Laser System to be Tested in Boulder, CO 318
luv_jeeps writes "Ball Aerospace is going to test fire a laser beam on Sunday night, as part of the CALIPSO project. If you live in the Colorado/Wyoming area, chances are good that you could see it. The article, a little light on details, says that the beam could be as big around as a basketball hoop."
I for one am excited (Score:1, Interesting)
Ozone Layer??? (Score:-1, Interesting)
Birds? (Score:1, Interesting)
I get the part about aircraft, but how will they protect the birds? I also wonder if this laser is powerfull enough to fry a bird.
tape it please (Score:5, Interesting)
Please
S. Boom (Score:3, Interesting)
This is, after all, what one hears when a lightning bolt strikes.
Question... kinda.... star trek reference... (Score:3, Interesting)
The Allan Parson's Project, Phase 1 (Score:5, Interesting)
prepare to be scanned (Score:5, Interesting)
Re:Light on details? (Score:2, Interesting)
Re:I for one am excited (Score:3, Interesting)
But I cannot tell, as I have not heard of the project for a year or two. I am not sure if that means it's a failure or that I am lost.
See Infrared? (Score:5, Interesting)
from the post
"If you live in the Colorado/Wyoming area, chances are good that you could see it."
from the data on the sat:
"Part of NASA's Earth System Science Pathfinder program, Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO), is a mission dedicated to studying the impact that clouds and aerosols have on the Earth's radiation balance."
solar beam test (Score:1, Interesting)
also the thing reminds me of the ion cannon from command and conquer, though I know that beam won't have the power to zap stuff from space.
Boulder (Score:2, Interesting)
LASER ? (Score:3, Interesting)
That's why you can use powder or smoke (which is composed of tiny piece of material) to actually see them (by reflection of the photons on the particle).
If it's a real laser can someone tell me why we should see it ?
I know that the atmosphere is polluted, but not THAT much, is it ?
Are they giving out safety goggles? (Score:3, Interesting)
Re:Caution (Score:5, Interesting)
Re:Question... kinda.... star trek reference... (Score:5, Interesting)
Phaser [bbc.co.uk]
A ray gun that can stop people in their tracks without harming them may sound like science fiction, but some experts believe it could soon be reality.
The gun is designed to zap its victim with an electric current, using a laser to carry the charge along a beam of ultraviolet light.
The light particles, called photons, would create a path through the air that will be capable of conducting electricity up to a distance of about 100 metres (330 feet).
When the current hits someone, it would interfere with the tiny electrical charges that control the victim's muscles, making movement impossible.
Vital organs protected
But vital organs like the heart and diaphram would not be affected because they are protected by a greater thickness of body tissue.
Corinne Podger of BBC Science: "The stuff of science fiction". Weapons that freeze muscles are already on sale in the United States, but in order to work they have to be held against the victim's skin. They also have to be recharged after each use.
Apart from having a considerable range, the new 'freeze ray gun' could in theory be fired around corners if mirrors were used. It could also have a constant power source.
Talks in California
The gun is the brainchild of American inventor, Eric Herr, vice-president of HSV technologies. Scientists from the UK's Defence Evaluation Research Agency have already been to California to discuss it with him.
No details of the discussions have been disclosed, but a spokesman for the UK Ministry of Defence said the weapon's potential uses were being considered.
So far, Mr Herr's ray gun remains just an idea. He has taken out a patent on the device, but has yet to raise the $500,000 needed to build a full working prototype.
'Ideal weapon'
Initially, the 'freeze ray' could be the size of a small suitcase, but might eventually be reduced to something more like a flashlight.
Mr Herr believes it could be an ideal weapon for peace-keeping forces, or police facing violent criminals.
But already the project has its critics. They argue that such a laser would be impractical in many situations, and could easily damage the sight of innocent by-standers.
Link to HSV Tech [hsvt.org]
Re:laser beam spread (Score:2, Interesting)
I skimmed over the CALIPSO site linked as well as the nasa site linked from that page but was unable to find a detailed explanation of how the system worked.
The explanations did mention that it is planning on mapping the atmosphere, I would venture a guess that they were doing some processing based on known information about the indices of the different regions of the atmosphere and some gathered information from the laser source that had diffracted through the atmosphere and been sensed. Thus it may make sense that they may want an expanded and/or non-collimated beam.
I don't know much about this project, or very much about optics but I do know that not all lasers systems require a collimated beam.
In Kassel already in 1977 ... (Score:2, Interesting)
Another occasion when art was faster than science ? Well, not really.
CC.
Re:laser beam spread (Score:2, Interesting)
Light Amplification by Stimulated Emission of Radiation
Laser light is monochromatic and in phase and polorized, but there is no reason why it should not spread. In fact, I have put a lens in front of my laser and it spreads quite nicely.
PS: did you know that air of different temperatures or pressure has a different diffractive index and could be used as a lens?)
Re:See it? (Score:3, Interesting)
Most high-powered green lasers make green light by doubling the 1064 nm light produced by a diode-pumped Nd:YAG laser. So it's probably 532nm - it certainly looks like it. Google confirms that doubled Nd:YAG is indeed a popular laser source for LIDAR applications. The experiment also uses IR light, so you can conveniently use the infrared pump as the source for that part of the experiment. Another group has done something similar [iap-kborn.de], albeit at somewhat lower powers (i estimated in another comment that the Ball system uses about 200 W (average) of green, while the experiment i linked to uses about 10W of green).
2 cool lasers... (Score:5, Interesting)
Gulp.
Then there's (2) the shuttle-based LIDAR, which actually shoots a laser from the open shuttle bay to the ground, and ranges the distance to the ground, to sub-meter accuracy / 1-10 cm precision. This means a pretty darn bright laser is shot at the ground and typically ranges the tallest thing it finds - they hope for canopy for land cover work, but in an open area, it might be you. NASA usually told people it was "like radar" which it is in its methods...
but it uses laser light.
So somewhere tucked into the mission materials for the shuttle flights that contained it is a cute little disclaimer telling you that yes, it is a laser and yes, it could conceivably pass right over you and yes, if you looked up right into the path of the lidar you could get hurt - so FER CHRISSAKE DO NOT LOOK DIRECTLY INTO THE SHUTTLE BAY LASER AS IT PASSES DIRECTLY OVERHEAD or words to that effect. But they put them somewhere where it was legally required, buit they did not pass out press materials that said a giant space laser might be shot at your house sometime in the next two weeks... they traded full disclosure for widespread panic.
That plus the innumerable people who would JUST HAFTA go outside armed with jpass and JUST HAFTA look right up the barrel... like looking in the garden hose to find out why the water ain't coming out. Here's your sign.
Re:One thing in Colorado's favour... (Score:2, Interesting)
Nah, this is just the latest idea in snow removal.
Says he who spent today clearing two feet of white stuff from the paths by hand today after the rubber band in the damn snowblower broke.
Its a pity they don't have snow down in Texas. Just think Dubya would have woken up thinking 'hey it must be Christmas', then spend the next five minutes looking for his nose spoon until he finaly remembered he had given it up.
Yeah, we need that laser driven snow clearing. Far fewer moving parts.
I think someone needs to persuade the folk doing the 9/11 memorial to look at lasers. At the moment they are proposing designs with 3000 odd lightbulbs. Chances of that being maintainable are zero. A much better way to do the same job is to shine a laser at a holographic plate. That way you could do names and even have different colors for different groups, the ones in the planes, the firefighters etc.
Re:Too many scifi movies (Score:5, Interesting)
Actually, if you would be looking at the satellite in space and see it explode, you would very much hear it. While it is true that the near absence of air means that a person would not hear any sound from a shockware that travels through the air, but from the explosion that person would very well hear the many high-velocity particles ticking, and thunking against his/her vessel. If you have experienced any explosions of significance, or have enough imagination, you will know what kind of rain of particles I'm talking about. Just a week ago, astronauts were shaken up by a sound that probably was produced by such a space particle [floridatoday.com]. So you would hear the explosion in space, just differently than on earth.
Now about the no air - no sound thing: Things like "there is no sound in space" that they teach kids in high school are ususally oversimplified or just plain wrong [space.com]. Did you know that black holes [space.com] actually emit sounds?
Re:One thing in Colorado's favour... (Score:2, Interesting)
Re:prepare to be scanned (Score:1, Interesting)
Also, the spacecraft is moving so fast that you can only get one pulse hitting you unless you are in an airplane following the track of the satellite and looking upward at the same time.
Re:Caution (Score:2, Interesting)
Also, if they are claiming a continuous power of at most 200 W ( 4.5 W/cm^2), and maybe as low at 50 W, that is about equivalent to at most 500mW, and maybe a 100mW laser, which is powerful enough to damage an eye, even in reflection, but a far cry from the 10 W lasers that can mark a surface, or the 100+W lasers that can do some damage.
Re:tape it please (Score:4, Interesting)
Dogg
Re:Birds? (Score:3, Interesting)
You have to be careful with power measurements with lasers; there are several different ways to measure power and they all come up with similar units...
The key thing here is that this laser is q-switched, while a laser pointer is continuous-wave. Meaning the laser pointer is on all the time, while this laser is on for brief instances several times a second.
The power delivered, during that brief instance, may be 40,000 times as powerful as a laser pointer, which is not really that impressive... that's possible with significant cooling with off the shelf surplus hardware... because this laser might be on for 2 ns and off for 50 ms (Nitrogen lasers have exactly that sort of switching)... if it had a periodicity like that, it would actually be less powerful than a laser pointer in terms of energy delivered over time...
However, if the AVERAGE power delivered is 40,000 times as powerful as a laser pointer, that means the pulses may be a million times as powerful, and the energy delivered measured over any significantly long period of time will be the equivalent of 40,000 laser pointers.
But whenever reading laser manufacturer specs, it is important to know the difference between pulse power and average power...
A magnesium flare is certainly for the brief time it goes off much more powerful than my coffee maker. But that single magnesium flare would never be able to completely boil away 1 gallon of water... which is something that my coffee maker routinely does when I forget to turn it off...