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Particle Beam Weapons: More Than Just Flashlights?

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Konraden:
First things first, hey. New here obviously, figured I would say hey, enjoying\enjoyed the game. (I think I "beat" it, but I'm not sure). I've been trying to get X-Com: UFO Defense to run on my PC for two years now with no satisfactory luck. UFO:AI is something i've been so desperatly searching for since the begining of time. Thanks Dev's for throwin' in together over the last few years.

Now, to the Particle Beam Weaponry you guys enjoy so much. The idea of the weapons themselves sound good, but the actual physics seem...off.

You guys never really define what a particle is in your description. From what it sounds like, I first thought light photos, but laughed a little when I realized you basically created a flashlight. I realize that isn't what you are going for.

However, you could also say particle means atom, which is a legitamate defintion. To quote your UFOpedia

--- Quote --- Particle-beam weaponry is designed to hit a target object with a stream of accelerated particles moving at near-light velocities, therefore carrying tremendous kinetic energy. Until now we've only seen the aliens use this technology in large UFO weapons. Now, however, they're using it on the ground in the worst way.
--- End quote ---

It says a stream of high-energy particles What exactly does this mean? From my understanding, launching particles out of a weapon isn't going to get you anywhere, especially considering the lack of mass.

Momentum = Mass * Velocity. (P=MV) Our velocity is "near light speeds,". C=299,792,458 m\s. However, our mass of these particles is undefined. Let's play out the numbers a little. (feel free to correct me, I don't have a PhD)

If M = .000001kg (one milligram, a rather large amount of particles to be swirling around inside the ammo-boxes). P = MV, P = .000001 * 299,000,000 (near light speed). P = 299kgm/s.

EDIT EDIT: Alright, I think I got it.

F = kgm/s2, all I need to do is divide by a time for that momentum to stop in, say .001 seconds. (a millisecond). 299/.001 = 299000N ~ 68000lbs of force. Apparently my argument goes in an unexpected but still valid way. That gun will literally launch the shooter into orbit. Good luck.

Either I'm missing something, or you guys might need to rethink your weapon.

To me, the weapons seem impractical.

blondandy:
relativistic momentum, p = mass * velocity * gamma

gamma = 1 / sqrt (1 - velocity^2 / c^2)

(I do have a degree in Physics)

The kinetic energy of a relativistic particle is generally more useful than talking about its speed. eg a 15MeV electron has a speed which is near c. in fact it is 5E-4 below 1 times c. Some folk even talk of its mass being 30 times its rest mass. I use these in radiotherapy most weeks.

The most obvious problem is storing the energy. If I recall the ufopedia correctly, they are accelerated and kept in a mini storage ring, in the gun's magazine. keeping particles moving in a circle using a magnetic field, could take very little energy.

I find it harder to suspend disbelief for the plasma gun: but this has been done to death before, so let's not go there again.

Konraden:
Does it have the force to knock someone on their ass is the question. I never did the entire radiation thing.

blondandy:
"near light speed" encompasses a huge range of energies (and hence momenta).

Unless the particle is specified (would have to be proton mass or heavier) and the kinetic energy (or something else that allows the momentum to be calculated), it is not possible to say.

Konraden:
Play it out then, doc.

I'm a little ignoramus when it comes to anything more than kinetics, torque, and simple physics. Physics 101 doesn't cover much more. Radiation and Electric fields, magnetism, etc is all beyond me.

So, assume it is what you were rambling about. It's a proton traveling at the speed of light. You can calculate force and\or momentum from that, can you not?

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