Theories in Science

Theories in Science

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The word theory is derived from the Greek theoria: a speculation or view. It is used in both technical and ordinary language in a variety of meanings. Thus one speaks of Plato’s theory of ideas, Kant’s theory of knowledge, Cantor’s theory of sets, Hobbes’ political theory, the impressionist theory of art, and music the­ory. In each of these instances the word has a slightly different connotation. They all rest on different conceptual frameworks. In common parlance, simple beliefs are sometimes referred to as theories. Thus, a detec­tive might say, “My theory is that it was Mrs. Jones’ paramour who put the poison in the pudding.” The belief, once popular, that the right ovary produced male children, and the left ovary female ones, is sometimes referred to as a now discarded theory.

In scientific literature, and especially in physics, theory has a clear meaning and function. Yet, here too there are philosophical debates and disagreements as to what constitutes a theory. A theory in science is meant to serve the principal explanatory goal of science. Efforts to explain physical phenomena and their generalizations (empirical observations and laws) instigate the formulation of the­ories. A theory in science is the conceptual development of a set of basic ideas and inter-relationships concerning the physical world in terms of which carefully observed phenomena and empirically derived laws may be explained and understood.

Thus, for example, if we consider Kepler’s first law of planetary motion according to which planets move in elliptical orbits, we may ask why planets follow such orbits rather than, say, circular or square ones. Newton’s theory of gravitation, based on some fundamental assumptions about the physical world, is a whole body of mathematical elucidation in terms of which the empirically derived laws of plane­tary motions can be satisfactorily explained. Similarly, Bohr’s theory of the hydrogen atom is based on certain basic assumptions, and its function is to account for the empirically ob­served results pertaining to the spectral lines of hydrogen. Or again, consider the biological transformation of species which is an observed fact. It is adequately explained in terms of Darwin’s theory of evolution which brings in the notion of adaptation and survival. However it is important to remember, as was stated in a resolution adopted by the American Society of Parasitologists in 1982, that “The word `theory’ has different meanings to the scientist and layman. Virtually all scientists accept the evolution of current species from fewer, simpler, ancestral ones as undisputed fact. The `theory’ of evolution pertains merely to the mechanisms by which this occurs, and the much-touted arguments among scientists about evolution are over details of these mechanisms, not about the factuality of evolution itself.”

A theory must explain, not simply describe, something. To simply say that God created Adam is not a theory, nor science, because it doesn’t explain anything.