(NaturalNews) Researchers from the University of Central Florida (UCF) have developed a new technique that can generate rain and lightning in a region by firing a laser at clouds.
According to Britain's Daily Mail, the technique involves firing a "double laser" into a cloud to stimulate certain particles within it. Scientists say the technique could one day be used to create rainstorms and even lightning at will.
Scientists at UCF's College of Optics & Photonics, as well as researchers from the University of Arizona (UA), say the key to the success of their experimentation was to surround the laser beam with a second beam that acts as an energy reservoir, making it possible to fire the central beam further than was previously possible.
The secondary "dress" beam is capable of refueling and therefore preventing dissipation of the high-intensity primary beam, which, if fired on its own, would break down quickly. A report on the experiment, "Externally Refueled Optical Filaments," was published recently in the journal Nature Photonics.
'A soup of electons'
Scientists say that water condensation and lightning activity in clouds are linked to large amounts of statically charged particles. Stimulating them with the right kind of laser can hold the key to perhaps one day causing a rain storm when and where it is most needed.
"Lasers can already travel great distances but 'when a laser beam becomes intense enough, it behaves differently than usual -- it collapses inward on itself,'" said Matthew Mills, a graduate student in the Center for Research and Education in Optics and Lasers (CREOL), according to the Daily Mail.
"The collapse becomes so intense that electrons in the air's oxygen and nitrogen are ripped off creating plasma -- basically a soup of electrons," he said.
When that happens, the plasma immediately tries to spread the beam back out, which then causes a struggle between the spreading and collapsing of an ultra-short pulse laser. The struggle is called "filamentation," and it creates a filament or "light string" that only spreads for a bit before the properties of air make the beam disperse.
"Because a filament creates excited electrons in its wake as it moves, it artificially seeds the conditions necessary for rain and lightning to occur," said Mills.
Other researchers have managed to create "electrical events" in clouds, but not any lightning strikes.
The UCF-UA team is now developing a way to get close enough to direct the beam into a cloud without it being disintegrated by lightning. "What would be nice is to have a sneaky way which allows us to produce an arbitrary long 'filament extension cable," the researchers said.
Getting more out of the beams
"It turns out that if you wrap a large, low intensity, doughnut-like 'dress' beam around the filament and slowly move it inward, you can provide this arbitrary extension," Mills explained. "Since we have control over the length of a filament with our method, one could seed the conditions needed for a rainstorm from afar.
"Ultimately, you could artificially control the rain and lightning over a large expanse with such ideas."
Thus far, the Daily Mail reported, Mills and another graduate student, Ali Miri, have been able to extend the pulse from 10 inches to nearly 7 feet in diameter. They are currently working to extend it even further.
"This work could ultimately lead to ultra-long optically induced filaments or plasma channels that are otherwise impossible to establish under normal conditions," noted Prof. Demetrios Christodoulides, a scientist who is working with the graduate students on the project.
"In principle such dressed filaments could propagate for more than 50 meters or so, thus enabling a number of applications," Christodoulides said. "This family of optical filaments may one day be used to selectively guide microwave signals along very long plasma channels, perhaps for hundreds of meters."