Posted by
michael
on from the also-useful-for-making-popcorn dept.
KeyShark writes: "An article on FoxNews describes how front-line troops soon will be protected by battlefield lasers designed to shoot down rockets, artillery shells and even mortars."
Re:are artillery shells that delicate?
by
silicon_synapse
·
· Score: 2, Informative
It's the armor that makes the explosion possible. If you've ever held a match to a pile of black powder, you'd know that it doesn't do a whole lot. BUT if that black powder is confined to a small space, the pressure of the gasses builds until the container bursts. Hence the explosion. Now an artillary shell contains a lot of explosive and need to make a big bang. Therefore it needs a very thick, strong shell to contain the immense pressure of the gasses until enough gas has been produced to create the desired crater. That thick shell will also make it difficult to destroy enroute.
Re:Arm the cats
by
Zalgon+26+McGee
·
· Score: 2, Informative
Book(n): Utensil used to pass time while waiting for the TV repairman
Re:This raises some frightening questions
by
Anonymous+DWord
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· Score: 5, Informative
There's an international treaty that the US has actually signed (wonder of wonders!) against using lasers on people. I tend to doubt it'll be followed in practice though, when "our" forces are involved.
-- "If he thinks he can hide and run from the United States and our allies, he's sorely mistaken." Bush on bin Laden
Re:This raises some frightening questions
by
Razzak
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· Score: 3, Informative
There's a lot of treaties like this to minimize the "horrors" of war. For example, it's a war crime to use an anti-tank rocket or a.50 cal machine gun on infantry.
Re:Not too hard.
by
Knobby
·
· Score: 5, Informative
Am i forgetting something here?
Yep.. You're missing density variations and laser induced heating of the local atmosphere. Both of which will degrade the power of your beam, and complicate aiming the device. The Air Forces Airborne laser program attempted to solve these using a pair of low power lasers to sample the atmosphere and track the object. Given the information from the low power lasers, the optics for the primary laser could be corrected to hit the target. I'm not sure they ever got the system to work, but I seem to recall the power of the beam to be roughly equivilent to 30 ocyacetylin (sp?) torches focused on a single point.. There was a lot of speculation in the articles I read, suggesting that the laser power would be attenuated by some staggering amount by the atmosphere, and the chances for success were considered minimal by some of the scientists working on the project..
Don't forget, the owner of Fox News is Rupert Murdoch... You know, the guy who owns The National Enquirer, and numerous other tabloids... Hardly worth calling a reputable source (ironically his tabloids are the sort that would have paid well for pictures taken of Princess Di by the freelance French papparazi that chased her to her death, and even more ironic, that shortly thereafter her brother gave them an interview on teevee)...
Mind you, this was common knowlege over 10 years ago when Murdoch took over Fox, the NY Post, et al...
-- Just because you can mod me down, doesn't mean you're right.
Shoes for industry!
Re:This raises some frightening questions
by
Anonymous Coward
·
· Score: 1, Informative
The treaty is probably more related to the possible (and easy) use of lasers for blinding large amounts of people permanently (but I haven't looked, so I am posting cowardly to not spread unfounded rumors).
Arthur C. Clarke was a scientist who, among other things, wrote a paper explaining and introducing the principles of geostationary communications satellites before he sold his first hard science fiction story.
Tom Clancy got his degree in English, and worked as an insurance broker before he became a military drama novelist.
Re:Treaties
by
Anonymous Coward
·
· Score: 1, Informative
Germany, Japan, Italy, and a bunch of other european coountries.
There are only something like 9 countries which have nukes.
Re:This raises some frightening questions
by
Fesh
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· Score: 3, Informative
Hmm. Then the.50cal sniper rifles that the SEALS and other forces use are anti-equipment weapons? Pardon my cognitive dissonance here...
I thought the rule was anything larger than.50cal. 'Course, I'm sure that being strafed by 20mm is no picnic... (Hell, being attacked with anything would put a crimp in my day...)
-- --Fesh
Kill -9 'em all, let root@localhost sort 'em out.
Coil Guns don't
by
dmaxwell
·
· Score: 3, Informative
A rail gun vaporizes a thin conductive coating on the back of a shell and electrostatic repulsion of the vaporized coating thrusts the shell forward. This vapor is very hot so it wears away a good bit of the rails on it's way out.
A coil gun is a different sort of electropropellent. The "barrel" of the gun is a multitude of coils laid in a row. The coils are driven by banks of capacitors in rapid sequence. They work just like a solenoid except that a sequence of coils is employed for greater acceleration. A working coil gun can be fired many times as no hot plasma is involved in accelerating the shell.
The problem is that it is much harder to build an effective coil gun than it is a rail gun. The timing of the coil firings must be timed precisely. Fire a coil too soon and the shell is braked rather than accelerated. Fire it too late and little to no accelleration is imparted at all. Secondly, it takes a number of coils to do this. One big coil won't do much since it is pointless to increase power once the (ferrous) shell has been magnetically saturated. So multiple coils have to kick the shell up to speed. A lot of coils isn't the problem in and of itself. Each coil will need a large bank of capacitors to itself, this will serve to make the weapon very bulky. The capacitor banks also have to be recharged between firings. It will also take some doing to cool the system. Ever play with a home made electromagnet? It's going to get HOT.
So to recap, the device will have sophisticated sensing and timing requrements for the coils; the generator and capacitor banks will be bulky; getting a high rate of fire is problimatical and it will require a large cooling system as well. I haven't mentioned any sort of targeting system or the engineering requirements that will be imposed on the shells either.
Basically, a battlefield practical electromagnetic mass driver is at least as hard as this laser system.
Re:This raises some frightening questions
by
Stonehand
·
· Score: 2, Informative
Sure, it could be used as anti-equipment.
That 0.50-BMG cartridge was originally designed as an anti-tank (WWI era tank...) round, if memory serves. It likely has enough penetration to still be good enough for damaging many things besides flesh and blood today.
-- Only the dead have seen the end of war.
X-rays are refracted.
by
Futurepower(tm)
·
· Score: 3, Informative
X-rays are refracted and dispersed by the water vapor in clouds. Very short wavelengths might work, but I don't think they are feasible.
Slashdot Mirror
Military Lasers High and Low
Battle lasers are rapidly moving from the realm of theory into operational reality
The Airforce Association
http://www.afa.org/magazine/0999lasers.html
Most people would die sooner than think; in fact, they do.
http://lasers.llnl.gov/lst/helstf.html
It's the armor that makes the explosion possible. If you've ever held a match to a pile of black powder, you'd know that it doesn't do a whole lot. BUT if that black powder is confined to a small space, the pressure of the gasses builds until the container bursts. Hence the explosion. Now an artillary shell contains a lot of explosive and need to make a big bang. Therefore it needs a very thick, strong shell to contain the immense pressure of the gasses until enough gas has been produced to create the desired crater. That thick shell will also make it difficult to destroy enroute.
Gah. Hate to reply to myself, but I found a link!
---
Book(n): Utensil used to pass time while waiting for the TV repairman
There's an international treaty that the US has actually signed (wonder of wonders!) against using lasers on people. I tend to doubt it'll be followed in practice though, when "our" forces are involved.
"If he thinks he can hide and run from the United States and our allies, he's sorely mistaken." Bush on bin Laden
There's a lot of treaties like this to minimize the "horrors" of war. For example, it's a war crime to use an anti-tank rocket or a .50 cal machine gun on infantry.
Am i forgetting something here?
Yep.. You're missing density variations and laser induced heating of the local atmosphere. Both of which will degrade the power of your beam, and complicate aiming the device. The Air Forces Airborne laser program attempted to solve these using a pair of low power lasers to sample the atmosphere and track the object. Given the information from the low power lasers, the optics for the primary laser could be corrected to hit the target. I'm not sure they ever got the system to work, but I seem to recall the power of the beam to be roughly equivilent to 30 ocyacetylin (sp?) torches focused on a single point.. There was a lot of speculation in the articles I read, suggesting that the laser power would be attenuated by some staggering amount by the atmosphere, and the chances for success were considered minimal by some of the scientists working on the project..
Don't forget, the owner of Fox News is Rupert Murdoch... You know, the guy who owns The National Enquirer, and numerous other tabloids... Hardly worth calling a reputable source (ironically his tabloids are the sort that would have paid well for pictures taken of Princess Di by the freelance French papparazi that chased her to her death, and even more ironic, that shortly thereafter her brother gave them an interview on teevee)...
Mind you, this was common knowlege over 10 years ago when Murdoch took over Fox, the NY Post, et al...
Just because you can mod me down, doesn't mean you're right. Shoes for industry!
The treaty is probably more related to the possible (and easy) use of lasers for blinding large amounts of people permanently (but I haven't looked, so I am posting cowardly to not spread unfounded rumors).
Arthur C. Clarke was a scientist who, among other things, wrote a paper explaining and introducing the principles of geostationary communications satellites before he sold his first hard science fiction story.
Tom Clancy got his degree in English, and worked as an insurance broker before he became a military drama novelist.
Germany, Japan, Italy, and a bunch of other european coountries.
There are only something like 9 countries which have nukes.
Hmm. Then the .50cal sniper rifles that the SEALS and other forces use are anti-equipment weapons? Pardon my cognitive dissonance here...
.50cal. 'Course, I'm sure that being strafed by 20mm is no picnic... (Hell, being attacked with anything would put a crimp in my day...)
I thought the rule was anything larger than
--Fesh
Kill -9 'em all, let root@localhost sort 'em out.
A rail gun vaporizes a thin conductive coating on the back of a shell and electrostatic repulsion of the vaporized coating thrusts the shell forward. This vapor is very hot so it wears away a good bit of the rails on it's way out.
A coil gun is a different sort of electropropellent. The "barrel" of the gun is a multitude of coils laid in a row. The coils are driven by banks of capacitors in rapid sequence. They work just like a solenoid except that a sequence of coils is employed for greater acceleration. A working coil gun can be fired many times as no hot plasma is involved in accelerating the shell.
The problem is that it is much harder to build an effective coil gun than it is a rail gun. The timing of the coil firings must be timed precisely. Fire a coil too soon and the shell is braked rather than accelerated. Fire it too late and little to no accelleration is imparted at all. Secondly, it takes a number of coils to do this. One big coil won't do much since it is pointless to increase power once the (ferrous) shell has been magnetically saturated. So multiple coils have to kick the shell up to speed. A lot of coils isn't the problem in and of itself. Each coil will need a large bank of capacitors to itself, this will serve to make the weapon very bulky. The capacitor banks also have to be recharged between firings. It will also take some doing to cool the system. Ever play with a home made electromagnet? It's going to get HOT.
So to recap, the device will have sophisticated sensing and timing requrements for the coils; the generator and capacitor banks will be bulky; getting a high rate of fire is problimatical and it will require a large cooling system as well. I haven't mentioned any sort of targeting system or the engineering requirements that will be imposed on the shells either.
Basically, a battlefield practical electromagnetic mass driver is at least as hard as this laser system.
Sure, it could be used as anti-equipment.
That 0.50-BMG cartridge was originally designed as an anti-tank (WWI era tank...) round, if memory serves. It likely has enough penetration to still be good enough for damaging many things besides flesh and blood today.
Only the dead have seen the end of war.
X-rays are refracted and dispersed by the water vapor in clouds. Very short wavelengths might work, but I don't think they are feasible.
Bush's education improvements were