Scientists use laser beams to control rainfall

In a discovery that may have weather forecasters the world over eyeing the job vacancy websites, scientists at the University of Geneva in Switzerland claim to have found a way to control the weather using laser beams.

According to the results of a study published in the Nature Communications journal this week, the researchers have found a way of using laser beams to make water droplets in the air through a method called laser-assisted water condensation. This is a safer method than current rain-inducing techniques, which fill the air with tiny particles of dry ice and silver iodide.

With laser-assisted water condensation, nitric acid particles are formed when powerful laser beams are fired into the air, with the effect of drawing water molecules together. So far in the research, the molecules that have formed have been too light to fall as rain, but the scientists hope they will soon be able to control the size of the droplets. If that happens, they would be able to determine when it does or doesn’t rain.

The scientists said that the technique only works in humid air, not dry air, so there are limits to where and how it can be used.

Jérôme Kasparian, a physicist at the University of Geneva who worked on the project, said of the discovery, “Maybe one day this could be a way to attenuate the monsoon or reduce flooding in certain areas.”

And the physicist has little doubt as to the advantages of laser-assisted water condensation over more traditional methods. “The laser can run continuously, you can aim it well, and you don’t disperse huge amounts of silver iodide in the atmosphere,” he said.

[Via Telegraph/Guardian]