Chris,

>>>"I recently read that the earth's magnetic field switches every 250,000 years."

You should read more than one or two sources. In fact, the changing of the magnetic poles appears to have happened at such irregular intervals that no real pattern can be properly derived from what we know. At times it's taken a million or more years for a single reversal, and at other times it seems to have taken just a few thousand years.

Besides, the switching of magnetic poles is a process that itself takes several centuries. Apparently it's not exactly what you'd call an abrupt event. I don't think we're all going to wake up one day and realize the poles have reversed themselves.

-LH

• I know that - fasteddy - August 11, 2002 - 20:36 UTC