National Geographic : 2012 Aug
• It's summer, and he's driving a big, black De- nali pickup pockmarked by hail and pulling a 16-foot trailer out tted with high-speed cameras and other electronic gear. A laptop computer is mounted inside the cab to the right of the driver's seat, and with one hand on the steering wheel and the other on a trackball, Samaras is mous- ing his way around a weather radar map of the Oklahoma Panhandle. A blob of colors---red in the middle surrounded like an oil slick by orange, yellow, green, and blue---shows a thunderstorm forming northeast of Boise City. "It's starting to spit out some pretty good light- ning," he says, looking at the little yellow crosses popping up on the radar. He glances again at the laptop, where another window is tracking our position with GPS. en comes the buzzing of his tires against the rumble strip, and he calmly steers the rolling laboratory back onto the road. With bugs splashing onto the windshield and a spiderweb of cracks---more old hail damage--- gradually growing wider, we pass through Boise City, following the storm east toward Guymon. Ahead of us clouds are boiling up like cauli ow- er, the classic sign of the warm, moist updra s that separate negatively charged water droplets and ice particles from positive ones (no one knows exactly how), creating multimillion-volt potentials---like the one that just exploded in the sky ahead of us. "Did you just see that strike?" Samaras ex- claims. en comes another, and another. He's got a pair of reading glasses dangling from his It's a good thing there's a rumble strip running along the shoulder, because Tim Samaras can't keep his eyes on the road. By George Johnson Photographs by Carsten Peter mouth, which he puts on to look at the radar, then swipes o to glance at the road. "See how that storm is anchored right there? at's what we want." e ashes are coming every few seconds now, and the truck is hitting the rumble strip again and again. But just as he's looking for a place to pull over, the blob on the radar starts shrinking. Samaras picks up speed, but by the time we reach Guymon, 60 miles down the road, the sun has appeared, and a rainbow is arcing overhead. "Whenever you see the rainbow, it's game over," he says. "It's a goner. I can't believe it." But at 6 p.m. his day is just beginning. e radar shows another blob forming over southern Kan- sas, 80 miles away. LATE SUMMER IS THUNDERSTORM season in this part of the country, and since 2006 Samaras has been trying to do the impossible: capture an im- age of a lightning strike the moment it is born. e process typically begins when a descending zigzag of negatively charged electricity---a stepped leader---feels its way from cloud to ground. When it gets near enough, positive ngers of charge reach up from the earth. e instant the two come together, a dazzling surge of current---some 30,000 amps traveling at a third of the speed of light---leaps toward the sky. e burst of light from this "return stroke" is what you see with the naked eye, which o en interprets the motion as downward. From beginning to end, the entire process takes as little as 200 milliseconds. In Samaras's trailer there are two Phantoms, high-speed cameras capable of shooting 10,000 frames per second. ey have allowed him to capture stunning slow-motion videos detailing George Johnson's most recent book is e Ten Most Beautiful Experiments. Carsten Peter's story on Mount Erebus in Antarctica appeared last month.