Set phasers to stun!

JimmyB27 · Feb 23, 2007

http://news.bbc.co.uk/1/hi/sci/tech/6380789.stm

We're getting close to a real, working laser weapon. Ok, so it needs a 9 metre trailer to lug it around on, so Han won't be shooting Greedo under a cantina table anytime soon...

Ordinary_Guy · Feb 23, 2007

I've been following this one for a while – and it's kinda cool (though I wouldn't want to be on the other end).

DEWs have come a long way in the last few decades. I remember some general, wish I could remember the name, once saying something along the lines of "...the only way lasers will be used on the battlefield is if we drop it on them..."

PeeDee · Feb 25, 2007

We've been 'getting close' for a long time. The quote that Ordinary_Guy offers is pretty accurate, right now you could use it to bludgeon someone to death better than anything else.

But it's a slow, steady business that's progressing at least. I can't wait until we have laser cannons. I just hope they have better effects than the Star Trek Original Series "the screen flashes colors and people fall over" effect.

benbradley · Feb 28, 2007

Ordinary_Guy said:
I've been following this one for a while – and it's kinda cool (though I wouldn't want to be on the other end).

DEWs have come a long way in the last few decades. I remember some general, wish I could remember the name, once saying something along the lines of "...the only way lasers will be used on the battlefield is if we drop it on them..."

The only problem there is the weight, and if you can get it up in the air. OTOH, if it gets near the battlefield, it probably gets their in an airplane.

Still, 67kW is nothing to sneeze at:

"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."

Okay, you can probably do as well or better with a "traditional" weapon such as a the gun on a tank turrent firing DU bullets. But in that seven seconds you could run a 25kw laser across dozens or even a hundred enemy troops which would disable them with burns and blindness.

Just thinking about that, it might be against some Geneva Convention agreement to use such a weapon directly against people.

There are quite powerful lasers that were envisioned and designed for "Star Wars" (President Reagan's Strategic Defense Initiative, not the movie) such as the X-ray Laser designed to shoot down ICBM's in midflight, though I doubt this was ever tested (it would be hard to hide such a test). I forget what material it is, but there's something that generates x-rays when bombarded with high-energy neutrons (probably most any material, but this works better than most), and when made into a rod and neutrons sent into one end, a short burst of x-rays comes out the other. The only practical source of a large number of high-energy neutrons is a nuclear explosion, so a millisecond after firing, the X-ray Laser is destroyed. It's obviously a one-shot deal rather than continuous, but the instantaneous power would be in the megawatts or gigawatts - it's definitely way up there, and will heat up and destroy its target in microseconds (not counting speed-of-light delay).

JimmyB27 · Mar 1, 2007

PeeDee said:
I just hope they have better effects than the Star Trek Original Series "the screen flashes colors and people fall over" effect.

And that they aren't subsonic and dodgeable, like the ones in Star Wars.

Pthom · Mar 1, 2007

benbradley said:
But in that seven seconds you could run a 25kw laser across dozens or even a hundred enemy troops which would disable them with burns and blindness.

I always wondered why in the movies, users of ray-gun-type weapons (phasers, disruptors, lasers, etc) bother to aim them as they do projectile weapons. Because the actors learned how to shoot by aiming cap pistols at one another playing cowboys and indians, I expect...and no one thought to analyze just how unnecessary that is with a particle ray. You just press the firing stud and wave it about, causing mayhem on whatever the ray strikes (hopefully not mirrors).

I suppose a valid reason for not turning the ray on and waving it about, is that the amount of energy needed to sustain a ray is, as mentioned above, immense. Unlike say, a machine gun, that uses ammunition with self-contained energy packets (the cartridge in each round) to propel many bullets to the general region of the target, a particle ray weapon is more like a rocket. You send the energy out and, if you've aimed well, you hit the target. Unlike a rocket, though, it's difficult to redirect the ray once it's left the weapon.

Roger McMillian · Mar 4, 2007

Pthom said:
I always wondered why in the movies, users of ray-gun-type weapons (phasers, disruptors, lasers, etc) bother to aim them as they do projectile weapons.

Phasers and lasers project a beam of coherent light that must be aimed, though I suppose that sweeping the target would have some effect. Ray guns may have a wider dispersion, but I imagine that the 'battery' life suffers, theoretically .

Pthom · Mar 4, 2007

My point is just that since it's a "stream" of energized particles, whether photons or other sub-atomics, it's like using a fire hose--or a machine gun. You don't need to aim a fire hose--or a machine gun--much.

I think any energy weapon that used a dispersal pattern would require so much initial energy as to render it impractical (inverse square law).

The requirement for aming a laser, today, is that while one might burn its way through heavy plate armor, it does so gradually, compared to say a shaped charge. But in the movies (and this is where my original complaint arises), the users of ray-type weapons fire them exactly as if they were Colt 45 revolvers.

They even look like revolvers somewhat.

PeeDee · Mar 4, 2007

I liked the logic and design behind Babylon 5's PPGs. Let me see if I can go find out how they worked...

THat wasn't as informative as I hoped, but here's the gist...

Usenet said:
Q: How do PPGs (Phased Plasma Guns) work?
A: A super-heated burst of plasma, burning through the air.

Ordinary_Guy · Mar 14, 2007

Pthom said:
My point is just that since it's a "stream" of energized particles, whether photons or other sub-atomics, it's like using a fire hose--or a machine gun. You don't need to aim a fire hose--or a machine gun--much.

I think any energy weapon that used a dispersal pattern would require so much initial energy as to render it impractical (inverse square law).

The requirement for aming a laser, today, is that while one might burn its way through heavy plate armor, it does so gradually, compared to say a shaped charge. But in the movies (and this is where my original complaint arises), the users of ray-type weapons fire them exactly as if they were Colt 45 revolvers.

They even look like revolvers somewhat.

Revolvers? Eh, I'd venture to guess that it was just a producer that fancied himself a "story teller" but not a tech expert. Script says "guns" and they just do what they know.

As for the actual application of DEWs in combat, I can see your point. OTOH, I can see several considerations for aiming. One is collateral damage, especially if you're shooting in an urban environment. Second thing is the same reason you don't always to fire tracers: it would be easy to trace your position back and return fire.

Dispersal pattern: AFAIK, most DEWs fire collimated beams, that is – they're focused so they don't spread.

Also; x-ray laser note: x-ray lasers may be soon be practical. The immediate application would be for medical x-rays though depending on power scalability, it's highly likely it would find its way to defense applications. Check out the ScienceDaily article on it...

Set phasers to stun!

JimmyB27

Hoopy frood

Ordinary_Guy

Industrial Strength

PeeDee

Where's my tea, please...?

benbradley

It's a doggy dog world

JimmyB27

Hoopy frood

Pthom

Word butcher

Roger McMillian