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Science

Magnetic Propulsion Pellet Gun Achieves 20km/s 66

Posted by timothy from the phwippp! dept.
"Researchers at Sandia National Laboratories have used their Z Accelerator, a magnetic accelerator used in equations of state research, to accelerate pellets to speeds of about 20 km/s (about twenty times faster than a high-powered rifle bullet). Full story is here." Uses projected for this technology include simulating the impact of space junk, and, Yes, as the core of a hyper-velocity weapon.
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Magnetic Propulsion Pellet Gun Achieves 20km/s More

Magnetic Propulsion Pellet Gun Achieves 20km/s

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  • The biggest problem with this is that if I'm going to nuke some city and I think they have anti-missile defenses, I will detonate a high altitude burst to generate an EMP, disabling most defenses you might have.

    Miltary equipment is EMP hardened. I don't think this would be an option. EMPs probably serve best as a strike against civilian life and "public order".

  • ...this is one of the best ways known to get material off the moon. Required energy (and hence barrel length) is much lower, and there's no atmosphere to cause problems.

    I'm assuming you mean the Z-pinch machine, not magnetic launchers in general.

    I mean magnetic launchers in general (actually, gun-like launchers in general; magnetic just happens to be one of the more convenient forms).
  • You can access the full text here if you have a subscription. Unfortunately I don't understand their technique. Can you explain it to us ?

    Possibly. If I had a subscription :).
  • Some people much more knowledgeable then me in this area say this:

    A railgun consists of two parallel conductors, the "rails," bridged by a non-ferromagnetic conducting armature. The railgun is fired by creating a current loop that flows from some large power source, down one rail, across the slug, and back up the other rail. This current loop induces an enormous magnetic field which, in turn, pushes the armature down the rails with a force proportional to the magnitude of the current, the separation distance of the rails, and the magnetic field.

    So, while the projectile is propelled by a magnetic field in both cases, a "rail" gun uses a specific method (rails+ conductive armature) to generate the field. For more information see railgun.org [railgun.org]

  • What are you talking about? This sounds nothing like what a true rail gun is because it is nothing like what a rail gun is.
  • I think one other thing that might be fairly interesting is the fact that they could use this to send items into permanent orbit around the earth. As I learned in Physics class, all that is needed is a velocity of 8km/s and Then I can send an object into orbit around the earth (This is true because of the effects of gravity vs. the slope of the earth would maintain the orbit). So, if we can have the pellets going at 20 km/s What will they do when they can get bigger things going at this velocity?
  • Uhh, make me. I know more about aerodynamics than any three people you've ever met.

  • I don't think this would make a very good Zero-G weapon. Momentum would have to be conserved in the firing of a pellet. If you fired a small pellet at 20 km/s the person firing it would feel a pretty big recoil.

    If the pellet is 2 grams and the person firing it is about 100 kg (with equipment and the gun), then the person would have a velocity of 40 m/s in the direction opposite of the pellet. That's a heck of an acceleration for a person to undergo.

    Perhaps you could mount it on a space station, but it would still probably give the space staton a pretty good jolt.

    provolt
  • >Seriously, at 20000m/s, that would probably sound-off like a siren. Probably not suitable for hunting.

    Not really...it depends on what you are hunting. If you are going for a single large animal, this would take him down quickly before he could react to the sound. Just don't miss...and make sure of a couple things, 1) that you've got a mountain behind your shot to stop the projectile and 2) that some hunter isn't going to kick your butt for scaring all the other animals away.

    TheGeek

  • With no moving parts (other than the projectile) and not having to rely on a chemical reaction a magnetic weapon makes the perfect sniper weapon. Think about trying to fight in thick cover without being able to tell where shots are coming from (no audible sound), I shudder to think of the possibilities.

    This would also make a good weapon in a Zero-G environment, again, no chemical reaction required.

    -----

  • I wonder if they could scale this up to shoot payloads into orbit? With a relatively low trajectory they could concievably build a long enough barrel to prevent acceleration from damaging the cargo. Probably would flatten a human but maybe not hurt computer hardware, or fuel, or O2, H2O or other necessary supplies.

    -Moondog

  • Well...the barrel would have to be a mite long if the projectile were going to orbit. But what if you wanted to shoot the barrel itself into orbit, using recoil from (expendible) projectiles?
  • This would also make a good weapon in a Zero-G environment, again, no chemical reaction required.

    Actually, there was a handgun intended for use in space developed several years ago. The projectiles it fired were actually miniature rockets. The chemical reaction wasn't a problem. They were more concerned with recoil.

  • You're just realizing that you've been hit that the bullet is already 20 km away. That IS scary.
    --

  • African or European?

  • Could this shoot down incoming nukes?

    Assuming the aiming problems can be overcome, yes. Sorta. The biggest problem with this is that if I'm going to nuke some city and I think they have anti-missile defenses, I will detonate a high altitude burst to generate an EMP, disabling most defenses you might have. Then (shortly) will follow the real attack. The EMP burst can be done in low orbit, putting it probably out of the reach of most anti-missile defenses.

    There are a ton of other ways, most cheaper than that, for getting around or disabling anti-nuke defenses.

    could this become a feasable way to get pico-satelites in orbit?

    Well, maybe. Have you ever seen a meteor? That's what hapens when a gravel or sand sized particle hits the upper atmosphere at 20 - 70 km per sec. If you could shield it enough it might work. There are probably some serious engineering issues to overcome to make it practical, though.



  • Basically, this sounds like the concept of a rail gun. There was a group (military?) a while back that supposedly demoed such a weapon, but in fact rigged the target with explosives to make it "more spectacular"...
  • WARNING: NO SPECTATORS AT THE LAUNCH SITE!

    I wonder what's the environmental impact of a stream of 20km/s heavy projectiles slamming into the ground under an ascending spacecraft?

    Seriously, though, I suspect it wouldn't work. The mass of this particular electromagnetic device is horrendous (a large building) and it shoots small (a gram or two) slugs. And 20km/s is not all that high as exhaust velocities go. And, it almost certainly works by storing power off the grid in capacitors or other storage devices - the launch vehicle would have to carry some way to generate that electricity.

    In rocketry you want to take the minimum weight of fuel+reaction mass to produce the maximum exhaust momentum. If you're going to do it with electricity, an ion engine is your best bet among existing technologies.

  • With no moving parts (other than the projectile) and not having to rely on a chemical reaction a magnetic weapon makes the perfect sniper weapon. Think about trying to fight in thick cover without being able to tell where shots are coming from (no audible sound), I shudder to think of the possibilities.

    Only if they slowed it down by a factor of 100. The sound of a bullet travelling at 20km/sec would most definitely make a very loud noise. Now the fact that it travels that fast means if you have good enough scopes, you could hit someone from 10 miles away without having to worry too much about gravity drop. That, and the fact that it would be a molten chunk of metal by the time it actually hit.

  • Anon. Cow. - You are the rude asshole. Ablative technology is one of the key historical reasons for our comparative success as a space power, at least he can discuss something highly technical at an intellectual level, without resorting to the kind of histrionics, and bullcrap pseudo intellectual nonsense you tend to put in these pages just praying to get 1 insightful per week. Cut the personal crap or get out yourself. And BTW if you can't get insightful, try a little harder for funny the ... pitiful thought and understanding you put into posts is pretty ugly.
  • Sarcasm will get you nowhere jerk.
  • Anon. Cow. : At it again are we? Get a clue, and try to make some useful comment, esp. if you are going to spend 8+ hours in here/day (probably can't get a real job.... so let's insult every other person on the planet) .... So he's ultranationalist/facist to think of the applications of a system in the context of the defense of the nation which gives assholes like you the freedom to go around and slam every thoughtful person in the place??? Whats that make you? a slimebag draft dodger?, a creeping socialist? a very large oedipal complex waiting to happen? or just an asshole? On the original post: Interestingly satellites are a great application of the technology as a weapon, but you would have to lead the target... quite a bit ;-) Terrorists best use of satellites are to buy through shell corps. imagery from the new 1M class of commercial birds. So... if you shoot the terrorists bird, you also shot your own commercial bird, and despite Anon. Cow.s posts it is MNC's who have enough money and clout (against the advice of the DoD, but with the support of congress) to launch 1M recon sats (not the DoD) which are the real threat to us. Yeah the 1M stuff is of vast commercial utility, but the potential for misuse is also HUGE!!! even moreso than it is for the black agencies who control the birds now. Another use as you site is to launch small/micro satellites. Take a look at the AFRL site for MightySats and you will get the idea on the unclassified state of the practice for birds. You can make some extrapolations on the size of rail gun you might need to launch something large enough. Begins to be impractical for several reasons, but that is for another post. Suffice it to say you could launch a very small object into orbit, but at what size vs. mission is the satellite useful. mdw ;-)
  • It's not really a railgun, but for a neophyte the principle is sufficiently similar. Hopefully not too many people will rail on folks who tend to confuse the two.
  • Hello, actually, the hole in the tip of a hollow point bullet is more for weight distribution and explosive expansion than an aerodynamic effect. In a bullet, the more weight that you can move back towards the rear (thicker) part of the bullet, the better the bullets stability, that's one reason why almost all "match grade" rifle bullets are "Spitzer boat tails". Another reason for boattails is that the reduction in the base (trailing) edge of the bullet reduces drag to some extent. There is actually a "new" (about 15 years old) style of bullet called a "ballistic tip" (T.M. Nosler) that is basically a hollowpoint bullet with a hard delrin insert in the tip that makes it have the aerodynamics of a "spitzer" type bullet (most full metal jacket rifle bullets are spitzers, for the shape think 1950's era "rocket ships")but the weight distribution of a boattail hollowpoint. Also, in response to "kotetsu", almost all military electronic weapon systems are EMP shielded, that's one of the reasons why they are so damn expensive (not to mention kickbacks and other hiddens). EMP would only seriously affect the civilian populace, an M-1a tank for example can withstand EMP from a ~250 MT nuclear blast, but obviously not the blast itself. S.
  • Oh Yeah? What if I've met you and know 2 other smart types! ;)
  • ...in Riff's arsenal. [sluggy.com] You paying attention, Pete?

    Seriously, at 20000m/s, that would probably sound-off like a siren. Probably not suitable for hunting.
    Thus sprach DrQu+xum.
  • The paper mentioned in the article is Journal of Applied Physics Vol. 89, No. 3, pp. 1625-- 1633, 1 February 2001. You can access the full text here [aip.org] if you have a subscription. Unfortunately I don't understand their technique. Can you explain it to us ?
  • I can email you the PDF if you like. You can find my email address in my user info.
  • Now I've got to figure out how to get a potato gun to shoot at 20Km/sec. What's the escape velocity of a potato anyway?
  • I remember seeing a bit on a railgun on some show on the discovery channel that impressed me. I don't remember any of the specifics, but I remember them showing what a very oddly shaped projectile did to a block of steel that looked to be about 6" thick. Simply put the hole through it appeared to be roughly twice the diameter of the projectile. To me that's a very impressive display of kinetic energy.
  • I'm tired of you commie pinkos trying to tell me which guns I can and can't have. "Being necessary to the security of a free state, the right to bear arms shall not be infringed." --2nd Amendment. So, in short, you soy eating, godless, Church of Satan youth basketball Nite league playing, primitive, reefer smoking, hippy screwheads can just suck my boom stick. I'm going to hunt with whatever the hell I want, as is my God given right (at least if Moses and the NRA have anything to say about it).
  • I would imagine that at 20 km/s, you might see a nice glow. I suppose the ambient light in the day time would probably wash it out, but at night I would think it would be quite a site.
  • AFAIK, the first rail-gun was tested a few years ago...it cosisted of a turned metal tube, about 2 inches thick with a 1 cm hole bored in it, filled with water and a ball bearing, then a HUGE capacitor bank (4700 nF @ 25,00b0 volts!) was discharged through the water...BANG! The ball bearing, when fired at a lump of clay, spiral'd into it and made a huge entry wound...then they tried it with the bearing...same thing! SCARY! Don't try this one at home...that sort of capacitor bank can explode the skin off your bones a la BlipVerts from Max Headroom... EdSi.
  • No, it's not a railgun. Neither is what your talking about. That is a coilgun.

    - dave f.
  • That would be redundant. It already says the right of the people to keep and bear arms. This includes hyper-velocity railguns, AK47s, and muzzle loaders. Of course, it's not very practical to own a railgun now is it. I reckon they're a bit expensive.
  • I don't know about that... I've read that an EMP strike could take out most of our airforce, while the old USSR fighter-planes, which still used vacuum tubes, would servive to fight a post-apocolyptic war.
  • Are we surprised? When are we going to go metric, anyway?
  • Put orbiting farms/factories around Venus, can food, pop it into something like this, and BAM send it on it's way to a Mars Colony. It's been regarded as Science Fiction, but even Communcation Satellites were SciFi once long ago.

    BTW, to put something orbit, you wouldn't necessarily have to get the mass all the way there in one shot - just give it a boost. If we could develop a large magentic gun to boost the rocket on its way, we use less chemical fuel and hence can carry a larger actual payload.

  • You would have to detonate within a reasonable distance for EMP to disable anything. This system reaches 3 times escape velocity. It can hit anything within line of sight long before it got close enough to be dangerous. This thing could take out geosynchronous satelites.
  • Just in case youre serious, I think the escape velocity of all objects is the same. It doesn't depend on the charatereistics of the object. So according to the other posts, 7 miles/sec or 11 km/sec if you're a potato or a horse.
  • I have a better idea, bring a large one into space and use it to launch huge barrels of trash out of our orbit and towards the sun...or maybe not...but i think it would like to shoot mr gates into an eternal 20km/s trip through space.
  • The idea was to set up a standing pressure wave in the nose cavity, so the moving air would cool the projectile.

    I'm not sure I understand the physics of that. We cool off in air (on a hot day, or in the breeze) because the sweat evaporates from our skin, carrying off heat. Bullets don't sweat, and aren't moist. The moving air itself could carry off heat, but a normal bullet is hot because the air is moving past it fast enough to heat it by friction. I would guess then that the air in the cavity isn't leaving the cavity, and moving "slowley" inside, or vibrating (sound wave). Was that the idea?

  • Could this shoot down incoming nukes?

    could this become a feasable way to get pico-satelites in orbit? It sounds like, with further testing, they can get even acceleration that doesn't do too much damage to the pellet.

    oh, one more thing, where can I get one? :)

  • I would suspect that this rail gun would not be the thing to ignite another cold war, especially seeing as the other possible nations that could face off against the US are either allies, or have enough internal problems to deal with already.

    one more thing: technilogical superiority because you've got the fastest gun? there are many other things to consider, most of which the US does have, but this gun isn't THAT significant, I don't think.

  • ...this is one of the best ways known to get material off the moon. Required energy (and hence barrel length) is much lower, and there's no atmosphere to cause problems.
    I'm assuming you mean the Z-pinch machine, not magnetic launchers in general. What makes you think that this would have enough aiming and velocity accuracy to be able to put things where they are desired? The Princeton mass-driver appears to be much better for that, because the length of the track produces accurate aiming. You can launch much heavier and more fragile payloads, too; the long travel reduces acceleration and instantaneous power requirements.
    --
    spam spam spam spam spam spam
    No one expects the Spammish Repetition!
  • Hey I have an idea. you can use this thing like the Galeilio telescope, fire this sucker up with a chemical rocket, then lit her rip in space. The only thing I see as a problem is that there might be a power shortage.. um probably more problems...
  • That reminds me of "Jay's" cricket gun from MIB. Small and simple but boy does that little bugger have one mighty kick! See www.meninblack.com for more details.

  • We need to amend the Constitution (Score:2)

    by Anonymous Coward
    "A well-regulated Militia being necessary to the security of a free State, the right of the people to keep and bear hyper-veolcity railguns shall not be infringed."
  • I've seen a detailed proposal for a 15g man rated coilgun capable of launching 1 ton into (very) LEO. It's a 250 mile long fiberglass vacuum tube surrounded by a electromagnets. A launch takes 15GW of electrical power for about 30 seconds. The passenger rides in a crash couch (obviously at 15g) in front of a superconducting coil. For the first 25s, the thrust is forwards. For the next 5s the thrust is upwards, as the end of the gun bends up a convenient mountain. Shortly before the payload reaches them, the muzzle doors open, and the thrust is then backwards (air resistance) for the few seconds it takes to clear most of the atmosphere. Aerodynamic control surfaces on the projectile bend the orbit into an ellipse whose perigee just grazes the atmosphere, with apogee just above. Finally a very small rocket firing 45 minutes later raises the perigee to stabilize the orbit long enough for pickup by an inter-orbital shuttle.

    It seemed a completely plausible design, although the failure mode analysis was likely to be tricky.
  • I can email you the PDF if you like. You can find my email address in my user info.

    Sent a day ago, and still waiting. Was it eaten by the 'net daemons?

    If necessary, you can find my email address in the Linux Media Labs web-board (http://www.linuxmedialabs.com and hunt around).
  • Could anyone with closer ties to this project brief me on exactly what the working principles of this are? The article doesn't go into very much detail.

    Before I get six different descriptions of how railguns work - I already know how most varieties of magnetic gun work. I want to know *which* this uses.

    My best guess is something that uses the same principles as a coilgun (conducting object is repelled by the rapidly changing magnetic field), but the article still doesn't go into enough detail to confirm this.
  • Earth escape velocity is ~7 MILES/second or ~ 11.3 KILOMETERS/second. But the officials at our national lab says in the article that it is 7 KILOMETERS/second and then goes on to use that to show just how fast this thing is...

    Perhaps they meant the velocity required to attain orbit; this is about 8 km/sec.
  • The current wording if enough. After all, the founding fathers knew that weaponry would change over time.

    LK
  • Because. We're talking about a small pellet here.. to send anything of size this would have to be orders of magnitude larger. See other posters who discuss this.
  • You've got it. The idea was to decrease the mean airspeed around the nose of the projectile, by setting up a standing pressure wave (sound wave) in the cavity.

    They're not so much trying to dump heat as they are decrease the ablative forces on the tip of the projectile, and prevent the tip from heating up so much in the first place. Heat can be dumped into the body of the projectile much more rapidly than it could be dumped back into the air, but they were discovering that the heat built up so quickly in the tip, that they'd have to play some interesting games to keep the thing at a reasonable temperature.
  • How about we consider using this device (or a modified version of it) for sending materials into low Earth orbit? It would be a lot cheaper than sending them up via rocket or space shuttle. Gathering materials in low orbit isn't a major problem (assuming they aren't moving too fast.) People (or anything else living) would have to go conventionally. It'd be like airlines being able to fly your luggage there for pennies on the pound, but you costing quite a bit more.
  • This would also make a good weapon in a Zero-G environment, again, no chemical reaction required.

    No it wouldn't. You ever hear of a guy called Newton? You'd still go backwards with the equivalent force you sent the shell out with.

    Newton's third law.
  • I would imagine that at 20 km/s, anyone with infrared goggles is going to see the superheated column of air in the wake of the projectile.

    In fact, I wouldn't be suprised if surface of the projectile got hot enough to boil off and leave a residue of buring gas behind it. I doubt you'd be able to see this in the daytime...

    Of course, if I wasn't such a lazy ass I'd do some math, and find out...
  • Next thing we'll know, this thing's gonna get stolen and we'll be seeing a psycho hanging around night clubs waiting for 50+ people to get in line, then FOOM! 50+ victims in one bullet.. The fallacy of ever-improving weaponry is that the guys holding the trigger (or worse, the funding) just don't get smarter. Now I'm all for research and I can imagine this has plenty of other uses besides railguns (small spacecraft launches perhaps), but people are still people, smart, dumb, genius, psycho, whatever. Some 21st century Saddam Hussein will find a way to make us regret this evolution, it's only a matter of time.
  • A press release from a national lab gets the escape velocity of the Earth wrong?

    Earth escape velocity is ~7 MILES/second or ~ 11.3 KILOMETERS/second. But the officials at our national lab says in the article that it is 7 KILOMETERS/second and then goes on to use that to show just how fast this thing is...

    Maybe I'm being too picky but it does make them look like idiots when they don't do trivial fact checking.

  • Working principles. (Score:3)

    by Christopher Thomas ( 11717 ) on Friday March 09, 2001 @09:03AM (#379047)
    (I've been forwarded a copy of the research paper, so here's how this thing really works.)

    Ok. The Journal of Applied Physics article (Feb. 2001) does not describe this as a "gun" at all.

    The device uses the Z-machine current source to send a large amount of current through two concentric pipes that are connected at one end. Current goes up the outer pipe and down the inner one.

    This sets up a very strong magnetic field between the pipes, which pushes the two pipes apart (crushing the inner one and pushing outwards on the outer one). This is the same kind of effect that you get in a loop of wire that carries current (motor principle).

    Samples on plates are stuck to the sides of the outer pipe. Magnetic forces accelerate these plates outwards rapidly, and the samples deform. This deformation is measured, giving a lot of useful materials information (the purpose of the experiment).

    It's unclear from the article whether the plates, the samples, or neither go flying. The velocity quote is probably just the maximum velocity achieved while the pipe is expanding outwards under pressure. Letting the plates fly would give a somewhat better experiment, but would cause practical problems (they'd destroy whatever part of the machine they finally smacked into).

    Physics-wise, this works on exactly the same principles as a railgun (motor principle with DC current). It's optimized for pressure experiments, not for firing projectiles; you could probably build a railgun that was more efficient at the second task.

    Inductive effects do occur (this is a short current pulse), but are considered a source of error in the experiment, and so presumably aren't the dominant effect.

  • Launching things into orbit. (Score:3)

    by Christopher Thomas ( 11717 ) on Wednesday March 07, 2001 @01:19PM (#379048)
    I wonder if they could scale this up to shoot payloads into orbit? With a relatively low trajectory they could concievably build a long enough barrel to prevent acceleration from damaging the cargo. Probably would flatten a human but maybe not hurt computer hardware, or fuel, or O2, H2O or other necessary supplies.

    This or any of a number of other magnetic cannon techniques could work, or even a compressed gas gun (like the "Super Gun" from years ago).

    The problems are twofold:

    • Your barrel has to be stupidly long, making your gun extremely expensive.

      To reach orbit, you need an energy of about 30 MJ/kg (for a velocity of about 8 km/sec). Energy is force (mass times acceleration) times distance, so for a given acceleration, you can calculate the barrel length of the gun required. For a 3g accelerator for humans, you get a gun 1000 km long. If you can overcome the engineering problems and build a gun that accelerates cargo at *3000* gravities... you still have a gun 1 km long (about 0.62 miles, if you were wondering).

      This can be built, but it's *expensive*. There would have to be a very strong incentive to build it, and amortizing the cost of the gun will raise your launch costs by quite a bit.

    • The atmosphere will cause big problems.

      You'll notice that the experiment discussed in the article was done in vacuum.

      Your gun will have to have an enclosed barrel (even if it's a magnetic gun). Otherwise, the mach-16 sonic boom will tear the firing coils off their mountings or otherwise harm the gun's structure.

      Your gun (and anything near it!) is still going to have a lot of wear from the effects of a hypersonic projectile smacking into the atmosphere on leaving its muzzle.

      Lastly, your projectile is going to have to have shielding around it to keep it from burning up while leaving the atmosphere. This will add weight to the projectile, and require a higher muzzle velocity (because the projectile will slow down).

      All of these problems are manageable, but they increase the cost of the gun and the cost per kilogram of payload even more.


    In summary, yes, we can scale up this and other guns like it; however, they're a royal pain to build and use, and there isn't enough demand at present to make them practical.

    OTOH, this is one of the best ways known to get material off the moon. Required energy (and hence barrel length) is much lower, and there's no atmosphere to cause problems.
  • The range on this thing wouldn't be stupendous, I bet. Particularly with small particles (ones with a low kinetic energy/cross sectional area) aerodynamic drag is going to really kill the velocity quickly. At these velocities, you have to play fun games with the shape of the projectile to cool the thing, so it doesn't just ablate away.

    My aerodynamics prof at UT Austin was working on a railgun project for the Army at Balcones a couple years ago. He brought in some videos of the experiments they did with projectile shaping. Basically, the idea was to make a circular indentation in the front of the projectile (think like a hollow-point bullet) whose depth was tuned to the expected velocity of the projectile. (insert obscenely complex mathematics here) The idea was to set up a standing pressure wave in the nose cavity, so the moving air would cool the projectile. The tests I saw were with a plastic blank, but the full-on projectiles were going to be 2" diameter tungsten rods. I can't even really imagine enough heat to ablate a tungsten rod, but damn if that's not just what happens at those velocities.

    The computer models I watched of these rods impacting armor plate were amazing. It looks just like those slo-mo milk drop photos, except instead of milk it's molten steel. Wow.

  • Re:It's about time some money got spent on defense (Score:3)

    by Ig0r ( 154739 ) on Wednesday March 07, 2001 @11:29AM (#379050)
    About time?!

    What percent of the federal budget do you think is spent on 'defense'?

    --

  • 20 million amps? (Score:4)

    by slickwillie ( 34689 ) on Wednesday March 07, 2001 @07:36PM (#379051)
    Now I know why there is an energy crisis in California.

    BTW, this DOESN'T sound like a rail gun. A rail gun uses a series of magnets to propel a projectile. This sounds like it uses one rapidly expanding magnetic field.

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