What follows was prompted by Nicholas Wade’s New York Times Book
Review (October 11, 2009). My comment is about scientific DATA, FACTS,
LAWS, THEORIES, ETC. I hope this will be useful. Distinctions between
DATA and FACTS, or between LAWS and THEORIES are important. Comments,
as always, will be appreciated.
Ludwik
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Cognitive Structure of Science (This is my title, not his.)
a) Any recorded piece of information, about a natural phenomenon, is
DATA. It can be the result of an observation or an experiment; it can
be qualitative or quantitative.
b) A piece of data recognized as valid, by most practitioners in a
given field, becomes a FACT. Laboratory facts are confirmed data; any
scientist using the same protocol is expected to obtain the same data;
at a specified level of reproducibility. Science is not mathematics;
that is why the level of reproducibility, for example 90%, should be
reported.
c) A LAW is a generalization of facts. I am thinking about Kepler’s
Laws (how planets move), about Mendeleyev’s Law (how elements are
ordered in a chart), Faraday‘s Law (how changing currents can be
induced), etc.
d) A THEORY is an explanation of a law. I am thinking about Newton’s
gravitational theory, about Maxwell’s equations, about quantum
mechanics, about Heizenberg’s principle, etc. Distinctions between
laws and theories (and between facts and theories) are worth
recognizing. Unfortunately, this is not always done.
e) Theories are based on assumptions which may or may not be valid.
Assumptions can be based on facts, on laws, or on intuition.
f) Scientific theories are validated not only on the basis of their
logical (mathematical) correctness but also on the basis of their
ability to guide to discoveries of unknown facts. Scientific theories
evolve; some theories are more powerful, more general, and more
elegant, than others.
g) The concept of ‘absolute truth,’ often used by mathematicians and
theologians, does not belong to science. Wade wrote: “A theory,
however strongly you believe it, inherently holds a small question
mark. The minute you erase the question mark, you’ve got yourself a
dogma.”
h) An hypothesis is a tentative idea to be confirmed. It is a common
instrument of human thinking. Hypothesizing is used by all those who
collect data, who turn data into facts, who generalize from individual
facts, and by those who explain facts of nature. Tentative assumptions
are made by all thinking people, not only by physical scientists.
i) To avoid confusion, scientists try to define their terminology. The
term ‘theory,’ for example, does not mean the same thing as the term
‘hypothesis.’ But non-scientists often confuse these two terms. In
common language the words ‘theory’ and ‘speculation’ are often used as
if they were synonyms.
j) ‘Force,’ ‘energy,’ and ‘power’ are commonly used interchangeably by
non-scientists. Novice physics students often find this confusing.
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Ludwik Kowalski, a retired physics teacher
5 Horizon Road, Apt. 2702, Fort Lee, NJ, 07024, USA
Also an amateur journalist.
Food for thought:
"Absence of proof is not proof of absence."