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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."
Ok, I see the obligatory "sharks" tag, but what about the "pewpewpew" tag?
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.
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Fail.
From you're own link, the bullet performance shows 702J as the highest energy output.
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.
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.
^photons. These are lasers, not particle guns.
Really? Compare the USP and the Glock pistols in Counter-Strike - which one does more damage?
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.
the knife:
http://www.youtube.com/watch?v=cudCajMNRM0&feature=player_embedded
The Kruger Dunning explains most post on
Then I take it GNU renders you apoplectic.
Protoplasm. Quiet Protoplasm. I like quiet protoplasm.
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?
I want peace on earth and goodwill toward man.
We are the United States Government! We don't do that sort of thing.
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.
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It begs the question of why people use big sounding words and phrases they obviously don't understand. It literally makes my head explode.
Post may contain irony: discontinue use if experiencing mood swings, nausea or elevated blood pressure.
I would like an elegant weapon from an more civilized age.
sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
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".
Irregardless, I could care less about your head explosions.
How can you guys deflect protons when you're being so negative?
-- John Truong
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?!
The enemies of Democracy are
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.
11*43+456^2
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]
"linux is just DOS with a UNIX like syntax" -- Galactic Dominator (944134)
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....
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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.
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.
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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...