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Sci-Fi Star Wars Prequels Idle

The Science of Lightsabers 232

Posted by samzenpus
from the this-had-better-have-nothing-to-do-with-midichlorians dept.
sethmad writes "As everyone who's ever passed the GRE knows, there are two major hypothetical operational problems with Star Wars lightsabers. More accurately I should say there were two problems, because I solved both of them."
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The Science of Lightsabers

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  • by perpenso (1613749) on Friday June 10, 2011 @01:09PM (#36402798)

    More accurately I should say there were two problems, because I solved both of them.

    What are your patent numbers? :-)

  • The British.... (Score:3, Informative)

    by Anonymous Coward on Friday June 10, 2011 @01:10PM (#36402820)

    We would call them Torches you idiot!

  • by Zakabog (603757) <john@nosPAm.jmaug.com> on Friday June 10, 2011 @01:15PM (#36402882)

    If you're using a magnetic field to control the plasma then any magnet can still interfere with the light saber. For some reason I was expecting a much more technical article than 'its got a metal rod in the center, tada!'

    • by larry bagina (561269) on Friday June 10, 2011 @01:17PM (#36402932) Journal
      Yeah, this was stupid and pointless, even by idle standards. Maybe /. needs to add a retarded section.
      • heh heh yup. I also thought that the largest problem with a lightsaber being plasma is that to cut as efficiently as portrayed it would roast anyone within a football field of it. Little problem called convection and the laws of thermodynamics.
        • The biggest problem with lightsabers isn't even the science of them.

          It's that they're insane weapons.

          Look, if you have something that can cut through anything, you shoot it at people. Imagine a dual-lightsaber that's 3 inches long, operates for five seconds, and is shot, spinning, at people. Hell, forget shot, you could put a release timer on them and throw them at people, having them spring into action a quarter second after release.

          Perhaps there could be spinning death frisbees. Can you curve a light blade around the edge? ;)

          Or perhaps you could just fire the 'blade' itself, leave the generator behind. But I think that's disallowed under the 'rules' of lightsabers, which says the light blade goes out and then comes back, which also has the benefit of saying that lightsabers don't use power unless they're actually cutting something, otherwise, they're 100% efficient. (Except that they're always cutting the air, hence the hum, so always use a tiny amount of power.)

          All I really know is waving it around near your body is a good way to lose parts of your body.

          But, even stupider, there appears to be no reason you can't slide your blade down the other guy's blade and cut off his fingers. Unlike traditional swords, there's no guard, nor can there be one.

          Likewise, as they're weightless, there's no reason to not have very long ones. Lightpikes, you just aim them at the enemy, push a button, and the blade extends twenty feet out, straight through their torso. You jerk it upward, slicing them in half. Then cut off the blade and go to the next guy, or just wave it back in forth in an arch if they're all coming at once. (Hell, you wouldn't even need to be a Jedi to safely use one of those!)

          Granted, you couldn't block blaster fire with one, but there's no reason you couldn't have short and long setting, or at least a duel-weapon with a short and long side.

          • All I really know is waving it around near your body is a good way to lose parts of your body.

            I always thought it was funny, that jedi and sith would do flips while holding one. If it is a plasma jet in a magnetic field, it is still going to produce a lot of heat, and that heat will rise. Doing a flip while holding one is probably a good way to get a third degree burn...
            • by Rei (128717)

              This all simply argues that they're not plasma, not something superheated but which simply creates incidental light or diffracts in the air (such as actual light). Everything else falls under the principle of "sufficiently advanced tech = magic". Remember that the canon already well established force fields of various kinds (shields, tractor beams, hovering craft, etc), so the concept of the two objects not passing through each other without a solid physical core should not seem absurd if you accept the p

          • by geekoid (135745)

            That assumes the material is cheap enough and readily available.
            The tine and expense needed to make one is insane; especially when you have convention weapons that work fine.

            Also, they don't cut through anything, hell most thing take time to cut through.

            Waving it around near you body is a good way to get injured with any weapon. That's why hey are highly trained.

            The basis for your ill thought out write up also ignored the fact that they are trained force users. So they can foresee simple moves, or even comp

        • by tibit (1762298)

          I'm not so sure. Ever seen a plasma cutter go through steel blades that are many inches thick? You can stand fairly close to it.

          • Yes, but it doesn't do so instantaneously now does it? A light saber by contrast can pass through inches of steel in the blink of an eye, which requires an amount of energy several orders of magnitude higher than a plasma cutter generates.
        • by geoskd (321194)

          heh heh yup. I also thought that the largest problem with a lightsaber being plasma is that to cut as efficiently as portrayed it would roast anyone within a football field of it. Little problem called convection and the laws of thermodynamics.

          Not to mention that "metal rod" he's so proud of being obliterated the moment the plasma was turned on.

          -=Geoskd

    • by Kell Bengal (711123) on Friday June 10, 2011 @01:30PM (#36403104)
      When I was younger (and nerdier) I once proposed a similar but more sensible version using in-universe technology that was well understood by Starwars fans: force fields. Obviously, starships have shields that keep asteroids, debris, weapons and projectiles from damaging them. Similarly, speeders and various devices apply forces at a distance to hover and float. Why can't this technology be used to harness a plasma field as a cutting device?

      It stood to reason that the interaction of these repelling, focussing fields would result in the spark and fizzle of lightsabres clashing, as tiny amounts of plasma escaped. Likewise, the interactions would prevent the blades from passing through each other and also account for occasional 'sabre lock' where two blades are periodically joined and must be separated.

      As I said, I was younger and nerdier back then.
      • by PitaBred (632671)

        You were just younger. The fact that you're bragging about it now means you're still just as nerdy, if not more so ;)

      • When I was younger (and nerdier) I once proposed a similar but more sensible version using in-universe technology that was well understood by Starwars fans: force fields. Obviously, starships have shields that keep asteroids, debris, weapons and projectiles from damaging them. Similarly, speeders and various devices apply forces at a distance to hover and float. Why can't this technology be used to harness a plasma field as a cutting device?

        Because force fields are just as improbable as light sabers and for a lot of the same reasons. Force fields are more widely employed in sci-fi but that doesn't make them any closer to the reality we actually live in.

        • the reality we actually live in

          You may live in reality, but this is /. - the rest os us have successfully avoided reality for most of our lives!

          • by Culture20 (968837)

            You may live in reality, but this is /. - the rest os us have successfully avoided reality for most of our lives!

            That reminds me.
            Mom! Replicate me a Sandwich, Earl of, hot.

      • by geekoid (135745)

        "starships have shields that keep asteroids"

        I seem to remember a star cruiser having to blast asteroids to try and find some run away smuggler.

        Of course, in that series they where light sabers, not plasma torches.

      • by EdIII (1114411)

        Likewise, the interactions would prevent the blades from passing through each other and also account for occasional 'sabre lock' where two blades are periodically joined and must be separated.

        Gimme your geek card. Right now. RIGHT now.

        You were talking about Star Wars at first.... then went straight to Space Balls. I'm pretty sure that two people fighting with light sabers are not going to casually cooperate with each other to get one foot on the other guys knee to pull the entwined light sabers apart.

        Not to mention in Space Balls, it was NOT a sabre. They were rings you got from some Yogurt merch. Which brings up whole other questions of why Yogurt would be putting insanely powerful weapons

    • by erroneus (253617)

      Yeah, I want to go with "a constant flux state between energy and matter" which is why it seems to have the properties of both matter and energy.

    • Well, that's just it, I don't think it's a form of plasma on the sabers (or that it cannot be). It has to be something projected through a crystalline substance. The heat of plasma is enough to cut through steel, a crystal would melt because of the intense heat it would require to generate it. Not to mention the fact that the saber itself would be incredibly hot to handle.

  • You failed to solve #2. You retain the magnetic field, but don't offer a solution to the problem of interference.

  • by ceoyoyo (59147) on Friday June 10, 2011 @01:19PM (#36402944)

    Come on. Half the comments on this story are probably going to be better than this dork's.

    A light saber that used plasma would likely be hot. Hot enough that holding it would get very uncomfortable, magnetic field or no. And if the magnetic field is confining it, how does it get through the porous metal? Without destroying the metal? Where does the plasma come from if it's constantly leaking out? Why do lightsabers require focusing gems? How does a light saber deflect blaster and laser hits that would otherwise melt metal? How can lightsabers be an ancient weapon and the guy who designed them is still living on some planet somewhere?

    • A light saber that used plasma would likely be hot. Hot enough that holding it would get very uncomfortable, magnetic field or no.

      Valid point. Though temperature is highly dependent on the substance used to make the plasma and the amount of plasma to start with. And since we're in this fictional world - the handle could have a built-in cooling method that abates the temperature as it gets closer to the holder - that could even be part of the power system used to heat the plasma.

      And if the magnetic field i

      • by kimvette (919543)

        And, of course, there is the simpler solution which applies only in the fictional Star Wars Universe - the light saber itself is not actually a laser/light/plasma blade but made up of the force (in a physical, more concentrated form of the midoclorians) as manipulated by its wielder, thereby requiring the ability to manipulate the force to use it (consistent with Star Wars AFAIK). Stronger users of the force could therefore have longer blades if desired, and the focusing gem is just a focal point for the wi

        • You can't "explain" fiction by adding your own fiction. IF you want to play the game of debating a fictional universe, you got to accept that universe as it is.

          Lightsabers are for most of the lore of Star Wars ordinary weapons that anyone can use. However, since blasters do exist ONLY someone skilled enough to deflect incoming blaster shots (not laser shots) would survive long enough to make any use of it.

          Once you can make use of the lightsaber to deflect incoming shots it becomes a valuable weapon with som

          • by Sarten-X (1102295)
            According to the Wookiepedia (which I've been reading lately, because I know far less about Star Wars than someone of my nerdiness should), the blade has a significant gyroscopic effect, and as such requires great dexterity to use. Somehow, being sensitive to the Force makes that easier, to within the reasonable limits of human capacity.
        • Liam Neeson thought that it was all "will power or something" until they told him during the making of "The Phantom Menace" that "No, there is a switch right here. See?".

          Can't seem to find the video of that though.

        • by bryan1945 (301828)

          Don't feel too bad, I just found my old tautaun figure (complete with a tummy flap) in my parent's garage. So I took it and put in on one of my wife's bookshelves, staring at her computer seat. She wasn't pleased when she finally noticed it.

          And everyone knows that a lightsaber is just a manifestation of the Schwartz!

        • by AmiMoJo (196126)

          What happened to just enjoying a fantasy story at face value and not geeking out over the petty little details?

          Frasier: Think about it, Niles. What's the one thing better than an exquisite meal? An exquisite meal with one tiny flaw we can pick at all night.

    • You are debating this tiny kids silly answer of there being a metal rod inside when there can't be one inside from the fiction that came up with the idea.

      This kid think he is so smart but forgets to actually read the material where the lightsaber originated. Whatever the lightsaber is, it is a "X" that is focussed through crystals, uses very little if any power if the blade is not used in combat, behaves as a solid with immense heat on contact but no radiation. That is what the fiction of the movies have cr

      • by geekoid (135745)

        they key problem is that then lkight saber changed in the mnyth.

        Artical written in the 70s clearly indicate it's a condensed beam of light.

        Plasma was added later. A mistake, in my opinion.

        In fact, they have been making excuse for them for decades.

        The number ONE reason to use hem is that if skilled you can block blaster shots.

        also, as a sign of an elegant weapon from a more civilized age.
        .

  • Rearrange title to make a well known phrase or saying.

  • by camperdave (969942) on Friday June 10, 2011 @01:24PM (#36403016) Journal
    What's a GRE and why would passing one allow you to know hypothetical problems with Star Wars tech. I passed a truck full of pigs on the 401 and the only thing I learned is "stay upwind of the pig trucks"
  • by mwvdlee (775178) on Friday June 10, 2011 @01:25PM (#36403026) Homepage

    I'd like to say this was copied from the TV series in which Dr. Michio Kaku presented the exact same "solutions" to those two lightsaber problems (http://www.youtube.com/watch?v=xSNubaa7n9o), but in the same series he also discusses a time travel machine, so who know; he may have copied the ideas from this kid.

  • He hasn't solved the most difficult problem, though: the noise. Normally, a light saber like that would be completely silent. How do you let it make those whooshing sounds?
    • He hasn't solved the most difficult problem, though: the noise. Normally, a light saber like that would be completely silent. How do you let it make those whooshing sounds?

      The same way you did with a stick when you were a kid. Make "Vruu Vruu" noises while swinging it. ;-)

    • by Alioth (221270)

      A speaker and a small 8 bit microcontroller-based sound generator in the handle, and a couple of accelerometers to detect it being waved around.

    • Anything with a big 'ol vibrating transformer in it will make a similar noise. My dad has a power conditioner on his computer that makes a similar noise if you pick it up and swing it around.

      • by bughunter (10093)

        Anything with a big 'ol vibrating transformer in it will make a similar noise.

        No. Those make the wokk wokk wokk sound when they transform from a 14-inch phallus that goes bzzzzzzzzrrrrrrzzzzzrrrrrrrrrrzzz into a Harley-Davidson V-Rod Muscle 1250, that goes chugchug chugchug chugchug... ROARRRRR!. My lesbian aunt keeps one in her purse.

        Oh. Sorry. I thought you said "transforming vibrator."

        My mistake.

    • by savi (142689)

      Yes, but if we have to account for lightsaber sounds, then we have to account for noise and fiery explosions in space.

  • "The collapsible rod extends out of the handle of the lightsaber when activated, much like a high-tech version of a toy lightsaber with a flickable blade. The plasma and magnetic field are energized immediately when powered up"

    For the rod to be able to fit inside the handle it would firstly have to be of very, very thin material, otherwise it would simply not fit in there. Secondly, there's not that many ways of making something that could expand and retract in such a limit space without making it very frag

    • "The collapsible rod extends out of the handle of the lightsaber when activated, much like a high-tech version of a toy lightsaber with a flickable blade. The plasma and magnetic field are energized immediately when powered up"

      For the rod to be able to fit inside the handle it would firstly have to be of very, very thin material, otherwise it would simply not fit in there. Secondly, there's not that many ways of making something that could expand and retract in such a limit space without making it very fragile. Combine that with the aforementioned fragile material and these things wouldn't be able to even sustain their own weight; fighting with those would be completely out of the question.

      I was thinking the same thing and imagining them collapsing and folding over in the same way wrapping paper tubes do when my daughter uses them as lightsabers.

      Of course who knows what magical materials there must be in that galaxy from a long time ago and far far away. Judging by the size of the windows in their ships and how they can get to orbit an maneuver around in space w/o refueling they've obviously invented some pretty impressive tech.

      • by geekoid (135745)

        well, they do have complete control over gravity, so power probably isn't an issue for them.

    • For the rod to be able to fit inside the handle it would firstly have to be of very, very thin material, otherwise it would simply not fit in there. Secondly, there's not that many ways of making something that could expand and retract in such a limit space without making it very fragile. Combine that with the aforementioned fragile material and these things wouldn't be able to even sustain their own weight; fighting with those would be completely out of the question.

      I don't see this as an issue. Right now you could build a 5-foot telescoping titanium baton that could retract into something the size of a large flashlight and would be strong enough to swordfight with. Consider that people used to have real, no-shit life-or-death swordfights with rapiers. Those aren't beefy swords.

  • but it was a funny read. And, if you had billions of dollars, maybe you could pull off a prototype that would have no real world functionality. Besides maybe a mexican jedi fiesta with jaba the hut pinata's.
  • by SanityInAnarchy (655584) <ninja@slaphack.com> on Friday June 10, 2011 @01:33PM (#36403144) Journal

    I don't remember where I've heard this before, but I've definitely heard it. But there are some very large problems you haven't solved.

    First, this is still going to require a large amount of energy. Where does that come from? And if you've got something superheated into a plasma, how do you keep the metal from melting?

    Second, as others have pointed out, you haven't actually solved the magnetic-field problem. Basically, any Jedi could have his lightsaber entirely disabled, or even turned back on him, by inducing a magnetic field on the room he's in.

    Third, it doesn't explain the part where lightsabers are incredibly difficult to wield, due to weird gyroscopic effects, such that only someone with force-sensitive reflexes should be able to wield them properly. Ok, Han Solo can cut open a tauntaun, but that's a pretty crude motion -- try to swing it around, and if you're not careful, you could end up cutting yourself as easily as your opponent.

    Fourth (!), what are blaster bolts, and how does a lightsaber deflect them? It makes very little sense to suppose that a blaster bolt is just some plasma wrapped around a tube in the same way -- that seems awfully complicated compared to alternatives like just firing the plasma as a projectile -- and then, why would they bounce off force fields the way they do, as if they were somehow slowly-moving laser light?

    Finally, how do you explain the phenomena in Episode 1... Alright, maybe you want to pretend that didn't exist, but this phenomena is fairly commonly observed and generally accepted as something that it'd be reasonable for a lightsaber to do. Anyway, what about the point where Qui-Gon and Obi-Wan are trying to break into a room by slowly melting the blast door with their lightsabers? I suppose the metal rod could be collapsing, but then I'd expect that when you pull it out, it'll have to slowly extend again -- and it also suggests that lightsabers would collapse entirely too easily. If they're made of light, this makes much more sense, but then we have all the same problems as light.

    So, cool idea, but let's just accept that Star Wars is science fantasy. It's enjoyable science fantasy, and there's no shame in wanting to be a jedi, but you'll never have a lightsaber. (Also, there's no Santa. Sorry.)

    • fourth is obvious, a the magnetic rod in the middle would deflect plasma (and it would have to be magnetic to keep form getting eaten by the plasma). Even you solved your objection after that.

      • fourth is obvious, a the magnetic rod in the middle would deflect plasma (and it would have to be magnetic to keep form getting eaten by the plasma). Even you solved your objection after that.

        It wouldn't deflect the projectile as if it were a solid object; it would instead partially get caught inside the same magnetic field that holds the saber's own plasma and the rest of the projectile would just disperse around the saber.

    • by DavidTC (10147)

      Third, it doesn't explain the part where lightsabers are incredibly difficult to wield, due to weird gyroscopic effects, such that only someone with force-sensitive reflexes should be able to wield them properly. Ok, Han Solo can cut open a tauntaun, but that's a pretty crude motion -- try to swing it around, and if you're not careful, you could end up cutting yourself as easily as your opponent.

      I've never heard of any 'gyroscopic effects'. Lightsabers would be hard to wield in the real world, simply bec

  • Is getting enough energy in a handheld device.to power it for more than a microsecond.

    (Dr Kaku's explantion for that was "nano-batteries" )

  • by shadowrat (1069614) on Friday June 10, 2011 @02:05PM (#36403574)
    midichlorian waste. when yoda says, "luminous beings are we" he's describing how someone is full of glowing damaging midichlorian poop. a lightsaber draws this toxic waste out of a jedi's body like tanuki foot pads, stores it, and focuses it as a weapon. midichlorian poop behaves EXACTLY like a light saber. Problem solved. It's how it works.

    btw: do you feel tired? do you not have as much energy as you want? As someone with innate jedi abilities, you really need to take special care of yourself. You are probably full of toxic midichlorian waste. I suggest buying my magnetic rare earth bracelets. may the force be with you.
  • fencing (Score:4, Interesting)

    by snookerhog (1835110) on Friday June 10, 2011 @02:27PM (#36403844)
    I once had a discussion about light sabers with a Olympic fencing gold medalist. His job was sword fighting and his main gripe with light sabers (which was not addressed in this article) was that since the blade is made of light, it has no weight and thus the speed of your strikes is not limited by the blade in any way, only by how fast you can manipulate the handle. In his opinion (and mine) this would make saber duels quite short indeed.
  • Number of working light sabers that exist: 0

    Damn. Wish I'd filled out a grant application to get funding to study that for 8 years first. Oh well.

  • http://www.youtube.com/watch?v=T819usZLQtE&feature=channel_video_title [youtube.com]

    I wonder why Star Wars didn't have any of these guys.
  • Next on his list--proving the plausibility of armoires that are wormholes to vast parallel universes where the law of physics is christian allegory.

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