The giant iron ball at the center of the Earth appears to be spinning a bit faster than the rest of the planet. The solid 1,500-mile-wide inner core, which is surrounded by fluid, rotates about one-quarter to one-half degree more than the rest of the world every year, scientists from Columbia University's Lamont-Doherty Earth Observatory and the University of Illinois at Urbana-Champaign report in today's issue of the journal Science. The spin of the Earth's core is an important part of the engine that creates the planet's magnetic field, and researcher Xiaodong Song said he believes magnetic interaction is responsible...