Eliezer S. Yudkowsky writes:
> Back in real life, I've heard rumors of an amateur shoulder-mounted
> "bazooka" laser, I believe pulsed infrared, that could punch through
> steel. Anyone hear anything about that?
Oh, there are NIR laser diode (arrays) which lase strong enough to be used for material processing. Though still expensive, solid-state is the obvious thing to go. Currently, the best you can hope for is to inflict nasty skin burns or set the clothes on fire. Obviously, you need blocking filter goggles for that particular wavelength, or you'd be rendered blind by the reflexes from your own laser source (the best location for which would be a la Borg fashion, to allow for easier targeting).
> I've had some ideas about nonlethal and inconspicuous self-defense for
> the extremely rich. I'd like to see two things: First, a pulsed laser
> that would automatically target enemy eyes and render them blind for a
> few minutes without permanent damage. Preferably the bulk of the laser
> would be on your belt, which would pump into an optical fiber (can
> lasers do that?), and the targeting equipment would be a small,
> motorized mirror set in your shirt button.
This is difficult. The amount of damage depends on the angle the person's eye are facing you, and, most importantly, how they are currently focused. Without realtime measurements, it is essentially impossible to distinguish between no effect at all and permanent blind spots on the retina (not even the whole of it).
Obviously, inflicting permanent damage on a person's vision is even more questionable than blasting off their kneecaps.
> The real challenge, I think, would be the targeting, which would require
> visual AI plus some way of picking one face out of a crowd. There are
> methods that can track where your eyes are focusing, and I think once
> you used that to indicate the face, then neural-networks vision is good
> enough to pick out the eyes. So I think this is actually possible,
> although it would be expensive. You'd also need a way to indicate an
> order to fire; probably a particular pattern of bent fingers.
The low tech (but surefire) way to do it would use a high-voltage capacitor-battery-driven Xe flash of sufficient strength and synchronous photoshutter goggles. It is kinda difficult approaching a person emitting random flashes each of them sufficient to blind someone for several minutes straight.
Of course above thing is entirely unpractical, but fun to speculate about.
> The second thing I'd like to see would be some way of launching
> something like small bullets (but preferably without the noise) that
> could automatically target guns and knock them out of someone's hand.
> Pretty much the same tech as the eye-targeting laser, I think, except
> that it'd be harder to make it inconspicuous.
It would be interesting what one could do with a butane-driven flechette gun (a resonating combustion chamber driving a superalloy blade chopping a stainless steel capillary filled with anaesthetic or toxin and launching the fragments). Electromagnetic railguns would be fun, too, but kinda finicky/unwieldy.
The obvious problem with higher-tech weaponry is that you must make it (N)EMP-proof, which can grow arbitrarily difficult.
> If you can do all that, then you have "sufficiently advanced
> technology". Consider: Person A pulls a gun. Person B raises her
> hands in a peculiar gesture. Person A's gun is knocked out of his hand
> and he shouts "Aargh, I'm blind!" How's that for using the Force?
Alas, we still don't have such things. For now, you must settle for lead azide-tipped minirocket launchers, or pyrocharge-driven handheld aluminum trialkyle dispensers. Plays great, more killing.
> Obviously this is way more expensive than bodyguards, but it'd be more fun.