In a first, scientists use car-sized laser to divert lightning strikes

A team of scientists have created a way of what they describe as their attempt to guide lightning strikes with a first-of-a-kind car-sized Laser Lightning Rod. The findings of their study were published in the journal Nature Photonics which took place on top of the Säntis mountain at an altitude of about 8,200 feet in north-eastern Switzerland. Researchers were able to guide a lightning bolt for more than 50 metres with a powerful laser near a 124-metre-high telecom tower which is struck by lightning at least 100 times a year and is often referred to as one of Europe’s most affected by lightning structures.

Lightning bolts are huge electrical discharges and a single one can reach up to a 30,000 degree Celsius temperature five times hotter than the surface of the sun. It is a complex phenomenon caused by an imbalance of positive and negative charges between storm clouds and the ground, however, some travel upward. Furthermore, while the chances of a person getting struck by lightning are rare, it has caused thousands of deaths and also tens of billions of dollars worth of damage to infrastructure every year.

Therefore, the research has major implications as scientists are looking for newer ways to protect lives and infrastructure from the typical lightning rod, the idea of which was first conceived by Benjamin Franklin in the 18th century. “Metal rods are used almost everywhere to protect from lightning, but the area they can protect is limited to a few metres or tens of metres,” said Aurélien Houard, a physicist at Ecole Polytechnique’s Laboratory of Applied Optics in France and the lead author of the study, to the Guardian.

Add WION as a Preferred Source

According to the study, the total lightning flash rate worldwide, based on satellite data, is between 40 and 120 flashes per second while the number of lightning fatalities is well above 4,000. The large car-sized device which uses lasers manufactured by Germany-basedTrumpf Groupweighs at least five tonnes and is capable of firing up to 1,000 pulses per second. Last year, between July and September the team rapidly fired laser pulses at thunderclouds for more than six hours and observed its effect by using high-speed cameras several kilometres away.

They found that they were able to guide an upward negative lightning leader over a distance of 50 metres which was then recorded by two separate high-speed cameras. “We wanted to give the first demonstration that the laser can have an influence on lightning - and it is simplest to guide it”, said Houard. In simple terms, the laser acts as a virtual lightning rod which mimics metal conductors which intercept and divert lightning bolts.

While such experiments using lasers to guide lightning bolts have been conducted before in 2004, according to Houard, they did not emit enough pulses per second for lightning, which brews in milliseconds and therefore were unsuccessful. However, there is a catch, as lasers pose a risk to the eyes of pilots flying by. In fact, the study was conducted after temporarily shutting the air traffic over the test site.

“Indeed, there is a potential issue using the system with air traffic in the area because the laser could harm the eyes of the pilot if he crosses the laser beam and looks down,” said Houard, as per Reuters. But scientists believe that this technology could be used in designated areas where no-fly restrictions apply.

(With inputs from agencies)