Lightning strikes that threaten to damage facilities such as airports or rocket launchers. Courtesy of Getty Images Bank
Scientists have succeeded in manipulating the path of falling lightning using laser beams. It is expected to lead to technology that protects major facilities such as airports and rocket launch pads from the threat of lightning strikes.
The research team led by Professor Aurelien Houard at Ecole Polytechnique in France published the results of the study on the international journal ‘Nature Photonics’ on the 16th (local time).
Lightning strikes occur when static electricity gets caught in a storm cloud and breaks up molecules in the surrounding air. When a lightning strike reaches the surface of the ground, a current of 30,000 amperes (A) is transmitted, which is powerful enough to puncture a building or set things on fire.
A metal lightning rod developed by American inventor and politician Benjamin Franklin in 1752 is used to avoid lightning strikes. The lightning rod installed on the roof and guiding the current to the ground has the disadvantage of not being able to handle much current due to its small size. The radius at which lightning can be absorbed is also limited to about 10 m.
Scientists have paid attention to laser beams that can reach higher skies as a technology to replace lightning rods, but so far no successful experiments have been conducted to control real lightning strikes.
The research team conducted an experiment to change the direction of lightning with a large laser device on an unprecedented scale. A femtosecond laser device was installed next to a 124m telecommunications tower on the summit of Mount Santis in northeastern Switzerland. The laser specially designed for this experiment was 1.5m wide, 8m high, and weighed 3t, and cost 2 million euros (approximately 2.68 billion won).
In the 10-week experiment, the research team fired laser beams at four lightning strikes during a total of six hours of thunderstorms. The high-speed camera accurately captured the twisting path of the lightning according to the laser. It succeeded in maneuvering about 50m of the final trajectory of the lightning strike.
The research team explained that they were able to change the path of the lightning strike thanks to the superior performance of the femtosecond laser device used in the experiment. The laser devices used in previous experiments fired a few pulses per second, but this femtosecond laser fired 1,000 high-energy pulses per second.
Laser beams have succeeded in manipulating lightning strikes, but it will take time for the technology to become commercially available. “The problem is that there is only one device for this laser,” said Professor Uar, who led the study. “It will take time to make a cheaper and more practical device.”
