The adage “Everyone complains about the weather but nobody does anything about it,” may one day be obsolete if researchers at the University of Central Florida’s College of Optics & Photonics and the University of Arizona further develop a new technique to aim a high-energy laser beam into clouds to make it rain or trigger lightning.
The solution? Surround the beam with a second beam to act as an energy reservoir, sustaining the central beam to greater distances than previously possible. The secondary “dress” beam refuels and helps prevent the dissipation of the high-intensity primary beam, which on its own would break down quickly. A report on the project, “Externally refueled optical filaments,” was recently published in Nature Photonics.
Water condensation and lightning activity in clouds are linked to large amounts of static charged particles. Stimulating those particles with the right kind of laser holds the key to possibly one day summoning a shower when and where it is 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). “The collapse becomes so intense that electrons in the air’s oxygen and nitrogen are ripped off creating plasma – basically a soup of electrons.”
At that point, the plasma immediately tries to spread the beam back out, causing a struggle between the spreading and collapsing of an ultra-short laser pulse. This struggle is called filamentation, and creates a filament or “light string” that only propagates for a while until 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,” Mills said. Other researchers have caused “electrical events” in clouds, but not lightning strikes.
But how do you get close enough to direct the beam into the cloud without being blasted to smithereens by lightning?
“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.”
So far, Mills and fellow graduate student Ali Miri have been able to extend the pulse from 10 inches to about 7 feet. And they’re working to extend the filament even farther.
“This work could ultimately lead to ultra-long optically induced filaments or plasma channels that are otherwise impossible to establish under normal conditions,” said professor Demetrios Christodoulides, 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. 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.”
Other possible uses of this technique could be used in long-distance sensors and spectrometers to identify chemical makeup. Development of the technology was supported by a $7.5 million grant from the Department of Defense.
This is indeed a great idea to solve drought but this laser is fired at an existing cloud- what if there are no clouds? Can this laser just from clouds out of thin air? Or are they going to aim a laser at a dam or pond to create clouds? This project was funded by the Department of Defense thus there was military aspects to this research- can this laser be used to form lighting over our enemies that can possibly do harm to innocent people because lighting can’t be controlled or can it? Thus I conclude that making existing clouds rain that can possibly rain on its own to be not the most fruit bearing research. This is only a idea to coverup the true military uses for this laser.
There is no doubt concerning the fact that the world’s water supply is diminishing.
The “dressed laser” would ensure the limited supplies of water would be used more sustainable and efficiently. Farmers would have the ability to control the amount of rainfall and the area in which it occurs therefore reducing crop loss due to drought as well as enabling crops to be grown in previously baron areas of land. Rain could also be induced above lakes or reservoirs supplying water to a town when they run low. The laser’s ability to initiate a lighting strike enables the increase in the rate at which the nitrogen cycle occurs as lighting is key to nitrogen fixation(essential for plant growth and nutrition).
The potential problem with this promising technology is that price at which it will cost to utilize. Small scale farmers will be unable to afford the technology placing them at a disadvantage to the large farming companies who have to ability to use all the water in the atmosphere, leaving no remaining water for the small scale farmers.
As long as this technology is used in a conservative and efficient manner it could be an important element in solving the worlds water crisis.
This innovation will improve our daily lives tremendously as people will never again have to worry about droughts and desertification. We would be able to get water when it is needed and not have to worry about when the next rains will come. Although this could aid us in many way we cannot help to stop and think of whether or not we are interfering with nature. Should we not just let nature decide whether it should rain or not? If this innovation proves to work efficiently without any disruptions to nature and with no side effects, then it could become advantageous to us and in the end benefit humans in a positive way.
No doubt that this type of technology might very well improve the world’s food production and even better the conditions of people who live in rural regions that survive with very little, but even considering all the possibilities of what such a device could hold, I can’t help but also think of how such a device could hold various disadvantages as Jordan McLeod has also pointed out.
If we start to poke at something without fully knowing what the consequences would be, something that holds great promise might blow up in our faces. Think of it in this way as we ‘extract’ lightning and rain from the atmosphere at our will we might upset natural systems. For instance, if we take nutrients out of the air via lightning we might inadvertently cause eutrophication in water regions nearby the targeted area.
Or the device could cause a disruption in the cycle of water condensation and produce weather pattern changes and even disastrous storms. The device might also give the opposite effect of what is expected. For example it might cause our atmosphere to take up more water than what was extracted or cause a thin or unstable (maybe both?) atmosphere. My prediction of the disadvantages may be an overreaction but I can’t help but think of the worst case scenario when we try to intervene in a natural cycle.
All in all the device might hold much promise but I think we should also be cautious as this type of new technology develops.
This is truly an amazing innovation as it brings us a step closer to making science fiction a reality! Weather machines are on the way! This innovation has very promising applications such as bringing relief to drought-stricken areas. However, it also has a dark side as we have people now playing God and if it is used maliciously the consequences could be disastrous; for example floods could be caused in densely populated areas.
Also very interesting is the other uses of the filament besides weather control such as being used to selectively guide microwave signals which could have massive effects in communications, as well as, other fields.
I look forward to seeing this technology further developed and utilised.