That Higgs boson that everyone was so eager to find last year? As it turns out, it could be the end of everything -- in the wrong circumstances, anyway. In his upcoming book Starmus, Stephen Hawking notes that the once-elusive particle could become less than perfectly stable at energy levels of 100 billion giga-electronvolts or higher. If it gets to that state, it could trigger a vacuum bubble that would expand at the speed of light, eventually collapsing all space and time; you wouldn't even know the disaster was coming if the event happened on Earth.