December 15, 2010 by Conway

When I was young, I read an essay by Isaac Asimov that still remains fascinating to me.  He told the story of a mathematician who predicted the perihelion precession of the planet Mercury in the 1800′s.  When observations were made, the prediction was off by a small amount.  The mathematician figured that a small planet closer to the Sun than Mercury might be causing the difference.  Vulcan is the name he gave to this proposed planet.

The search was on, but the planet was never found.  Instead, Newton’s theory of gravitation was found to be lacking.  Einstein’s general theory of relativity predicted a value for Mercury’s perihelion precession that was very close to the actual measurements.  So, the planet Vulcan was no longer needed.

This is the heart of scientific progress.  When theories make predictions that can be tested through experimentation, and when odd experimental results propel new theories forward, we gain a deeper appreciation of the mysteries that surround us.

For more information, you can look up Vulcan (hypothetical planet) on Wikipedia.