Magnetic Storm

You probably thought the 2003 action movie The Core was full of ridiculous sci-fi hokum, right? Think again. As demonstrated in this fine NOVA episode, some intriguing and potentially critical changes are taking place within the Earth's molten core (which generates the magnetic field that protects our delicate planet from a constant barrage of deadly radiation from space). According to geological physicists, our precious magnetic field seems to be in an accelerated process of reversing itself, shifting from "magnetic north" (as indicated on a normal directional compass) to "magnetic south." Worse, the entire field could conceivably weaken and vanish altogether, rendering our planet uninhabitable (but don't panic: the process would take millions or billions of years, if it happens at all). Studying such diverse magnetic sources as Hawaiian lava flows, prehistoric lava deposits in the mountains of Oregon, ancient clay pottery (which carries measurable records of Earth's magnetic history), and traces of magnetism on Mars, the scientists featured here ponder Earth's fate in the distant future. DVD extras include a wealth of DVD-ROM and web-accessible (and printable) study materials. Recommended. Aud: J, H, C, P. (J. Shannon)