An extremely powerful laser has diverted the course of lightning, according to new research.
The study, published in Nature Photonics, suggests that lasers could be used instead of, or in addition to, physical lightning rods (also called Franklin rods, after their 18th-century inventor).
They could ultimately be used as extra, portable, protection for airports and other big infrastructure. They could even reduce the risk of bushfire from dry lightning strikes.
Researchers have been interested in using lasers to change the course of lightning for decades – almost since the development of lasers in the 1960s.
The logic is that powerful laser pulses create tiny amounts of plasma in the air – called laser-induced filaments. These filaments can conduct and direct electricity.
But while the trick has worked in labs, attempts to do it in the real world – including in the US in 2004 and Singapore in 2011 – have been unsuccessful. Until now.
This international team of researchers at Ecole Polytechnique, France, installed a car-sized terawatt laser near a telecommunications tower on the stormy Säntis Mountain, Switzerland.
The telecommunications tower is hit by lightning roughly 100 times a year.
Between July and September 2021, the researchers ran the powerful laser for a total of six hours during thunderstorms.
Over this time, it successfully diverted four lightning strikes.
As well as directly recording one of the strikes with a high-speed camera, the researchers were able to confirm that the diversion worked by detecting the electromagnetic waves and X-ray bursts coming from the four lightning strikes.
While the researchers are excited by the results, they want to run a few more experiments in different places to confirm their findings before recommending every airport install a laser.
Nevertheless, they hope their technique can provide a new way to protect objects, and people, from lightning.
