NASA's fling with anti-gravity

Anti-gravity-this year's "cold fusion"? Gravity is one force that has always seemed immutable. But if dreams come true at NASA, a device that uses a spinning disk of superconductor to defy gravity could one day revolutionize spacecraft propulsion.

Anti-gravity research jumped into the news last month when the London Sunday Telegraph came out with a story touting a soon-to-be-published paper by engineer Eugene Podkletnov, a sometime researcher at Finland's University of Tampere, on "the world's first anti-gravity device." In the ensuing publicity-which included confusion over the identity of a co-author-Podkletnov withdrew his paper,...