The Jet Fighter Laser Cannon

fahrbot-bot sends in a Register piece about DARPA issuing the penultimate contract for what is intended to be a jet-mounted laser cannon. The Reg outdoes itself in a BOTEC involving downsizing to shark scale. "The US military will shortly issue a brace of contracts for 'refrigerator sized' laser blaster cannons. One of the deals will see a full-power ground prototype built which will be the final stage prior to America's first raygun-equipped jet fighter. ... If it scales down far enough, this would seem to put handheld HELL-guns within an order of magnitude of the striking power offered by conventional small-arms. A 9mm pistol bullet has about 750 joules muzzle energy: a 5kg portable HELL-ray weapon would put out this much energy in a blast less than a second long. ... A dolphin can carry a human being weighing up to 100kg along for a ride. A thoroughbred shark in good training can surely match this. Thus, we seem to be looking at practicable head-[laser] output in the 20-kilowatt range."

Comments

Tags

[Shadyman]

Ok, I see the obligatory "sharks" tag, but what about the "pewpewpew" tag?

Re:Tags

[nlawalker]

I see your uid, but you get an obligatory "you must be new here". All aircraft-mounted laser weaponry stories must be tagged with "realgenius", "ihatepopcorn" or some variant thereof.

Re:Tags

[Garridan]

Ok, what we have here is:

Laser Fight: Sharks vs. Jets

Yes, I think a "pewpewpew" tag is obligatory.

Re:Tags

[Haxzaw]

My guess is it is supposed to be the sound the laser gun will make, like the Enterprise firing a photon torpedo.

Re:Tags

[kaizokuace]

is it like a football laser fight?

Re:Tags

[syousef]

Ok, I see the obligatory "sharks" tag, but what about the "pewpewpew" tag?

Why? Because the story stinks? Peeewwwwwwww!

Re:Tags

[Have Brain Will Rent]

And what the heck are thoroughbred sharks? What? Like a mongrel shark isn't good enough to carry a laser now? Damn discrimination everywhere.

Re:Tags

[Genda]

Hmmmm... Sharks vs. Jets... I presume this implies a "Westside Story" tag as well...

Re:Tags

[mcrbids]

Dang. I was going to pipe in with some popcorn related joke or something, but it's no fun when you aren't first to the punch-line...

Re:Tags

[CarpetShark]

And what the heck are thoroughbred sharks?

They'll be the ones the navy feeds LSD to.

Re:Tags

[mcgrew]

Hey, don't bring religion into this!

Re:Tags

[mcgrew]

You jest, but I see far less discrimination than in my youth. Hell, afaik I'm completely from European roots and have hazel eyes and brown hair, but I've been called both "bro" and "nigger" by young black guys (whodathunkit). The world is getting better, not worse.

Re:Tags

[elrous0]

And what has become of /. when this gets no "popcorn" tag? And you call yourselves nerds?!?!?

Re:Tags

[Lord Pillage]

Well it depends. If we're up north with a slab of ice, I'd put my money on the Sharks. Otherwise, the Jets would crush them.

9mm?

[Shakrai]

Why not compare it to a real handgun caliber? ;)

Re:9mm?

[TheKidWho]

Fail.

From you're own link, the bullet performance shows 702J as the highest energy output.

Re:9mm?

[Shakrai]

Negligible benefit? Then why have so many police agencies abandoned the 9mm in favor of other calibers? Why did the Federal government settle on the .357 SIG (for the USSS) and .40S&W (for the FBI) instead of the cheaper and more commonly available 9mm? Most law enforcement agencies don't issue .45s but the fact that they've abandoned the 9mm in such large numbers ought to tell you something.

Personally, I'm not married to the .45. I have one, because I love the 1911 platform, but I'd also trust my life to a .40S&W, .357 magnum or 10mm. I've just read about too many spectacular failures of the 9mm to be willing to trust my life to it. To each their own though.

Re:9mm?

[kalirion]

Really? Compare the USP and the Glock pistols in Counter-Strike - which one does more damage?

Re:9mm?

[Lonewolf666]

Those people are not up to date. The .50 Action Express (http://en.wikipedia.org/wiki/.50_AE) is a much better gun-penis ;-)

Re:9mm?

[Shakrai]

The .50 AE is a waste of money. It's useless for self-defense (too much recoil and over-penetration) and if handgun hunting is really your thing there are better and more powerful cartridges on the market.

Re:9mm?

[Ethanol-fueled]

Then why have so many police agencies abandoned the 9mm in favor of other calibers?

Because you can get hit with a 9mil round and still keep running. Not so much with the .40. From what I understand DHS also switched to the .357 and the .40.

Re:9mm?

[TheKidWho]

You're/your before I get castrated by the grammar Nazis.

Re:9mm?

[geekoid]

the knife:

http://www.youtube.com/watch?v=cudCajMNRM0&feature=player_embedded

Re:9mm?

[Shakrai]

Yeah, the Air Marshals use the .357 SIG, as does the Secret Service. The Coast Guard adopted it as well. I believe the FBI is still using the .40 S&W but I could be mistaken.

The 9mm is a joke. It's even worse for the military because they aren't allowed to use expanding ammunition. Buddy of mine who deployed in Iraq tells a story of an insurgent whom wasn't stopped in spite of the fact that he had absorbed no less than six center of mass hits from the M9. Makes you question the wisdom of the military abandoning the Model 1911, doesn't it?

Re:9mm?

[Shakrai]

WTF does that have to do with anything?

Re:9mm?

[confused one]

If you feel you're going to need a .50 cal, then use a 20ga shotgun (0.620" bore) loaded with slugs. At least then you'll be able to control the recoil. You will be able fire it faster. Maybe reload it faster. Use it as an effective club when you're out of ammo. And you'll be able to afford the ammo.

Re:9mm?

[Anonymous Coward]

As a matter of fact, yes, they sometimes do. But don't let facts bother you, by all means continue living in your childish fantasy world where all one's chosen profession dictates every aspect of their personality.

Re:9mm?

[bertoelcon]

I prefer a pistol grip on a shortened 12 gauge with buckshot myself.

Re:9mm?

[Shakrai]

Well yeah, but those are rather hard to wear on your person when you visit the grocery store ;)

Re:9mm?

[Trepidity]

I'd be interested in numbers on those outcomes. Did police agencies who switched from 9mm to a larger caliber have measurably better outcomes, under some relevant measure (controlling for other variables, of course), after the switch than before? Do agencies in comparable situations that use different calibers have anything measurably different about their outcomes?

Re:9mm?

[Rei]

Well, it's all irrelevant anyways, because if you want to compare damage, duration is just as important as energy. A one second laser pulse is nothing like a millisecond bullet impact. And furthermore, how the heck are you going to keep the beam on a single spot for a whole second, esp. at any sort of distance? Perhaps if you're talking stationary armor or something and you've got a tripod...

One of these cells may leave a nasty burn or blind you, but it's not going to kill you.

(Speaking of blinding: if serious lethal laser weapons ever do become common, that's going to be a new horror of war. Even the tangential reflections from any laser powerful enough to rapidly kill a person -- or worse, cut through armor -- are going to do catastrophic eye damage to everyone around them.)

Re:9mm?

[EnglishTim]

9mm is obviously better because it's Metric.

Re:9mm?

[sexconker]

Perhaps you should go fuck yourself and the horse you rode in on :) Might be more enjoyable than the plastic bag and pillow that you usually use.

Mod parent up insightful.
(About what Hognoxious should do, not about which is more enjoyable. I have no experience with bags or pillows or horses.)

Re:9mm?

[Kral_Blbec]

If you feel you're going to need a .50 cal, then grow up

there, fixed it for you. 9mm is my caliber of choice. Where it hits is more important than how big it is, and with 9mm you get a LOT more practice.

Re:9mm?

[NoYob]

9mm just punches holes: no stopping power. You need at least a .40 to take someone down.

That was stupid of the military to dump the .45ACP for the 9mm.

--Father in Law, Ex - Army shooting and sniper trainer.

Re:9mm?

[sco08y]

Care to share your psychological theory about why people post hateful remarks on the Internet?

Re:9mm?

[Shakrai]

Easier said than done when the adrenaline is pumping and your fight or flight response kicks in. The instructor who taught the CCW classes that I've taken said that if your regular group size is 2" across on the range it will measure 10" or more when the chips are down and you are fighting for your life.

There's a reason why even the professionals are trained to shoot CoM first.

Re:9mm?

[Lehk228]

I don't know, why don't you?

Re:9mm?

[socz]

But it doesn't have the look of the desert eagle! That is one bad ass looking gun... also one of the most used in movies no doubt to it's very aggressive look! I don't own a gun, but if I did it would be a DE, .50 AE with extended barrel. Not sure what length though.

My buddy said many years ago, "why would I want to carry that heavy POS? Look, i can fit a shotgun in my pants and most people can't tell. But you try walking with that thing in your pants and you can't because it's too heavy. (Proceeds to show me how a short barrel shotgun (mossberg) fit in his pants)."

My reply was, well, if the.50 hits you, it's pretty much over Vs a 9mm or almost anything smaller. As well as being able to go through walls and what not. But at close range the shotgun will most definitely win. But, as he put it, sometimes, for the use of some people, it's not about actually using but rather the threat of using. So you might have a shotgun out, but you wouldn't want to risk it against the .50.

Then again, I would go for the gold or chrome plated cause it's all about the intimidation and hey look at my big ass hand canon factor! :P

Re:9mm?

[Crimson Wing]

The catch there is that there's a large gap between the range at which one can reliably connect with a shot aimed at center mass and the range at which one can do the same with a shot at the head. And if a hostile target is within the latter range, and closing, few people will remain calm enough to aim properly.

Re:9mm?

[bonze]

Huh, but the .454 Casull is endorsed by Alucard.

Re:9mm?

[frosty_tsm]

Well, it's all irrelevant anyways, because if you want to compare damage, duration is just as important as energy. A one second laser pulse is nothing like a millisecond bullet impact. And furthermore, how the heck are you going to keep the beam on a single spot for a whole second, esp. at any sort of distance? Perhaps if you're talking stationary armor or something and you've got a tripod...

One of these cells may leave a nasty burn or blind you, but it's not going to kill you.

(Speaking of blinding: if serious lethal laser weapons ever do become common, that's going to be a new horror of war. Even the tangential reflections from any laser powerful enough to rapidly kill a person -- or worse, cut through armor -- are going to do catastrophic eye damage to everyone around them.)

Two thoughts:

1. To avoid eye damage, I bet soldiers will be issued goggles for protection.

2. Lasers have a very small area of effect. Even if you fired one of these guns and pierced the enemy soldier's body, the blood loss will be small if any due to 1) the small size and 2) the bleed-stopping effect of the heat. A hit on the heart might cause internal bleeding, but I can't imagine even a hit on lungs having much of a take-down effect. On the other hand, if you see bullets fired through blocks of clay or ballistics jell you see the damage area is far large than the bullet due to the impact and the spinning of the bullet.

Re:9mm?

[Shakrai]

It's hard to come across good data for stopping power because every shooting scenario is obviously different. What is known is that there have been a lot more failures of the 9mm to stop an aggressor than there have been of the .45, .40 or .357. Here in NYS the State Troopers abandoned the 9mm in favor of the .45 GAP (Glock's knock off of the .45 ACP) after a Trooper was killed by some scumbag whom he had repeatedly shot but whom wasn't stopped.

Don't get me wrong -- you can find a failure to stop for every caliber on the market. One of the ones that sticks out in my mind involved a South Carolina State Trooper. He landed five center of mass hits on his aggressor with a .357 magnum and was then killed by a .22 derringer of all things. His attacker lived. Just plain rotten luck. No caliber is a sure thing -- but the 9mm stands out as having more failures to stop than most.

Most knowledgeable people will tell you to carry the most powerful caliber that you can shoot accurately and have a decent follow-up time with. The .45 does you no good if it takes you five seconds to reacquire the sights after the first shot. Most shooters are capable of handling something bigger/more powerful than the 9mm though. The .40 S&W seems to be the current favorite among law enforcement agencies.

Re:9mm?

[MBGMorden]

And furthermore, how the heck are you going to keep the beam on a single spot for a whole second, esp. at any sort of distance?

You wouldn't want to - and that's the whole point. If you kept a laser beam on the same spot for a plane for a second you'd get a nice small pinhole through the craft - that might take it out if in the right spot, but isn't likely too.

Instead, you turn on a laser of any wattage high enough to pierce the hull - then let the target's own momentum drag itself across the beam cutting a line down the structure.

A single hole through a wing ain't so great. Slicing the wing off with a 1-2 second pulse works much better.

Re:9mm?

[MBGMorden]

So are most .45ACP's and 9mm's though. At least for those of us who don't wish to design their entire wardrobe and lifestyle around carrying. I mean I'm all for concealed carry laws and such, and to each his own, but it seems too many people let the gun influence them too much. Wearing a heavy coat in the summer just so I can conceal a 1911 is the point when carrying is more hindrance than it's worth - I'll take my chances if that was my only option.

As such when I carry I carry a little Kel-tec .380. Fire's the same projectile as the 9mm Luger (less power charge behind it though, but still decent energy delivery) but it fits nicely in my front pocket with no wardrobe adjustments.

Re:9mm?

[flydude18]

Comparing it to handgun calibers seems pretty pointless, seeing how the article is about a laser that's to be mounted on fighter jets. You know, to replace this thing.

Re:9mm?

[Shakrai]

and with 9mm you get a LOT more practice.

If that's your metric then the .22LR is the best self-defense round.

Where it hits is more important than how big it is

Don't dismiss the size of the hole. The only surefire way to stop a determined aggressor is to destroy the central nervous system or to cause enough blood loss that they can't continue attacking you. A larger wound channel is going to accelerate the rate of blood loss and stop them faster than a smaller one.

Choose the most powerful round that you can shoot accurately. Most people can manage to do so with something more powerful than the 9mm.

Re:9mm?

[photon317]

Even more fail, back in TFA, is that there's absolutely no bases for comparing the energy (in J) of conventional small arms fire to the energy of a 1-second laser pulse. Even when comparing two conventional cartridges, J is a weak comparator, as there are many other more important standard measurements in gelatin that raw J does not infer (such as penetration depth, the profile of the wound channel, and in rifle calibers hydrostatic shock effects). The J's of energy dumped by a laser of the course of 1 second will have a completely different type of effect on the human body than the Js from a conventional bullet.

Re:9mm?

[Shakrai]

It's not an 'appeal to authority'. It's an appeal to professional studies of the issue at hand. The FBI spent millions of dollars investigating the issue of stopping power after the Miami shootout. After all of their research they opted not to select the 9mm as a carry weapon for their personnel. What does that suggest to you?

Re:9mm?

[photon317]

Mostly they did it for stupid reasons, if you really read up the informed sources on these things.

The truth is 9mm is every bit as capable across a broad range of handgun scenarios that LE are likely to face as any other reasonable semi-auto cartridge (.40, .45, .357Sig), assuming one makes the correct ammo choices (on that point I'll concede: correct ammo choices matter more in 9mm than they do in .45, but not by a huge amount). Add to that the 9mm's lower perceived recoil, faster followup shots, and larger round counts in the same physical magazine size, and the 9mm looks quite good. That's why most of the world's militaries, including the US, and all NATO and UN types, have standardized on 9mm. Operator skill and unpredictable situational factors will make far more difference than any you can find between the calibers in any case, so the whole argument is really just a religious debate.

Back to the point about the fed branches though. The FBI originally tested the 10mm Auto to replace 9mm. The 10mm Auto actually *is* arguably a superior round to everything mentioned above in terms of "incapacitate in as few shots as possible". That is, of course, if you're willing to make the tradeoffs in mag capacity, ammo/gun weight, and extreme recoil. Once they had mostly settled on 10mm Auto, they did some testing with agents, and found that many (mostly females - it's in the reports, I'm not trying to be sexist here) simply could not handle the 10mm recoil and would not use it. So S&W came up with a "10mm short", which became the .40 we know today, as a compromise package that would be "like the 10mm (at least in diameter)" but lower recoil. It's basically a 10mm Auto that's been cut down with a lot less powder behind it.

And like all irrational "compromise" solutions of that sort, it's a complete practical failure. All objective testing indicates at best it's on par with its 9mm and .45 cousins (certainly nothing like the original 10mm), and arguably you're better off with one of those two. It just takes generations for people to admit those kinds of mistakes and move past them when you've got industry giants and federal government branches involved.

Re:9mm?

[photon317]

Unfortunately your father in law is misinformed. It's common for even people with a great deal of field experience to be misinformed about these things. Ask a qualified ballistics expert and you'll find the diameter of the entrance wound is a relatively small factor. Proper bullet design, and proper consideration of the correct weight to use for the platform in question, are much bigger factors. A 147gr Winchester RA-9T ("LE" ammo, but civilians can legally buy it if they find nice dealers) out of any full-sized 9mm handgun will vastly outperform a standard "chunk-o-lead" target-shooting round out of a .45, for example. Using that level of ammo in both, the difference between the wounds from the two is negligible.

Re:9mm?

[bertoelcon]

I wonder if I need a CHL to carry a non handgun out in the open. Its isn't concealed or a handgun so I wouldn't think a concealed handgun license applies in the situation.

Anyway, to carry it in the open you use a belt or a strap on your back, its really easy to carry.

Re:9mm?

[Mikkeles]

'One of these cells may leave a nasty burn or blind you, but it's not going to kill you.'

Which means that you're still hors de combat and will tie up more people for your hopitalization.

Re:9mm?

[bertoelcon]

Yes, yes I do.

Re:9mm?

[Wraithlyn]

Oh FFS, there's no fallacy in recognizing that law enforcement, who deal with the life-and-death effects of handguns on a daily basis, are particularly well suited to judge their merits. Do you think using expert witnesses in court is fallacy?

Or as Wikipedia puts it:

arguments from authority are an important part of informal logic. Since we cannot have expert knowledge of many subjects, we often rely on the judgments of those who do. There is no fallacy involved in simply arguing that the assertion made by an authority is true. The fallacy only arises when it is claimed or implied that the authority is infallible in principle and can hence be exempted from criticism.

The GP is not claiming law enforcement is infallible and couldn't possibly be wrong, he's simply recognizing the obvious fact that they have massive experience that is relevant here. I agree with him. Maybe you don't, but that doesn't make it a logical fallacy.

Re:9mm?

[Ortega-Starfire]

Not really. My neighbor has a Serbu Super Shorty he wears in a CC rig (shoulder holster with ammo and handgun on the opposite side), and it is perfectly concealable.

The trick is to learn how to dress when carrying.

Re:9mm?

[Shakrai]

The truth is 9mm is every bit as capable across a broad range of handgun scenarios that LE are likely to face as any other reasonable semi-auto cartridge (.40, .45, .357Sig)

Then why are there so many more stories of the 9mm failing to stop determined aggressors than there are of other calibers? The .40 and .357SIG are newer calibers so you can explain them away as not having been around long enough to accumulate such stories, but the .45 and .357 magnum have been around for a long time. Both of them have better reputations than the 9mm does.

That's why most of the world's militaries, including the US, and all NATO and UN types, have standardized on 9mm

Except that the US forces who are most likely to need to use their handguns don't use the 9mm. They use the .45. Marine Force Recon, Delta Force and the Navy Seals all use .45s. So does the FBI Hostage Rescue Team and LA SWAT team. If the 9mm is so great then why aren't these pros using it?

Operator skill and unpredictable situational factors will make far more difference than any you can find between the calibers in any case

No argument there. Most of the knowledgeable types that I've talked to would advise you to pick the most powerful caliber that you can shoot accurately and stop worrying about it. A hit with a .22LR is better than a miss with a .50 BMG. I can shoot the .45 as accurately as the 9mm and my state limits me to 10 round magazines anyway so I don't see any compelling reason to carry the 9mm.

Re:9mm?

[Ortega-Starfire]

>As such when I carry I carry a little Kel-tec .380. Fire's the same projectile as the 9mm Luger (less power charge behind it though, but still decent energy delivery) but it fits nicely in my front pocket with no wardrobe adjustments.

I had that gun. I shot ballistic gel with it and the penetration was good.

Then I put a leather jacket in front of it. Penetration went down to 4 inches in 10% ballistic gel.

You should consider the kel-tec 9mm as a replacement option, and with all pocket pistols, use FMJ instead of JHP.

Re:9mm?

[bsDaemon]

I'm 6'4" and ~240lbs. The 1911 is slim enough that it can be concealed without terribly much effort on someone my size. As to the stopping power issue, the .38spc can get up to 319J of energy, and is not an insignificant round. The Army switched the .45ACP in the Filipines after the Spanish-American War, because the .38 wouldn't take down the Filipino warriors, who would take drugs prior to battle, sort of like Viking berzerkers.

The 9mm may be high velocity, but in practice that sometimes has a tendency to carry through, rather than giving the nice "thud" with a .45ACP, especially when shooting ball ammunition. Personally I used Federal Premium Low Recoil JHP and have no reason to believe that it wouldn't sufficiently take someone down, if need be. I'd live a .357 Sig though -- basically a 9mm round in a .40cal case that's crimped down around it.

Though, I honestly just don't believe the 1911 can be beat on aesthetics... like a Colt 1851 Navy, the Winchester Repeater and the M1 Garand, they're just sort of iconic of America. Of the Brits hadn't become so pussified over guns lately, I'd assume they'd feel the same way about the Webley revolver and the SMLE rifle -- tools of empire building.

Re:9mm?

[Rei]

To avoid eye damage, I bet soldiers will be issued goggles for protection.

To wear 24/7? And how do the soldiers see? And do all civilians in the country get them, too?

2. Lasers have a very small area of effect. Even if you fired one of these guns and pierced the enemy soldier's body, the blood loss will be small if any due to 1) the small size and 2) the bleed-stopping effect of the heat. A hit on the heart might cause internal bleeding, but I can't imagine even a hit on lungs having much of a take-down effect. On the other hand, if you see bullets fired through blocks of clay or ballistics jell you see the damage area is far large than the bullet due to the impact and the spinning of the bullet.

That's why it's proper to compare joules delivered. It's not a bullet traveling through you that does all that damage; it's the force of impact on your internal organs. Yes, the manner in which a given number of joules is delivered does matter, but it lets you know how much total energy is being imparted and how quickly it is imparted. So the energy may no longer be in the form of a projectile rapidly losing kinetic energy, but perhaps, for example, it'll be in the form of flash boiling of internal organs.

As for the size of the wound, that depends on how tightly you focus the beam.

Re:9mm?

[Rei]

But it has to be on a single spot for a whole second just to have the energy of a 9mm. What you're talking about is more like a BB gun. If that. You're not going to "slice" anything.

Re:9mm?

[evanism]

A plane gun that uses throwing knives? Cool.

I recon one that shoots spiders, say, Tarantulas, would be far cooler. Spider cannon!

Re:9mm?

[Shakrai]

Wearing a heavy coat in the summer just so I can conceal a 1911 is the point when carrying is more hindrance than it's worth

I can conceal my 1911 under an oversized t-shirt (i.e: buy an XL instead of an L) with the tail out. Get yourself an inside the waistband holster. You'd be surprised how easy it is to conceal a large framed pistol. The 1911 has another advantage going for it too -- the single stack magazine gives it a thinner profile than most modern handguns of a similar size.

As such when I carry I carry a little Kel-tec .380. Fire's the same projectile as the 9mm Luger (less power charge behind it though, but still decent energy delivery) but it fits nicely in my front pocket with no wardrobe adjustments.

The problem with pocket guns is that they aren't very fun to shoot and most people won't practice with them enough to become proficient. Too little mass to absorb the recoil. They do have their place though. I have a snubnose .38 for the rare occasion where I don't want to carry the 1911. Load it with +Ps and you've got yourself a weapon with more power than the .380 and one that can't jam.

Re:9mm?

[apoc.famine]

Don't get me wrong -- you can find a failure to stop for every caliber on the market.

I think 120mm gets you out of this range.
 
  (Yeah, I wish one of those suckers was on the market....)

Re:9mm?

[smoker2]

Does a 9mm handgun weigh 5kg ? If not, then this argument is irrelevant. Oh, sorry this is /. where the irrelevant is somehow more relevant than the truth.

Re:9mm?

[AniVisual]

The non-expanding ammunition is so that they can penetrate body armor. Though it's useless in this situation. Actually, I remember there being an international treaty forbidding the use of expanding ammunition

Re:9mm?

[Rei]

Blind, yes. Burned, probably not. But a fair point to raise.

Re:9mm?

[Shakrai]

Though, I honestly just don't believe the 1911 can be beat on aesthetics... like a Colt 1851 Navy, the Winchester Repeater and the M1 Garand, they're just sort of iconic of America.

Yeah, that's kind of how I wound up buying one. Hard to find a more American handgun than the 1911. It helps that the first time I ever fired one I did really well with it. Couldn't hit the broad side of a barn with the revolvers that I played with that day but the 1911 almost seems to aim itself, at least for me.

Funny that you mentioned the Garand. I'm still in the process of saving up the money to get one from the CMP. Personally I'd rather have an M1 Garand than a AR or AK. More powerful cartridge, longer range, semi-auto operation and no legal hassles to contend with, as my state has it's own version of the now expired Federal assault weapons ban.

Maybe I'm just a sucker for the nostalgia :)

Re:9mm?

[killthepoor187]

http://www.penny-arcade.com/comic/2004/03/19/

Re:9mm?

[drinkypoo]

and in rifle calibers hydrostatic shock effects

That's some of the great fun of .45 ACP, it too provides ample opportunity for hydrostatic shock when hot rounds are used.

Re:9mm?

[confused one]

Very true, very true. A 9mm is good enough -- that's both of my brother-in-laws carry on duty. My sister carries a .40s&w. (Yes, there's a tendancy toward law enforcement in the family). In the home I prefer a shotgun for self defense, because buckshot would be less likely to kill the neighbors kids. Some people seem to think they need a cannon... I don't care what the guy with the .50 says, a shotgun, any shotgun, is pretty damn obvious -- It'll get the bad guys attention pretty quick.

Re:9mm?

[Sir_Lewk]

Expanding rounds are forbidden from being used in war by the Hague Convention of 1899. Full metal jacket rounds may be better at penatrating armor, but the real reason they are used is because using expanding ammunition (in war) is a war crime.

[the relevant section of the treaty]

Re:9mm?

[confused one]

Flash doesn't impress me. I would actually think I had a better chance, believing that you'd never fired it, because it was pretty. I might assume that if you're pointing a gun at me, you're intending to shoot me with it; so, I'd not wait to find out. Besides... You might not want to shoot someone with that cannon. In some states there can be legal consequences for using a weapon that might be considered "excessive", even if otherwise you'd be in the right.

Re:9mm?

[Kral_Blbec]

and with 9mm you get a LOT more practice.

If that's your metric then the .22LR is the best self-defense round.

Its not the only metric, but it is a big one. I'd rather have my 9 that I get to put a couple hundred rounds in a month than a 45 that i can fire about half as much. Even a 22 can be deadly if placed well by someone with enough skill/luck. Accuracy and capacity both go down with increasing caliber so there has to be a balance though. I'm much more comfortable with 10+1 of 9mm than I would be with 6+1 of .45 (I know you can get more than that, but mine is a subcompact)

With good JHP ammo, 9 is plenty on an unarmored target.

Re:9mm?

[Kral_Blbec]

I know shotguns are the classic home defense, but I don't really lean that way. Too messy ;P
Even at home I'm more likely to stick with a handgun with DRT ammo. (http://drtammo.com/) to avoid over-penetration.

Re:9mm?

[SETIGuy]

Yes, as an antipersonnel weapon, a 750 watt continuous laser leaves much to be desired, besides as a way for a sniper to blind someone. It would have to be limited to use against stationary targets. For example the control system of a stationary AAA battery would be a suitable target. There it would have significant stealth advantages for the user, assuming it doesn't go "pewpewpew". Anywhere a sniper can put a crosshairs would be fine.... Even then, a stabilization system would be require to keep the beam on a single spot for long enough to do damage.

The fighter mounted one has 200 times the power, and I assume it is steered to target by computer. It could blind IR sensors on a jet fighter at quite a distance. Blinding the opposing pilot is also an option, since current strategy is to keep your eyes on the enemy. Just do a rapid raster scan across the target. I'd have to do a little math to figure out how long it would take to punch a hole through aircraft skin or detonate incoming ordnance.

It would be interesting to know the specs in more detail....

Re:9mm?

[FelixNZ]

I see your Tarantula shooting gun, and raise you a Flaming, Tit endowed, Shuriken and Lightning shooting gun!

Re:9mm?

[adavies42]

there are usually laws about "brandishing" and more general "deadly weapon" laws that come into play there. the legalities vary significantly state to state (and locality to locality), and the practicalities vary mostly based on the attitude of the local law and whether you have any pull.

Re:9mm?

[mister_playboy]

Sissy stuff... how about this?

If it's good enough for Agent Smith, it's good enough for me!

Re:9mm?

[mister_playboy]

/. denizens are more likely to have FPS training than actual firearms training, and in FPS, it's all about the headshot... :)

Re:9mm?

[Zantetsuken]

Personally, this is why the Saiga exists - upscale an AK47 into a 12 gauge semi-automatic (full auto for Gov't/Military) shotgun.

http://en.wikipedia.org/wiki/Saiga-12
http://www.youtube.com/watch?v=-jPI5j3jjqo&feature=player_embedded

Even with a 10 shell box magazine, load that with slugs. Assuming you're military with authorization to do so, get one with a short barrel, maybe an assault grip, and you'd have a helluva semi-auto hand-cannon or super high caliber smg...

As to so many people yelping about the Desert Eagle, it has the potential to *occasionally* look kinda cool, but if you're really needing a high caliber pistol, you'd be going with a revolver anyway. A revolver basically can't jam, and can use much higher and uncommon rounds that any other handgun design would not be able to handle the stresses of firing.

Re:9mm?

[SETIGuy]

As for the size of the wound, that depends on how tightly you focus the beam.

There are limits to that. The divergence of the beam depends upon the size of the optics. For a man portable weapon system, I'd guess 10 cm is about the maximum optics diameter that would be useful. Assuming a wavelength of 1 micron, 10 cm gives a divergence of 1e-5 radians, so at 100 meters you could focus to a 2 cm diameter spot for an irradiance of 240 watts per square cm. At 1000 meters you're up to a 20cm spot for a fairly insignificant irradiance of 2.4 watts per square cm. If you want something useful at a kilometer, it's not going to be man portable.

Lets put that into terms every slashdotter will understand. Remember your 5 cm diameter magnifying glass and its 20cm focal length? It projected an image of the sun 1.7 mm in diameter with an irradiance of 122 watts per square centimeter, almost exactly half of our laser gun at 100 meters, and 50 times larger than our gun at 1000 meters.

So now, lets build a magnifying glass to match our laser gun. We want a 2 cm diameter spot, so we'll need a longer focal length, by the ratio of 20/1.7, which turns out to be 235 cm. We'll also need 750 watts of sunlight or 0.53 square meters of collecting area. That means a lens 82 cm in diameter. Feel free to build one and put a steak in the focus for one second. Please post your results to slashdot. I personally doubt that a second in that spot would be fatal to a human, but it would hurt a hell of a lot.

Re:9mm?

[thethibs]

That's a girl's round. How about a nice 50.

Re:9mm?

[tibman]

Sounds like they needed to blame something.. then change something to make it look like they're actually making things better.

Re:9mm?

[vivian]

Any military that uses these are going to have to prove that the primary use of the weapon is NOT to blind, as blinding weapons are banned by the Geneva convention, as stated here:

Protocol IV on Blinding Laser Weapons prohibits the use of laser weapons specifically designed, as their sole combat function or as one of their combat functions, to cause permanent blindness to unenhanced vision, that is to the naked eye or to the eye with corrective eyesight devices. The High Contracting Parties shall not transfer such weapons to any State or non-State entity.

Re:9mm?

[Shakrai]

With good JHP ammo, 9 is plenty on an unarmored target.

I'll wager that most of the police who died because their 9mm rounds failed the stop the aggressor were using "good JHP ammo" (as if you'd use anything else for self-defense work). Seriously, how do you explain away the numerous stories of the 9mm failing to stop aggressors and the fact that large segments of the law enforcement community have abandoned it?

Re:9mm?

[Shakrai]

So is the 11.43x23mm automatic colt pistol ;)

Re:9mm?

[jeffrey.endres]

Except that lasers for blinding are against the additional protocols of the Geneva convention. cf Protocol IV of the UN Convention on Certain Conventional Weapons http://www.un.org/millennium/law/xxvi-18-19.htm

Re:9mm?

[tibman]

Pretty sure NSW gets to use whatever sidearm is in the kit.. which includes 9mm and .45. Marine recon is 1911. SF is 9mm and Delta is a subset of that.. but i'm sure they get to choose from an assortment. Either way, there's still a big mix of sidearms out there. To most soldiers, your sidearm is seriously the LAST thing you pull.. just before you start throwing rocks/chairs/whatever. Prior to that, it's a piece of equipment you have to clean and carry around.

I started on an M9 and i still prefer that to this day. Because i know it works as advertised and i'm very comfortable with it. My guess is that's the same for most people. If you started with 10mm and shot that a lot.. you will probably swear by it the rest of your life.

If a pistol is your primary weapon, caliber sizes and small differences in performance might be of value. But as a sidearm.. who cares. Whatever you prefer is best.

Re:9mm?

[blueskies]

I don't think you know what an appeal to authority is.

Re:9mm?

[KibibyteBrain]

All it would have to do is heat up the fuel tanks to combustion. It may not even have to do that, the thermals on jet fighter engines are insane. The exhaust leaves at far greater than the melting temperature of the alloy the engines are made out of. Therefore all sorts of tricks like laminar airflow cooling are used. However, an external source of heat into the system could totally mess up those cooling techniques...

Re:9mm?

[Shakrai]

If a pistol is your primary weapon, caliber sizes and small differences in performance might be of value.

As a civilian it is your primary weapon. You can't exactly take the AR-15 or 12 gauge with you to the grocery store. It probably qualifies as the primary weapon for most law enforcement officers too. They have access to shotguns and other weapons but the pistol is the one that's always on hand and ready to bring into action when needed.

The point is valid for soldiers though. The Marines don't even issue the M9 any longer to officers under the rank of full bird colonel. They issue the M4 carbine instead.

Re:9mm?

[lwsimon]

In the US (a few state laws aside), you can shorten then barrel is 18" without issue. To go shorter than that, you have to file a form, pay a $200 tax, and go through a background check.

Assuming your state doesn't have an "assault weapons ban", there is no regulation for an "assault grip" (I assume you mean a pistol grip).

FWIW, I own a Saiga-12 with an 18.25" barrel and pistol grip.

Re:9mm?

[lwsimon]

Depends on the state. Here in Arkansas, you can't carry an exposed weapon, period, regardless of whether or not you have a CHL.

That said, I've walked many miles on the roadside with a rifle going between my family's houses when I was younger (1995-2002 or so). No issues.

Re:9mm?

[lwsimon]

You neighbor must hate his wrists :)

Aguila makes some low-recoil, shortened rounds that fire and cycle beautifully in the SSS.

Re:9mm?

[MBGMorden]

The problem with pocket guns is that they aren't very fun to shoot and most people won't practice with them enough to become proficient. Too little mass to absorb the recoil. They do have their place though. I have a snubnose .38 for the rare occasion where I don't want to carry the 1911. Load it with +Ps and you've got yourself a weapon with more power than the .380 and one that can't jam.

I've tried revolvers but even on the smaller ones the cylinder is just too wide for my tastes. Practicing with my Kel-tec is no problem though. I put plenty of rounds through it, but I'm a bigtime hobby shooter. I reload my own ammo and own several other handguns - a CZ 52 in 7.62x25, a CZ 82 in 9mm Mak, a Ruger P-95 in 9mm Luger, a SIG P225 in 9mm Luger, an FIE E15 .22LR revolver, an 1895 Nagant in 7.62 Nagant, a replica (Pietta) 1858 Remington Army, and even a 1911 in .45ACP built up on a Double Star frame (I've got a lot of rifles too but we won't go into those). Despite having all those available though (and I'll say that when TARGET shooting my preference is for the SIG), the Kel Tec still comes with me when I leave home.

The 1911, while a fun gun on the target range, I'm just not a fan of for carry. It is thin, but there are other single stack guns out there (my Kel Tec, SIG, and the CZ 52 are single stack). It has a lot of sharp corners that can snag - some custom gunsmiths can do a reshaping on the frame and slide that I've seen referred to as "melting" (though it's not really melting any metal) that smooths out the edges for carry, but that's an expensive job. #1 reason I don't like it for carry though is it's single action. I know people still use them, and a few of my guns are single action, but for anything outside of range work to me single action guns are a technology whose time has come and gone. I'd far rather carry a nice double action than worry about carrying cocked and locked or fumbling with a hammer if I need the gun. I'm also just not a fan of little things - the internal extractor is usually picky and has to be precisely tuned for each gun - which is why most 1911-redesigns went to an external extractor. The trigger moving straight back instead of pivoting on a hinge pin also feels off to me. Don't get me wrong the fact that the design has been used for as long as it has is a testament to it's maker, but the design is almost 100 years old now and it's starting to get just a bit long in the tooth.

Everybody has their preferences though. :)

Re:9mm?

[MBGMorden]

Remember though that this is a test weapon. In time the technology will improve - energy output will get higher, the device will get smaller, etc. Both of those are very simple evolutions in the process. The idea behind the tests (and the lack of any need to have the beam "track" the target to remain at a fixed spot) is still sound.

Re:9mm?

[Shakrai]

I've tried revolvers but even on the smaller ones the cylinder is just too wide for my tastes

I'd second that. I bought my snubnose because I had a lot of negative experiences with pocket automatics. I rarely carry the thing though. It's funny but it's more comfortable for me to carry a government-model sized 1911 than a snubnose revolver.

It has a lot of sharp corners that can snag

??? Mine doesn't have any sharp corners. I've got thousands of draws with it and it's never snagged on anything. Which model 1911 do you have?

but for anything outside of range work to me single action guns are a technology whose time has come and gone

I find it easier to only have to learn one trigger pull. To each their own though :)

'd far rather carry a nice double action than worry about carrying cocked and locked or fumbling with a hammer if I need the gun.

Why would you worry about carrying cocked and locked? The original 1911 had two different safety systems -- the sear/thumb safety interface and the half cock notch. The modern designs will usually add a firing pin safety as well. I'd agree with you on messing around with the hammer though. I know a few people that lower the hammers on their chambered 1911 but I personally regard that as a very bad and dangerous move. Bad because it leaves you with a gun you can't shoot in an emergency. Dangerous because it's just begging for a negligent discharge.

the internal extractor is usually picky and has to be precisely tuned for each gun - which is why most 1911-redesigns went to an external extractor

YMMV but I've had worse experiences with the redesigns with external extractors. Most of the issues that I've seen with extractors on 1911s wind up being the fault of the magazine, not the extractor. I ran into it with the first one I bought -- the stock magazine had a nasty habit of jamming on the last round, particularly when feeding hollowpoints. I bought 8 round magazines from Wilson Combat and haven't had any hiccups since.

The trigger moving straight back instead of pivoting on a hinge pin also feels off to me.

The ones that pivot feel strange to me. I guess it's all what you are used to :)

Don't get me wrong the fact that the design has been used for as long as it has is a testament to it's maker, but the design is almost 100 years old now and it's starting to get just a bit long in the tooth.

I'm not a Browning groupie. I love many aspects of the 1911 (the grip angle, the single action operation, the thin profile, etc.) but there are also a lot of things that could stand to be improved with the original design. To pick one, it's a mystery to me why the extended grip safety (to prevent hammer bite and enable a higher grip on the gun) wasn't a feature of the original design. That's the first thing I notice whenever I pick up a mil-spec 1911. The original sights also left a lot to be desired.

Re:9mm?

[RMH101]

Laser weapons designed to blind or similarly incapacitate are specifically banned by teh Geneva Convention. This might not stop the US ("enemy combatants", etc) but there you go.

Re:9mm?

[dunkelfalke]

Dude, 9x19mm is still much better than, for example, 9x17mm (.380 acp for you americans) or 7.62x25mm TT, with former being pretty weak and latter being great at penetrating body armour but pretty much without any stopping power whatsoever.

Re:9mm?

[triffid_98]

I believe that the Lord Humongous swears by the .50 AE for penetrating steel plate and cracking timing casings.

Wait, you wanted to shoot PEOPLE with this gun?

Just walk away. I will give you safe passage in the Wasteland. Just walk away and there will be an end to the horror. I await your answer. You have one full day to decide.

Re:9mm?

[Inda]

Any of my European friends worried about the vast knowledge our acquaintances from over the water know about guns, bullets and how well they kill each other?

Re:9mm?

[Faaln]

Good thing we never, ever declare war on anyone anymore.

Re:9mm?

[terminal.dk]

Because a bullet that does not hit will not stop anything.

Hitting the target at the right place with the right ammo/weapon is key.

And since many law officers have a 20 pound trigger pull (because they are nervous, and has not learned how to handle weapons), the weapons makes it almost impossible to hit.

1 pound trigger pull, and teach them to put the finger on the trigger only if they are ready to fire would increase stopping power of any caliber. But also increase accidental discharges, as they are not ready for the situation.

Stress management and smooth weapons wins. Not stress and cannons

Re:9mm?

[icebrain]

Depends on the state. In Georgia, for example, it is generally accepted that you can openly carry a rifle or shotgun without a license, since the law doesn't prohibit that. Carrying a handgun (open or concealed) or concealing a rifle/shotgun (if you physically can, anyway) is specifically prohibited, unless you posess a Georgia firearms license (functionally, a carry permit).

Of course, concealing a knife is still illegal, even if you do have a GFL. People legally carrying handguns have been arrested for having a knife in their pocket.

Re:9mm?

[Custard Horse]

I take it we are quite a way from the Stubb Gun then?

Re:9mm?

[cyn1c77]

Yeah, the Air Marshals use the .357 SIG, as does the Secret Service. The Coast Guard adopted it as well. I believe the FBI is still using the .40 S&W but I could be mistaken.

The 9mm is a joke. It's even worse for the military because they aren't allowed to use expanding ammunition. Buddy of mine who deployed in Iraq tells a story of an insurgent whom wasn't stopped in spite of the fact that he had absorbed no less than six center of mass hits from the M9. Makes you question the wisdom of the military abandoning the Model 1911, doesn't it?

That's because god was on his side, obviously.

That said, if you have time for 6 center of mass hits, you have time for 2 headshots, which works every time.

Re:9mm?

[Coren22]

Nice job.

Re:9mm?

[confused one]

I've seen that; but, personally don't have a use for it. I'm not military. While I have 3 family members who are in law enforcement, I'm not (You might say I'm the geek of the family). A standard Mossberg is good enough for me.

Re:9mm?

[cmiller173]

How about http://en.wikipedia.org/wiki/45-70 the 300gr Pb has 2404J and the 300gr (strong) JHP has 4676J.

Here is the handgun that shoots it. http://www.theothersideofkim.com/index.php/ggps/6615/ Eventually I'll inherit a pair of these with consecutive serial numbers

Re:9mm?

[immortalpob]

That's not how lasers work. you are not focusing a light source to a point you are generating a beam of light where all the waves are running parallel. Distance is moot to lasers the impact point does not grow significantly the further away you get. Lasers don't use heavy optics to focus they are just generating a light source that does not diverge in the first place.

Re:9mm?

[cyn1c77]

There's a reason why even the professionals are trained to shoot CoM first.

Semi-professionals are trained to shoot two-to-three shots CoM and then to reassess the situation. Real professionals put two in the chest and one in the head.

Of course, I do agree with you that real professionals also do not use 9mm ammunition... or handguns for that matter.

Re:9mm?

[gura]

Distance DOES matter to lasers, take a look at all of the work they've done on the Airborne Laser to reduce diffraction.

Re:9mm?

[immortalpob]

Yes to reduce DIFFRACTION not DIVERGENCE. I was simplifying but that does not disprove my point. Diffraction would be the light getting scattered while passing through smoke for example. The GGP was describing divergence being an issue. Optic focusing is useless unless the target is a fixed distance away, the scenario he was describing would require some system to determine range and focus the beam.

Re:9mm?

[GameboyRMH]

The Desert Eagle - the first anime weapon ported to meatspace. Wieldable giant swords and weaponized yo-yos coming soon!

Re:9mm?

[CompMD]

Another problem with 10mm Auto is that it wore out weapons quickly, namely the FBI's MP5s. There were numerous problems with wear, and HK decided that 10mm Auto MP5s were too much hassle, so they stopped producing them. Still, an FBI agent's standard weapon when they want "extra firepower" is a 10mm Auto MP5, however they must train with 9mm MP5s to keep from trashing the actual duty weapons. FBI SWAT has moved to the .223 cal M4 though.

Re:9mm?

[phoenix321]

No, my handgun weighs around 900 grams fully loaded with 15 rounds. The spare magazine is another 15 rounds for 300g and after that I can only make one well-aimed throw.

For offense or mobile use, this is better than a 5kg laser-gun, which probably needs an energy source of even higher weight.

For stationary defense, a 5kg laser-gun would be pretty awesome, because I guess the plain old AC wall socket would provide sufficient energy. That way, it never needs reloading, never jams, never causes ricochets, is silent and highly accurate. As long as AC power and cooling are operational, it could defend its position for a very long time.

This alone would make the unit worth billions. But with proper servo actuators and an advanced targeting system, it could also protect the perimeter against ordnance like RPGs, mortars, cruise missiles and maybe even air-to-ground munitions.

Re:9mm?

[GooberToo]

I know this stuff is hotly debated, but just in case you don't know, here are some interesting facts for you.

.357 SIG

That is *literally* a 9mm round - the exact same you reload 9mm pistols. Most people don't know that. Yes, literally 9mm. And several studies have show it tends to over penetrate. Meaning, it tends to pass through without delivering maximum damage to its target. I guess that's good if you tend to get into shootouts where you need to shoot though doors and cars, etc...and FBI does, moreso than police. But for typical law enforcement, this is certainly not required and doesn't happen often. Stats, by a wide measure, support this fact.

Besides +P and +P+ (ya I know, no official +P+ standard and its barrel of monkeys) rounds actually deliver spitting distance of the same energy as .40SW. The caliber difference between 9mm and .40sw is generally not worth talking about. Even the statistics by the FBI, once you account for noise, show there isn't much difference between a 9mm and .40sw for single shot, torso kills. You find most quality personal defense rounds, including what police typically use, are +P or +P+ rounds. The only way a .40sw makes a real difference compared to a 9mm is if you use a +P(+) with the maximum grain bullet you can load in a .40sw - in which case you'll likely find it harder to control and at night will be far more blinding. Which makes it, generally speaking, an inferior choice compared to 9mm.

Personally, I'm not married to the .45. I have one, because I love the 1911 platform, but I'd also trust my life to a .40S&W, .357 magnum or 10mm. I've just read about too many spectacular failures of the 9mm to be willing to trust my life to it. To each their own though.

Bluntly, 9mm is about the perfect compromise for a general purpose, all environment round. If you want to specialize because of your likely encounter or are a highly trained marksman in combat situations, then you should consider using something else. But for the masses, 9mm is by far, ideal. Realistically, .357 Sig is a crappy choice, save for a select few who require its over penetration capabilities. And once you get into .357mag, .44M, or 10mm, you're trying to compensate for something because they are horrible defense rounds, if for no other reason second shot accuracy is going to **horribly** suffer - and in confined space you'll lose situational awareness from being temporarily deafened.

Realistically, people who knock 9mm are simply ignorant of the facts or are operating well outside of the general self defense environment. Or worse, trying to compensate for something. Realistically, 9mm is a very deadly round and more than capable of doing its job (90%, single shot, torso hit, kill stat, using +P FMJ - use of HP/frag, etc was not reported).

Re:9mm?

[TheLink]

Yep. Energy does not tell even part of the story. Sliding a very sharp knife into a human body doesn't have to take that much energy.

Re:9mm?

[EXrider]

This alone would make the unit worth billions. But with proper servo actuators and an advanced targeting system, it could also protect the perimeter against ordnance like RPGs, mortars, cruise missiles and maybe even air-to-ground munitions.

That just reminded me of the laser perimeter fence in the movie Congo with the badass robot operated turrets, except they'd have some frickin' lasers mounted on 'em, sweet...

Re:9mm?

[GooberToo]

Then why are there so many more stories of the 9mm failing to stop determined aggressors than there are of other calibers?

Because its the most prevalent round. Because police have used various experimental bullets (new and improved) over the years which have failed. You know, all those high tech bullets which are available now - you can thank 9mm and police. And lastly, because police have to blame their own failure to shoot straight on something other than themselves. It's called bravado and is very much alive in most arms of law enforcement. The FBI's own stats show they are full of, well, bravado.

The .40 and .357SIG are newer calibers so you can explain them away as not having been around long enough to accumulate such stories,

That's an extremely common misconception. .357 is NOT a new caliber. In fact, is literally a 9mm parabellum bullet.

Except that the US forces who are most likely to need to use their handguns don't use the 9mm. They use the .45. Marine Force Recon, Delta Force and the Navy Seals all use .45s. So does the FBI Hostage Rescue Team and LA SWAT team. If the 9mm is so great then why aren't these pros using it?

You're confusing many issues here. Its common. In no way, shape, or form, can you compare NATO FMJ to what is commonly used by police and/or people for self defense. So for starters, what the military uses is completely irrelevant. They have no choice in legal ammunition - save only sub-sonic variants. Because of this, their only legal option is a larger caliber. Because of this, new 9mm rounds are currently being tested. Current tests show this new 9mm round to be as effective, if not more effective than a NATO .40 FMJ in actual combat performance. Go figure.

If the 9mm is so great then why aren't these pros using it?

The pros are using 9mm. Every day. And in much larger quantities than the exceptions above. A minority exception does not a rule make. Furthermore, some people actually require over penetration capabilities. Squads such as you point out are more likely to need this capability whereas, you don't. You think you'll need to shoot someone through a car door? Through a wall? Not likely you will. Very possible these guys will.

Re:9mm?

[GooberToo]

not more effective than a NATO .40 FMJ in actual combat performance.

Opps. That should have read, "not more effective than a NATO .45 FMJ in actual combat performance."

Re:9mm?

[GooberToo]

Because you can get hit with a 9mil round and still keep running. Not so much with the .40. From what I understand DHS also switched to the .357 and the .40.

That's completely untrue. Every study shows its false. ALL rounds either stop/drop someone or they keep running. Period. There are only ever two reasons people drop. Dropping is a trained behavior or a fear response. The other case happens when an organ is disabled - bone breaks, tendons severed, etc. There are no exceptions. Period.

Whoever told you the above is full of shit.

Re:9mm?

[Shakrai]

What's wrong with having 'vast knowledge' about this subject or any other subject in particular?

Re:9mm?

[EXrider]

Any of my European friends worried about the vast knowledge our acquaintances from over the water know about guns, bullets and how well they kill each other?

You don't live here, I assume handguns are likely outlawed in your country. So why are you so worried about it?

Re:9mm?

[DrVomact]

Yeah, but now we have full metal jacket rounds that tumble on impact, causing a large amount of damage—just as an expanding round would. (For example, the 5.56 NATO round is designed to do that.)

Re:9mm?

[mea37]

"does not diverge in the first place"

Not so. You can characterize the idea that all of the light from a laser is moving parallel as a simplification or an idealization, but not as reality.

Now, I do agree that GP is applying the wrong principles and the wrong formula, but the idea of a perfectly-contained beam of light energy that remains "small" over any distance is simply fiction.

Re:9mm?

[R2.0]

Cool - can we start the debate about 5.56x45 vs. 7.62x51? Or 30-06? 'Cause I don't think the /. buffers are ready fro that.

Re:9mm?

[2obvious4u]

I have contractor friends in Iraq and the only thing I've seen them shoot are 30mm rounds from Apaches and 50 cal rounds from sniper rifles. There isn't much left after getting hit with either of those rounds.

Re:9mm?

[SETIGuy]

The divergence is due to diffraction, moron. WTF do you think I was calculating? If you send a laser out of a tiny hole it diverges a hell of a lot because of diffraction. To collimate a laser so it will be effective at large distances you need to significantly expand the size of the beam.

Once it leaves the source, a laser is subject to the same inverse square law as any light source. The formula I posted is accurate enough for the purposes to which it is being put.

Next time post about what you know, rather than what you think you know

Re:9mm?

[SETIGuy]

Yes to reduce DIFFRACTION not DIVERGENCE.

I apparently have a lot more training in optics than you do. (A couple dozen years professional experience in designing X-ray and UV optics. What did you have, a class in grade school). What do you think the primary effect of diffraction is on a laser beam, if not causing divergence? Divergence is divergence whether it results from diffraction or geometric effects. If you had any optical knowledge you would see that I had used a diffraction approximation in my calculation.

Optic focusing is useless unless the target is a fixed distance away, the scenario he was describing would require some system to determine range and focus the beam.

Yes, and an stabilization system that tilts one or more optical elements to hold it on target while counteracting shake due to an unstable platform (i.e. a person). It's funny, but my $1k digital SLR has all of those items, so I think that it might be possible to put them in to a $100k weapons system.

Re:9mm?

[SETIGuy]

Now, I do agree that GP is applying the wrong principles and the wrong formula

The quote above is the only part of your post that is wrong.

Re:9mm?

[tsotha]

So what you're saying is this thing will be great for killing ants at a distance?

Re:9mm?

[SoupGuru]

R. Lee Ermey told me from the TV that full metal jackets were developed as a result of increased muzzle velocities that were melting the lead of the bullets as they traveled down the barrel.

And if R. Lee Ermey is telling us something, you won't find me calling him a liar.

Re:9mm?

[R2.0]

"Dude, 9x19mm is still much better than, for example, 9x17mm (.380 acp for you americans) or 7.62x25mm TT, with former being pretty weak and latter being great at penetrating body armour but pretty much without any stopping power whatsoever."

The last part is somewhat debatable. 7.62x25/.30 Tokarev penetrates body armor not because it's designed to per se but for the same reason rifle bullets will - it's moving fast. And that speed matters.

There are 2 ways to "stop" someone with a projectile weapon, outside of hitting an organ that kills you instantly:
1) Momentum transfer
2) Shock

In momentum transfer , the idea is to have the bullet expend all it's energy in the body which physically pushes the body back - strict newtonian mechanics. So you want a larger diameter, heavier bullet to carry the most energy with it into the target, and this is generally how self defense cartridge development in the US has gone. But the other way is to use a small, fast bullet that is still moving at a high speed when it enters the body. Now fluid dynamics takes over: the fast bullet, while leaving a smaller "wound channel", does massive damage to the surrounding tissue via the fluid shock wave that it causes. This can cause a person to go into physiological shock, which puts them on the ground pretty well.

Another point is penetration. The heart is 3" in, the spine farther in. Big, slow bullets tend to penetrate less - that's what they are designed to do. So the odds of hitting one of those parts are smaller.

Note that I'm not advocating one over the other, but I will say that if one's only choice was ball ammo, I think I'd pick the 7.62x25 over the 9x19. And then steal the first .45 I could find.

Re:9mm?

[R2.0]

"Actually it's all about stopping the enemy, not about sending him 30 meters backwards in hundreds of little bits. "

Well, the person IS stopped...he just reverses direction and disintegrates immediately thereafter.

Re:9mm?

[phoenix321]

While we don't know if the system will be capable of emitting a continuous beam instead of a pulsed one, but if it were, it could with cut an entire army off at waist level. In one sweep.

Gore movie plot material aside, it could spell the end to the Human Wave tactic once and for all.

Re:9mm?

[R2.0]

"Unfortunately your father in law is misinformed. It's common for even people with a great deal of field experience to be misinformed about these things. Ask a qualified ballistics expert and you'll find the diameter of the entrance wound is a relatively small factor. Proper bullet design, and proper consideration of the correct weight to use for the platform in question, are much bigger factors. A 147gr Winchester RA-9T ("LE" ammo, but civilians can legally buy it if they find nice dealers) out of any full-sized 9mm handgun will vastly outperform a standard "chunk-o-lead" target-shooting round out of a .45, for example. Using that level of ammo in both, the difference between the wounds from the two is negligible."

Apples and oranges. You are comparing a modern bullet design with a 100 year old one. In the military, the bullet you suggest isn't allowed. So, would you rather put a 12.7mm hole in someone, or a 9mm one? keeping in mind that the latter has 1/2 the cross sectional area?

Or put it another way - are you proposing that a 147gr Winchester RA-9T is equal to the 230grn RA45TP? They are both the old "black talon" design.

Re:9mm?

[R2.0]

"Any of my European friends worried about the vast knowledge our acquaintances from over the water know about guns, bullets and how well they kill each other?"

If not, you should be - and not for the reasons you think.

Re:9mm?

[R2.0]

"Some people seem to think they need a cannon... I don't care what the guy with the .50 says, a shotgun, any shotgun, is pretty damn obvious -- It'll get the bad guys attention pretty quick."

True, but with a Barrett M82, the bad guys don't get close enough to really matter, now do they?

Re:9mm?

[Hognoxious]

Wow, that's some pretty fucking tough typing you're doing there.

Re:9mm?

[Hognoxious]

Dude, you aren't allowed to disagree with Shakrai. He'll start stalking you as AC, the needledicked little ponce.

Re:9mm?

[myrdos2]

The HELLADS is supposed to be 150 KILO watts. I believe 67 kilowatts will blow a hole an inch thick through solid steel in under a second. From the BBC: "In our 25kW configuration and our 2.5 sq cm spot size on a one-inch thick steel target, we blow a hole through it in seven seconds."

source: http://news.bbc.co.uk/2/hi/sci/tech/6380789.stm

Re:9mm?

[Rei]

No, this is a goal. It's not even a test weapon yet. Perhaps after (if?) they hit this goal, they might set a more ambitious goal. But for now, this is not an effective "raygun".tripod.

Re:9mm?

[Rei]

Even then, a stabilization system would be require to keep the beam on a single spot for long enough to do damage.

Meh, at least from the software side of things, I could output the required beam offsets in realtime using nothing more than a webcam mounted to the scope, a cluster of laptops, and Cinelerra. :)

Re:9mm?

[confused one]

1 lb is a bit light, isn't it?

Re:9mm?

[confused one]

I'm not arguing with a sniper rifle. BBut the guy who thinks a .50AE handgun is a better choice for close quarters (which is what I was responding to): Most people can't control a .50AE. I've seen too many people like this in the range, who think they're hot shit because they have a hand cannon... But can't hit a man sized target at 25 yards.

Re:9mm?

[DocHoncho]

What you are observing here are "Gun Nerds." I can assure you that most Americans don't have anywhere near this level of knowledge of arms and weaponry. Most folks haven't ever even touched a gun, let alone fired one.

Re:9mm?

[R2.0]

I know - I was joking. .50 is such a scawy number, I swear I once heard a politician being outraged that .50 caliber rifles were allowed for hunting in his stated. He's right - during muzzle-loader season.

Re:9mm?

[Shakrai]

"Gun nerds"? I love it!

Interestingly enough there seems to a disproportionate number of IT people involved in the shooting sports. At my local shooting range virtually all of the shooters under the age of 40 are involved in IT in one way or another.

I guess a firearm is nothing more than technology once you strip away the mystique and fear surrounding them. Maybe that explains why so many IT geeks seem to get a kick out of playing around with them.

Re:9mm?

[confused one]

It takes all kinds... of idiots. The world's full of them.

Re:9mm?

[confused one]

I wonder what he would say if someone casually mentioned that people use .72 caliber rifles to hunt deer. A 12ga deer gun with a rifled barrel is around .72 caliber, if I remember correctly (using a .50 caliber slug in a sabot generally).

Re:9mm?

[ncc74656]

One of these cells may leave a nasty burn or blind you, but it's not going to kill you.

It's usually considered better to wound your enemy than to kill him. This isn't out of any concern for his welfare, but for the consideration that a wounded enemy ties up more enemy personnel: his buddies at first, followed by medics when they can get to him. While they're looking after him, they're not shooting at you. If you kill him outright, they can keep on shooting at you.

Re:9mm?

[GooberToo]

Wow....some dumbass, uneducated troll moderator. Pull your head from your ass you piece of shit. This is a freebie given fucked up nature of your worthless moderations. Holy shit you're stupid.

There is no such thing as "stopping power". Period. That's the facts. Suck it.

If you incorrectly believe there is such a thing, please inform the rest of the scientific world on how your nose picking proves. Seriously, there is no fucking thing.

Re:9mm?

[GooberToo]

How the fuck is stating FACT flamebait?!?

What is wrong with these fucking idiotic moderators?!?! Holy shit they are stupid!

Re:9mm?

[Kral_Blbec]

As sad as it may be, many police barely pass the muster for shooting qualification. I'm very active in self-defense and shooting communities (online and off) and talk to cops often. There is a distinct divide between those that are in it to actually do the work and those that just like the badge. Those that are in it because they love it are usually those I talk to, and are great shots. The others use their gun for intimidation and barely visit the range enough to pass. Frankly, the idea that only cops should have guns because they are trained is bull. Most citizens who have been raised around guns are going to be a better shot and better handling of firearms than these types.

As for how this relates to why some areas are moving away from 9mm, its because they can't trust their cops to get a clean shot. If you can't get a clean shot, then 9 might not be enough. Same for 45, but its more likely to be.

About good JHP, there really is a difference between brands. "Good JHP" is very expensive, and many don't use it. They go for the cheap stuff because they think JHP is JHP.

Furthermore, law enforcement have a lot of red tape to go through if they actually kill a suspect. They have a lot of disadvantages that civilians dont have. They try to avoid lethal force as a"last resort" and by the time they react it might be already be past that point. For example, how far away do you think a knife wielding attacker needs to be before firing? 5ft? 10ft? Come on, its only a knife. Actually, its 21ft. Its called the Tueller distance. That is the distance that and average person with a knife can run and hit you before the average person can remove a pistol from a holster (OWB) and fire. Cops usually are already within that distance when working with someone. Really when bringing a knife to a gun fight, the knife wins under 21 feet.

In summary, comparing cops usage to civilian self-defense isnt really possible. There are different scenarios and limitations that the other side doesn't have and what works for one might not for the other.

Re:9mm?

[Kral_Blbec]

Because gun crime went up in England after the handgun bans started?

Re:9mm?

[Shakrai]

Frankly, the idea that only cops should have guns because they are trained is bull. Most citizens who have been raised around guns are going to be a better shot and better handling of firearms than these types.

No argument there. I've known a fair amount of cops that can't hit the broad side of a barn.

As for how this relates to why some areas are moving away from 9mm, its because they can't trust their cops to get a clean shot. If you can't get a clean shot, then 9 might not be enough. Same for 45, but its more likely to be.

Even if you practice every single day I don't think you can be assured that you'll get a clean shot. With a clean shot you could kill an aggressor with a .22 but that doesn't mean that you want to carry one around. I'm sure you have a better chance than the aforementioned cop who draws his gun once a year when it's time to re-qualify but it still isn't a sure thing and your ultimate success or failure may depend as much on luck as it does on skill.

About good JHP, there really is a difference between brands. "Good JHP" is very expensive, and many don't use it. They go for the cheap stuff because they think JHP is JHP.

I would hope that cops aren't using the cheap stuff. I do know my fair share of civilians that carry the cheap crap. Pretty stupid place to try and save money. It's your life we are talking about after all. Personally I carry golden sabers. I replace them every twelve months and when doing so fire off at least a hundred rounds of the new batch. If I have a jam or malfunction then I'm starting over from scratch after I identify the problem. I had to experiment with several different types of JHP before I found the most reliable one. It was expensive, but it's my life, not gonna cut corners.

Penultimate means "second from last"

[Anonymous Coward]

"Penultimate" means "second to last" and nothing else.

It sounds like "ultimate", and it is derived from "ultimate", but it still doesn't mean "super awesome".

Re:Penultimate means "second from last"

[Unordained]

... where "ultimate" means "last". If you assume "last = best" (and thus "ultimate" = "awesome", as is common) then "penultimate" is "the next best thing". None too shabby, especially in situations where "ultimate" is assumed to be unachievable. (Example: assume there is a concept of an "ultimate weapon", which no weapon can match. That concept is itself unachievable. The penultimate weapon, then, is the next-best-thing, the most awesome weapon that actually exists; it will lose its standing as the penultimate weapon when a better one is devised.)

Re:Penultimate means "second from last"

[Hognoxious]

On slashdot, you're allowed to take a word, find a longer word that sounds a bit like at and assume it's just a cleverer synonym of the original word. If anyone calls you on it, you just whine about languages evolving.

I'd expect an illuminary like you to know that.

Re:Penultimate means "second from last"

[amicusNYCL]

Sounds perfectly cromulent to me.

Re:Penultimate means "second from last"

[Chris Burke]

Michelangelo: I've got it! I've got it! We'll call it "The Last But One Supper"!

Pope: What?

Michelangelo: Well there must have been one, if there was a last supper there must have been a one before that, so this, is the "Penultimate Supper"! The Bible doesn't say how many people were there now, does it?

Pope: No, but...

Michelangelo: Well there you are, then!

Pope: Look! The last supper is a significant event in the life of our Lord, the penultimate supper was not! Even if they had a conjurer and a mariachi band. Now, a last supper I commissioned from you, and a last supper I want! With twelve disciples and one Christ!

Michelangelo: One?!

Re:Penultimate means "second from last"

[vivian]

Time to hand in your geek card.

This is a reference to the little known piece of art painted by Mchelangelo, as documented by Monty Python. Presumably, after all the ensuing trouble, the pope ended up getting Leonardo to do the much more famous one which didn't feature a fat JC & two skinny JC's, not to mention the afore mentioned mariachi band and all the rest.

Re:Penultimate means "second from last"

[Yamata no Orochi]

"Penultimate" means "second to last" and nothing else. It sounds like "ultimate", and it is derived from "ultimate", but it still doesn't mean "super awesome".

I can't figure out what you're replying to, as the only result when searching for that word is your post and the correct usage in the summary.

Basically, who are you talking to?

The Future

[colmore]

When I read the summary I wondered if they'd be putting one of those on flying robot drones and then I realized that yes, it's 2009 and we live in the fucking future.

Re:The Future

[evanbd]

Give credit where credit is due.

We live in a world where there are actual fleets of robot assassins patrolling the skies. At some point there, we left the present and entered the future."

Re:The Future

[sakdoctor]

Something went wrong with the future.
We crossed into a time-line where there are no flying cars. Who's going to go back in time and fix this?

Re:The Future

[Chris Mattern]

Flying cars had (and have) two basic flaws that prevent their implementation:

a) Controlling a vehicle in three dimensions takes more skill than the average person has. Remember the last idiot you saw on the road? Which would have been today if you've driven today, by the way. Now imagine him *flying*.

b) a vehicle that generally operates with the ground 500 or 1000 feet below it needs better reliability than can be obtained with the way the average car is maintained. Doubly so when you remember you not only have to be worried about the vehicle and its passengers but whatever the vehicle might fall on.

Re:The Future

[Virak]

That line bears only the most vague resemblance to his post. This is not the patent system. Credit is not due just because someone else came up with a similar idea before you.

Re:The Future

[ceoyoyo]

Yeah, I'd expect it to be easier to put on a drone. It wouldn't take up much more room than a pilot and cockpit on a regular fighter.

Welcome to the world of precision death from the skies. Not precision as in total destruction in a 10 m radius, but precision as in a pencil sized hole drilled in the top of your head.

Re:The Future

[EdIII]

Basically we can boil your argument down to "people are too fucking cheap and stupid".

I totally agree. If it were not for concerns about government totalitarianism I would wholly support a 100% public transportation system in which only licensed, heavily regulated, and *REGULARLY TESTED* operators could use any transportation equipment in a public space.

The average person just does not have the responsibility and skill to be operating motor vehicles next to other average people. The real problem is that you are also mixing the slow, stupid, and inconsiderate with the fast, reckless, and homicidal. Not a good idea.

Ohh, and I totally include myself in the list of people that should not be driving on the roads. I am easily just a few months away from going Road Warrior on the rest of your asses out there. The moment one of you idiots starts doing 20mph less than the speed limit in the fast lane, I am *severely* tested in my ability to not drive your ass off the road with a well placed "bump".

I honestly don't know how much longer I can hold out.

Re:The Future

[icebrain]

I think one concept that keeps coming up is to mount it in the F-35. As I understand it, the plan is to use the B model (STOVL one), remove the lift fan, and put a turreted laser system there. The power take off shaft from the engine (which used to drive the lift fan) would drive a generator to power the laser.

Re:The Future

[mcgrew]

Odd how such an insightful comment is modded +5 funny. Kids, sheesh...

Re:The Future

[daem0n1x]

Dear mods, you may not agree with my comment, but why "Offtopic"?

Re:The Future

[EXrider]

So true... wish I had mod points.

Re:The Future

[bar-agent]

Next year: Laser Cats.

We has it.

Author, slashdot reader?

[DavMz]

After reading the article, I cannot be sure that the US military spoke about scaling the lasers down to a shark-sized one. My guess is that Lewis Page wanted to please the slashdot community.

Effect on humans?

[Singularity42]

I've never heard an analysis of effects on humans. Bullets are good a disrupting tissue, often causing death. A laser might deliver a cauterized burn, or blindness if in the right spot.

Re:Effect on humans?

[mujadaddy]

I take it you're volunteering.

Re:Effect on humans?

[CannonballHead]

Of course. I will willingly volunteer to shoot the laser at something to analyze the results. ;)

Re:Effect on humans?

[mujadaddy]

:-) Sorry, we're up to our gills in firing testers.

Re:Effect on humans?

[CrimsonAvenger]

A laser might deliver a cauterized burn, or blindness if in the right spot.

Blinding weapons are a violation of the Geneva Conventions (Protocol IV, if I recall correctly - and no, the USA isn't a signatory to Protocol IV last I looked).

Re:Effect on humans?

[smellsofbikes]

I can tell you from personal experience that high power lasers cause cauterized burns (in fact, if it's a big enough UV laser you get to watch your skin glow briefly: everything fluoresces and phosphoresces if you hit it with enough photons, I think) and causes blindness. Weird corollary: visible lasers are the nasty ones because they blow holes in the back of your eye, where we can't fix things. Most of the visible-wavelength laser PhD's I've worked with have had partial blindness in some area because they've cooked their retinas. However, IR and UV lasers, while seemingly more dangerous (because you can't see them and don't know you're being hit until it hurts/your vision goes fuzzy) are actually nicer since they primarily bake the front part of the eye, and we can repair that, either with corneal transplants or new intraocular lens implants. One of the PhD's I was working with on a massive UV laser had given himself DIY laser keratotomy: he'd flattened one cornea when a laser discharged a single pulse while his right eye was in the beampath. (It was one hell of a laser: we'd warm it up in the morning using a brick, because they're cheap and *anything* in front of a kilowatt laser is disposable so you might as well go with cheap.)

The fluorescence/phosphorescence was the most interesting thing to me. They're the same effect but different phenomena: you hit something really hard with a bunch of UV, and the surface -- the stuff that didn't get ablated -- is now covered in molecules with electrons blown up into higher orbitals. The ones that fall down immediately (within nanoseconds) are what produce fluorescence. The ones that have absorbed enough energy that they're in an orbital/spin combination that won't allow them to directly drop down to their original orbital, take a long time before they can do something like electron tunnelling to return to their orbital -- where by 'long time' I mean from a millisecond up to maybe six hours. So that's where you get actual glow-in-the-dark. I could put a notecard up in the beam and trigger a shot, and there'd be a nice yellow glow off the piece of paper for maybe half a second, and then the paper itself would be a moderate brown color. Next shot and it'd be gone. The individual shots were on the order of a microsecond long.

Interesting factoid that I wish I didn't know: fluorine gas smells somewhat like Elmer's Glue. Deep UV lasers often use fluorine as an excimer and when you have to replace the cavity mirrors, no matter how many times you purge it with argon, there's still some fluorine in there when you finally open it up. Gack *cough*.

Re:Effect on humans?

[ceoyoyo]

I've read that a multi kW laser beam hitting an object is more like an explosion than you might think.

At the very least a sufficiently powerful laser beam should cause the water in your body (70% or so) to flash into steam near the beam. That should do plenty of damage. If not, wiggle it around a bit.

Re:Effect on humans?

[Stray7Xi]

Blinding weapons are a violation of the Geneva Conventions (Protocol IV, if I recall correctly - and no, the USA isn't a signatory to Protocol IV last I looked).

Weapons designed to blind are a violation. Weapons that may inadvertently cause blindness are acceptable. Just about every weapon we have can cause blindness. I suspect this weapon will be designed to burn a hole into their head rather then blind.

But Law of War also says you limit collateral damage. Will diffuse reflections from these lasers cause collateral blindness. When dealing with highpower lasers in a dynamic environment, there's really no predicting where reflections might end up.

Re:Effect on humans?

[c6gunner]

Blinding weapons are a violation of the Geneva Conventions (Protocol IV, if I recall correctly - and no, the USA isn't a signatory to Protocol IV last I looked).

And?

Weapons designed for the purpose of blinding people would violate the convention. Weapons designed to kill people which may, on occasion, blind someone, are perfectly legal. Soldiers get blinded by bullet fragments and shrapnel too, you know.

Re:Effect on humans?

[jeffrey.endres]

Protocol IV, if I recall correctly - and no, the USA isn't a signatory to Protocol IV last I looked

Actually they are. http://www.unog.ch/__80256ee600585943.nsf/(httpPages)/3ce7cfc0aa4a7548c12571c00039cb0c?OpenDocument&ExpandSection=1%2C2#_Section1 I recall China was designing a anti-laser designation device for their tanks. It would detect when it was being painted and then quickly fire a powerful laser back in the same direction with the intent to blind, and therefore illegal.

Re:Effect on humans?

[MobyDisk]

These guys may have PhD's, but they aren't very smart if they stand in front of giant lasers.

Re:Effect on humans?

[kmac06]

Most of the visible-wavelength laser PhD's I've worked with have had partial blindness in some area because they've cooked their retinas.

What?? I don't (personally) know anyone who has blinded themselves, and I know a lot of laser guys (myself included).

And I'd say near-IR lasers are more dangerous--they still get focused to the back of the eye and absorbed there (they don't get absorbed at the front like you suggested), but you can't see it (in fact I read that the way to know if you're getting hit is if you hear a popping sound from your eye as the fluid boils!). Longer wavelengths (longer than 1.4 or so) either don't get focused by the lens in your eye, or don't get absorbed in the back of your eye, and so you can sustain much higher power without damage.

Re:Effect on humans?

[smellsofbikes]

None were fully blind, but of the 5 PhD's I've worked with, 2 had sector blindness in one eye (both from working with 500mW green pump lasers for ultrafast Ti:sapphire systems) and 1 had changed one eye by a couple diopters from an inadvertent UV exposure. Both the people with partial blindness had actually been wearing glasses, but they weren't against-the-cheek, and they'd been exposed from specular reflection off hardware, so that particular lab was near-fetishistic about matte black hardware. Even the screwheads had to be black.

I'll remember to not work in a near-IR lab. (I'm in the process of building a CO2 laser at home... hm. Maybe I'll put up another enclosure.)

The main problem seems to be that most of these guys are research guys and there's not even any attempt at safety standards. The industrial place I worked, we had the UV laser in an enclosure, and had interlocks on the doors so when the laser was running you couldn't get in unless you were let in, and there were UV goggles in bins beside the doors. The last research-based business I worked in, who had been a university lab until they spun off, had all these watt-level green lasers sitting in the open, no enclosures, no curtains. I walked into a room that was usually used for system assembly and they had a live green laser pointed right at the door because it was a convenient place to set it up. I open the door and, y'know, GREEEEEEEN! and I'm like what the HELL at least put up a curtain or a sign on the door!?!

Anyone who thinks all OSHA does is hinder American innovation should go spend six months working in a laser research lab, and then I'll listen to what they have to say.

Re:Effect on humans?

[kmac06]

I'm surprised specular reflection of a 500 mW beam would be enough to cause damage. I think the rule of thumb is ~5mW is safe, so they would probably need at least 20 mW or so to cause much of a problem...getting 4% of a scattered beam into your eye seems unlikely. Also a 500 mW pump sounds kind of low for a Ti:Saph, maybe that was more?

I toured a lab recently (a federal lab no less, at NIST) and they had half a dozen class IV lasers on all the time, and didn't think anything of it! Would not feel comfortable working there haha...even looking at scattering off of some of the optics seemed a little too bright to be safe.

Re:Effect on humans?

[mcgrew]

They're used in eye surgery as well, for the reasons you mention. LASIK uses a laser to shape the cornea, using the laser like a scalpel, while retina specialists use a laser to weld a torn retina back together. There is some pain involved in getting your retina welded.

Unfortunately for a detached retina they have to stick needles in your eye. That's not the bad part, though, it's holding your head down for the next two weeks until the eye replaces the nitrogen gas the surgeon replaced the vitreous with with new vitreous.

Re:Effect on humans?

[smellsofbikes]

I didn't work extensively with the greens because I didn't *want* to, so they might've been more than 500mW, but I know they were in that range -- under 2W, at least. Class II lasers assume your blink response will prevent you from getting injured, and even so the threshhold is 1mW. 5mW is all the way up to Class IIIM, if I remember correctly, which means the risk of injury is low but not zero, even taking into account the aversion response. Another thing to keep in mind is that the eye is a really excellent optics system, so even though a couple milliwatts doesn't seem like much, once it's focussed by the eye you get a *lot* of power per unit area.

The big industrial place I worked for, my desk was in a room containing seven excimer laser systems, big monster Spectra-Physic units. It was pretty cool. I was on earlier about the fluorine, and one thing I thought was hilarous: we had alarm systems for fires, and for fluorine. When the fire alarm went off people would sit around and look at each other, and finally if it kept going off we'd say 'ho hum' and get up and look out into the main manufacturing floor and see if there was actually a visible fire and then wander outside finally and socialize. When the fluorine alarm went off, people broke wrists running for the doors. We were required to sit within 30 feet of an exit door because they calculated that's how far we could run without having to take a breath. Oddly enough, we never had a fluorine leak, but we did have a number of fires, and I actually got to go in with a SCBA and a couple fire extinguishers and put one out. Even with a SCBA, halon makes you cough like a smoker for a week afterwards, so if you have the choice, grab the CO2.

Re:Effect on humans?

[smellsofbikes]

Dude. They suck out your vitreous and just pump in nitrogen? Zowie. What a crazy thought. I had no idea. (One would think I'd know these things since my gf is an ophthalmic tech...)

I did find out an interesting thing about how the vitreous humor works or doesn't work: my mom was seeing sparkles and flashes, and apparently the vitreous humor is in a sort of sac, and if it's not filling fast enough (an aging thing) it'll sometimes pull away from the retina and that stimulates the rods and cones. Again: I had no idea. It's an idea that I think is simultaneously cool and disgusting.

I've read about laser-riveting detached retinas back in place, and my gf has aided in that process. She says it's awesome, but I keep in mind which end of the needle she's on when I hear her say that.

Re:Effect on humans?

[mcgrew]

They suck out your vitreous and just pump in nitrogen?

Actually it's a bit more complex than that, or it wouldn't take two and a half hours. What I know about it is from my layman's research and listening to the surgeon because I had to get a vitrectomy. The surgeon has stuff stuck in your eye smoothing the retina back down. If your gf is an ophthalmic tech she could probably fill you in on some of the details, but again, a retina specialist does the actual surgery and would know far more.

You can look it up in wikipedia, but don't if you have a weak stomach.

my mom was seeing sparkles and flashes, and apparently the vitreous humor is in a sort of sac, and if it's not filling fast enough (an aging thing) it'll sometimes pull away from the retina and that stimulates the rods and cones

It's from the... I forgot what my surgeon called it, but it's that sack pulling on the retina. What your skin nerves would interpret as pain, the optic nerve interprets as light.

Have your mom see an eye doctor; those sparkles are a cause of torn and detached retinas (a more common cause is getting hit on the head real hard). It doesn't always foreshadow retinal damage, but it did in my case. If she sees black specks she needs to see the doc immediately as that means the eye is bleeding internally. Nearsightedness is the cause of this (the nearsighted eye is oval rather than round). I'd bet money your mom is nearsighted, isn't she?

I've read about laser-riveting detached retinas back in place, and my gf has aided in that process. She says it's awesome

She wouldn't if she was on the other end of the laser. The first few "pops" are painless, but it starts hurting before the procedure is done. Not nearly as bad as cryotherapy. Especially when they stick that nitrogen supercooled probe on the sclera (white of the eye) right where a major nerve is!

Re:Effect on humans?

[R2.0]

They'd need to give me a general. I've worn contacts for almost 30 years, so I can poke or prod my eye with no problem. But if someone else gets near them, I freak out. I'm also quite nearsighted, and my optometrist warned me about retinal detachment, so after reading your description the first thing I'm going to say to the doc is "Put me under. Now!"

Re:Effect on humans?

[mcgrew]

That was my reaction, and then I let the anesthesiologist talk me into a local. DON'T! Especially if you have spinal arthritis. Even with a local they do knock you out for a short time and you're unaware when they stick the needles in.

However, if you get cataracts they'll insist on a local and you ARE awake when they stick the needle in for that procedure. I distinctly remember a momentary freakout when they did, but it was painless.

The upside was, I don't need glasses or contacts anymore! It's a great feeling to be able to wake up in the morning and not have to fumble with glasses or contacts to be able to see the clock.

Stay away from steroids! Steroid eyedrops caused my cataract, but cataract surgery cured both my nearsightedness and my age related presbyopia. I guess you take the good with the bad.

Re:Effect on humans?

[fm6]

I think it would be pretty hard to argue that a weapon based on intense light is not designed to blind.

Hey, here's a fun fact! The full title of the protocol is Protocol IV on Blinding Laser Weapons. Next time, RTFT before correcting somebody about what it says.

Re:Effect on humans?

[c6gunner]

I think it would be pretty hard to argue that a weapon based on intense light is not designed to blind.

No, it would be shit simple.

Hey, here's a fun fact! The full title of the protocol is Protocol IV on Blinding Laser Weapons. Next time, RTFT before correcting somebody about what it says.

Oh REALLY? Wow, thanks! What would I do without twits like you on here to correct me! I mean, without people like you around I might actually have to have a conversation with people who have read the fucking protocol instead of stopping at the title!

Here:

It is prohibited to employ laser weapons specifically designed, as their sole combat function or as one of their combat functions, to cause permanent blindness to unenhanced vision, that is to the naked eye or to the eye with corrective eyesight devices. ...

Blinding as an incidental or collateral effect of the legitimate military employment of laser systems, including laser systems used against optical equipment, is not covered by the prohibition of this Protocol.

In other words, STFU you ignorant, egotistical jackass.

Re:Effect on humans?

[fm6]

In other words, STFU you ignorant, egotistical jackass.

When you say something stupid, expect to be called on it. Insulting people only makes you more of an idiot.

Re:Effect on humans?

[fm6]

(Takes a deep breath.)

Also, when you quote something, don't just quote the parts that you can twist around to back up your argument. The protocol also says "It is prohibited to employ laser weapons specifically designed, as their sole combat function or as one of their combat functions [italics mine], to cause permanent blindness to unenhanced vision..." If a weapon only burns and blinds people, you can't just say that the burning makes the blinding OK. The clause you quote is clearly designed to allow laser weapons that are designed to destroy equipment, not people — and even there, you're supposed to make every effort to avoid blinding people while using it.

I only mentioned the title because your reference to the protocol seemed to imply that you were unaware of the fact that it was specifically about lasers. You claimed that it just banned weapons that were designed to blind (you used those exact words). Sounds to me like you hadn't read the protocol either.

Re:Effect on humans?

[c6gunner]

Also, when you quote something, don't just quote the parts that you can twist around to back up your argument. The protocol also says "It is prohibited to employ laser weapons specifically designed, as their sole combat function or as one of their combat functions [italics mine], to cause permanent blindness to unenhanced vision..."

Wow. You really are a special case. You accuse me of not quoting the whole thing, and then quote exactly the same passage that I did ... except even LESS of it!

What the hell is wrong with you?

The clause you quote is clearly designed to allow laser weapons that are designed to destroy equipment, not people

No, you've just got a comprehension problem. The protocol is designed to stop the development/distribution of weapons whose intended use is to induce blindness. If blindness is an unintended byproduct (or, as the convention puts it, an "incidental or collateral effect of the legitimate military employment of laser systems"), then the weapon isn't prohibited.

You're talking from a position of ignorance, as someone who's never had to deal with weaponry or with the Geneva Conventions. We saw the same sort of idiocy back when the US was accused of violating the ban on chemical weapons because they were using white phosphorous in Iraq. It's just ignorant, egotistical civilians spouting off on topics they've never researched and know nothing about.

As a matter of fact, though, I just noticed that you are the same ... "individual" who was having comprehension problems in a different discussion I was engaged in. Once again - if you can't even parse a dictionary entry, I certainly don't expect you to understand the Geneva Conventions. I'm bowing out of this "conversation", too.

Re:Effect on humans?

[fm6]

You're talking from a position of ignorance, as someone who's never had to deal with weaponry or with the Geneva Conventions.

Assuming that you're not an expert in international law, I assume that means that you're a service person who's had training on interpreting the Geneva Convention in the field. That entitles you to speak with authority on practical steps to take to comply with the Geneva convention on the battlefield. That does not make you an authority on how Protocol IV applies to a hypothetical weapon, any more than passing a drivers ed course makes you an expert on traffic law.

(U.S. personnel will probably never go before an international war crimes tribunal. But if it should ever happen to you, don't tell the lawyers that they're wrong because it contradicts your training. Doesn't work in traffic court, either.)

You keep parsing texts differently from me, and claiming that your parsing is "obvious" while mine is illiterate. That's a cop out. Especially when (as in that other thread) you make silly claims about the meanings of very common words in order to avoid with the very argument you yourself started.

Mirrors

[HEbGb]

Time to get into the mirror business! It's a lot easier to deflect protons than bullets, I'll tell you that.

Re:Mirrors

[Orange Crush]

^photons. These are lasers, not particle guns.

Re:Mirrors

[MichaelSmith]

It's a lot easier to deflect protons than bullets

Umm...

Re:Mirrors

[TheBig1]

I know this was a joke, but to be pedantic, there are more neutrons than protons in lead... 125 vs 82 respectively. ;-)

Cheers

Re:Mirrors

[Grenamier]

How can you guys deflect protons when you're being so negative?

Re:Mirrors

[ceoyoyo]

Meh. Take those neutrons out of the lead and you'll find out you actually have a handful of protons and electrons.

Re:Mirrors

[joe_frisch]

Corner Cubes. Somewhat seriously, it would be pretty easy to figure out what wavelength they are using and build high reflectivity mirrors. Rather bad for your radar cross section though. Still don't see how this will stop suicide bombers.

Re:Mirrors

[maxume]

Make sure you keep it clean.

Re:Mirrors

[jgostling]

By deflecting the protons towards themselves?

Re:Mirrors

[mea37]

Most of those responding are hung up on the typo, but really it's the factual errors that need a bit of attention.

A flawless, clean mirror might reflect 95% of the beam energy. It's going to have to be awfully durable to remain flawless and clean for very long while absorbing 5% of the energy from laser weapon.

If you do deploy a mirror shield that reflects enough energy to keep from being destroyed, a clever opponent will either hit it with a projectile first and then aim the laser at the resulting cracks, or splatter the shield with something (anything non-reflective) and aim at that. Either technique will increase the amount of energy converted to heat before you get the chance to reflect it, causing further damage to the shield.

I suspect in a battlefield situation a mirror might by you a few seconds against an opponent with a laser.

Re:Mirrors

[TCPhotography]

I was told a story by a guy who worked in the ABM field in the 80's.

They wanted to see if mirroring an ICBM would work against lasers, and they had a whole lot of money they needed to spend, so they bought a top of the line astronomical mirror (the kind that astronomers would kill their grandmother for), and pointed a big laser at it. The mirror reflected something like 99.99% of the light that hit it. The .01% though heated the mirror up so that a few microseconds later, the reflectivity was down to 99.9%, a microsecond later it was down to 98%, and less than 20 microseconds later it was close to 80%. Then the mirror exploded from the thermal stresses.

Mirroring doesn't work with weapons grade lasers.

Acronym of an acronym?

[gurps_npc]

HELL = "High Energy Liquid Laser"

"LASER" = Light Amplification by Stimulated Emission of Radiation. It strikes me as wrong to use the first letter of an acronym as the last letter of another acronym.

It should be HELLASER = High Energy Liquid Light Amplification by Stimulated Emision of Radiation.

Re:Acronym of an acronym?

[Drishmung]

Then I take it GNU renders you apoplectic.

Re:Acronym of an acronym?

[amicusNYCL]

It could be worse. It could stand for the HELL Energetic Liquid Laser.

Also, I'm wondering when the military brainchidren are going to develop the GREATSATAN weapon. Surely this too will help improve our image among people who already think we're controlled by the devil.

Re:Acronym of an acronym?

[cheesybagel]

Well, there is a weapon with the NATO codename SS-18 SATAN. It is a large MIRV ICBM. It can either launch a single 20 mton warhead or 10x 550-750 kt MIRV warheads.

Re:Acronym of an acronym?

[mcgrew]

LASIK (laser-assisted in situ keratomileusis)? You would have it be LASERASIK? "Laser" started as an acronym but has become a noun in its own right. You never see LASER in caps, it's "laser". A simple noun.

Legal Mambo-Jumbo

[Frosty Piss]

...a brace of contracts...

I get lost with all the legal verbiage.

Re:Legal Mambo-Jumbo

[Zordak]

I'm even a lawyer, and I've never heard anybody say "a brace of contracts." I've heard "a brace of pistols," and I think Samwise caught a "brace of conies" in The Two Towers, but I would just say "two contracts." Still, at least the guy posting the story used "penultimate" right.

Re:Legal Mambo-Jumbo

[AniVisual]

Dead, I brought home a goose I'd hunted; it's gagged to death. No risk of lead poisoning.

Joe, what have you done! And why are you covered in black feathers! What are these carcas- dead crows!

Re:Legal Mambo-Jumbo

[sphazell]

...a brace of contracts...

I get lost with all the legal verbiage.

Its like going to the pub and ordering a brace of lagers

over one second?

[painandgreed]

We've been down this way back during the star wars days and trying to shoot down missiles. Any sort of energy that is released in the term of a second or so is useless against anything but stationary targets where you can assume you will hit the same point for that entire second. Bullets on the other hand expend their energy in a range of ten thousandths of a second. Until lasers or other beam weapons can deliver enough energy in a short enough amount of time similar to a bullet or supersonic missile, they simply will not make good weapons. Just make your missiles spin and any energy hitting them will be over a very large area. Similarly, the energy given for a 9mm hitting a human target that is moving around will be affected less than the firer of a 9mm who will probably absorb that energy over a shorter time and less area due to recoil.

Re:over one second?

[MichaelSmith]

It might depend a bit on your objectives. If you want to spread terror by setting fire to (say) Baghdad then cruising around the sky with a laser might be more efficient than dropping bombs all over the place.

Re:over one second?

[CannonballHead]

But you can keep a laser focused on something a lot easier. Light moves a whole lot faster than a supersonic missile. If you think of it as a "photon machine gun," it's a lot easier to keep the "bullets" hitting the target when your bullets fire rather rapidly and can move at the speed of light. One second of laser-shining-on-a-moving-object can't be TOO hard.

Re:over one second?

[T Murphy]

I don't doubt the engineers involved see the glaring problems that need to be fixed before this can be deployed, but if DARPA thinks they've got the potential to produce the real deal they'd do well to throw money at this project to speed development.

In any case, these lasers just have to replace some roles for more expendable munitions, assuming firing the laser is significantly cheaper than dropping a bomb or firing a smart missile.

Re:over one second?

[v1]

tho especially considering the criticality of weight, it's a lot easier to coat a missile with chrome than armor plating.

One would assume that all ICBMs around the world are either already chromed or can be retrofitted very easily should the laser tech become more mainstream.

Re:over one second?

[hAckz0r]

In theory you are right, but the real world presents many problems for such technology. For one, an aircraft flying through a chaotic air stream has a real problem with keeping the laser on target, hence the funding for the airborne missile defence laser getting yanked by Congress. A fighter will bounce around a lot more than a 747 class aircraft, so if you can't knock it out in a couple of nanoseconds of burst, good luck with trying to heat it up as it travels through the atmosphere cooling off. Most thing that travel fast are designed to take the heat, as friction can play a major role in military equipment and is designed into most anything that matters. And all that is still assuming that the target is steady and the air refraction at that wavelength of light is optimal for the distance, humidity, and air pressure you are operating at. Light bends when it travels through air of varying densities.

My take is its hard enough to hit something using a stationary laser, so good luck with one that is bouncing around at even a short distance, unless it is VERY powerful. A Gigajoule laser would be helpful but you won't find one of them in a fighter-jet any time soon.

Re:over one second?

[socceroos]

One second of laser-shining-on-a-moving-object can't be TOO hard.

I thought that the star wars system failed because of this very fact?

Re:over one second?

[DerekLyons]

Any sort of energy that is released in the term of a second or so is useless against anything but stationary targets where you can assume you will hit the same point for that entire second.

That's based on two mistaken assumptions: First, that the last doesn't have any tracking and pointing mechanism. Second, that only delivering 100% of the energy onto the target is militarily useful.
 

Bullets on the other hand expend their energy in a range of ten thousandths of a second.

Yet, fighters and soldiers both are equipped with machine guns because it's hard to get a bullet on target.
 

Just make your missiles spin and any energy hitting them will be over a very large area.

That would be true - if spinning the missile was easy. For a large variety of reasons, missile designers go to great lengths to prevent their missiles from spinning. (And the other aircraft, manned and unmanned, that will be main target of a laser equipped fighter can't spin.)

Re:over one second?

[Martin Blank]

Most ICBMs that I've seen are painted, presumably to help battle corrosion as their service lives may be measured in decades. The Minuteman III is painted, as are the Trident SLBMs. On the Russian side, every color picture of a current-service ballistic missile I can find shows that they are painted. Chroming them would probably be expensive and may add weight, a critical point to consider on a weapon where range is of primary concern.

Re:over one second?

[yurtinus]

Except at the energy levels involved- while you may reflect an initial portion of the energy, the energy that did not get reflected will ablate the surface and pretty quickly remove your shinies.

I mean, did you even *see* what the fingerprint smudge on the lense did in Real Genius?!!?

Re:over one second?

[ceoyoyo]

They've demonstrated the HELL system shooting down missiles and (spinning) artillery and mortar shells.

Re:over one second?

[BitZtream]

Just for reference, the Star Wars lasers of yesterday are very much becoming a reality today.

Last weekend NatGeo or Discovery, can't remember which was running a series of shows showing lasers being used to destroy missiles and other lower powered versions being used to simply blind them, causing them to lose tracking and not hit the target.

Due to defraction (is that the right word?) in the atmosphere, you don't even hit the target with a 'laser beam' like you see in the typical TV show, its already a beam of light thats spreading out over distance anyway.

Lasers are already being used to shoot down targets from larger aircraft ( large bombers who can carry the currently large required hardware ) and UAVs have already been fitted with systems to track targets heat seeking missiles and blind them.

They will not make good weapons

They already ARE weapons, they just need some refinement before they become good weapons.

Re:over one second?

[barath_s]

"Until lasers or other beam weapons can deliver enough energy in a short enough amount of time (10 thousandths of a second) similar to a bullet or supersonic missile, they simply will not make good weapons" How about using lasers to deliver 4 MJ of energy in a few picoseconds, resulting in 500 TW of power?. That's expected to be enough to cause fusion. Of course, this plan will deliver it to a stationary capsule instead of a missile, but surely that's engineering ? http://en.wikipedia.org/wiki/National_ignition_facility

re:over one second?

[Anonymous Coward]

I worked on a laser system that was designed to shoot down rockets and mortars. I can tell you that there's enough energy put onto the target to melt through inch thick or thicker rocket/mortar casings easily within the time of flight.

As to the spinning, that's actually better. When a laser is melting metal, the melted part gets in the way of the beam. On non-spinning targets you actually have to wiggle the beam a bit to counteract that problem. If the missile spins, then you just keep it on the target and you melt a nice ring through it.

I see two problems with the laser in the article though
1) too weak, 150 Kw isn't really weapons grade
2) lasers melt, they don't explode, so you have to have very precise targeting to put energy on something that goes boom, otherwise you just melt divots.

Re:over one second?

[astat]

Your parent message already gave you the counter-argument: Simply make the missile spin, and you have (at least) an entire circumference to cook instead of a single point.

Re:over one second?

[Valdez]

Any sort of energy that is released in the term of a second or so is useless against anything but stationary targets where you can assume you will hit the same point for that entire second

Northrop Grumman's Mobile/Tactical High Energy Laser system disagrees with your assessment... just ask the mortar shells it shot down. They've been able to shoot down large and small caliber artillery rockets, artillery shells and mortars.

Last I heard someone decided it was too expensive given the current technology and cut funding. NG was working on a less expensive version dubbed Skyguard, which may be able to protect traffic at commerical airfields from shoulder-launched anti-air missiles. (Haven't seen any videos of that system yet).

There's also the YAL-1A, same concept but mounted on a turrent in the nose of a 747.

All these systems use chemical lasers, and while we can fit them into "a few semi-trucks" (or a 747) right now, they're far from being hand-held. In any event, we're past the "Can we shoot down X with a laser" argument and are currently figuring out how to make it smaller and more cost effective. It takes intermediate research programs such as these if we ever want our ships, tanks, or soldiers making pewpewpew noises when they pull the trigger.

Re:over one second?

[TCPhotography]

There are reasons why ballistic missiles don't spin. Most are related to the thin-wall structure that they use, and others are related to the fuel not linking being spun at the RPMs needed to have any effect. As for mirroring, see my post here: http://tech.slashdot.org/comments.pl?sid=1447506&cid=30149430

Re:over one second?

[avandesande]

There has been huge gains made in efficiency and maximum power of lasers in the last decade.
Look up 'fiber lasers'

Re:over one second?

[TCPhotography]

Except there are technical reasons why spinning a ballistic missile is a Bad Idea.

Re:over one second?

[TCPhotography]

No, the SDI program did go somewhere, it's called the Ground Based Interceptor and the Air-Borne Laser (YAL-1A, not the program mentioned in TFA), both of which you can blame President ZerObama for gutting!

Re:over one second?

[socceroos]

Wasn't the original goal to have these lasers mounted on satellites?

Re:over one second?

[TCPhotography]

Orbital Lasers were one option, the issue is that the current lasers that have the needed power output are chemical, which means you get a handful of shots before you need to reload. Once we build a powerful enough Solid state laser, then you just need to orbit a big solar array and a nuclear reactor, and you're ready to go for quite a while.

Somewhere in the Universe.....

[Sean Trembath]

Greedo is starting to sweat

Re:why is this word never used correctly?

[Anonymous Coward]

Presumably, the ultimate contract is the one that actually puts the lasers on the sharks. Most Slashdot readers would have understood that from the first sentence alone!

nice

[nomadic]

Now that's a slashdot article title I think we can all approve of.

Obligatory

[Dripdry]

Val Kilmer seen running around MIT hollering with joy.

Re:Obligatory

[DragonWriter]

Val Kilmer seen running around MIT hollering with joy.

"Pacific Tech" from Real Genius was modelled on (very closely, in many areas) Caltech, not MIT.

Re:Obligatory

[cfa22]

I know someone's house that's full of unpopped popcorn...

Recoil

[Doc Ruby]

Does firing a laser bring recoil opposite the laser's direction with the energy equal to that in the laser, the way firing a bullet does?

Re:Recoil

[MichaelSmith]

Does firing a laser bring recoil opposite the laser's direction with the energy equal to that in the laser, the way firing a bullet does?

Yes, but not enough to notice. In theory a laser can be used as a rocket drive, as can my LED torch. Just not a very good rocket.

Re:Recoil

[Doc Ruby]

If the recoil has the energy of the projected laser but in the opposite direction, the way a bullet gun's recoil does, how is it not enough to notice? The lasers in this article, including the hypothesized portable version, pack quite a wallop.

Re:Recoil

[MichaelSmith]

If the recoil has the energy of the projected laser but in the opposite direction, the way a bullet gun's recoil does, how is it not enough to notice? The lasers in this article, including the hypothesized portable version, pack quite a wallop.

The recoil has the momentum of the projected laser. Photons, like atoms, have mass-energy which, along with velocity determines momentum. But a lot of energy gives very little mass. So photons have a lot of velocity (C) and hardly any mass, so they have hardly any momentum for a lot of energy.

The atoms in normal rocket exhaust have less velocity but heaps more mass-energy, most of which is just dead weight.

Re:Recoil

[volsung]

Because recoil due to conservation of momentum, not conservation of energy. The "projectiles" (ok, summing over many, many projectiles with the laser) leave with the same kinetic energy, but the rest mass of the photon is zero. Since we're dealing with photons, we would really need to do the math with conservation of relativistic 4-momentum to get the right answer. (Newtonian conservation of momentum says there would be no recoil at all from a laser, but that's not quite true. It's just really, really tiny.)

Re:Recoil

[XSpud]

The recoil doesn't have the same energy, but it will have the same momentum.

Re:Recoil

[jpmorgan]

Photons have no rest mass; they have a very high energy:momentum ratio. So yes, there is some recoil, but it's insignificant.

Re:Recoil

[v1]

Does firing a laser bring recoil opposite the laser's direction with the energy equal to that in the laser, the way firing a bullet does?

Most of the energy of a laser is in the heat, and very little in the mass of the photons being fired. Bullets work the other way, their energy is almost all in the mass, and very little in their heat.

So lasers have almost zero recoil.

That being said, the kinetic (mass) energy of a bullet is basically converted to heat when it hits, and it can be considered to burn/melt through armor to some degree as well as punch a hole in it.

Re:Recoil

[Doc Ruby]

Right - momentum is equal in trajectory and recoil, not energy. There's not a lot of momentum in even a high powered laser beam compared to the inertia of the laser machine firing it, absorbing the recoil.

Re:Recoil

[MichaelSmith]

Should be simple

e=m*c^2

m=c^2/e

momentum = mass * velocity

=v*c^2/e

Or maybe thats naive.

Re:Recoil

[Chris Burke]

Naw, that doesn't work, though the real answer is still simple. You have to use the relativistic energy/momentum relation. E^2 = (pc)^2 + (m0*v^2)^2, which for a photon is simply E = pc. Also, E = hf, so you get hf = pc, or p = hf/c = h/lambda, Plank's Constant divided by wavelength.

Re:Recoil

[stoborrobots]

Surely, that should be

m = e / c^2

But more importantly, that equation is for a particle at rest.

It's a special case of the Energy-momentum relation, for objects as observed from their rest frame.

For light, (or other massless quantities), the relevant special case is:

E = pc

(energy = momentum * speed of light)

Re:Recoil

[Eudial]

The recoil has the momentum of the projected laser. Photons, like atoms, have mass-energy which, along with velocity determines momentum. But a lot of energy gives very little mass. So photons have a lot of velocity (C) and hardly any mass, so they have hardly any momentum for a lot of energy.

The atoms in normal rocket exhaust have less velocity but heaps more mass-energy, most of which is just dead weight.

Photons have no mass at all. If they did, they couldn't travel at the speed of light. Now they can't travel in any speed -but- the speed of light.

They still have momentum though, but it is not classical momentum in the sense of "mass times speed", but it's like momentum every way that counts though. The equation for momentum of a photon is p=E/c, where p is momentum, E is photon energy and c is the speed of light.

Wake me ...

[Archangel Michael]

Wake me when they make a {voice=Arnold}"phased plasma rifle in the 40 watt range" {/voice}

Re:Wake me ...

[MichaelSmith]

I think we are way beyond 40 watts now.

Re:Wake me ...

[v1]

The idea is to have a weapon with LOW power requirements

Does not exist. Most (non-tactical) weapons are designed to do a maximum amount of disruption to the enemy, that means doing "work". Hence the majority of weapons deliver the most energy they practically can on target, in a way that's destructive.

When you say "power" I think you mean to say "energy". And there's a lot of kinetic energy in say, a bullet. In the case of the lasers, it's in the temps created by the photons. Either way you are sending energy ("power") downrange in such a way that the enemy can't handle it and it causes damage.

In the case of bullets, gunpowder holds a good deal of energy and is fairly efficiently converted to energy doing damage downrange. Lasers are just a different way of sending chaos-inducing energy downrange. They have different advantages and disadvantages over bullets.

Getting back to your original statement, there's a massive amount of "power" in an M16's magazine. The problem with lasers is their efficiency really really stinks, whereas gunpowder's good. So you have to carry a lot more energy with you for a laser weapon, and waste most of it. (not delivered downrange with consequences) Imagine how impractical an M16 would be if the bullets (bullet in cartridge) were the size of softballs? That's sort of what they're trying to fix with the lasers right now. The tech works, it's effective, it's just not convenient yet.

Re:Wake me ...

[Chris Mattern]

40 watt? So basically, you want a flashlight.

Re:Wake me ...

[maxume]

It depends on how efficiently the 40 watts are delivered. For instance, touching a hot light bulb generally isn't particularly pleasant.

Is a comparison to bullets apt?

[Zouden]

It seems to me that 750 joules of kinetic energy in a bullet would do a lot more damage to a target than 750 joules of electromagnetic energy. A laser can only burn through tissue, and that'll always take longer than a metal slug takes to penetrate, given the same amount of energy, right?

Re:Is a comparison to bullets apt?

[BlueKitties]

What you're thinking of is impulse -- when car hits a brick wall, it loses the same energy it does when it uses its breaks, the difference is impulse (though the momentum remains the same.)

I'm not sure how much that applies to lasers; You have to realize a laser will never "bounce," the energy distribution is entirely different. It's like comparing catching someone on fire to shooting them in the face. A laser of that power might burn a four inch hole, whereas a bullet might shoot right through.

Re:Is a comparison to bullets apt?

[geekoid]

no.
It depends on the lengths of time the 750 is delivered

"A laser can only burn through tissue,"
I don't know why you think that, for 400 bucks you can buy a LASER that cuts metal.

Re:Is a comparison to bullets apt?

[esampson]

Yes and no. The amount of energy isn't a terrible base line of comparison if you are doing "apples to apples". There are really 3 factors involved; the energy, how rapidly and efficiently the energy is transferred to the target and over how much area. Sunlight is a pretty good way of illustrating this. In full sunlight you can assume that 1 square foot (30cm x 30cm) receives about 100 watts of energy. Since 1 Joule is 1 watt per second that means that in about 7.5 seconds an area roughly the size of your chest would receive about as much energy as a 9mm bullet.

Obviously this has practically no effect on you. However take a magnifying glass a bit over 1 foot across (32 cm) and focus all of the energy into a spot a little under 1/3 of an inch (9 mm) across and all of a sudden you're causing some serious skin trauma. Likewise if the sun were suddenly 7.5 times brighter you would start to peel and blister in a hurry. Combine all the light of 7.5 seconds into a circle 1/3 of an inch across and apply it all in 1/100th of a second and you'll inflict some real damage.

Unfortunately the laser in their example delivers all its energy about 100 times slower than that. There's also a question of how big the target spot is and of course the fact that just the color of the target can cause a substantial amount of the energy to be reflected (substantial in this case being perhaps a few hundred Joules). So while the total amount of energy isn't a terrible way to compare them that does assume that the beam is focused relatively tightly (probably a safe assumption) and delivers the energy as a sudden single shot (which it clearly doesn't). As it is the comparison is less "apples to apples" and more "apples to orangutans".

Re:Is a comparison to bullets apt?

[DragonWriter]

It seems to me that 750 joules of kinetic energy in a bullet would do a lot more damage to a target than 750 joules of electromagnetic energy.

That's going to depend primarily on how the energy is distributed (both in space and time). The particular hypothesized device here would deliver the 750J over a much longer time than the firearm it is being compared to (nothing is said about the area in which it would be concentrated), but there is nothing inherent in lasers which means that this would necessarily always be the case.

Re:Is a comparison to bullets apt?

[ceoyoyo]

If your laser is intense enough it won't so much burn through tissue as vaporize it. In the case of a person, that means turning water into steam. Steam has a volume something in the neighbourhood of 1500 times that of water, so that phase change really qualifies as an explosion (nitroglycerine expands by about the same factor when detonated).

Re:Is a comparison to bullets apt?

[caller9]

I agree it could be more powerful, but I thought the point of lasers was silence, precision, very little splash damage, and light speed travel to the target. Bullets are way slower than light, more adversely affected by wind, windows, etc. The use for this would probably be sniping guys with guns off a mosque with a drone instead of blowing up all their civilian shields and getting on the news.

Slightly more info and likely a big part of TFA's source:
http://www.ga.com/purchasing/pdf/HELLADS.pdf

heh, captcha is ablation ;)

cool

[xynopsis]

looks cool

Moving Mass

[SuperKendall]

Think about how a gun works - you are accelerating a substantial mass (bullet). With a laser, you are accelerating photons which have almost no mass, so even though the same amount of energy is involved you have far less recoil.

...and so does "final stage prior to..."

[DragonWriter]

"Penultimate" means "second to last" and nothing else.

Which is exactly the sense in which it is used here, as is indicated by the language from TFA quoted in TFS: "the final stage prior to America's first raygun-equipped jet fighter."

So, in the series in which the last (or "ultimate") stage is the contract for a laser-armed jet fighter, the contract for the ground-based prototype is the second to last (or "penultimate") stage.

So, great job of knowing what "penultimate" means, but next time work on reading and understanding the post in which it is used before accusing someone of using it wrong.

Re:...and so does "final stage prior to..."

[sexconker]

So, great job of knowing what "penultimate" means, but next time work on reading and understanding the post in which it is used before accusing someone of using it wrong.

I think you mean "accusing someone of using it incorrectly".

Re:...and so does "final stage prior to..."

[Logic and Reason]

I think you mean "accusing someone of using it incorrectly".

I think you mean "I am a pretentious git".

Re:...and so does "final stage prior to..."

[TFGeditor]

No, the summary used it exactly as the OP stated, and said use was incorrect. Pulling a lame justification out of your ass doesn't change that.

Kent... Wake up Kent.

[Anonymous Coward]

All you'd need is a large spinning mirror and you could vaporize a human target from space. Better go make sure someone didn't steal Kents tracking system.

Plus sharks with FRICKIN LAZER BEAMS attached to their heads?

I like the first movie better.

Energy T Y P E matters -- HOT water

[redelm]

OK, so 702 joules sounds impressive. It is, but only for mechanical energy. Those same 702 joules only heat 10 mL of water 17'C (30'F). Not even enough for a burn! But maybe enough to blind.

Re:why is this word never used correctly?

[Hatta]

One of the deals will see a full-power ground prototype built which will be the final stage prior to America's first raygun-equipped jet fighter.

This prototype is second to last(penultimate) contract in this project. The last one (or ultimate) will be for the actual jet. The use is valid.

It is used correctly

[DragonWriter]

penultimate: last but one in a series of things; second to the last

[At risk of being modded redundant (but since none of the three posts I've seen making the same criticism of TFS have been yet, maybe not)]

This is exactly the sense in which it is used here, as is indicated by the language from TFA quoted in TFS: "the final stage prior to America's first raygun-equipped jet fighter."

So, in the series in which the last (or "ultimate") stage is the contract for a laser-armed jet fighter, the contract for the ground-based prototype is the second to last (or "penultimate") stage.

So, great job of knowing what "penultimate" means, but next time work on reading and understanding the post in which it is used before accusing someone of using it wrong.

Darpa’s ‘Liquid Laser’ Gunship

[auric_dude]

More information via http://www.wired.com/dangerroom/2009/11/darpas-liquid-laser-gunship-program-pushes-ahead/

That's great, but...

[esampson]

From TFA:

If it scales down far enough, this would seem to put handheld HELL-guns within an order of magnitude of the striking power offered by conventional small-arms. A 9mm pistol bullet has about 750 joules muzzle energy: a 5kg portable HELL-ray weapon would put out this much energy in a blast less than a second long.

Since 9mm guns tend to be pistols they weigh a lot less than 5kg (11 lbs.). Most semi-automatic pistols are also capable of accurately firing 3-4 rounds per second and as has already been mentioned keeping a 750 joules laser on a target for an entire second would be close to impossible unless the target was completely incapable of movement, so that energy is going to be diffused across the target reducing it's effectiveness pretty severely.

I guess the last thing I feel obligated to point out is that a handheld HELL-gun that is within an order of magnitude of the striking power offered by conventional small arms would have about 75 joules of muzzle energy and would be about as dangerous as a BB gun (You could put your eye out with it). An order of magnitude is a factor of 10.

Re:That's great, but...

[Plekto]

Most semi-automatic pistols are also capable of accurately firing 3-4 rounds per second and as has already been mentioned keeping a 750 joules laser on a target for an entire second would be close to impossible unless the target was completely incapable of movement

Add to that that most aircraft mounted guns are .50 BMG, which puts out a whopping 17625 joules and has a several mile range(as well as being dirt cheap and plenty effective) and you're looking at probably 20-30 years to equal that. It's a nice first step but nothing more.

Re:That's great, but...

[esampson]

Most aircraft mounted guns also weigh significantly more than 5 kg. I know, my first thought was why are they mentioning 9 mm when they are talking about aircraft mounted weaponry? Turns out that they are discussing scaled down versions in that section to the article.

Re:That's great, but...

[Martin Blank]

Most aircraft-mounted guns used for anything other than anti-personnel (like troop-carrying helicopters) are significantly larger than .50BMG. If you're strafing, you're mostly using 20mm (M61 Gatling series on US fighters, M197 on Cobras), 25mm (GAU-12U on the Harrier), or 30mm (GAU-8A on the A-10, M230 on the Apache) rounds in most cases. AC-130 gunships primarily make use of 20mm, 25mm, 30mm, 40mm, and 105mm cannon.

Re:That's great, but...

[caller9]

TFA is just speculating a linear scale down to handheld and shark-mounted lasers as a joke. Pretty funny too.

The goal weapon is 150kW which will put out the .50s 17kJ in about .11 seconds.

Nothing mentions the diameter or frequency of the beam used, but as another person alluded exposed human parts would explosively vaporize, metal would melt, and clothing would ignite(sufficient to stop combatant) pretty quickly.

36.6C, 40kg body water raised to boiling 63.4 degrees.

40kg * 63.4C * 4.18kJ/(kg * C) / 150 kW = 70.7 seconds to boil a 40kg person.

But that isn't how it works, it's focused on say 20 cc of water. .02kg * 63.4C * 4.18kJ/(kg * C) / 150 kW = .035 seconds. So 20cc * 1700 = 34000cc BOOM!
http://www.wolframalpha.com/input/?i=.02kg+*+63.4C+*+4.18kJ%2F(kg+*+C)+%2F+150+kW

So (according to wolfram alpha http://www.wolframalpha.com/input/?i=.035+s) between .4 to .7 of a "blink of an eye" 20cc of water turns to 34000cc of steam with what was a part of your body...and nobody said they turn the beam of here.

That probably over-simplifies how the energy would be converted and propagate through tissue, but who knows the frequency or diameter of the beam?

Re:What about the ultimate contract?

[DragonWriter]

OK, so did they also let the ultimate contract

No, the "ultimate" contract "for what is intended to be a jet-mounted laser cannon" would be the contract for a jet-mounted laser cannon. The contract described here as "penultimate" is for "a full-power ground prototype" intended as to "be the final stage prior to America's first raygun-equipped jet fighter" and which is, therfore, correctly described by TFS as being "the penultimate contract for what is itended to be a jet-mounted laser cannon".

There is lots of misguided pedantry here ragging on TFS for using "penultimate" correctly.

Re:useless against the enemies of freedom

[Nefarious Wheel]

How are the headaches doing, Czarangelus?

Re:useless against the enemies of freedom

[Areyoukiddingme]

Not only Godwinned but also... Satan? Surely there's a law for that too...

Even though this read mostly like a paranoid rant, it contains just enough grains of truth to be uncomfortable. It IS corporate welfare for Boeing and Raytheon, America DOES fund its own enemies, and the deaths of American soldiers DO enrich military contractors.

The only reason the last paragraph remains a paranoid rant is because I'm worth more to Goldman Sachs as a LIVE victim, rather than a dead one. My taxes justify their bailout.

Re:why is this word never used correctly?

[hey!]

It begs the question of why people use big sounding words and phrases they obviously don't understand. It literally makes my head explode.

Laser blasters are the weapons of barbarians.

[140Mandak262Jamuna]

I would like an elegant weapon from an more civilized age.

Re:Laser blasters are the weapons of barbarians.

[commodoresloat]

a musket?

Re:useless against the enemies of freedom

[czarangelus]

Empires fall from within first, due to corruption and incomptance. Clinton was selling American missile secrets to the Chinese, that sleazeball, I wouldn't be surprised if America had a long history of trying to get out of its debt obligations to China by providing them with military technology.

How did we get sharks to fly at jet speeds? with a

[Joe The Dragon]

How did we get sharks to fly at jet speeds? with a laser on them?

Re:useless against the enemies of freedom

[YrWrstNtmr]

We love you too, CZ. Have you paid off those student loans yet?

Re:useless against the enemies of freedom

[czarangelus]

Actually, my parents decided their Consumer Loyalty Oath score was more important than their money (the bank didn't accept my repayment offer, which at the time was every dime not going to rent, food, gas, and other necessity.) I'm a free man now supporting myself in the private sector by my own strength and the grace of God.

Re:why is this word never used correctly?

[LandDolphin]

It literally makes my head explode.

That had to hurt!

Re:why is this word never used correctly?

[JStegmaier]

Irregardless, I could care less about your head explosions.

Bullets and the LHC

[Roger W Moore]

Time to get into the mirror business! It's a lot easier to deflect protons than bullets, I'll tell you that.

That's strange considering that bullets, at least lead ones, are 40% protons by mass. It's also a real shame that you didn't tell us that before we designed the LHC - it would have been a lot easier to use mirrors to bounce the protons beams about the ring instead of using superconducting magnets. Perhaps you meant photons....

Fly in the clouds

[Ralph Spoilsport]

in a craft with reflective skin - lasers no longer a problem.

NEXT!

Re:Fly in the clouds

[WindBourne]

Any dirt on the surface will EXPLODE that theory AND the skin. INSTANTLY.

Re:Fly in the clouds

[BitZtream]

Reflective to what part of the spectrum?

Clouds don't block all wavelengths equally, nor does a mirror reflect all wavelengths equally.

Re:Fly in the clouds

[TagrenHawk]

In principle I would agree with you .... if there weren't such things as radar, SAMs and standard fighter jets. A highly reflective airplane, even in the clouds, would be a huge target for most modern radars. So, load up your jet with a laser AND a few missiles. Boom. No more pretty, shiny jet.

Even if you don't carry missiles on your fighter jets, fly in such a way to force the enemy to fly over your SAM sites. They would show up just as well for a ground radar.

There is a reason that most military aircraft aren't shiny any more.

Now, if you could create a paint that is highly absorbent to a variety of wavelengths, and can dissipate the heat, that would make more sense.

Makes me wonder just how well our current composite paints for aircraft like the F-117 would absorb a laser hit. I bet someone has the corollary defense contract for this laser.

Re:What about the ultimate contract?

[yurtinus]

Can we still rag on TFS for being precocious by using words like "penultimate?"

Re:What about the ultimate contract?

[DragonWriter]

Can we still rag on TFS for being precocious by using words like "penultimate?"

I'm not sure why you'd "rag on" something for being precocious ("unusually advanced or mature in development, esp. mental development"), but, sure, knock yourself out.

You say that now...

[hellfire]

But what happens when you need to heat up your giant bag of popcorn?

Re:What about the ultimate contract?

[yurtinus]

...well played.

power storage?

[WindBourne]

Hmmm. Just several years ago, these units did not have the power to run for multiple shots and would not be ready until after 2015. Now, it appears that we have solved the power issue. Chemical storage (batteries) can not do it (high energy, but not enough power). Likewise a chemical approach would not allow for lots of shots (it would be more like 10-20 shots; no more).
What changed? Is there a new supercap coming that has VERY HIGH power storage? Perhaps with high power AND high energy (charge it on the ground and then take the energy up)?

Re:why is this word never used correctly?

[selven]

Because it is a socioeconomic imperative that the integrated global community leverages its synergies and initiates large-scale paradigm shifts in order to stay competitive in tomorrow's world.

ObRealGenius

[TheSync]

Looks at the facts: very high power, portable, limited firing time, unlimited range.

All you'd need is a big spinning mirror and you could vaporize a human target from space.

Re:why is this word never used correctly?

[EdZ]

It begs the question of why people use big sounding words and phrases they obviously don't understand.

It begs the question

big sounding words and phrases they obviously don't understand.

You're damn lucky your sig covers this eventuality.

PLASMA CANNONS. Come ON!

[Kingrames]

Seriously, how many times to I have to ask this. The Razer needs a total of SIX plasma cannons; two mounted on the tips of its wings and 4 along the hull. This prototype they've sent us will do for now, but what are lazers supposed to do againt giant frickin mechs? and don't get me started on projectile weaponry. With an aerial combat vehicle like this we get one shot at a stealth strike, and a one shot one kill weapon is the best we can hope for.

I ain't taking this on any test runs until you deliver me some real firepower.

(kudos to anyone who gets the reference)

Re:PLASMA CANNONS. Come ON!

[Jedi Alec]

Hmmm....Earthsiege 2? And if I remember correctly, I flew the Razor(sp?) with 2 plasma cannons, 2 autocannons and 2 missile launchers.

Re:useless against the enemies of freedom

[Areyoukiddingme]

My city is so profitable I drive over two brand new bridges every day, and over or under 4 more that are less than 4 years old. Guess I'm safe.

On board generator

[EdZ]

If I recall correctly, the original plan was to put this in the F35. Take out the lift fan, and use the driveshaft to power a generator.

Re:why is this word never used correctly?

[evanism]

Thats a very cromulent explanation. Enbiggening for its own sake is endumening.

I need sleep

[Das Auge]

I read that as "I would like an elephant weapon from an more civilized age."

I thought, "What kind of weapon is an 'elephant weapon'? And before I could stop myself, I had a mental picture of an elephant slamming into a Mig fighter.

Re:I need sleep

[Rennt]

What kind of weapon is an 'elephant weapon'?

Usually a .600 Nitro double barrel.

That does it! This is insane!

[Jackie_Chan_Fan]

A dolphin with a laser taped to its head, nailed to an airplane?!!

THIS IS MADNESS!

not very effective

[assert(0)]

5kg, 750 J? Seriously?

Wake me when 5kgs of marine mammal weapon systems produce 4.5E17 J.

the thing that's really cool about this

[commodoresloat]

is that it's a laser Canon, so it makes prints and copies too! Nothing like taking out your enemies with laser clarity, high resolution, and extreme prejudice.

Laser defences

[TandooriC]

Could a mirror deflect a laser cannon blast? Or should we just stick to the more conventional deflector shields? Full power to shields!

Re:liquid fuel laser = fail

[BitZtream]

Thus the "ammo" for the laser is no longer limited by custom nasty liquid fuels, but by the available jet fuel in the plane, which already has an extensive refueling infrastructure readily available, aka a tanker refuel.

You realize that tanker is actually carrying ... liquid fuel right? And that the aircraft is powered by ... liquid fuel, which you are then suggesting to use to power the weapons package.

Regardless of how you look at it the energy has to come from somewhere. If electricity from the turbine was more efficient, that would probably be the energy source used. However conversion and the related losses make it so that right now its more efficient to carry a separate weapons specific fuel payload. Just like is done with every other form of weapon on the aircraft. Missiles use their own solid propellents, as do cannons. Use the right power supply for the job.

Its not like it would be overly difficult to add a refueling system to deal with this secondary weapons system if it were that useful.

In reality, air to air refueling isn't done to keep an aircraft in combat longer, its to keep it on station (without being in combat) longer or to allow it an extended range. After a pilot has had an encounter he/she generally needs some cool down and recovery time from the stress alone, not to mention that the aircraft generally needs some maintenance work. It doesn't happen like you see in the movies. Pilots don't shoot down 8 aircraft with missiles then 5 or 6 with the cannon and hang out for a while covering their wingman while Iceman slides in for the shot on Viper. Even if the weapon provided an endless supply of shots, all you would be doing is ending up with a pilot who stayed in combat until fatigued to the point of being killed. Then you've lost a good man and an aircraft.

Re:Energy T Y P E matters -- HOT water

[Cassini2]

Those same 702 joules only heat 10 mL of water 17'C (30'F). Not even enough for a burn!

I think you nailed the key problem. Any laser energy hitting human skin is likely to be absorbed as heating water. The human body is 60% water, and water requires a great deal of energy to boil and do significant damage. Essentially, if the person remains still, the laser beam will cause serious surface burning. The natural reaction for a person being burned is to move. If the person moves, the laser may only do superficial damage. If the person is wearing clothes and moving, getting hit by a 750W laser might equate to a nasty soldering iron or welding burn. It might hurt, but it won't slow down an enemy soldier in combat.

Re:why is this phrase never used correctly?

[jeffrey.endres]

Read the second sentence and signature.

pewpewpew!

[Narcocide]

That's the sound *mine* is going to make, I'll tell you that for sure right now however the the laser emitter itself will probably make something more like a quiet hum.

Re:why is this word never used correctly?

[WoodenTable]

LOL! (metaphorically i mean)

Re:why is this phrase never used correctly?

[grcumb]

It begs the question...

No, it does not.

Might I suggest you re-read the post. I suspect the writer's head did not 'literally' explode, either. I further suspect there might be a touch of dry humour to be inferred from the deliberate misuse of language in a tirade against the misuse of language.

One might even go so far as to call it a rather witty example of sarcasm.

All of which leads to the inescapable realisation that the proper idiom for the moment is, "Whooosh!"

Re:why is this word never used correctly?

[mabinogi]

. Makes you wonder why people use big sounding phrases they obviously misunderstand...

I'll give you a clue - it's like goldy and bronzy except it's made out of iron.

Body Armor

[neorush]

Would body armor for this weapon involve covering your self in something like tinsel to refract as much of the energy as possible? It would just be awesome to see a bunch of highly trained marines running around in Christmas Tree outfits.

weapon efficiency and "energy"

[CAIMLAS]

The amount of energy imparted has little to do with actual weapon performance. What matters is how well that energy is imparted to the subject/target. This is why many consider the .45ACP (a cartridge which has relatively little energy) a better stopping caliber than, say, .223 Remmington/5.56 NATO (which has a relatively larger energy). The percentage of PE to energy imparted from the .45 is significantly higher than from the .223 (which tends to just pass on through) due to bullet design.

  To get a laser cannon capable of "stopping power" (regardless of your target) you would need to, essentially, burn a crater into or a hole through the subject. I have no idea how much power is required for that, but if we're talking about kjoules, we haven't got nearly the technology for it. The article is pure fantasy: short of portable, weapon magazine ("clip") like nuclear power cells capable of short, multiple, controlled explosions, this won't be actionable for some time.

9mm para has about 450-550 joules

[Werrismys]

A typical 9mm pistol using a typical 9mm cartridge can achieve kinetic bullet energies in the 500J ballpark.

More than that requires overpressure variants (P+, +P+) or lighter-than-normal bullets.

P+/+P+ loads impose more wear and tear on the frame/slide, so I say using them is madness. Many use these in IPSC to achieve greater "power factor."

I see..

[dgr73]

the US taxpayer money is obviously hard at work again. The Taliban must be shaking in their boots when they hear of this... "A jetfighter with a laser?!?! How much rock can it penetrate?".

Don't be ridiculous

[Logos]

The laser is nailed to the head, so that it won't fall off during high speed maneuvers and the fish* is taped to the airplane so that it can be dropped on commando raids deep behind enemy lines - granted, they just sorta flop around on the ground afterward, but anyone walking by is likely to get quite a sunburn.

*Yes, we've been *told* they are mammals, but I believe its all a conspiracy started by the "late"** Douglas Adams to ensure that they wouldn't be seen as cannibals during the pre-release marketing for his fourth book in the trilogy.

**I put late in quotes because we know that he's just gone home.***

***OK, I've got nothing... POPCORN!

Understand?

[Civil_Disobedient]

Lets put that into terms every slashdotter will understand.

And then you go using centimeters instead of inches. FOR SHAME.

Stormtroopers

[corbettw]

Over 350 comments and no one has mentioned Stormtroopers (from 40k) carrying hellguns or made jokes about the AP value of these new weapons? For shame, Slashdot, for shame.

Meh..

[EriktheGreen]

HELL-guns are ok, but given a choice I'll take a godwyn pattern bolter any day of the week.

Erik

SHARK!

[DarthVain]

Stealth Harrier Armored Ray Kannon or S.H.A.R.K. is the latest is fighter laser technology!

sry the best I could do on short notice... you do better, I dare you!

The acronym department is failing

[ClintBartonWannabe]

There has to be some way to put Frickin into an acronym for the shark laser. That way it truly would be sharks with F.R.I.C.K.I.N. lasers on their heads. I guess you could lose the C if needed.

Dude where do you live (or shop)?

[GameboyRMH]

I've seen you mention taking a gun into the grocery store multiple times. I really feel sorry for anyone who lives (or shops) in such a bad area that they have to take a gun to the grocery store.

"Well, time to get the groceries. Come on honey, get the kids in the van! Whoops, better take my large-caliber handgun. In case I have to kill someone....while getting groceries..."

Re:Dude where do you live (or shop)?

[Shakrai]

It's folly to think that you have to live in a bad area to become a victim of violent crime. My state has granted me the right to carry a concealed firearm. I choose to exercise that right whenever it is legal to do so, hence my interest in different handgun calibers and the merits/lack thereof of each of them.

Forget Copyright

[d34dluk3]

We need shorter expirations on war crimes treaties.

Canon Laser Jet Printer

[OricAtmos48K]

Am the only one to percieve the heading like this ?

Re:Energy T Y P E matters -- HOT water

[holmstar]

yes, but what if that energy is focused on a 1 sq cm area? then you would be heating 1ml of tissue by about 170 degrees C. If you managed to do that in, say 1/10 of a second then you would have explosive vaporization of that tissue, the shock-wave of which causing damage to the surrounding tissues. Maybe not quite as bad as a bullet wound, but still a severe injury.

Arming fighters with pistols

[DrVomact]

this would seem to put handheld HELL-guns within an order of magnitude of the striking power offered by conventional small-arms. A 9mm pistol bullet has about 750 joules muzzle energy: a 5kg portable HELL-ray weapon would put out this much energy in a blast less than a second long.

I can't get the article to load, but that claim sure underwhelms me. So the author thinks it would be useful to put something that emits the equivalent of the muzzle energy of a 9mm (presumably Parabellum) pistol round per second? Even if that meant the beam had the destructive potential of such a round, it would be a ridiculous weapon for a very expensive, very fast fighter plane—they have automatic cannon that fire armor-piercing, tank killing shells, they have electric "gatling guns" that can fire thousands of rounds a second, they have missiles that can kill or destroy at great distances. And we're supposed to think it's a good idea to mount the equivalent of a pistol on such a plane? As for blinding enemies...well sure it might work for that. But why not just obliterate them?

In any case, comparing the kinetic energy of a projectile to the energy of a laser beam is not useful. While energy is pretty much irrelevant in pistol calibers (they are just good for making holes), the kinetic energy of a 5.56 NATO round can cause considerable damage if it tumbles inside you. A tungsten or depleted uranium 2cm cannon projectile has a lot more energy, and does correspondingly more damage. The problem with a laser is that unless you can deliver a lot of energy in a very small amount of time, you will wind up spreading that energy over a large surface area as your beam moves over your target, which is presumably not holding still and offering itself for frying. Then there are other factors that mitigate the effects of lasers as weapons; for example, if you manage to vaporize some metal on your target, the cloud of vapor may diffuse your beam, thus preventing it from doing further damage. A laser is also going to have trouble shooting through clouds, fog, or even rain.

I'm not saying we're never going to get science fictional blasters, but this is a long way from a useful weapon. By the way, does the 5kg include the battery? How many seconds of continuous fire is the battery good for? Dang, wish I could get the article to load.

Re:Energy T Y P E matters -- HOT water

[redelm]

OK, lets do the calcs a different way -- it takes 2500 J/g to heat water from 37'C and vaporize it at atm pressure (100'C). So the 703 J will flash 0.275 g of water (about 5 drops) which will occupy about 440 mL as steam. Hardly explosive on a macroscale. Still, very nasty on the retinas.

Laser cauterize wounds

[Dareth]

Laser cauterize wounds. We need a laser that leaves you bleeding!

Mosquitos / House Fly Laser cannon

[Wargames]

I think of a time when I can leave the room, flick a switch, come back, and sweep up the dead bugs and feed them to my fish.

Armed Predator

[freedomseven]

I imagine that these type laser weapons will first be seen in UAV's anyway. They are kind of perfect when you think about it because they can attack soft targets so well. Like say a group of miscreants planting a roadside bomb. You just fire the laser and if there is something explosive, it blows up in the face of the person planting it.

Awwww. He fall down and go boom.

Re:why is this word never used correctly?

[Flere Imsaho]

I'm sorry, allow me to attenuate my portentousness .

Re:why is this word never used correctly?

[drkoemans]

Beat me too it. However his sig says "post may contain irony" and I think misusing "begs the questions" would qualify as ironic in the context of this post, though I realize I run the risk of being wrong myself here.

Absolute vs. perceived

[mi]

Next time post about what you know, rather than what you think you know

If only it were possible for a person to tell the difference, oh flaming philosopher!..

Re:1 second = 9mm ?

[avandesande]

Yes, and they are now adopting a new measurement of laser power, "9mm seconds".

Re:why is this word never used correctly?

[Malc]

Jeeze, some people don't get out much. Flamebait? Try observation of the real world. There are words Americans use that have fallen by the wayside elsewhere, such as "fall" instead of "autumn".