If you've been paying attention to the radio talk shows, you're probably familiar with the dismissive phrase, "It's only a theory". However, it seems that only certain theories are picked upon to have the dreaded "only" added. For example, people seem to be able to talk about atoms without saying that atoms are "only" a theory. And almost everyone today accepts as fact that the earth revolves around the sun rather than vice versa, but you almost never hear someone say, "Oh, heliocentrism is only a theory!" Indeed, most people don't seem to realize that these are theories.
Yet other theories, as well founded as those mentioned, regularly get
the "It's only a theory" treatment. Part of the trouble, of course, is
that in everyday talking, we tend to treat theories as pipe dreams, whereas science
tends to treat theories as the best scientific explanations available. Unfortunately,
this makes any well founded explanation an easy target for someone who dislikes the
implications of a scientific theory. All they need to say is, "After all, it's
only a theory".
Contributor: Arthur H. Harris, Laboratory for Environmental Biology, Centennial Museum, University of Texas at El Paso.
Desert Diary is a joint production of the Centennial Museum and KTEP National Public Radio at the University of Texas at El Paso.