The Magnetic Flip

Ever since I took a geology class in college and learned that in the past the magnetic field has flipped every 100,000 years or so I've been fascinated by it. It has now been over 700,000 years since the last flip, but it could be that we are getting close to the next one. Nova aired a show last night that looks into this phenomena and what effect it would have on the Earth and the people who live here.