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Science

Force Fields And Plasma Shields Get Closer 210

Posted by timothy from the use-half-power-for-melting-butter dept.
one2boo writes: "I guess watching countless hours of Star Trek has paid off for Mounir Laroussi, an electrical and computer engineer at Old Dominion University in Norfolk, Va. Space.com writes: 'Laroussi has literally put plasma on the table: devising an apparatus that creates a mini-plasma inside a Plexiglas cube by passing an electric current through helium gas via specially calibrated electrodes.' This advance in 'Plasma Shields' will allow the shielding and cloaking of satellites and spacecraft. Low-temperature plasmas could one day also make possible an entire new generation of miniature lasers and ultra-low-energy fluorescent light tubes. You can read more on this story here." And for some reason, the relatively low power requirements remind of me of the guts of the Improbability Drive.
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Force Fields And 'Plasma' Shields Get Closer More

Force Fields And 'Plasma' Shields Get Closer

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  • "The Graduate" for the 00's: (Score:4)

    by emerson ( 419 ) on Tuesday July 25, 2000 @11:31PM (#905239)
    Mr. McGuire: I just want to say one word to you... just one word.

    Benjamin Braddock: Yes, sir.

    Mr. McGuire: Are you listening?

    Benjamin Braddock: Yes, sir I am.

    Mr. McGuire: "Plasma."

    --

  • Great... (Score:3)

    by Danse ( 1026 ) on Tuesday July 25, 2000 @11:33PM (#905240)

    Let me know when I can get my own personal force-field. Hmm.. if they get thin enough and are not hot, we could have plasma condoms.

    Remember kids. You shouldn't be having sex out of wedlock. But if you do end up doing it, remember to play it safe. Shields Up!

    Ok.. I already doffed my extra point. That's one less that you moderators will get from me! Ha Ha Ha!

  • Just on the subject of the improbability drive, I think it's highly unlikely such devices will ever exist. But you never know.

    Yes, this was a *very* bad joke.

  • Dune? (Score:4)

    by Lonesmurf ( 88531 ) on Tuesday July 25, 2000 @11:37PM (#905242) Homepage
    Did anyone else make the connection that these things are a lot like the personal shield things in Dune? They stop energy blasts and whatnot, but bullets and knives are still able to penetrate.

    Kinda similar except for the fact that in Dune, the fields stopped anything that was moving quickly too, so you had to slowly slip the knife into the field to kill someone.

    Yum!

    Rami James
    Guy with sand in his pants.
    --
  • Plasma has the potential to create huge amounts of damage. It will only take a certain amount of time before the miliatary find a "use" for it.

    Research into this should not be performed by any scientist who believes he has any morality.

  • Bah... (Score:2)

    by Danse ( 1026 )

    Tinkering with things we don't quite understand and learning about them can lead to all sorts of breakthroughs and new understanding that can help in many other areas. Look at all the cool stuff that has come out of NASA's research. A lot of it really has helped people. It's not just screwing around.

    Besides, there are many people researching cancer and other such things. But it would be silly to have everybody doing that sort of research. Then once it's cured, we're stuck with a bunch of biologists and such with nothing to do and then we have to send them back to school to learn how to be computer help-desk workers or something. It would be a sad, sad world.


  • Congratulations! A well laid flamebait - a work of art... Let's see how many will fall for this.

    //Frisco
    --
    "No se rinde el gallo rojo, sólo cuando ya está muerto."


  • Heh.. I'm _not_ a troll enthusiast, I just don't care about karma-whoring and don't give a fsck if some moron-moderator mods me down. I would actually like to ruin his flamebait... But, alas, I'm still adding to the posts of the thread... :)

    //Frisco
    --
    "No se rinde el gallo rojo, sólo cuando ya está muerto."

  • I don't think that rule applies to nicknames on the Internet because capitalization in the name is an integral part.

    Rami
    --
  • And why shouldn't Timothy start his sentences with "and"? His choice of words inhibits neither semantic clarity nor voiced flow. Any other requirement is imagined.

    Ryan
  • plasmas are not so exotic as some people like to make them sound. take your flourescent lamp, for example. to generate them all you need are two electrodes, some hight voltage, and some frequency. as far as using it for a shield goes, how would you make it go _around_ something? i suppose you could have the + at the front of the ship and the - at the end, assuming the rest of your hull was an insulator. you might be able to make it cloak radar if you happened to be using just the right atomic plasma and energy state to absorb just exactly the radar frequency the enemy was using, but was far as a defensive sheild goes, forget it. how much mass is in that plasma? a microgram? at best? that's not a lot of mass to put in the way of a bullet or even a couple kilojoule laser burst. physics before fantasy. micah
  • First, protecting space vehicles from microdebris. This would be the single most useful space application of this technology for sattelites, shuttles, etc., as dust particles tend to hurt metal a lot if they're travelling at relative speeds of thousands of miles per hour. Since the terrestrial version of this thing has to be contained, however, I don't know if this is possible.

    Second, fusion reaction containment. Since several plans for fusion technology seem to involve rather large heat generation, it'd be nice if this could be used to absorb the heat generated by the reaction and transmit it to generator equipment more safely (i.e. without frying the container). If the plasma is guided by magnetic fields (like so many things are), the extra energy should push the plasma bubble bigger, which can be used to induce currents directly. I'm guessing that this isn't a new idea, but I still think it's worth mentioning, especially since this would theoretically be one of the more efficient fusion->electricity conversions.

    Either of these would be a huge advance (along with the rest of the stuff mentioned), so this is an impressive development indeed!
  • From 98-99 Questions About Writing Archive [colostate.edu]:

    Starting a sentence with but.
    R. Murray

    I always learned that you aren't supposed to start a sentence with 'and' or 'but', but sometimes I want to because it makes sense at the time. Can I break this rule?

    Re: Starting a sentence with but.
    Nick Carbone

    R.

    Guess what! You're in luck. In this case, the rule has changed. The prohibition against beginning a sentence with a co-ordinating conjunction--and, or, or but--has been lifted because despite the prohibition, writers quite often did begin sentences with one of the three. And so the new rule now states, according to Sidney Greenbaum in The Oxford English Grammar (1996, Oxford U. Press), "sentences may begin with a co-ordinating conjunction that points back to a previous sentence or set of sentences" (381).

    [...]

    I'm only pointing this out to you, grammar nazi, because I want you to be the best damn grammar nazi you can be!

  • plasma is too inefficient to use as a weapon. all you get out of it is the heat energy put in to heating it, so basically you get the same pressure-detonation effect as LN in a coke bottle, only a little hotter.

    the real weapon of the future is antimatter. just spill it and BANG. plus no fallout. and limitless scalability. just think what would happen if you dropped a bomb containing, say, a ton of antimatter on a planet. bye bye.

    and i think that physicists with morality should work to foil those without...

    micah
  • And how is researching something that could possibly be used as a weapon inately immoral? Nuclear research led to the atom bomb. It also led to nuclear power plants, which are one of the most efficent and enviornmentally-friendly methods of energy production around (beaten only by hydro-electric dams and solar power). The first use for advanced metalurgy was cannons for use in war. That paved the way for almost every major invention of the last two centuries, including the steam engine, trains, automobiles, airplanes, buildings taller than 3 stories, and the computer you are using now. Speaking of that computer, have you forgotten that the first general purpose digital computer, ENIAC, was built by the US Navy for calculating missile trajectories? Or how about the fact that the Internet itself was invented by the US Department of Defense (ARPANet) to maintain communication in the event of a nuclear war? I can create huge amounts of damage with the PC I'm on right now if I wanted to, all it takes is a few quick hacks. No, wait, someone's already done that.

    Anything can be used for military applications, no matter how useful it is for benevolent endevours. If the fact that an invetion could potentially have a military "use" automatically means that moral scientists should avoid it like the plague, then the only "moral" scientists are those who limit themselves to stone knives and bearskins. (No, wait, stone knives can be used to kill people, too. I guess you're stuck with the bearskin, if you can get it away from the bear without using a stone knife, that is.)

    --GrouchoMarx

  • So, how exactly could this be used for low energy lighting ?

    Considering we still haven't a source of light that is even close to efficent, that would seem a much better application than using the plasma for shielding.

  • The two most important inventions to come out of the space program: Plastic and velcro. Especially velcro. :-)

    --GrouchoMarx

  • Plasma shields (Score:1)

    by Anonymous Coward
    The Soviets were experimenting with plasma stealth devices in the late 1980's and apparently the research was continued in the 1990's. They claim that the plasma stealth device can provide nearly 100% absorption of radar waves and make aircraft completely invisible to radar even close to the radar transmitter. Remember, the current stealth techniques provide only low observability, but stealth aircraft can still be tracked by some radar types. The plasma stealth device is of course experimental, but the Russians claim that it works well in a lab.

  • Not Quite Star Trek (Score:3)

    by GrouchoMarx ( 153170 ) on Wednesday July 26, 2000 @12:22AM (#905257) Homepage
    Just a quick note to the person who submitted this article: It's definitely an interesting concept, but not quite Trek-derived. Star Trek uses graviton-based shields, not plasma-based ones. Incoming weapons/space dust is deflected by graviton interference, a completely different realm of physics. Plasma is used as the power distrobution system, in place of electron-carrying metal wires.

    Yes, I watch too much Star Trek myself, why do you ask? :-)

    --GrouchoMarx

  • My opinion is by definition worth more than yours because I have been moderated up to a +1 bonus by the highly qualified moderators who we know are totally non-biased, and will not mod down an opinion they disagree with as a Troll.

    (Well, you did say "talk shit" so I am.)
  • 1. Because of its frequent misuse, using the word and at the beginning of a sentence is not widely understood. For those of you who didn't realize, the previous post illustrates how to start a sentence with the word and or the word but. This post of course illustrates how to start a sentence with the word Because or the word Opprobrium

    2."best damn grammar nazi you can be" come on people - it's funny


    3. isn't that -infinite- improbability drive?

    4. Opprobrium incurred by failing to be a good grammar nazi is unfortunately greater than that of those who fail to produce an infinite improbability drive or at least a manned mars mission after so many years whilst Star Wars technology continues to flow freely. (and I do mean Star Wars, not Star Trek. Think Ronald Reagan)
  • It's a sad day indeed when the best SciFi force fields reference they can come up with is Star Trek Voyager.

    $ cat < /dev/mouse

  • Engineering, can we outfit the deflector shield to make goat porn?
    We can do it, but it'll take 3 weeks....
    You have 12 minutes
    O.K. then send an away team to the planet. that always helps somehow.

  • I think the out put of those commands if from Star Trek Voyager.....
    (seriously, check it out)

  • State of Texas to invest in plasma research (Score:4)

    by mrogers ( 85392 ) on Wednesday July 26, 2000 @12:55AM (#905263)
    Research into cold plasmas is to receive a further injection of funding from an unexpected source: the Texas Department of Cruel and Unusual Punishments. This little-known government department researches new ways of executing and torturing prisoners at its lab near Fort Worth, TX. For the first time, it will be outsourcing its research to another laboratory, providing $2 million for cold plasma research. DCUP officials are said to be excited by the ability of cold plasmas to break down cell membranes, seeing them as a possible means of executing death row prisoners.

    DCUP spokesperson Dr Eric Mbunge sees a bright future for the penal application of cold plasmas. "With this technology we could execute prisoners by the batch, instead of one at a time," explains Dr Mbunge. "There would be this purple glow, and they'd all fall to the floor. Dead. It would be just like Star Trek."

    When it was pointed out that Star Trek does not feature executions, Dr Mbunge responded, "It would if it was set in Texas."

    The Department of Cruel and Unusual Punishments has not developed any new execution technologies since the introduction of the lethal injection in 1974. Its 1984 invention, the "microwave chair", was never used in Texas prisons because of fears that it might cause adverse health effects to prison wardens.

    $ cat < /dev/mouse

  • Plasma has the potential to create huge amounts of damage.

    Only to the vessel (ie box) that's trying to contain it, or possibly to someone who somehow manages to stick their arm into it, and even then only if it's a hot plasma.

    All a plasma is is a cloud of partly or completely ionised particles; nothing more, nothing less. Some plasmas aren't even that hot (the ones in flourescent lighting tubes, for example).

    Cheers,

    Tim
  • Comment removed based on user account deletion
  • Comment removed based on user account deletion
  • The first general purpose digital computer was ATLAS, built by the Brits at Bletchley Park to crack the German Enigma Code

    Wasn't that Collossus, or am I getting machines mixed up?

  • Plasma tube? Neon? (Score:5)

    by magi ( 91730 ) on Wednesday July 26, 2000 @01:00AM (#905268) Homepage Journal
    Laroussi has literally put plasma on the table: devising an apparatus that creates a mini-plasma inside a plexiglass cube by passing an electric current through helium gas via specially calibrated electrodes.

    Excuse me, but to my understanding the ordinary neon fluorescent lamps also contain "plasma" (when they are lit), caused by "electric current vis specially calibrated electrodes"....

  • Not so sure about that. If you cook or, even more important, if you're the lucky sod who gets to hand wash the dishes, you HAVE to put teflon in there.

  • The patents are more informative (duh) (Score:5)

    by zatz ( 37585 ) on Wednesday July 26, 2000 @01:17AM (#905270) Homepage

    The article has a rather high hype-to-explanation ratio... so I went looking for the patent [ibm.com] they mention. Not so technical as to be incomprehensible, and more useful than the article, IMO. My first impression is that the advance here is the impedance matching system used to maintain the plasma, which allows the compact equipment and low power requirements. (I suppose it searches for the natural resonance of whatever ions you have between the electrodes... just find the lowest-energy state/standing wave at which it remains permittive/permeable.) And if you have low power plus no sealed chamber (1 atm, random molecular gases allowed), it pretty much follows that the result is a low temperature plasma, since plasma tends to radiate continuously. The scalability aspect is nice too... good for more than a toy.

    Either I'm misunderstanding something, or the sterilization is done by the radiation from the plasma... basically just using the plasma as an efficient UV lamp. (The sterilization patent [ibm.com] talks about sterilizing liquids or gels up to 2cm deep... I can't see doing that with the surface interactions, which might be sufficient for polished tools and the like.) This doesn't appear to be sufficient for a low-volume irradiation system for food, which is unfortunate, because I like my hamburgers juicy. Oh well. (Of course, prions survive irradiation anyway, so I would still have to worry about BSE.)

    There is also a separate patent [ibm.com] for "surface shielding". Might be fun to set up on your car :) I'm having trouble figuring out how the leakage from this system would be less detectable than the reflected radio waves it would disperse, though... I suppose if you do it right, all the radiation is absorbed by the gases you are ionizing?

  • >It also led to nuclear power plants, which are one of the most efficent >and enviornmentally-friendly methods of energy production around >(beaten only by hydro-electric dams and solar power). I'm not too sure I can agree with that assessment. Nuclear power plants are quite fuel efficient, but with how insidious radiation is to living things, and how long nuclear waste remains, well, nuclear, they pose a very significant environmental hazard in containment, storage and (hopefully eventually) disposal. It can't just be swept under the rug, afterall. Whether it's any better growing a few spare limbs than choking over petrolium emissions remains to be seen, I guess. Personally, I've always thought it would be cool to have a tail. ;)

    similar story with hydroelectric dams, too. They're clean but not necessarily very environmentally friendly.

    Not that I mean to come off as an eco-nazi here. Just playing devil's advocate. I like my electricity. :)
  • Nice.

    The fact that death penalty still exists is just another demonstration of how the ignorant masses are allowed to rule.

  • Or no electrodes at all... a lot of fluorescent tubes just require an radio wave of appropriate frequency and magnitude... hold one near a power line some time.

    The point here is *low energy* plasma, and no need for containment... neon in tubes is typically energized to about 10^4 C, and breaking the tube puts an end to the fun.

  • Deflector shields as used in any science fiction starship warp space-time in order to deflect. Therefore EM fields or plasmas have nothing to do with it. Deflectors are more connected to the warp drive. Actually they are the same.

    Besides this, did anyone read the article and follow the links to see if the story checks out? "Plasmas are capable of shielding satellites": my ass, where's the link to the scientific background?

    "plasma" links to a story about plasma propulsion, nice but irrelevant.
    "energy systems like the deflector shields" link to a crap story about a medical doctor (!) working on a new Big Bang theory.
    "Cold plasma's... ...are ambient-temperature, ionized gasses related to those found deep withing the suns core": geez, this is unbelievable. Can someone explain to me what has been found in the suns CORE, and by whom and when?

    Please keep on posting this high quality space.com stories.

  • 'Star Trek'-esque shields and clocking devices? Come on people - think about it. The plasma might hide the satellite, but it does nothing for the big box keeping the plama in. Im pretty sure the Baddies will be at least be able to spot these big ass glowing boxes. Anyways - being able to keep a substance above its critical point at low temperatures means really really high pressures, and your average satellite isnt designed to withstand pressures youd find at the bottom of the ocean. Putting something into orbit costs its weight in gold - so 8 inch metal isnt the solution.
  • Yeah, it's bloody expensive and isn't really logical, but has stopped the military before?

  • Your suggested uses sound very much like the Langston field from _The Mote in God's Eye_. The first seems like a very bright idea, and it might apply in other situations where finished surfaces are exposed to high-velocity debris at relatively low pressures... self-cleaning rooms or fan blades with integrated ozonators would be cool :)

    But I don't follow you on the second. [Hot] fusion already involves plasma and ways of handling plasma without touching it... how exactly does adding another layer of *cold* plasma help?

  • Its sounds much more like thouse plasma balls that you can buy at specers and other palces that sell disco lights.
  • Isn't the reason for the communication blackout during a spacecraft's re-entry due to the ionization of the atmosphere around it? Is the re-entry vehicle also invisible to radar?
  • If I remember right a lasgun in Dune hitting one of their shields would cause a nuclear explosion. I'd be a lot more nervous in that sort of armor than out of it...
    --
  • Now all we need is a helium atmoshpere, and we're set. Anyone going to volunteer to field-test our shields on the surface of a star?
    --
  • What I like about this is the fact you can use it to sterilize foods so they can been sfer to eat and we can produce more and maybe even help so poor guy eat (Wishfull think here)
  • I have a cast iron pan myself for eggs. Never sees soap - scrub it out with a little salt. But the rest of my cookware, including my pots, are teflon coated. Even burned rice cleans up easy.
  • Hitting a shield with a lasgun would cause the shield and the gun to explode. Therefore nobody in their right mind would use a lasgun. There's a certain level of safety there, as long as you aren't up against someone not in their right mind. Fortunately this sort of person doesn't last long. There were apparently rules against using a lasgun on an automatic timer.
  • Who cares :)
  • Well a lot of the characters weren't exactly in their right minds...
    --
  • Stop it.

    We Brits (and anyone else who ever discovered aything) have to stop trying to correct the Americans all the time and finally realise that they were, in fact, the first to do everything in the history of the world. Ever.

    Not only did they invent the computer, they also invented the rocket, discovered Australia, invented government, the gun, Lara Croft and Television.

    :)

    troc
  • True, tilting at windmills is pointless. But it's equally stupid to deny the value of imagination.

    Basically there are two different approaches to research:

    • Looking at the current knowledge and trying to extend and apply it
    • Think up stuff that would be wonderful to have and then try to find a way to get there
    Obviously you don't think much of the second, but if you get down to it, it's just as valid and effective - if it's not overdone.
  • Some of us who reas Slashdot, and have been for many years are, indeed, fully qualified scientists and engineers.

    And we don't feel the need to prat around with silly AC prattle that adds nothing to a discussion except general anoyance and the feeling that one really should give in and start browsing at +1.

    Yes, ok this was also a useless post.

    heh

    troc
  • Damn, I forgot this: Plasma and force fields are what fusion reactors are made of, so this line of research could turn out to finally create the definitive clean energy source!
  • If you hold one end of a fl light tube in one hand and a Van De Graaf generator in the other, with the free end of the tube in free air and switch the generator on, the light will glow.

    not sure that's entirely relevant.

    troc
  • 1. Stand on dry carpet
    2. Plug in 9000 volt neon transformer
    3. Connect to one side of output. Other side is not connected.
    4. Hold flourescent tube up in the air. It will glow.
  • hey, it's gotta be better than latex, right?

    -------

  • Actually, it caused only the field to explode, but the blast would be strong enough to obliterate an area larger than the range of any lasgun.

    Still, it makes any army using these shields rather vulnerable against suicide attacks by even a single enemy. Considering how frequent such things are in wars, the shields would seem rahter useless to me. Still, it was a nice way to reintroduce large-scale melee combat in a future setting somewhat realistically.

  • Burning rice?!!

    Aww come on, it's not that hard to cook rice!

    We're talking about 'star trek' style technology and we can't even boil water without cocking it up!
  • Also, in the literatary work "The Time Machine", while traveling through time, the character sees something thats description resembles an atomic explosion. This was written before there was ever even a theory for atomic warfare. Science fiction can be non-fiction from 200 years later.
  • Yes, but this is inside a plexiglass cube.

    Ever get the impression that your life would make a good sitcom?
    Ever follow this to its logical conclusion: that your life is a sitcom?
  • Yes, the Nuclear power plant in itself is very clean, (until you have a meltdown, remember the words of Murphy). BUT the mining of uranium is very damaging to the environment. And there's also the problem of the radioactive waste you end up with for quite a long time.

    So given that
    a) You don't live near the uranium mines, or are in any way dependent of the nature surrounding it
    b) there are no more nuclear power plant accidents, ever
    c) you don't live near the place all the waste ends up at (and don't worry about all the things that can go wrong with it for the next couple of thousand years)
    then I suppose you can call nuclear power clean.

  • The gas in the current crop of fl lights is excited so as to release UV, then the UV hits a phosphorous coating on the inside of the tube. (That's why they're white) Just substitute that gas for this cold plasma, since both produce UV, and you're done. A new kind of fl light.

    You worry too much about your job. Stop it. You are not paid enough to worry.

  • Is this new? Sounds like a light bulb to me.

  • Highway here I come (Score:3)

    by ross.w ( 87751 ) <rwonderley@gm a i l . c om> on Wednesday July 26, 2000 @03:14AM (#905302) Journal
    So does this mean that the first the policeman manning the radar speed trap will see is this purple blur flying past at 200km/h?

    I want one!
  • Ever follow this to its logical conclusion: that your life is a sitcom?

    Maybe this is why Every room ive ever been in only has 3 walls, with the space where the fourth wall would be replaced with a black void out of which laughter and applause occasionally emanates, and why everythying stops for a week after a half hour of normal life, or maybe not. STOP LAUGHING VOID!

  • If you knew your (recent) history and saw the older star treks, you would know why your statement is illfounded. Just b/c something is in SF right now, doesn't mean it won't be. Most of the things thought to be pure fantasy in the original star trek is common place now. Science fiction is called just that because it does start off inthe basis of science.
  • Considering we still haven't a source of light that is even close to efficent,

    LED's are up to 55% efficient in converting electricity into light, Article here [photonicsonline.com] 55% is pretty darn good considering that say the light bulb is 5% efficient or so.

  • The surface shielding would probably work ok on cars. The trick there is that it radiates, but not on the frequency of the radar receiver, which is based on the Doppler shift to detect your speed.

    Regards, Ulli

  • Plasma shields, huh? Wouldn't it be nice if condoms were based on that principle? I mean...talking about 'bursts' of energy...
  • Right on! This marks the second of the only 2 reasons I'm proud to be an ODU grad! (The first was that Mr. Rogers spoke at graduation last summer.)

    The Divine Creatrix in a Mortal Shell that stays Crunchy in Milk
  • Wouldn't something that reflects radar energy 'like a mirror' be rather pointless as a cloaking device? Shurely better to scatter or absorb said energy.



  • An Anonymous Coward wrote:
    Dont be such a fucking dick. The chances are pretty good that someone reading SlashDot is a computer scientist, software engineer etc. We`re not all pussy little cowards, full of shit.
    Too easy... Which is why
  • Comment removed based on user account deletion
  • Yes, but this is inside a plexiglass cube.

    Great. So it should go perfectly with my Apple G4 Cube, and my Nintendo Star Cube, and my Sony GSCube....

    (If I don't see the Cubes, they won't hurt me. If I don't see the Cubes, they won't hurt me. If I don't see the Cubes....)

  • Comment removed based on user account deletion

  • Re:Space.com crap (Score:5)

    by gilroy ( 155262 ) on Wednesday July 26, 2000 @04:25AM (#905314) Homepage Journal
    Blockquoth the poster:
    Deflector shields as used in any science fiction starship warp space-time in order to deflect. Therefore EM fields or plasmas have nothing to do with it. Deflectors are more connected to the warp drive. Actually they are the same.
    Um, deflector shields as used in Star Trek, yeah. Believe it or not -- and I know this is heresy -- but there is science fiction other than Star Trek. An unconfirmed rumor even says that science fiction existed before Star Trek.
  • This makes me wish I had some moderation points to burn. "Off-Topic"

    It seems that someone always has to bring up some controvertial subject for everything. I just think thet I'm lucky and most of them get moderated to a -1, so I don't see them.

    Thanks a lump for furthering the stereotype that Texans are a bunch of unremorseful, 6-gun wielding cowboys who have nothing better to do than kill things. The fact is, if you've ever been put to sleep (for an operation, dentistry, etc.), then you've felt as much pain as any deathrow inmate put to death in Texas since the introduction of the lethal injection. And how much pain did the pregnant mother that the guy stabbed to death feel? Hmmm...


    luckman

  • I hope this isn't the same. Those shields would also cause atomic-level explosions if energy weapons hit them. I assume when thay talk about that in the article, that is not what they mean by "shielding."

    Someone with my username just has to comment on this...

  • Military uses? (Score:3)

    by Andy Dodd ( 701 ) <atd7&cornell,edu> on Wednesday July 26, 2000 @04:41AM (#905317) Homepage
    I don't see how this could be used to cloak/shield a satellite - Space is a vacuum, and hence all of the precious gas would leak. Plus this needs two large (read: radar-reflecting) plates on the sides.

    BUT - From what I recall, among other things the maximum power for a given laser is proportional to the number of excited atoms capable of radiating, i.e. the density of the gas in the case of a gas laser. With this kind of plasma-generating scheme, you would need a far smaller laser to get the same amount of power (Or conversely, you could get far more power out of currently-sized lasers).

    The patent applications don't mention the use of carbon dioxide as a gas to generate plasma from - But I'm willing to bet that unless there is some strange property of CO2 that prevents this from working (probably not, given the variety of other gases listed), CO2 has been tried.

    Carbon dioxide is one of the best gases for making high-power lasers. CO2 lasers are much more efficient than most other gas lasers, and are the easiest way for an amateur (or relative amateur, you still need glass-blowing skills...) to make a high-powered laser capable of cutting through numerous materials. (CO2 lasers are well within the range of a serious hobbyist, as opposed to some of the more exotic lasers in existence.)
  • Another good shield for space debris is aerogel, it's over 99% air so it's very light, but it is extremely strong and has elasticity so a layer of it around a spacecraft wouldn't add too much to the overall weight of the craft, but would help protect it from the smaller of the orbiting debris.

    --
  • Heavier than air flight was science fiction. Rockets to the moon were science fiction. Now, 'potions' is in the realm of fantasy, not science fiction, and I can't think of one reference to 'anti-gravity particle cannons'.

    It's your kind of thinking that made it 'common knowledge' in the past that the world was flat, and the sun revolved around the earth.
  • Either I'm misunderstanding something, or the sterilization is done by the radiation from the plasma...

    While I can't speak for the plasma device in question, I do know that many room-temperature plasmas devised for decontamination function by chemical means. The plasma forms highly reactive chemicals agents, such as oxygen free radicals, that can chemically alter target materials like sarin or VX.
  • People in texas just beleive that people who kill, should die. Very simple. Unless you are mentally retarded and didn't understand what you were doing, $murder == $death; That is the way it should be. Oh another thing, quit giving ppl 20 years on death row, they should have 2-3 years at the max
  • I wonder if this could be used as an electrical storage device? Or a generator?

    One commonly-discussed method of generating electricity is to convert solar energy to microwaves in space, then "beam" it to Earth. This plasma would absorb the microwave energy; would it then be converted into electrical potential at the electrodes?

    Even better, would it do the same thing with radioactive decay?

    Judebert
  • Well, the plasma you speak of there refers to the state of matter in which all electrons lose their bonds to nucleuses, and produce a sea of free electrons(metals only give a few electrons for free movement). Your flourecent light bulb isn't remotely capable of generating this. Another thing to note is that this kind of device isn't practical for something in relative motion.. like a car or plane.. the plasma would instantly blow off. But then again, who says somebody won't devise actual and working cold fusion out of this. ;) ...although I'd rather they work on the translucent holographic terminal :D
  • Ah yes...I've been tracking the elusive D-cup for years now...In the past, I've found a couple B-cups (Bureau of Cruel and Unusual Punishments), a C-cup (Committee for Cruel and Unusual Punishments) and several A-cups (Association for Cruel and Unusual Punishments)...but never a D-cup...I'm told they are quite a wonder to behold...I have to assume that's due to the cold plasma.

    If you have any leads on the location of D-cup, please send me their name, number and a recent photo, and I will be sure to initiate a deep probe into the matter... ;)

  • This of course begs the question "Where can I buy a Lamp with LEDs which I can put on my desk?".

    I think the answer is - nowhere.

    What I said in my first post is still true, generating light is still extremely unefficient when it comes to everyday usage.

    If plasma were more efficient I'd happily use it.

  • Thanks a lump for furthering the stereotype that Texans are a bunch of unremorseful, 6-gun wielding cowboys who have nothing better to do than kill things.

    I know humor is a difficult concept, particularly for the humor impaired, but try to follow me here:

    Texas has an execution wielding, social throwback of a presidential candidate in the form of "dub uh yuh", which they want to inflict upon the rest of the country. This raises public awareness of Texas and its social policies, which are by most people's definition very far to the right (many would say "extreme").

    Better get used to the stereotyping. The govorner of Texas and his policies have made Texas ripe for it, just as the Kansas school board made Kansas ripe for their brand of stereotyping.

    No one seriously thinks all Texans are idiots, but that won't stop any of us from mocking their more blatant absurdities, and a blood thirsty penal system coupled with draconian laws (at least one couple recently served time in Texas for living together unmarried, and at least a couple of people are serving life without parole for selling hemp of all things) is a better reason than most.

    As long as Texas insists on behaving like a collective political and social idiot, with throwback social policies remeniscent of the 19th century, the rest of us will continue to snicker.
  • "Cold plasmas can cloak satellites and spacecraft from radar view and shield against attack from
    certain kinds of energy weapons."

    Hmm -- maybe we should work on developing those Energy Weapons before we start shielding our satellites against them?
  • Hear hear. George W. Bush puts the "goober" back in "gubernatorial."
  • Well, you could have your traditional coat of metal around the craft, then a coat of plasma, then a coat of another soft material (plastic?) that will send the shock to the plasma, without it itself breaking.

  • ...how is this any different from the "plasma ball" device, which has been on the shelves of novelty shops for years, and which operates by passing an electric current through an inert gas contained within a plexiglas bulb?



    The Tyrrany Begins.... [fearbush.com]

  • Hmm... I don't know too much about the CO2 lasers, all I recall is that they're much more efficient/powerful than most others.

    If ionization of some sort is not how CO2 lasers work, what is the mechanism? They're not light-pumped, the gas is definately excited by the electrical current...

    Of course, if only a portion of the gas is ionized, it could be less efficient, since I recall the amount of amplification is proportional to the difference in the amounts of excited and ground-state ions... So there could be more ionized molecules, but even more non-ionized molecules sapping the efficiency.

    Wish I had my EE 306 notebook with me...
  • Well, sure, but I think the poster's point was that if someone merely had to develop a system that triangulated positions of objects based on radiation being emitted by this cold plasma (albeit it on a different frequency than radar), it probably wouldn't be a huge obstacle.
  • Or more accurately, if someone loses their life in a violent crime, someone else is going to lose theirs. If it happens to be the person that committed the crime, that's a bonus, but that only happens in about 50% of cases.

    --
  • http://www.theledlight.com/ they accept VISA MAstercard and American Express, lamps can run on 120VAC or on 12VDC your desk lamp is right here [theledlight.com]

  • I just think it's sad that when I introduce myself as being from Texas, the usual response is "oh, so what do you think about the death penalty?"

    Believe it or not I know how you feel. As an American who lived in Germany for a number of years (exchange student, summer intern, itinerant traveler), when I would admit to being American I was generally asked the same question (or some other stereotyped variation).

    What most Americans don't realize is that, as Texas is to the United States, so to is the United States to the rest of the world.[1]

    We'd better just develop a sense of humor about it, because everyone else certainly has. :-)

    [1] I think it is Robert Anton Wilson whom I am paraphrasing there, something about Texans being emberrassed about a (fictional) town called Bad Ass, while Americans in turn were emberrassed by Texas, while the Earth in turn was emberrassed by America.

  • How is this done without a vacuum? (Score:3)

    by BigBlockMopar ( 191202 ) on Wednesday July 26, 2000 @11:05AM (#905407) Homepage

    Quoted from article:

    Laroussi's process, specified in pending patent applications, is scalable; cold-plasma containers of virtually any size are feasible.

    Okay, I was about to poo-poo the article at this point, since it seemed like it was about neon signs.

    Not that neon signs aren't interesting or neat, it's just that when Crookes invented his first discharge tube in the late 1800s, it was news. But it isn't now.

    A neon sign; or one of those neat little high-voltage fireglobe things you can buy at The Sharper Image; argon, helium-neon and carbon dioxde lasers already use cold plasma at their cores, crystal lasers like ruby and YAG:ND use xenon strobes (cold plasma) to excite them. For that matter, the strobe lights in a dance bar or the electronic flash on your camera. Even the tiny little NE-2 and NE-2H glow lamps you can buy at Radio Shack for $2 are perfect examples of cold plasma, and as the array of devices I've listed will demonstrate, it's already very versatile and scalable.

    Changing the gases inside the device will change the colors. Neon is usually an orangy-red, argon is green, etc. Different mixes of the gases (usually noble (inert)) will result in different electrical and optical properties.

    No vacuum pumps are required, since the plasma is generated at normal atmospheric pressure.

    This is the part that finally made me stop, with some interest.

    Plasma is easily creatable both in a vacuum and at atmospheric pressure. All you really need to do is excite a gas, generally using high voltage electricity. The higher the pressure of the gas, generally the higher the voltage required to excite it actually is.

    Simply walking across a rug on a dry day and having static electricity jump from your fingertip is a wonderful display of atmospheric pressure plasma. But, like lightning, it's hot; if the spark were continuous, it would eventually burn you.

    (As one example, I've built dozens of tesla coils as a hobby, and it's fun to pull a spark off the top of them, using only your fingertip [teslasystems.com] (use proper safety precautions if you try this). That's a great example of atmospheric pressure plasma. But the problem is, it gets damned hot if it arcs for too long to any given spot on your body.)

    Consider the temperature of lightning. Fine, there's less energy involved here, so the temperature is less. But I can still pull an arc from my favorite tesla coil, using my fingertip, and then use my other hand to move pieces of paper into the arc. The paper catches fire almost immediately.

    Cold plasma exists in neon lightbulbs and numerous other devices. But, at atmospheric pressure it's quite a development. I can't wait to play with it.

  • My source is a (possibly misremembered) report on convicted murderers awaiting execution where DNA evidence was not brought forward in the trial, but DNA testing was subsequently done. Texas, it should be noted, does not allow this, but several other states do, notably Illinois, which now has a moratorium on executions.

    So my quote was a little over-generalized. I should have said that 50% of death row inmates who did not have a DNA test at the time of the trial, but did have a DNA test subsequent to conviction, are innocent.

    The fact remains that if you are falsely accused of murder, your best chance of getting off is if the real murderer left some DNA behind.

    --

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