Photo: TRUMPF/Martin Stollberg
We are often advised to unplug electronic devices when it rains accompanied by a thunderstorm that resounds. Lightning carries a large amount of electricity, so its strikes are very dangerous and can even take lives. For this reason, lightning rods are installed to protect the building and the people in it when lightning strikes. Unfortunately, these metal rods with pointed ends have a limited range, so we need to find ways to reduce the potential damage on a larger scale.
Laser light is believed to be able to block the arrival of lightning before it reaches the surface of certain areas, and this theory has been successfully proven recently.
A team of scientists led by Aurélien Houard, researcher at Ecole Polytechnique at ENSTA Paris, presented the results of the world’s first “successfully guiding lightning using a laser” experiment. This achievement is expected to be an opportunity to realize a lightning rod with sophisticated laser technology.
“Humans have been afraid of lightning since time immemorial,” wrote the researchers in Education published in journals Nature Astronomy. “Satellite data estimates lightning can strike up to 40-120 times per second, resulting in considerable damage and loss of life.”
To test his theory, Houard and his fellow researchers conducted an experiment on the summit of Mount Säntis, Switzerland, in 2021. On top of the mountain, there is a telecommunications tower that is prone to being struck by lightning. They set up a massive laser near the tower, then shot its beam into the sky during a thunderstorm. The laser beam is capable of diverting the trajectory of lightning originating from the ground as far as 50 meters four times. These findings show that a laser-powered lightning rod installed at a height of hundreds of meters has the potential to protect an area within a radius of nearly one kilometer.
“This is the first time that laser-induced filaments—which are formed by short, intense laser beams in the sky—are known to guide lightning over considerable distances,” the researchers continued. “We believe this experimental breakthrough can lead to more advanced lightning protection devices.”
When fired into the sky, the laser beam can transform particles and molecules in the air into plasma structures. So Houard’s team tried a number of techniques to see if the plasma could trigger the lightning, as well as push its trajectory elsewhere. They can only divert the direction of discharge of positive charge from the ground to the clouds.
“Our experimental results at Säntis in the summer of 2021 indirectly prove that a filament formed from a short and intense laser beam can ward off lightning over a considerable distance,” concluded the researchers. “These initial findings need to be studied further with new configurations.”
