Scientists manage to deflect rays using laser – 01/17/2023 – Science

An international scientific team has announced that it has, for the first time, managed to use a laser to redirect beams. The experiment took place on a Swiss mountain.

Atmospheric rays reach the Earth’s soil between 40 and 120 times per second. Every year, they kill more than 4,000 people and cause billions of dollars in economic damage.

The main protection so far has been the lightning rod, a simple pointed metal bar invented by the American scientist Benjamin Franklin in 1749.

Comprised of experts from six different institutions, the team has been working on an alternative for years.

His proposal, published this Monday (16th) in the journal Nature Photonics, is to continuously launch an impulse in the form of a laser to “guide” the ray, instead of just attracting it, as the metal bar does.

“We wanted to offer the first demonstration that a laser can influence rays and that it is easier to guide them,” Aurélien Houard, a physicist at the Laboratory of Applied Optics at the Polytechnic School of Paris, told AFP.

Houard is the lead author of a project developed over two decades with Jean-Pierre Wolf of the Applied Physics group at the University of Geneva and other collaborators.

Lightning is a discharge of static electricity built up between two clouds during a thunderstorm, or between those clouds and the Earth, while laser is an induced emission of radiation to generate a halo of light.

By emitting the laser into the sky, Houard and Wolf’s team manages to create a plasma (air charged with ions and electrons) that is partially conductive and that “becomes, therefore, a preferential path for the ray”, adds Houard.

Scientists attempted an experimental test in 2004 in New Mexico, which failed due to errors in the laser and because it was difficult to calculate where the beam would land.

They found the solution at an altitude of 2,500 meters, on top of the Säntis mountain in northeastern Switzerland. In that place, there is a telecommunications tower with 124 meters of height that receives about one hundred rays every year.

Scientists built, for two years, a powerful laser inside a telescope. Due to its characteristics, the instrument manages to concentrate the intensity of the light beam in a few centimeters.

In the summer of 2021, they were able to attract and guide lightning to over 50 meters, a successful experiment that has been repeated three times. The long-term goal is to trigger and conduct this powerful electrical spark and thereby protect strategic facilities such as airports.