2 ms·

The problem is that the beam propagates so far that, unlike if you want to injure someone with a car or a handgun, you are far removed from the effects of your

by lutorm 16y ago

The problem is that the beam propagates so far that, unlike if you want to injure someone with a car or a handgun, you are far removed from the effects of your actions and are much less likely to be identified. I'd say that in terms of the combination of the range at which you can permanently disable someone, the ability to conceal the device, and the low visibility of "discharge", this is one of the most dangerous things I can think of.

3pt14159 16y ago
Lasers are really hard to aim at long range. Simple trigonometry means you basically need to set up a computer and a telescope to get anywhere near your target. If you want to cause damage there are plenty of ways of doing it. An iron bar sitting on a thin layer of electric insulation then sitting on the third rail of a subway will produce a shit ton of casualties once a subway car runs over it.
- lutorm 16y ago
  They're no harder to aim than a gun at the equivalent distance, and you get the added benefit of continuous emission rather than a single shot (and no wind drift or lead). However, the tech specs for that laser show the "Nominal Ocular Hazard Distance" at which a 0.25s unprotected exposure does not cause lasting effects to be 149m. That's far, but not THAT far. So as long as the subject doesn't stare into the beam (which probably is more likely than you think given the brain's almost compelling instinct to look at sudden movements), you still have to get pretty close. (Unless you fit it with a collimator, of course.)
  - Retric 16y ago
    Bullets are dangerous when they hit a 1m^2 target, 1w lasers are dangerous when they hit a 1cm^2 target. Aiming at a 1m^2 target at 150m is hard, aiming at a 1cm^2 target at 150m is next to impossible.
    - lutorm 16y ago
      At 150m, the beam is 1.5m across (the divergence is 1.5mrad). Putting a 1cm^2 target at 150m within a 1.5m beam is not at all hard.

by lutorm 16y ago

3pt14159 16y ago

Lasers are really hard to aim at long range. Simple trigonometry means you basically need to set up a computer and a telescope to get anywhere near your target. If you want to cause damage there are plenty of ways of doing it. An iron bar sitting on a thin layer of electric insulation then sitting on the third rail of a subway will produce a shit ton of casualties once a subway car runs over it.

lutorm 16y ago
They're no harder to aim than a gun at the equivalent distance, and you get the added benefit of continuous emission rather than a single shot (and no wind drift or lead). However, the tech specs for that laser show the "Nominal Ocular Hazard Distance" at which a 0.25s unprotected exposure does not cause lasting effects to be 149m. That's far, but not THAT far. So as long as the subject doesn't stare into the beam (which probably is more likely than you think given the brain's almost compelling instinct to look at sudden movements), you still have to get pretty close. (Unless you fit it with a collimator, of course.)
- Retric 16y ago
  Bullets are dangerous when they hit a 1m^2 target, 1w lasers are dangerous when they hit a 1cm^2 target. Aiming at a 1m^2 target at 150m is hard, aiming at a 1cm^2 target at 150m is next to impossible.
  - lutorm 16y ago
    At 150m, the beam is 1.5m across (the divergence is 1.5mrad). Putting a 1cm^2 target at 150m within a 1.5m beam is not at all hard.