More than twenty years that part of the team has been waiting for this: channeling lightning using a laser. Between July 21 and September 30, 2021, at Mount Säntis in the Swiss Alpstein, at more than 2,000 meters above sea level, the feat was achieved by a collaboration of the Ecole polytechnique, the University of Geneva , the Federal Polytechnic School of Lausanne and ArianeGroup, in particular. Four times, they fired and measured differences with 16 other lightning strikes that fell during the period, as they explain in Nature Physics of January 16.
The lightning did not disperse into several branches, but remained straight, shooting towards the tip of the 124-meter lightning rod. The lightning also fell faster, sending more X-rays into the air. Until now, only laboratory experiments had demonstrated the domestication of lightning. The laser, manufactured by the German company Trumpf Scientific Lasers for around two million euros, is more energetic than a previously tested version and, above all, fires a hundred times more per second.
Before deploying such a system near an airport, industrial sites or military installations, there are still many improvements to be made. The set should be more compact and easier to implement than the three hours required before each session of the experiment. Increasing the energy will make it possible to enlarge the channel which could exceed 100 meters, or even reach the kilometer. It would also be necessary to increase the conductivity of the filament to increase efficiency, but, for this, a better understanding of the mechanisms at work in the guidance will be necessary… New requests for funding are therefore in progress to withdraw from this peak struck a hundred times per year by lightning. The hope is also to succeed in triggering lightning even before the first flashes, like rockets firing metal wires towards the clouds.