In regards to this thread --> http://www.ngemu.com/forums/showthread.php?t=62564
I have found various articles you all may find interesting.
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The lightsaber. What could symbolize Star Wars' unique tension between hyper-technology and feudalism better than this high-tech/low-tech amalgam? At once both traditional and out-of-this-world, these handy-dandy devices seem so tantalizingly plausible. Any chance of getting hold of one anytime soon?
The question begs the larger issue of what exactly the lightsaber is, or isn't. Is it a laser? In the first Star Wars film, lightsabers appeared to cast shadows, something we wouldn't expect from a beam of light like a laser. This may have been due to the fact that they were filmed with solid staffs which were later redone by special effects to look like beams of light. Now in the age of advanced computer graphics such clumsy expediencies as solid shafts on set can be dispensed with, but lightsaber shadows have been firmly established in the iconography of the weapon. That's to be expected. Designing a sword analog calls for some very unlaser-like characteristics.
For one thing, one laser beam won't stop another laser beam the way one lightsaber will stop another. But what would the art of swordsmanship be without parrying and blocking? Let's say we were willing to do without the swordsmanship, but wanted a belt-carried laser beam that could chop our enemies in half without ruining the furniture. It has been said that the rationale for an archaic-style weapon like the lightsaber in a high tech world like Star Wars was to avoid making holes in the hulls of spaceships. That points to what is probably the most challenging aspect of the lightsaber: the self-limiting length of the energy blade.
One simple way to design a fixed-length laser beam would be a hacksaw-like design where a reflective or absorbent tip could be held a metre or so away from the source of the laser by a stiff filament or rod. But this implausible design would take the fun out of the laser, reducing its efficiency as an omnidirectional weapon and making it more difficult to use or carry around. We went to Dr. Marc Nantel of Photonics Research Ontario for some other ideas.
Nantel is the head of the Laser Micromachining Facility at Photonics Research Ontario a government funded research institute. His work involves cutting objects by focusing laser beams on them. Nantel agrees that a laser sword without a fixed length could be a bit of a liability. "If you were in a bread and circuses type situation in an arena, the characters would kill every one," he points out.
"Laser beams are parallel rays of light - they'll go very far at the same intensity. That's what they're good for," begins Nantel. "If you put a lens in the way, you can bend the rays of light so that they converge to a focal point. After that the rays start diverging. The intensity will get weaker and weaker the further you go from your focus."
Nantel explains that you can get more intensity from the same laser when you converge on a single point rather than simply beam parallel rays. By the same token, if you use what he calls a "strong" lens, one with a very short focal length, you get a stronger cutting focal point than if the focus converges over a longer distance. Nantel himself uses a 12 watt laser that has to be tightly focused on the object he is cutting. The rays of light converge very quickly, then diverge only a short distance behind the target plane.
But a laser that focuses less sharply, in more of a "tall" X shape rather than a "short" X shape, will still remain hot along a longer length, though its focal point will never get quite as hot as it would if it was more sharply focused. "At the very focus point is where it's going to cut best, but near the focal point it will cut too, as long as you're above the damage threshold of what you're trying to cut." You would have, in effect, a laser with a limited length over which it would be able to cut through objects. Just which objects would depend on how strong your power source was.
Well, it's not quite a lightsaber, but it's a laser blade that can chop someone's head off without burning a hole in the ceiling. There's only a few problems left. One is the issue of reflective surfaces. If you shone the blade into a concave reflective surface, it could refocus at some unknown point and burn something unintended, possibly yourself. When we see our reflection in a spoon, Nantel explains, our face appears upside down because it has become refocused by the concave reflective surface. "Don't use the weapon in a kitchen," he cautions.
Then there's the problem of an adequate power supply. As technology goes nowadays, we simply can't cram sufficient power into the handle of a lightsaber to output a searing laser. But who knows what the future may hold? As Nantel points out, "Nobody would have thought a laser pointer would be possible when the first laser was such a clunky thing, but now we have laser pointers powerful enough to cause damage to someone's eye."
-data-
I have found various articles you all may find interesting.
-data-
The lightsaber. What could symbolize Star Wars' unique tension between hyper-technology and feudalism better than this high-tech/low-tech amalgam? At once both traditional and out-of-this-world, these handy-dandy devices seem so tantalizingly plausible. Any chance of getting hold of one anytime soon?
The question begs the larger issue of what exactly the lightsaber is, or isn't. Is it a laser? In the first Star Wars film, lightsabers appeared to cast shadows, something we wouldn't expect from a beam of light like a laser. This may have been due to the fact that they were filmed with solid staffs which were later redone by special effects to look like beams of light. Now in the age of advanced computer graphics such clumsy expediencies as solid shafts on set can be dispensed with, but lightsaber shadows have been firmly established in the iconography of the weapon. That's to be expected. Designing a sword analog calls for some very unlaser-like characteristics.
For one thing, one laser beam won't stop another laser beam the way one lightsaber will stop another. But what would the art of swordsmanship be without parrying and blocking? Let's say we were willing to do without the swordsmanship, but wanted a belt-carried laser beam that could chop our enemies in half without ruining the furniture. It has been said that the rationale for an archaic-style weapon like the lightsaber in a high tech world like Star Wars was to avoid making holes in the hulls of spaceships. That points to what is probably the most challenging aspect of the lightsaber: the self-limiting length of the energy blade.
One simple way to design a fixed-length laser beam would be a hacksaw-like design where a reflective or absorbent tip could be held a metre or so away from the source of the laser by a stiff filament or rod. But this implausible design would take the fun out of the laser, reducing its efficiency as an omnidirectional weapon and making it more difficult to use or carry around. We went to Dr. Marc Nantel of Photonics Research Ontario for some other ideas.
Nantel is the head of the Laser Micromachining Facility at Photonics Research Ontario a government funded research institute. His work involves cutting objects by focusing laser beams on them. Nantel agrees that a laser sword without a fixed length could be a bit of a liability. "If you were in a bread and circuses type situation in an arena, the characters would kill every one," he points out.
"Laser beams are parallel rays of light - they'll go very far at the same intensity. That's what they're good for," begins Nantel. "If you put a lens in the way, you can bend the rays of light so that they converge to a focal point. After that the rays start diverging. The intensity will get weaker and weaker the further you go from your focus."
Nantel explains that you can get more intensity from the same laser when you converge on a single point rather than simply beam parallel rays. By the same token, if you use what he calls a "strong" lens, one with a very short focal length, you get a stronger cutting focal point than if the focus converges over a longer distance. Nantel himself uses a 12 watt laser that has to be tightly focused on the object he is cutting. The rays of light converge very quickly, then diverge only a short distance behind the target plane.
But a laser that focuses less sharply, in more of a "tall" X shape rather than a "short" X shape, will still remain hot along a longer length, though its focal point will never get quite as hot as it would if it was more sharply focused. "At the very focus point is where it's going to cut best, but near the focal point it will cut too, as long as you're above the damage threshold of what you're trying to cut." You would have, in effect, a laser with a limited length over which it would be able to cut through objects. Just which objects would depend on how strong your power source was.
Well, it's not quite a lightsaber, but it's a laser blade that can chop someone's head off without burning a hole in the ceiling. There's only a few problems left. One is the issue of reflective surfaces. If you shone the blade into a concave reflective surface, it could refocus at some unknown point and burn something unintended, possibly yourself. When we see our reflection in a spoon, Nantel explains, our face appears upside down because it has become refocused by the concave reflective surface. "Don't use the weapon in a kitchen," he cautions.
Then there's the problem of an adequate power supply. As technology goes nowadays, we simply can't cram sufficient power into the handle of a lightsaber to output a searing laser. But who knows what the future may hold? As Nantel points out, "Nobody would have thought a laser pointer would be possible when the first laser was such a clunky thing, but now we have laser pointers powerful enough to cause damage to someone's eye."
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I wonder if anyone will ever be able to create a lightsaber similar to the SW ones. interesting theories 
