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Rail Guns Closer to Reality 475

emtboy9 writes "Yahoo News is reporting that scientists at Sandia National Labs have created a magnetic pulse gun (rail gun) that can accelerate small aluminum plates at 34 kilometers per second, faster than the Earth travels through space. The accelerated plates strike a target after traveling only five millimeters, or less than a quarter-inch. The impact generates a shock wave -- in some cases, reaching 15 million times atmospheric pressure -- that passes through the target material turning matter into various states almost instantly (solids into liquids, liquids into gas, and even gas into plasma)."
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Rail Guns Closer to Reality

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  • by CyberBill ( 526285 ) on Wednesday June 08, 2005 @10:47PM (#12765156)
    I think the knife has a longer range than this thing.

    They should use some of the technology for cold fusion to accelerate small metal plates into things... That would be hella fun!
  • Yeehaw! (Score:5, Funny)

    by gbulmash ( 688770 ) * <semi_famousNO@SPAMyahoo.com> on Wednesday June 08, 2005 @10:48PM (#12765159) Homepage Journal
    One of them, a jug of whiskey, and a bunch of squirrels, and you got yourself a party!

  • Quake (Score:4, Funny)

    by YOystick ( 704806 ) on Wednesday June 08, 2005 @10:48PM (#12765162)
    Sounds like we have our Quake 4 in real life before it is released...
    • by TWX ( 665546 ) on Thursday June 09, 2005 @12:27AM (#12765684)
      ... if you're running around being chased by someone with one of these, chanting, "I refuse to be railed! I refuse to be railed!" repeatedly at high speed will cause them to lose their nerve and not be able to hit the broad side of a barn.

      At least, it worked that way in Quake II at LAN parties.

      Though it sometimes caused the person with the gun to drop out of the game, reboot into Linux, and start denial-of-service attacking the guy who was chanting...
  • faster, how? (Score:3, Insightful)

    by Speare ( 84249 ) on Wednesday June 08, 2005 @10:50PM (#12765177) Homepage Journal
    faster than the Earth travels through space

    Faster, measured against what frame of reference? A marker on the equator versus the center of mass? As seen from the moon? Sol? Alpha Proxima? Vega? The center of Andromeda's galactic core?

    • Please read the first linked article. Answered in second paragraph.
    • Re:faster, how? (Score:5, Informative)

      by js7a ( 579872 ) <james@COMMAbovik.org minus punct> on Wednesday June 08, 2005 @10:57PM (#12765228) Homepage Journal
      Obligatory Monty Python [htcomp.net] answer:
      Just remember that you're standing on a planet
      That's evolving
      And revolving
      At nine thousand miles an hour.
      It's orbiting at nineteen miles a second,
      so it's reckoned,
      'Round the sun that is the source of all our power.
      Now the sun, and you and me,
      and all the stars that we can see,
      Are moving at a million miles a day,
      In the outer spiral arm,
      at fourteen thousand miles an hour,
      Of a galaxy we call the Milky Way.

      Our galaxy itself contains a hundred million stars;
      It's a hundred thousand light-years side to side;
      It bulges in the middle
      sixteen thousand light-years thick,
      But out by us
      it's just three thousand light-years wide.
      We're thirty thousand light-years
      From Galactic Central Point,
      We go 'round every two hundred million years;
      And our galaxy itself is one of millions of billions
      In this amazing and expanding universe.

      Our universe itself keeps on expanding and expanding,
      In all of the directions it can whiz;
      As fast as it can go,
      that's the speed of light, you know,
      Twelve million miles a minute
      And that's the fastest speed there is.
      So remember,
      when you're feeling very small and insecure,
      How amazingly unlikely is your birth;
      And pray that there's intelligent life
      Somewhere out in space,
      'Cause there's bugger all down here on Earth!
      The Sun circles the center of our Galaxy at about 250 km/s, but the Local Group of galaxies moves at about 600 kilometers per second relative to the primordial radiation of the big bang. [nasa.gov]
    • Re:faster, how? (Score:2, Informative)

      by Russ Steffen ( 263 )
      Clearly a solar centric frame of refernce, as (1 AU * 2 * pi) / (1 year) is roughly 29,700 m/s. Which is close to, but less than, the speed quoted.
    • Faster, measured against what frame of reference? A marker on the equator versus the center of mass? As seen from the moon? Sol? Alpha Proxima? Vega? The center of Andromeda's galactic core?

      Probably the Earth's orbital speed around the Sun.

      It's far too small to be in reference to the cosmic microwave background radiation. The temperature of the CMBR varies as a dipole across the sky, with a temperature difference of 7.7 mK, because the Sun is traveling toward the Leo constellation at about 370 km/s relat
    • Re:faster, how? (Score:5, Informative)

      by OO7david ( 159677 ) on Wednesday June 08, 2005 @11:04PM (#12765283) Homepage Journal
      This is unneed pendantry. If you are not only able to list off these places as frames of referrence but also think of them in the first place, odds are you already know the answer.

      Most sensible people would take it as being the sun spinning around the sun, and leave it there.

      Since there is no pleasing you therein, the earth is more or less 149,668,992 km from the sun, which gives a circumfrence of around 940,398,011 km which over 365 days gives 29.8 km/second.

      So, there you go, it's around the sun.
    • As some have noted, the speed mentioned in this case is that of rotation about the sun. There is, however, a more universal method to measure our speed through the universe. You can do this by looking at the cosmic microwave background. Just because relativity says there's no preferred frame of reference, doesn't mean we can't choose sensible ones based on the things we see around us.
  • by cheesebikini ( 704119 ) * on Wednesday June 08, 2005 @10:50PM (#12765180)
    Plates don't liquify people. People liquify people.
  • LAQ (Live Action Quake)?
  • by Anonymous Coward on Wednesday June 08, 2005 @10:58PM (#12765238)
    "a magnetic pulse gun (rail gun) that can accelerate small aluminum plates at 34 kilometers per second"

    We were taught this at the age of 14 - what were you doing?

    Acceleration is measured in distance per second per second. 34 km/s is a velocity. So did you mean it accelerates it to 34 km/s? Or did you actually mean it accelerates at 34 km/s/s? This is /. were pedantic nerds with nothing better to do hang out, not CNN.
  • Call it a "rail launcher" and fire satellite payloads into orbit. Of course you'll have to slow down the velocity or the payload will ionize in the atmosphere upon launch. Rail launchers are more practical in a vacuum, as there is no atmosphere to interfere with hypervolocity launches. Perfect for chunking mined ore from the Moon to Earth?

    I'll bet this railgun on fires a few millimeters because they have problems with longer magnetic "barrels" exploding from the shockwave produced by an object moving "at t
  • by H_Fisher ( 808597 ) <[h_v_fisher] [at] [yahoo.com]> on Wednesday June 08, 2005 @11:07PM (#12765302)
    Imagine a Beowulf cluster of those ... no ...

    How about this: In Soviet Russia the Railgun ... ummmmm ...

    No, I can't really see any easy beneficial (which is, I guess, to say "non-military") applications for this tech, unless you can tell me how this could aid in space exploration (a means of launching spacecraft, maybe?) ... or how it might help in the advancement of processing or data storage technology...

    Wait! I've got it:

    Railgun confirms: Tank crew is dying.

    Ahh, that's more like it. Now I can sleep. :-)

  • by Dun Malg ( 230075 ) on Wednesday June 08, 2005 @11:07PM (#12765303) Homepage
    "Yahoo News is reporting that scientists at Sandia National Labs have created a magnetic pulse gun (rail gun)

    Let's hear it for reading comprehension! Between yahoo news and he submitter, we're somehow left with the impression that this is a rail gun. It's nothing of the kind. It's an implosion machine. As described in the LiveScience.com article linked: "The Z uses a short burst of intense electricity - only a few 10 billionths of a second long - that forces an ionized gas to implode." So we can stop the handwringing over the morality of this "weapon", as to use it as such would require luring the enemy into a chamber the size of a soup can and asking him to hold still while you blast him.

  • by RailGunner ( 554645 ) on Wednesday June 08, 2005 @11:10PM (#12765326) Journal
    Oh - you said RailGun. I guess my brain just saw the additional three letters.
  • If you've a plate travelling at 34 kilometers per second, how are you going to keep the peas from rolling off?

    On a serious note, this seems a useless device for most purposes. It MAY have implications for nuclear fusion, especially if used in any future space-based drives, as you can't exactly place the JET fusion laboratory in space - it's rather big.

    It MAY also have implications for subway systems built along similar lines as the Japanese Bullet Train. What I am picturing here is a subway system that

  • better link (Score:2, Informative)

    by Evil Willow ( 24876 )
    I believe this link [livescience.com] better describes what the Z Machine has to do with rails guns.
  • Wrong (Score:5, Informative)

    by brian0918 ( 638904 ) <[brian0918] [at] [gmail.com]> on Wednesday June 08, 2005 @11:16PM (#12765367)
    I work at Sandia, on this very topic. These are just flyer plate experiments, using the Z-machine's Marx Generators to isentropically accelerate small aluminum flyer plates up to high velocities, in order to better understand the behavior of metals at high pressures/densities/temperatures. This has been around for a while now. The only difference is they've recently attained these higher velocities by having the Marx Generators switch at slightly different times, rather than all at once.

    Nothing to see here, move along. (and pay no attention to the man behind the curtain)
    • Re:Wrong (Score:5, Funny)

      by dnaboy ( 569188 ) on Wednesday June 08, 2005 @11:25PM (#12765413)
      And to think I thought Marx generators only transferred energy from the bourgeoisie to the proletariat...
      • Re:Wrong (Score:5, Funny)

        by pegasustonans ( 589396 ) on Thursday June 09, 2005 @12:12AM (#12765618)
        No, Marx energies appear to transfer energy to the proleteriat, but, in fact, they only spread noise among elite intellectuals. Lenin energies then convert the noise into energy useable by the proleteriat and Stalin energies then destroy all other particles in the vicinity.
        • Are you saying that In Soviet Russia energy converts YOU?

          Anyway, nice one, you should elaborate that into a treatise on marxistic-leninistic high energy physics.

      • Re:Wrong (Score:5, Funny)

        by Pogue Mahone ( 265053 ) on Thursday June 09, 2005 @12:45AM (#12765758) Homepage
        ... and Marx energies, as any fule kno, are transferred by elementary particles called chicions, harpions, grouchions, gummions and zeppions.

        Sorry, couldn't resist. So mod me down.

    • by Richard Kirk ( 535523 ) on Thursday June 09, 2005 @03:19AM (#12766243)
      Ages ago, I used to work on this sort of thing too. Railguns as weapons were experimented with in the fifties - perhaps earlier for all I know (some Tesla fan will probably tell me he had one). You cannot make a shell go faster than the propellant's natural velocity, and you only get so many joules per gram with chemicals. To get close to this limit you have to stick the bangy stuff (tm) not only at the bottom of the barrel but at various intervals along its length, as in the V4 supergun. Driving a projectile with a magnetic field (energy but no mass, hooray) seems to offer limitless muzzle velocities. However, they have a history of throwing their breech into the ground at mach 2, rather than putting a bullet in the air when anyone over the rank of major is watching (I forget who I have to thank for this matchless description, but they worked on these, not I).

      Rail guns are unlkely to be useful for driving implosions. It would be very hard to focus a symmetric implosion with a railgun. However, you could use the same pulsed power to drive an implosion like a plasma gun. Get a thin gold tube, fill it with DT, and whack in a pulse. The pulse goes up the outside of the tube. The gold outside goes directly to plasma, stops conducting, and so the current can move inward. If you can get the shockwave reaction from the expanding plasma to approximately match the speed of the current penetration, then a nice, cylindrically symmetrical implosion should be yours, and the small burst of annoying penetrative radiation and the hair loss that goes with it.

      There is another effect - the Z-pinch - that is a bit railgun-ish. This gets a lot of mention in the Sandia webpage. People used to have great hopes for that - it was quite the thing in the seventies, when people could still use phrases like 'everlasting power from seawater' without laughing - but it is hard to get a symmetrical pinch before instabilities run riot.

      Don't take my word for it. Maybe, I'm too old, and things have moved forward since I last was in this field. Sandia is a seriously cool place, even if the people who write their webpages are a bit too keen now and then.

  • by SuperKendall ( 25149 ) * on Wednesday June 08, 2005 @11:17PM (#12765369)
    solids into liquids, liquids into gas, and even gas into plasma

    Let me guess - it then turns plasmas into solids.

    So the war of the future will be an evere more complex version of Liquid, Gas, Plasma, Solid - far more sophisticated than the three state method of old including Rock and Paper.
  • by dnaboy ( 569188 ) on Wednesday June 08, 2005 @11:19PM (#12765376)
    This put's the Flux Capacitor to shame. No where did I park that Delorean?
  • So this thing can fire stuff at many times the escape velocity of earths G pull. As soon as we can create a nuclear power plant that can launch its waste into space and have energy to spare we can switch all plants from fossil fuels to nuclear. Electricity might get a little more pricey but it'll solve that nasty C02 problem.
  • by Moiche ( 840352 ) * on Wednesday June 08, 2005 @11:20PM (#12765387)
    True, the Z Machine is not a gun -- it's a giant magnetic field generator. I guess referring to a giant magnetic field generator as a "gun" works better from a journalistic prespective.

    However -- rail guns are on the cusp of military viability. The University of Texas at Austin's Institute of Advanced Technology got 10 million dollars [utexas.edu] to develop viable rail guns. Just a month ago Janes reported [janes.com] that a prototype of the military rail gun had been tested, and that it was nearing viability.

    UT-IAT has devised a common low-cost projectile concept for both naval surface-fire support and army non line-of-sight (NLOS) engagements using an EM gun launcher. It has a flight mass of 15 kg and contains either multiple kinetic-energy flechettes or a smaller number of sub penetrators made of tungsten. In its naval guise it has a muzzle energy of 64 MJ; a muzzle velocity of 2,500 m/s; a maximum range in excess of 500 km and an impact velocity of 1,600 m/s. From a more size-constrained land tactical platform it would be expected to have a muzzle energy of 20 MJ; a muzzle velocity of 1,400 m/s and an impact velocity of 700 m/s out to ranges in excess of 100 km.
    That article really made me wish I had a Jane's subscription. Apparently, the limiting factor is the size of the capacitor -- if they can get this down than naval applications within a few years are plausible.

    Incidentally, a fun game, if you're ever bored, is to imagine what would happen to the human body if one were to hold and fire a rail gun [imdb.com](even a wimpy one that shot at a mere 1,600m/s and not at "near the speed of light"), and the law of conservation of momentum actually worked. Really! Try at parties!

    Fond wishes,

    Moiche

  • by Indianwells ( 661008 ) on Wednesday June 08, 2005 @11:22PM (#12765396)
    This is the huge tidbit that I haven't really seen discussed: "That's 50 times faster than a rifle bullet, and three times the velocity needed to escape Earth's gravitational field." A rail gun, of sufficient capacity to catapult raw materials into orbit, would be a gigantic breakthrough for the whole planet.
  • Does not. (Score:5, Informative)

    by Larthallor ( 623891 ) on Wednesday June 08, 2005 @11:22PM (#12765399)
    The article's title is extremely misleading.

    This does not bring rail guns any closer to reality, by which I mean it does not bring military rail guns any closer to reality.

    The Z-machine [sandia.gov] is a hanger-sized experimental device akin to a particle accelerator. This was an experiment designed to study extremely high pressures, such as those thought to have been important in Jovian planetary formation.

    Saying that this experiment brings rail guns closer to reality is like saying that the Large Hadron Collider (LHC) at CERN brings PPCs closer to reality.
    • Saying that this experiment brings rail guns closer to reality is like saying that the Large Hadron Collider (LHC) at CERN brings PPCs closer to reality.

      Thanks to Steve Jobs, PPCs are now closer to unreality. :(
  • On something that was being developed at White Sands Missle Range in the early 90's. A friend of mine was working on a device that accelerated a small plastic pellet (about 3mm) to hypersonic speed. They shot them at 6 inch square aluminium plates an inch thick. 3mm entrance and a 3.5 inch exit hole, I saw some targets. Very little splatter of molten metal, most seemed to be vaporized, as I was told, some did become plasma. This was part of the "star wars" space weapons. The shots were fired in a vacuum bec
  • by Goldenhawk ( 242867 ) on Wednesday June 08, 2005 @11:26PM (#12765420) Homepage
    The "small aluminum plates" are not just small... they're TINY. Others have already noted that "rail gun" is a big misstatement; the discs they're talking about here are merely 850 MICRONS thick. Let's get this thing in perspective, shall we? I know that "rail gun" makes many geeks twitch uncontrollably, but come on now, that's just karma whoring.

    Oh, and to link to a two-year-old image... with a caption of "have created" that implies it's brand new... PLEASE.

    Once again, the question must be asked: where's the moderation system for STORIES?
  • by NanoGator ( 522640 ) on Wednesday June 08, 2005 @11:31PM (#12765449) Homepage Journal
    Well railguns are neat and all, but I'm still not joining the Army until they invent the respawn point.
  • by Brad1138 ( 590148 ) <brad1138@yahoo.com> on Wednesday June 08, 2005 @11:52PM (#12765545)
    "The Constitution guarantees us the right to keep and bear rail guns!!!" Later followed by "Mommy... Johnny liquefied the cat again!"
  • The uses for this: (Score:5, Interesting)

    by Hartree ( 191324 ) on Wednesday June 08, 2005 @11:57PM (#12765567)
    The Z machine (and it's earlier configuration called PBFA 2) have been on Sandia for a long time.

    As said above, it's not a rail gun. It's not really even particularly useful for rail gun research.

    What it's for is to put small amounts of matter at tremendous temperatures and pressures.

    There are a lot of reasons to want to do this. Some of it is just basic research. i.e. What happens to matter and the laws governing it at these extreme conditions?

    Another application is fusion power research. You can compress deuturium and tritium to the point they will fuse in this machine. Though it's not made to generate power, you can learn about the details of the fusion reaction.

    That said, the main reason why this machine was built was indeed for military research. But even that is in a grey area. The US hasn't conducted a nuclear test detonation in quite some time. The reason it was able to do this is that computer simulations and other methods got good enough that they were able to be used instead of actually setting off a thermonuclear or nuclear device. Indeed, many of the Department of Energy's most powerful computers were created specifically to do that sort simulation (ASCII White, IIRC, for example).

    When running computer simulations, you have to have some way of calibrating the simulation and checking that it's getting the right answer.

    In the case of a supercomputer run simulating a car crash, you can validate it by conducting crash tests, and seeing how closely it agrees with them. Wrecking a few of a given car model is acceptable in return for it.

    But, when simulating nuclear weapons, you would often run into cases where to validate the code, you'd, at first glance, have to set one off. The conditions in a nuclear blast are so extreme, that it's difficult to put matter into that sort of state. If you're trying to maintain a test moratorium, that kinda undermines the whole idea.

    That's a big reason PBFA 2 and the follow on Z machine were made. They let DOE check the computer simulations and do basic research that would otherwise require nuclear testing. One of the biggest areas of interest is what happens when the materials in a bomb age. A lot of those weapons are getting quite old.

    They have many other basic research uses, but a big one is making it possible to keep the nuclear test moratorium.

    So, it's grey area. On the one hand, it's used for weapon research. On the other, it helps keep the test moratorium. It also has a lot of basic research uses. So, just like a supercomputer, you have to make your own decision about whether it, on the whole is a good or bad thing.
  • Bad link? (Score:4, Informative)

    by miquong ( 569138 ) on Wednesday June 08, 2005 @11:58PM (#12765573)
    Uh, was I the only one who got the wrong article on the "magnetic pulse gun" link? It should be here [livescience.com].
  • Acceleration (Score:2, Interesting)

    by eformo ( 552250 )
    Just need to do some thinking on the screen here...

    Accelrates at 34 km/s?? I thought that was a velocity. If .5 (at^2) = .005 m

    And at = 34000 m/s

    ...then that makes the time about 3e-7 s. That would be something like 11.8 billion g's.

    Not bad. Even for such a small projectile, that's an impressive impulse.

    -ex

  • Equal and Opposite (Score:3, Interesting)

    by PingPongBoy ( 303994 ) on Thursday June 09, 2005 @12:36AM (#12765725)
    For every force there is an equal and opposite reaction. Making something go from 0 to 34 in the distance of a gun must produce one major recoil.

    Now I foresee a human-carried model! Shoulder rocket launchers let the rocket go on its own - no recoil but don't stand behind the tube. Well, let's replace the burning rocket fuel with a rail gun. The rail shoots out the back in slow motion and the payload goes out the front much much faster. Right? But we're talking magnetic fields at work so....the rail can be curved!! What does that mean?

    North and south. Poles that is - double barrel shotgun. As long as both barrels shoot at once one side balances the other as long as the force should cancel at the back end.

    Just in case some entrepreneur wants to build one now, remember Equal and Opposite. The rail has to be flexed. In other words, think sawed off shotgun, and even think crossbow. The rail has to be horizontal for the most part until the ends where the ammo is turned by the electromagnetism to shoot forwards. Almost all the force should occur in the horizontal portion while the forward pointing portion doesn't give any more force than a normal gun.

    Kind of scary, espcially if the high speed projectile doesn't want to turn the corner at the end, not to mention the long lever arm will make the rails flap. Automatic fire will have to be timed.

    The only problem left? electric power for something like this must be pretty big. Kinetic energy = 1/2 mv^2 so even a small m will require a lot of car batteries. I don't see 007 running around with this weapon protecting ski bunnies while his batteries freeze.
  • by trongey ( 21550 ) on Thursday June 09, 2005 @10:01AM (#12769041) Homepage
    Heck, I can throw a rock faster than the Earth travels through space - as long as I'm at the equator, the local time is near midnight, and I'm throwing the same direction as the Earth is traveling. And don't go trying to get relativistic on me.

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