IN DEFENSE OF SCIENCE
(originally run:
February 10, 2006)
Over the past many years there has ranged considerable
discussion at the popular level as to the validity of evolution and related
scientific concepts. Perhaps it is time to examine some elements of this
discussion in this feature, although at best this can only be cursory.
Many objections to evolutionary ideas obtain not from any
scientific evidence, but rather from literal interpretations of certain
religious writings. For example, some individuals have claimed that the Earth,
and the entire universe, are only a few thousand years old, despite the many
billions of years indicated by the evidence. Throughout the universe, we
measure numerous objects' distances as being so great that it takes light many
millions, if not billions, of years to travel to us. The mere fact that we are
seeing that light means that it has completed the journey and indicates that
the objects in question, and thus the universe, have been around for at least
that length of time. While one could perhaps argue that the light was created
≥en route,≤ one could just as easily argue that the universe was created two
minutes ago, with each of us being created with memories of an existence prior
to that moment. Neither of these ideas can be disproven, but at the same time
there is no evidence to support either of them, and thus neither qualifies as a
valid scientific idea.
Some objections to evolution are based upon the phrase
that ≥it's only a theory.≤ But such objections misuse the concept of ≥theory;≤
while in popular usage ≥theory≤ might mean ≥guess≤ or ≥hunch,≤ in science
≥theory≤ means a comprehensive framework that explains a multitude of
observations and that has been subjected to rigorous testing and verification ≠
and, when necessary, has been discarded or modified.
For example, in a scientific sense, the idea that the
Earth is round is a ≥theory.≤ We accept this idea, not necessarily because the
Earth has been demonstrably proven to be round, but because the ≥round-Earth
theory≤ explains our observations much better than does the ≥flat-Earth
theory.≤ Similarly, the ≥sun-centered theory≤ of the solar system advanced by
Copernicus explains our observations much better than does the ≥Earth-centered
theory≤ that was accepted for the many centuries prior to Copernicus. In like
manner, the ≥theory≤ of evolution has been subjected to repeated testing for
well over a century, and is as well established as the ≥round-Earth theory≤ and
the ≥sun-centered theory.≤
Other objections to evolution are based upon
misunderstandings of scientific principles. One of the most oft-repeated of
these concerns the Second Law of Thermodynamics which, in a basic sense, states
that the amount of ≥entropy≤ in a system always increases. ≥Entropy≤ is often popularly
defined as ≥randomness≤ or ≥disorder,≤ but a more precise scientific definition
is ≥energy unavailable to do work.≤ It is a specific quantity that can be
calculated and measured with the appropriate experiments.
Based upon the common misinterpretation of the Second
Law, it would be impossible for a newborn human child to develop into a human
adult. The mere fact that this article is being written, and is being read,
shows that this statement cannot be true. Does this mean that every human being
is a violation of the Second Law? Of course not.
The Second Law of Thermodynamics applies only to closed
systems, that neither gain nor lose energy in any form. A human child that is
not nourished will soon die. If we consider the human being from a thermodynamics
perspective, we must consider the energy contained within the nourishment, the
energy expended in the metabolic processes that break the nourishment down, the
energy involved in producing the nourishment and in delivering it to the child
≠ and all this energy must be included within the system. When we do so, we see
that the entropy increase involved in providing nourishment to the child far
exceeds the entropy decrease involved in the child's development ≠ and thus the
Second Law is not violated. Similarly, when we consider life on Earth, we also
must include the energy produced within the sun which is then radiated to Earth
and utilized by life; the entropy increase involved in the sun's production of
energy is far greater than the entropy decrease involved in life's evolution.
Some have argued that phenomena such as life are so
complex that there must have been a ≥designer≤ or ≥creator.≤ Anyone who wishes
to believe in such an entity may certainly do so as a matter of personal
prerogative, and indeed many scientists possess such beliefs. But for this to
qualify as a scientific idea, a proponent must be able to provide some
information as to the nature of such a ≥designer≤ ≠ keeping in mind the
numerous, mutually incompatible, ≥creation≤ traditions that have existed
throughout human history. A proponent must also provide some hard scientific
evidence to back up such a claim, and propose experiments or observations that
would test the claim and thus help to verify or refute it. Unless and until this
is done, a ≥designer≤ idea does not qualify as science, regardless of any
individual's personal beliefs.
Of course, some of evolution's detractors may point to
this-or-that phenomenon and exclaim ≥this can't be explained!≤ ≠ at least, not
yet. Exactly! This is precisely why we have science in the first place. If
every phenomenon and process in our universe were to be completely and entirely
understood, there would be no further need for science. But any look into the
distant heavens on a clear dark night should be enough to dispel the thought
that we are anywhere near that point. As the Hindu poetess Avvaiyar wrote in
the 1st Century B.C.:
What
we have learnt
Is
like a handful of earth;
What
we have yet to learn
Is
like the whole world . . .
May this continue to be as true from now on as it was
back then.
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