Posting in Energy
Researchers have figured out a way to make rain from high-powered lasers.
I remember when I was in Australia a few years back, people complained that there was a severe shortage of rain. I had never heard water talked about so much in my life: Everything from radio programs to casual conversations revolved around the lack of rain.
Now the Aussies may have a solution for their drying woes. Researchers have figured out a way to use high-powered lasers to generate raindrops throughout parts of Berlin. But there is no need to carry umbrellas just yet because the researchers haven't exactly made anything resembling a torrential downpour.
However, the early results do look promising and using lasers to trigger condensation could one day be used to artificially induce showers — something that would be beneficial in drought-prone areas like Australia.
While optical physicist Jérôme Kasparian at the University of Geneva, Switzerland instincts to use a laser to make rain were right, creating rain on demand is a bit of an overstatement.
The lasers basically "squeeze" water from air, so water drops can form around the nuclei.
Trying to control rain patterns isn't new. People have been trying to pour silver iodide crystals on clouds so rain drops can form around it. However, it's unclear how "cloud seeding" actually works. And some are worried about how sprinkling chemicals all over the environment might be damaging.
This is how Kasparian made rain in the lab:
- Used a high-powered laser in an atmospheric cloud chamber containing saturated air.
- A low-powered laser was used to see and record any droplets that formed this way.
- Short pulses of intense light shot a trillion watts of energy into the cloud chamber.
- The drops were about 50 micrometers wide.
- And just 3 seconds later, the drops grew to 80 micrometers. The smaller ones joined together.
To see how this would work in actual clouds, Kasparian used a high-powered Teramobile laser to create an electrical discharge. Although the method did create condensation when the humidity was high, going beyond that remains a major hurdle.
Kasparian told Nature: "We can only create condensation along the laser channel, so we won't be going out and making rain tomorrow."
If this laser technology can ultimately induce showers it could have major implications for the agricultural industry.
Back in 2005, a lot of farmers were suffering though. The Australian Bureau of Agriculture and Resource Economics predicted winter crop production would drop by 55 percent in the region I was in if rain didn't come. Some even thought a water war would breakout.
Fortunately, rain fell for weeks. If a laser could have done the trick, the drought-prone area would have been relieved much sooner.
But not everyone thinks that a laser will work. Rain is more complex than that. So many other conditions must be met before this laser technique produces the rain patterns many long for.
Top Image: J-P. Wolf/ University of Geneva (via Nature)
Bottom Image: NASA
May 4, 2010
As other posters correctly indicated or implied, it's partly a matter of having water vapor over an area. In that regard, perhaps we can eventually form pressure differrentials that invoke movement? This is part of the idea along with other matters such as condensation nuclei, controlling precipitation, assessing risk, preventing hazards, and of course the energy requirements. Anway, well done and thanks for the topic.
What BBix et al fail to realise is 1) God exists and 2) He instructed us to MULTIPLY and FILL THE EARTH and 3) Planet Earth (it's original name when there was 25% water 75% land, not as it is now post-flood) is designed FOR humans, not FOR animals or decoration. The massive problems we see in the ecosystem and weather ARE caused by humans - but neither our number nor our technology. It's our SIN that causes the damage. You remember that now-unfashionable behaviour pattern, don't you? That one where humans thumb their nose at God and tell Him to sod-off because they know better? That one where those same said humans indulge themselves in ever more degenerate behaviour? That one that so few people realise is actual a physical force akin to any in physics? But no. The likes of BBix want to live in a world / universe that is devoid of God, so they don't have to relate to Him and find out what their purpose in this whole reality is. Talk about the clay jar telling the potter whose boss! Don't worry - all you skeptics out there will be faced with the bald truth very shortly. Planet Earth end countdown has begun in earnest...
So some areas don't have enough upwind evaporation and in other areas there is too enough. We need a world scale heat pump that can help move the hot and cold spots around. Maybe adsorb heat from the ocean in one area, beam it to a satellite, and beam it back down where you need it to boil the ocean. Or maybe build larger wind farms with MUCH larger windmills which can be run in reverse if needed to blow those pesky high pressure systems away. OR maybe we just need to wait for nature (human nature) to depopulate the earth to less than 10% of today's population and then the survivors can choose to live in only the best places and grow food and harvest wildlife in more sustainable ways. The "elephant in the room" that few people are willing to discuss is overpopulation.
they need to work on a device that can be placed in the ocean (speaking specifically for austrailia) that can either vaporize the ocean water off shore so that the vapor/clouds/moisture is available then they will be able to "make rain"
Hi, "The lasers basically ?squeeze? water from air, so water drops can form around the nuclei." From what I understand reading other articles, what actually happens is that laser pulses ionises (charges) the air. These ions (which attracts water) then provide the necessary condensation nuclei for water vapour to condense on, and form water droplets. So in a way, it does help to "squeeze" water out of the air, but the sentence and the article in general, seems to give the impression that the laser technology can magically produce water where there isn't any. Which is why I agree with Starman35, that if the atmosphere is too dry in the first place, no amount of laser nor condensation nucleus can save planet Australia.
I am a cloud physicist, so I know a thing or two about this topic. The problem with drought is the lack, not only of rain, but water vapor from which a cloud could form. The technique presented here only works in saturated air, so it is useless for relieving drought. Seeding clouds with ice nucleating chemicals is similarly useless - you can't seed a cloud that isn't formed. The only way to stop a drought would be to find some way to erode the persistent highs that create drought, and there is nothing man can do about that.
"The massive problems we see in the ecosystem and weather ARE caused by humans - but neither our number nor our technology. It's our SIN that causes the damage." And I foolishly thought that BBix was being nutty with "windmills blowing backwards". You're insane, you realize that, right ? Completely Mental. If only there was a cure for Religious Zealotry.
Hi Starman35, I was wondering about this topic with a friend for a while as an outsider, hearing news about droughts. Why can't they just move the rain clouds from the tropical areas to the areas in need? Maybe it's a naive approach to harmonize distribution. Thank you for your answer, Reka