Little boys and girls like to smash toy trucks into each other to see what happens. Physicists? They prefer firing particles through a 17-mile long inner tube under Switzerland and France and seeing what happens when they collide. The goal is to create a mini-Big Bang and unleash a new era of understanding about the world around us, which will of course lead to bigger and meaner weapons of mass destruction which we'll say Iran is trying to build so we can invade them. But some scientists worry that the experiment, called the Large Hadron Collider, will create a black hole that destroys the entire world. They turned the thing on yesterday anyway and good news: we still exist. "It will be weeks or months before two particles ever crash together in the giant tube," reports Reuters. Plenty of time for worrying!(Photo by AP/Nolfi)