Weather-controlling super lasers get closer to reality
Researchers 'fix' the inherent weakness of a laser beam, making it capable of creating rain and lightning from afar.
Tue, Apr 22, 2014 at 02:12 PM
Zeus, the Greek deity who ruled the sky and smote his foes with a strike of the thunderbolt, would not be pleased. But for mere mortals, who have long dreamed of controlling the weather, new research on lasers is taking us one step closer.
While cloud seeding has been in the works for a while, researchers from the University of Central Florida’s College of Optics & Photonics and the University of Arizona have developed a new technique to aim a high-energy laser beam into clouds to create rain or trigger lightning.
Both water condensation and lightning activity in clouds are dependent on large amounts of static charged particles; activating those particles with an effective laser is thought to hold the key to potentially inciting rain at will.
With current laser technology, laser light dissipates as it travels through the Earth’s atmosphere, a characteristic that has been prohibitive in the quest for weather control. When a laser beam becomes intense enough, it begins to collapse on itself.
“The collapse becomes so intense that electrons in the air’s oxygen and nitrogen are ripped off creating plasma – basically a soup of electrons,” Matthew Mills, a graduate student in the Center for Research and Education in Optics and Lasers, said n a statement for the study.
The problem then becomes how to get near enough to aim the beam into the cloud without being blasted into oblivion by lightning, or how to make a longer laser.
The researchers found a way to surround the beam with a second beam to act as an energy reservoir, sustaining the central beam to greater distances. Called “dressed” lasers, the secondary “dress” beam helps prevent the breakdown of the high-intensity primary beam, which would otherwise dissipate too rapidly.
“What would be nice is to have a sneaky way which allows us to produce an arbitrary long ‘filament extension cable.’ 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 said. “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.”
Development of the technology was supported by a $7.5 million grant from the Department of Defense. Zeus, be warned.
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