Cellphones put the power of the world at our fingertips. With the touch of a finger, you can instantly connect with your doctor, have food delivered to your office or simply obliterate your niece at Words with Friends. And it's all made possible by rocks formed millions of years ago, deep underground. Join us as we bust open our devices to figure out how these stones power our phones.Guests:Joshua A. Bell, curator of globalization at the Smithsonian’s National Museum of Natural HistoryMichael Wise, geologist in the department of mineral sciences at the Smithsonian's National Museum of Natural HistoryJosh Lepawsky, professor of geography at Memorial University of Newfoundland