
book Man's Origin, Man's Destiny1 which was published sometime ago in
Christianity Today. That excerpt drew accurate fire from a collection of
physicists and engineers
who correctly indicated that a complete misunderstanding of the "law"
was involved. Despite authoritative criticism, Dr. Wilder-Smith still
apparently
retains his position.
The Journal ASA 22, 117 (1970) contains a review by a chemist of Wilder-Smith's
book. I was disappointed to note that this argument was mentioned
with tacit approval. A biologist, in the same issue, also notes the idea with
more cautious approval.
I no more concur with the General Theory of Evolution than any of the
proponents
of this view, but it is a mistake to defend oneself with faulty
arguments. I hope
to show why this view is faulty. It is then the reader's responsibility to face
the truth honestly and act accordingly. There are significant questions of the
meaning of theories and laws which could be raised, but the basic
issue to which
I wish to speak involves the internal consistency of scientific thought. Thus,
I shall by-pass some philosophic difficulties and deal only with the
central mistake.
Not Technical
The mistake is not at all technical. Ordinarily the
Second Law is stated, "The amount of disorder in the universe
always increases
or remains unchanged for any process." Technically, one
substitutes the word
"entropy" for "disorder", but the correspondence
is sufficiently
close that no confusion will result from using "disorder".
Also technically,
the case where disorder does not change is probably physically unrealizable and
certainly it refers to cases (which are of no interest to us) where interacting
systems are in equilibrium so that no changes at all take place. Thus, we can
state the law, "The amount of disorder in the universe increases for all
processes", and be reasonably confident that we are making
scientific sense.
The error lies in overlooking the absolutely crucial phrase "in
the universe".
Let me give an example of how crucial this is.
Cooling Water
A warm glass of water can be cooled by placing it in a refrigerator.
If you looked
only at the water, you would have to conclude that the Second Law had
been violated.
How so? The agitation of the molecules (which is related to
temperature) decreases
with decreased temperature. Thus the entropy (disorder) of the water decreases.
For any given temperature change and quantity of water, this entropy decrease
can be precisely calculated. How can this be if the law demands an
increased entropy
for all process? The answer is that you have forgotten to look at the rest of
the "universe". The decrease of disorder in the water is
more than cancelled
out by the increase in disorder in the molecules of air outside the
refrigerator.
The refrigerator pumps heat into the ouside air causing a large increase in the
entropy of the room. The point then is this: Improperly limited parts
of the universe
do not necessarily obey the Second Law of Thermodynamics. The Law is followed
only when a sufficient part of the universe is included.
If we are to believe that General Evolution contradicts the Second Law, we must
then also conclude that all living organisms continually violate the Law.
Freezing Lake Michigan
It may be argued that my example was an artificial process and that evolution
is supposed to be natural or operative without human intervention. Then let me
choose another example. It can hardly be denied that Lake Michigan undergoes a
yearly entropy change. Every winter large quantities of ice are
formed. The total
entropy changes involved are many times greater than those for the
glass of water,
yet they still involve only the cooling of water. I do not anticipate
disagreement
when I say that this is as "natural" a
process as can be desired. Yet here again, if only the entropy change
of the lake
upon freezing is noted, you will conclude that you see a violation of
the Second
Law. Again, if attention is given to the changes in the atmosphere, differences
in radiation received from the Sun, infra-red radiation from the
Earth etc., the
Second Law will be found to hold true.
Protein Molecule
Therefore, we must conclude that an evolutionary process which
creates an isolated
area of decreased entropy (increased order) does not at all defy the Second Law
of Thermodynamics. If we include all involved systems, we will see that the law
holds. The hypothetical case of a protein molecule formed in a thin
"broth"
of "organic" materials by evolutionary processes can serve
as an example.
The molecule is a much more ordered situation for the atoms which form it than
that in which they previously existed. But the disorder of the
"broth"
will increase when the molecule is formed and its increase will more
than compensate
the decrease due to the formation of the molecule.
All Living Organisms
It should be noted that the processes of all living organisms are processes of
organization. Thus, all living organisms are continually increasing the order
of the molecules and atoms which they take in for nourishment. If then we are
to believe that General Evolution contradicts the Second Law, we must then also
conclude that all living organisms continually violate the Second
Law. Both conclusions
are, of course, erroneous. Nevertheless, this continual, large scale, ordering
in a universe which is supposed to be running down is sufficiently curious to
have arrested the attention of a few physicists. At least one theoretician has
made an attempt to explain this in terms of quantum mechanical models.2
Mathematical Improbability
The argument from the Second Law is sometimes confused with the argument from
mathematical improbability, but they are, in fact, distinct. The general theory
of Evolution is a fantastically improbable theory in a mathematical sense and
I think this is an important weakness. I know of no other theory which at all
approaches the improbability of General Evolution. Unfortunately, the argument
from the Second Law of Thermodynamics is not in the same sound position.
REFERENCES
1Wilder-Smith, A. E., Man's Origin, Man's Destiny, Harold Shaw,
Wheaton, Illinois,
1968.
2Frohlich, A., "Energy Storage and Long Range Coherence in
Biological Systems", International Journal of Quantum Chemistry
II 691 (1968).