Laser beams make lightning tunnels
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Laser beams make lightning tunnels

Lightning crackling through the sky may look a lot different than the tiny spark that starts a combustion engine, but they have something important in common: their unpredictability. Lightning can be drawn toward a lightning rod (or a key on a kite’s string), but scientists can’t predict the path it will take to get there. And when you create an electrical spark, you just have to hope it goes where you want it—until now. Scientists have discovered a way to control the path of a spark as it arcs between two electrodes, they report today in Science Advances. The secret? Shooting laser beams at the gas between the electrodes. The affected gas becomes super hot and gains an electrical charge, transforming into a plasma. That plasma attracts the spark and guides it along, as though the electricity were traveling through a tunnel. By constructing the plasma tunnel with differently shaped laser beams, the researchers successfully coaxed the sparks into curved and even S-shaped paths. But swerving around obstacles wasn’t the only option. The scientists also got the spark to hit an obstacle and reconstitute itself on the other side, something that had been observed before with certain kinds of laser beams, but never with electricity. The new technology could be useful in applications from manufacturing to electronic jamming—any time someone wants to deliver a spark of electricity to a very precise place. No word yet on whether the researchers have figured out how to control lightning storms—but here’s hoping that if they do, they can keep their supervillain instincts in check.