National Geographic : 2012 May
ON THE WAY HELP! 1,500 ft PHOTO: ANNIE O'NEIL. GRAPHICS: NGM ART TOP ; OLIVER MUNDAY NEXT DOOR TO AMNESIA A bedroom lightbulb burns out. New bulbs are in the kitchen. Off you go, but when you arrive you think, Why am I here? That brain blip may not be mere absent- mindedness. Gabe Radvansky, a psychology professor at Notre Dame, had study partici- pants carry objects around a house. "They couldn't remember objects as well when they crossed through a doorway," he says. Conclusion: Change of venue makes the brain "push old stuff out and focus on what's going on now," a good strategy for cavemen heading from forest to field. Modern solution: Take a Post-it (or burned-out bulb) with you. ---Marc Silver Miner Lifeline At West Virginia's Robinson Run--- a knot of tunnels bigger than Manhattan---600 miners brought up nearly six million tons of coal last year. Now the mine is testing a wireless system to keep miners connected during collection. Since radio waves can't penetrate the earth, miners going underground are trained to pound the roof with a wooden post to send seismic messages if trapped; at the surface, rescuers use explosives to create a vibration signal that they're looking. This new link uses magnetic energy, which can cut through rock, coal, and metal---letting trapped miners and rescue teams actually talk through the earth. Voice or text can move more than 1,500 feet up or down and 2,000 feet laterally, arriving in less than a minute. "I hate to even think it, but if for some reason I couldn't get out, I could communicate," says safety director Todd Moore. ---Johnna Rizzo How It Works 1 Voice, text, or SOS beacon gets wrapped in magnetic waves. 2 The now magnetic message moves through the earth. 3 Magnetic bubble pops when receiver recognizes source. An explosion- proof transceiver can conduct messages from a trapped miner by magnetic field.