A powerful laser can be shot into humid air to cause intense water condensation, scientists have discovered. The technology has the potential to replace cloud seeding widely used today.
When a short laser pulse is shot into the air, it forms a path of ionised nitrogen and oxygen. Some military researchers want to use this plasma channel to conduct electricity in futuristic direct energy weapons, but there appears to be a peaceful application.
The ionized molecules act as natural nuclei for water condensation and can potentially be used to cause rain. Optical physicist Jérôme Kasparian at the University of Geneva, Switzerland, and colleagues stumbled on it as they investigated the possibility of diverting lightning discharges via laser.
The cloud seeding method used today involves silver iodide or frozen carbon dioxide, which stimulate droplet formation in clouds. The chemicals are released by ground generators or dropped from planes wherever needed. The approach, which has been used for some 50 years now, is only moderately efficient and there are some environmental concerns over it.
So far Kasparian and the team have successfully tested the laser-induced condensation technology both in lab and in the field. They measured the number of new droplets by counting back-scatterings from a second low-energy pulse from another laser. In humid weather, they measured 20 times more of those after firing the first beam, they report online in Nature Photonics.
The technology, however, is in the early stages, and the scientists are yet to prove that it can effectively cause condensation over wide areas rather than along a narrow channel. They also need to investigate if it works in different environmental conditions.
Article from: RT.com