Slashdot Mirror


Battlefield Lasers

KeyShark writes: "An article on FoxNews describes how front-line troops soon will be protected by battlefield lasers designed to shoot down rockets, artillery shells and even mortars."

18 of 688 comments (clear)

  1. hard part by simetra · · Score: 4, Funny

    The hard part will be making the lasers make a cool zapping noise like on Star Wars.

    --

    "Would it kill you to put down the toilet seat?" -- Maya Angelou
    1. Re:hard part by isomeme · · Score: 5, Insightful

      Hey, any laser powerful enough to damage or divert artillery shells is going to make *thunder* when it fires. It's the same effect as lightning -- superheated air shocks away from the beam, then slams back in when the beam cuts off. That's way more impressive than zzzzt-whoosh-bleem, far as I'm concerned.

      --
      When all you have is a hammer, everything looks like a skull.
  2. Or, just use pen lasers by chancycat · · Score: 5, Funny
    Think about it:

    Eash of our troups has a pen laser and two house cats.


    1) Release cats between you and the enemy.

    2) Direct cats toward enemy trenches with pen light. Watch enemy freak out.

    --
    Evan - needs to hit preview before submitting
  3. Also under development: by Nindalf · · Score: 5, Funny

    Revolutionary new developments in extremely shiny rockets, artillery shells, and even mortars.

    1. Re:Also under development: by Nindalf · · Score: 4, Interesting

      Mirror coating, etc. doesn't make a difference.

      To be blunt, this is wrong. I do agree, however, that just polishing up a stainless steel shell until you can shave in front of it probably won't make enough difference. Most mirrors don't reflect nearly enough light.

      On the other hand, such powerful lasers are hard to make and very expensive. It would be tempting to make them just barely strong enough to work against existing designs which have no defense against such countermeasures. If a spinning (or randomly tumbling), mirrored shell, can cut down the rate of heating by something like 30%, and there's some extra heat-shielding inside, it might be enough to survive.

      All kidding aside, you also can't rule out, as I said, revolutionary new developments in mirrored armor. I mean, if there was no way to deflect the beam, there would be no way to generate or aim it!

      BTW, Tom Clancy is a novelist, not a physicist. His entire livelihood is sounding plausible about things he doesn't really understand.

      Besides, in the battle between bigger armor and bigger guns, the guns always win eventually.

      Ah, but which is which? This is an odd historical precedent to apply in favor of a defense mechanism.

  4. Is it really so difficult? by djrogers · · Score: 5, Funny

    All I asked for were some frickin' laser beams!

    --
    Think outside the... Hey, where'd the friggin' box go?
  5. Govexec.com says by hether · · Score: 4, Insightful

    http://www.govexec.com/dailyfed/0401/042301nj.htm

    that "These lasers also have a drawback--their energy comes from large tanks of industrial chemicals, which have to be mixed until they glow, like an outsize high-school science project. And they are so bulky that one weapon fills a large aircraft, or a small building. "

    Does this jive with the fox news article?

    --

    Most people would die sooner than think; in fact, they do.
  6. For a more technical overview... by mbessey · · Score: 4, Informative
    ...of specifically the solid-state high-power laser, take a look at Lawrence Livermore's page on the project:

    http://lasers.llnl.gov/lst/helstf.html

  7. This raises some frightening questions by joshjs · · Score: 4, Interesting


    What's to stop them from using these things on people? They have amazingly accurate targeting systems and they're cheap to fire (article says 25 cents (maybe dollars, I forget...) per shot.

    So what's to keep the defense dept. from using these things for assassinations, or ground warfare?

    Would that be cruel and unusual?

    Here's a question: is there a "right of the people" to keep and bear these? The idea doesn't sound assuring, I must say: what kind of signature would it leave. Bullets can be tracked, but this -- would there even be a body left?

    I'm not trying to complain or predict horrors, because I'm all about the advance of tech. I just want to know a little more about this kind of thing.

    Also: it's eerie that the article only mentions uses of these for defense, and not for attack, covert (which I think is a promising potential use for this technology) or otherwise. Just considering it's a time of "war" and all.

    1. Re:This raises some frightening questions by Anonymous+DWord · · Score: 5, Informative

      There's an international treaty that the US has actually signed (wonder of wonders!) against using lasers on people. I tend to doubt it'll be followed in practice though, when "our" forces are involved.

      --
      "If he thinks he can hide and run from the United States and our allies, he's sorely mistaken." Bush on bin Laden
  8. More handy links by mbessey · · Score: 4, Interesting
    Most of these haven't been updated in a while, though...

    The US Army's HEL sites:

    http://www.smdc.army.mil/FactSheets/THEL.html

    http://www.smdc.army.mil/FactSheets/HELSTF.html
    TRW's contribution:

    http://www.trw.com/thel

    -Mark

  9. MIRACL by sheetsda · · Score: 5, Funny
    The granddaddy of all the laser weapons is the Mid-Infrared Advanced Chemical Laser, known as MIRACL, which fills a large building and its surroundings at the test site.

    Nice acronym. Now every time I see a picture of someone standing in a beam of divine light from the sky I'm going to get a mental picture of him bursting into flames and melting.

  10. More bias/social engineering from the hawks at FOX by Sleepy · · Score: 4, Troll

    This wasn't news, it was a *commercial*.

    It's pretty simple:
    1) a chunk of your tax dollars goes to pork-barrel arms projects (that don't work).
    2) Said arms dealer profits.
    3) Arms dealer "lobbies" for more congressional pork.

    In the "old days" of the early 90's, #3 meant simply bribing the congressmen via his campaign "war chest". While that made effective lobbying, today we have Rupert Murdoch's lobbying group, "Fox" television. It's sad to have seen the name of a once-great US media company bought out by a "naturalized" foreigner whose intentions are simply to influence American politics.

    In other words, this is a LOBBYING EFFORT to raise taxes for yet another military boondoggle. It's just pretend news.

    Congress is already leery of "star wars" (the SDI kind), seeing how there is so much pressure to deploy the damn thing, when star wars misses 3 out of 6 targets in *lab* conditions.

    Now they want the same unproven technology on the ground. Fox runs nothing but editorials against "government pork" and "big government" EXCEPT when it serves the war hawks or their stock portfolio.

    Remember, these are the same maggots who ran "investigative reporting" how the USA supposedly never landed on the moon. Note this story ran JUST BEFORE renewed calls in Congress to both cut NASA funding (to make them less effective), AND to privatize NASA altogether.

    George Orwell was wrong. In the future we will be controlled by mindless, hypnosis-inducing corporate-sponsored "information", news, etc.

  11. Re:Not too hard. by Knobby · · Score: 5, Informative

    Am i forgetting something here?

    Yep.. You're missing density variations and laser induced heating of the local atmosphere. Both of which will degrade the power of your beam, and complicate aiming the device. The Air Forces Airborne laser program attempted to solve these using a pair of low power lasers to sample the atmosphere and track the object. Given the information from the low power lasers, the optics for the primary laser could be corrected to hit the target. I'm not sure they ever got the system to work, but I seem to recall the power of the beam to be roughly equivilent to 30 ocyacetylin (sp?) torches focused on a single point.. There was a lot of speculation in the articles I read, suggesting that the laser power would be attenuated by some staggering amount by the atmosphere, and the chances for success were considered minimal by some of the scientists working on the project..

  12. What about good old reflection? by Remote · · Score: 4, Insightful

    Ok, the system was reported to be able to melt down Katyushas. My bet would be that those were painted gray or olive green. What if one chrome-plates the damn thing? Would that make the rocket (or a shell, or a racing pigeon!) laser-proof? Would someone in the know tell me why this wouldnt be a protection?

  13. Treaties by Convergence · · Score: 5, Interesting

    Weapons treaties are there to be ignored by a the parties signing them.

    THink of it, you sign a treat to (say) not research biological weapons for offensive purposes, say, like Russia did. Then, you secretly violate the treaty, and now you have weapon the other side doesn't have. Its happened in the past, it'll happen in the future.

    Weapons treaties only penalize the honest countries. Dishonest countries won't care. At least we actually do (for the most part) obey our treaties.

  14. There's LOTS of stuff you can burn... by Ungrounded+Lightning · · Score: 5, Interesting
    "These lasers also have a drawback--their energy comes from large tanks of industrial chemicals, which have to be mixed until they glow, like an outsize high-school science project. And they are so bulky that one weapon fills a large aircraft, or a small building. "

    Does this jive with the fox news article?


    Yes. But it doesn't tell the whole story.

    The lasers they're talking about are spinoffs of the Star Wars missile defense system. They had to get a LOT of energy into a beam quickly, to shoot down missiles while still in space, or to bounce off a mirror in space to get them on their way up. One shot, one dead nuke, so cost wasn't much of an object.

    Neither was portability: You had either a fortified underground bunker as big as you wanted, or a satellite in zero-G.

    So they did something very strong, effective, big, and expensive.

    But lasers are EASY. Excluding superradiants (which are easier, if you've got the materials) all you need is a couple of well-alligned mirrors, one of 'em slightly leaky, with an "inverted population amplification light amplification medium" between them.

    For "inverted population light amplification medium" read "smoke from a fire".

    The medium must have the following characteristics:

    It has a state transistion (an "excited state", a "ground state" or less-excited state, and an allowed transition between them) with an energy difference corresponding to a usefully energetic photon.

    It must have significantly more of its atoms or molecules in the more-excited state than in the less-excited state. (This is the "inverted population" part.)

    It must have ENOUGH of a surplus of more-excited particles to produce a usable amount of power if you extracted the energy difference by de-exciting enough that you're down to 50/50 (or de-exciting them all if there's a further transition that drains the less-excited state).

    It must be transparent and reasonably uniform (i.e. non-distorting) at the light frequency corresponding to the state transition.

    When you burn darn near ANYTHING the resulting molecules start out excited. If they meet the other criteria you've got a suitable medium for a chemically-pumped laser.

    Burn a suitable fuel in a long, thin, rocket flame and run the exhaust at right angles between the pair of mirrors. You'll have a laser beam coming out as long as the flame lasts. Chose the right material and a large fraction of what would have been the heat of combustion ends up in the laser beam.

    Now there are some fancy and deadly fuels (fluorine comes to mind) that make an exhaust where the bulk of the energy can be extracted by a single transition. This is nice and efficient. And you don't want to be ANYWHERE NEAR them when in use, due to the toxic nature of the exhaust. So if you're going to be shooting down a nuke from a fort in the desert they're fine.

    But there are LOTS of others that are simpler, and might be more suitable for a battlefield.

    I expect that eventually we'll see a chemically-pumped laser rifle or pistol, about the same size as a normal rifle or pistol, with an optical cavity where the barrel would be, powered by cartridges of solid fuel that are fed by a mechanism similar to the one that feeds cartridges consisting of case/primer/powder/bullet.

    --
    Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
  15. "FoxNews, The Most Biased Name in News" - FAIR.org by Kraft · · Score: 4, Troll

    Thank you thank you thank you for pointing that out.

    I have a grudge with Fox, and this article didn't help either. I totally avoid it for any "War on Terror" news.

    Recently Fair And Accuracy in Reporting wrote a special report titled:
    The Most Biased Name in News: Fox News Channel's extraordinary right-wing tilt (note that's it's written before sep.11).

    Now that I am at it, CNN is no saint either, that's for sure. I feel like screaming BIASED! at the TV when I see Lou Dobbs et.al. wearing Stars and Stripes on their suit. All reporting is "WE need to fight this enemy...", "Protect OUR country...". So much for International.

    No thank you, I will stick with:
    - guerrillanews
    - mediachannel
    - and for TV, EuroNews or even BBC

    --

    -Kraft
    Live and let live