When the laser fires, it separates electrons from air molecules in the beam's path, creating charged particles in a process called ionization. In the new experiment, a high-powered laser turns a column of air into an electrical conductor. But metal is not the only way to lure lightning away from vulnerable targets. Regular lightning rods are made of conductive metal they provide a preferential point for the lightning to strike and then safely channel the charge around a building and into the ground. This electricity builds and eventually discharges, propelling giant sparks either upward or downward along the path of least resistance between the cloud and the ground. Lightning occurs when friction among water droplets and ice crystals creates a static electrical charge within clouds, usually during storms. “What they've done is very impressive,” says Jerry Moloney, an optical scientist at the University of Arizona, who was an early pioneer of this laser application but was not involved in the study. This “laser lightning rod” technique could one day deflect strikes from important large-scale infrastructure, the research team says. So, for a study in Nature Photonics, a team of scientists tested a high-powered laser to guide lightning strikes atop a mountain in Switzerland. But it has limited ability to protect larger swaths of land or sprawling facilities such as wind farms, airports and rocket launch pads. Pioneered by Benjamin Franklin, the lightning rod works well to defend a building. But researchers are exploring a more 21st-century solution: laser beams. This natural phenomenon is terrifyingly random, and we rely mainly on lightning rods-a nearly 300-year-old technology-to deal with it. Lightning protection may also be needed for gas piping.Īny lightning protection system should follow the national safety standards and requirements of the Lightning Protection Institute, National Fire Protection Association, and Underwriters Laboratories.Lightning strikes about 40 million times in the U.S. A complete system also includes electrical surge protection devices for incoming power, data, and communication lines and surge protection devices for vulnerable appliances. While lightning rods help protect a structure from a direct lightning strike, a complete lightning protection system is needed to help prevent harmful electrical surges and possible fires caused by lightning entering a structure via wires and pipes. It's very important that these components be properly connected (bonded) to minimize the chances for any sparks or side flashes. Note that lightning protection systems do not prevent lightning from striking the structure, but rather intercept a lightning strike, provide a conductive path for the harmful electrical discharge to follow (the appropriate UL-listed copper or aluminum cable), and disperse the energy safely into the ground (grounding network).

Lightning rods (and the accompanying protection system) are designed to protect a house or building from a direct lightning strike and, in particular, a lightning-initiated fire.