From PhysicsToday.org/Letters:Language of science I: Theories and laws: It was interesting to see in the January 2007 issue of PHYSICS TODAY two pieces that touched on the same question from
two different viewpoints. That question is whether an explanation is "just a theory" or an established
fact.
Helen Quinn's Reference
Frame article, "Belief and Knowledge—A Plea About Language" (page 8), dealt quite generally
with the interesting ways in which words are used. Scientists may use them one way while nonscientists
interpret them differently. Richard Kadel's letter, just a few pages later (page 12), lamented
the fact that relativity is referred to as Einstein's theory when, he argues, it really should be
called Einstein's laws of relativity.
President Ronald Reagan's
famous comment about evolution being "only" a theory comes to mind. We in the sciences need to have
a way of determining when an idea—whether we call it a hypothesis, a theory, or a guess—has
been established and accepted well enough that it deserves to be called a law.
Quinn's article correctly
emphasizes that some of the words we use have rather flexible meaning even among scientists. She
notes, however, that scientists are usually aware of the degree to which any particular idea is
supported by evidence, accepted by qualified colleagues, and considered well established by
the scientific community, regardless of whether the idea is referred to as a theory, law, hypothesis,
model, or other name. At the same time, Quinn says that nonscientists do not always understand the
extent to which any given idea is established and accepted. They usually rely on the often mistaken
belief that certain terms have rigid meanings; specifically, they believe that a law is a firmly
established principle and a theory is little more than a guess. That brings us to Kadel's letter.
Kadel accepts the fact
that, whether we scientists like it or not, the general public thinks that anything called a law
is a solid description of the truth and that a theory is yet to be proven. Therefore, he argues, relativity
should no longer be called a theory, but instead should be a set of laws. I wholeheartedly agree.
Yet I have to raise the question: Who decides?
I propose that a recognized
body of physicists, such as the International Uni0n of Pure and Applied Physics, the American Physical
Society, or the American Institute of Physics, should do this for ideas related to physics. The
determining group should then use the new term in its own activities and publications and strongly
encourage all its members to adopt the term.
Following Kadel's suggestion,
I think the designated group should start by declaring that "Einstein's theory of relativity"
should henceforth be called "Einstein's laws of relativity" and should promote the idea to the
public. The change (and the discussions leading up to it) could be likened to the recent decision
by the International Astronomical Uni0n to state that Pluto is not a planet.
The designated organization
should then cooperate with other groups that make such declarations by agreeing to support their
declarations. Thus, I would hope an appropriate biology or geology organization would declare
that the theory of evolution has now been sufficiently well established that it will henceforth
be called "the laws of evolution" and that the physics community would support biologists or geologists
in promoting this change in nomenclature.
William Hooper
(Fernandina Beach, Florida)
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Language of science II: Degrees of knowing
Helen Quinn (PHYSICS TODAY, January
2007, page 8) makes a very good point that the general public often misunderstands the meaning of
"belief" and "theory" as used by scientists. The problem originates, I believe, in the way science
is taught in the schools. As Thomas Kuhn noted long ago in The Structure of Scientific Revolutions
(University of Chicago Press, 1962), science is taught like religion: You'd better believe it
or you will get a bad grade. Fundamentalists opposed to evolution have a stronger threat: You'd
better not believe it or you will go to Hell.
Today, as a result of the
No Child Left Behind Act, US public schools place increased emphasis on testing. Unfortunately
this motivates teaching to the test, with little emphasis on the scientific method.
The most important thing
to be taught is how scientists have come to believe the present theories, usually after a long struggle,
as a result of many experiments and observations. Even for a limited part of physics, it is hard for
a student to recapitulate in a semester what may have taken scientists many years to discover. There
is always an attempt to cover too much material, as evidenced by the weight of the latest university
physics textbooks, which only the stronger students can lift. There is no simple solution, but
it is important to identify the problem.
Lincoln Wolfenstein
Carnegie Mellon University
Pittsburgh, Pennsylvania
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