Thaler on Wrong Scientific Beliefs

Over at The Edge, University of Chicago Business School Professor Richard Thaler, coauthor with Cass Sunstein of the influential book Nudge (Yale 2008), has raised an interesting question for regular Edge contributors:

The flat earth and geocentric world are examples of wrong scientific beliefs that were held for long periods. Can you name your favorite example and for extra credit why it was believed to be true?

I am not a contributor to The Edge, but I nevertheless sent Thaler the following message:

Already a couple of respondents have correctly indicated Newtonian gravity as a “wrong scientific belief.” Interestingly, it’s a wrong scientific belief that still seems to be treated as true, not by physicists of course, but by large segments of the public. I suspect there are two reasons for this: (1) gravity is both intuitive and conforms to our “common sense” of the world (of course, common sense is often treated as a infallible guide to judgment, but often is misleading); and (2) Newtonian gravity is only falsified at very high speeds, which none of us experiences. Thus, while Newton’s theory of gravity is scientifically false, it seems experientially “true.”

Long before Newton, when Aristotle’s “scientific” theories held sway for centuries, it was thought that objects move faster as they approach the earth because they sensed that they were approaching “home,” i.e., where they belonged. This theory, too, made some intuitive sense if one also accepted Aristotle’s belief that vacuums were impossible.

More generally, my sense is that all scientific theories, like all religious theories, are not only about people trying to comprehend the mysterious world and universe in which we live, but to establish regularities so as to be less frightened by the world and attain some (true or false) psychological equilibrium. The need for some such equilibrium is innate.