Muons Meet the Maya

At its most glamorous, the life of an experimental high-energy physicist consists of smashing obscure subatomic particles with futuristic-sounding names into each other to uncover truths about the universe—using science's biggest, most expensive toys in exciting locations such as Switzerland or Illinois. But it takes a decade or two to plan and build multibillion-dollar atom smashers. While waiting, what's a thrill-seeking physicist to do?

How about using some of the perfectly good, and completely free, subatomic particles that rain down on Earth from space every day to peek inside something really big and mysterious, li