Slashdot Mirror
Rail Guns Closer to Reality
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)."
Start a happiness pandemic
Sounds like we have our Quake 4 in real life before it is released...
Plates don't liquify people. People liquify people.
This is a non-military use. They are using it to simulate conditions deep within giant planets. Also this isn't really a rail gun. For one it doesn't use rails, and the whole aim of this experiment is unrelated to rail guns.
what sig?
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.
"a magnetic pulse gun (rail gun) that can accelerate small aluminum plates at 34 kilometers per second"
/. were pedantic nerds with nothing better to do hang out, not CNN.
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
If you can't get out of the way of the guy carrying a gun bigger than my house, I think it's probably best if your slow-ass organs die with you.
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.
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.
If a job's not worth doing, it's not worth doing right.
This is nothing to do with rail guns. It's just a silly inflamatory headline (or maybe railguns are cool 'cause they're in Quake).
This is all about generating massive shockwaves to examine the properties of matter in extreme conditions (without having to heat it up to enormous temperatures).
Repton.
They say that only an experienced wizard can do the tengu shuffle.
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)
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.
"There is more worth loving than we have strength to love." - Brian Jay Stanley
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 to develop viable rail guns. Just a month ago Janes reported that a prototype of the military rail gun had been tested, and that it was nearing viability.
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 (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
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.
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 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.
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?
--Brandon / Split Infinity Music
Well railguns are neat and all, but I'm still not joining the Army until they invent the respawn point.
"Derp de derp."
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.
Uh, was I the only one who got the wrong article on the "magnetic pulse gun" link? It should be here.
Try the new Soylent Green Energy Drink!
"How is it?"
"Well, it varies from person to person."
* Olaserov is in the process of thinking up a signature.
Point them at a country and demand their oil for power generation? :o
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.
HEAR HEAR! I quite agree with the parent. This should be a discussion about the morality of lureing your enemies into soup can sized implosion chambers and asking him to hold still.
(It doesn't sound cricket, if you ask me...)
HA! I just wasted some of your bandwidth with a frivolous sig!
Powering spacecraft or launching cargo or many other things...
How am I supposed to fit a pithy, relevant quote into 120 characters?
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.
From the linked Wikipedia article: Peaceful uses of railguns There is interest in using railguns as mass drivers for space exploration and mining. They would be useful for launching bulk ores into space, particularly from low-gravity bodies such as moons and asteroids; electrically powered from solar panels, they would not require any consumables such as rocket fuels. Rail guns have been proposed for use in delivering projectiles to space, especially from bodies without atmospheres (such as the Moon). Its main competitors are coil guns and ram accelerators. Also, railguns may be used to initiate fusion reactions, by firing pellets of fusible material at each other. The impact would create immense temperatures and pressures, allowing nuclear fusion to occur. However current railguns are not yet sufficient to achieve the energies required.