The X-Ray Death Ray
Physics lesson time guys.
So we’ve heard in the past 24 hours that:
a) Some guys totally built an X-ray death beam to kill Obama and/or “enemies of Israel”
b) Those guys were KKK but somehow pro-Israel too
c) The whole thing was a “portable Hiroshima” that ran entirely off the van’s cigarette lighter
d) They didn’t have the “radioactive” material yet
I’m going to just toss “b” out the window for the time being, because it’s just too damned stupid. There’s a lot of other stupid stuff here too, but I thought a little basic physics could clear up some misunderstandings about X-rays, death beams, and X-ray death beams.
Fact 1: “d” is just nonsense. You don’t generate X-rays from radioactive material – that’s just inefficient and dumb. If you have something so radioactive its giving off enough photons to be fatal, it’s going to kill you long before you install it in anything.
You generate x-rays from running a charge through a cathode (usually through thermionic emission, i.e. heating the crap out of a filament) to shoot electrons at a target in a vacuum tube. Neither the target or the filament is generally radioactive, nor would that be any advantage.
Now, if you think about it, cigarette lighters just heat up a piece of metal anyhow, so it’s not a huge leap to go from that to heating a filament. You can see where they thought it might be possible.
Fact 2: Let’s dispense with “c” real quick here as either bad science or crazy branding. The US attack on Hiroshima yielded 67 TJ (Tera-Joules). A good alternator operating at 100% efficiency (again, they just don’t) might kick out 2-3 MJ per hour, meaning that it’ll take that van 3,000+ years to produce the same amount of energy as Hiroshima, and that’s with the motor running.
As for “a,” I’m not going to go so far as to say it’s physically impossible to make an x-ray generator small enough that it would run off a cigarette lighter, but even the small non-killy ones that already exist need a healthy power source, and a car battery ain’t it.
There are huge sources of inefficiency throughout this system, and even when you’ve minimized them, electromagnetic radiation gets precipitously weaker the farther away the emitter is, so the idea that these guys can park this thing across the street and “zap” a crowd of Muslims or Democrats or whatever is just silly. Radiation doesn’t work that way.
That said, X-rays can be harmful with prolonged exposure, so if they got their “victim” to stand perfectly still right next to their generator-van, they might do him some harm eventually. But they’d probably have better luck throwing the thing at him.
There’s a reason energy-based weapons never really caught on, and it’s because they’re really energy inefficient. You might remember the Pentagon inventing that “anti-protester” ray gun awhile back. It requires a 100,000 Watt generator. So, not a car battery.
Oh, and it won’t kill you either. Not because the military wouldn’t like death rays, but because energy weapons don’t work very well.