Laser Cannons --> Military --> Spam

[Suicide Junkie]

why would a laser have recoil?

Because photons have momentum, and momentum is conserved. All the momemtum in photons going forward has to be matched by the momentum of everything else going backwards.

[Thermodyne]

The mass of the stream is such a small part of the mass of any weapon that could produce it, that there would be no recoil. The US has been testing an airborne system since the first gulf war, but the test were not all that impressive. I think they mostly helped prove the acquisition and targeting systems. Not to mention that it took a much overweight 747 to carry them. Any system that would be deployed in this time frame has to be basically ready for production. It would take that long to tool up for mass production.

[PvK]

Sure the recoil would exist, but of course Puke (and Thermo - posting as I write) is right - that recoil is extremely small because the emissions are photons, not metal bullets. The damage is done by burning from concentrated high-energy photons, not by kinetic energy imparted by the mass of the photons.

You'd have an extremely powerful laser before you'd have to worry much about recoil from the beam itself.

PvK

[ October 30, 2003, 23:12: Message edited by: PvK ]

[Cyrien]

The discussion of recoil isn't for all the laser weapons but was derived from the TSL-1 Laser Rifle having an estimated 90 lbs of recoil force. It is in the TSL-1 linked PDF document farther down. Bottom of page 5 I think.

[Puke]

Right, what Cyrien and I are talking about is not the recoil of the laser its self - i only mentioned that in the argument to disway anyone that might have wanted to nit-pick about the small external forces generated by the beam of light its self.

if you read about the laser rifle linked below, it is a chemical laser and works by means of compresed gasses reacting at extremely high velocities and pressures. one of the technical problems is that there has not yet been invented a mechanism to recompress the gas for a second shot. another listed problem is that the gasses surging through the weapon will exert a forward force of 90lbs. meaning that the weapon would leap out of your frikin hands.

because i took physics so long ago and dont know nearly as much as i like to let on, i cant understand this. to me, it seems like this should be an internal force, since none of the gas leaves the weapon. thus, my solonoid example. but the more i think about it, the solonoid will probalby twitch back and forth on the table - in a perfect system it would always end up in the same spot - but it would twitch none the less. i think. maybe. dont have a solonoid handy to try it out.

can someone with a better grasp on newtonian physics explain this to me?

[Cyrien]

Sorry. My own knowledge of such is limited and my earlier statement was pretty much a guess at how something might cause the force. Soooo...

Edit:

Actually I had a discussion with a Professor about this weapon and we both agreed that based on what they state it would be better used not as a standard infantry rifle but as a nice sniper weapon. But that was just us.

[ October 30, 2003, 23:55: Message edited by: Cyrien ]

[PvK]

Without knowing how the weapon is set up, it's hard to say, but from a Newtonian perspective, sure you have have a "jerk" from something that doesn't release anything. Try putting an energetic cat or dog (or yourself) in a box. An animate object in a box can shift its weight around in the box and make it hard to hold the box still. If it tries to run or jump inside the box, the box will jerk one way and then (when it stops/lands/hits the wall) the other direction. Net force may total zero, but it will move around. A clever animate object can even roll and jerk and get itself to move around using friction, rotation, and/or gravity, without leaving the box.

PvK