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Got to see a 1 Watt blue, handheld laser recently. I cannot think of a much more dangerous item for $300. I won't link but it's easy to find online. If one kno

Got to see a 1 Watt blue, handheld laser recently. I cannot think of a much more dangerous item for $300. I won't link but it's easy to find online. If one knows how to use it, the risks can be minimized. But you package something to look like a flashlight and have 1 Watt of 445 nm light coming out of it... that has bad idea written all over it. 10 microseconds of exposure is much greater than the max permissible exposure (http://en.wikipedia.org/wiki/File:IEC60825_MPE_W_s.png http://en.wikipedia.org/wiki/File:IEC60825_MPE_W_s.png). 100 mW is sufficient for star-gazing purposes. I can't think of any good reason for someone to have a 1 Watt laser on public property. As much as I hate regulation, I think a reasonable law at minimum is the battery cannot be in the laser during transportation over public property. What you do in your own home is up to you and your cornea.

lutorm 16y ago
A 1W handheld laser is amazing. I remember back in the early nineties, we got our hands on a, IIRC, 400mW Argon laser. I thought that was powerful, and it was a ~6"x6"x2ft box with a huge fan and a power cord. To have that sort of power in a battery-powered, pocket size package is... well, I'm amazed. FYI, in Sweden, what's called "Class 4" lasers (>0.5W, basically) are regulated (or at least back in those days they were.) You need a permit to operate one, and you need to implement strict safety arrangements to avoid exposure. (I got a waiver for my 10W home-built CO2 laser, but that's a different story... ;-)
Retric 16y ago
It's still far less dangerous than a gun. The problem is people don't view in that category. "It's just a flashlight" vs "This is dangerous and if I use it improperly I can go to jail for a long time". PS: When you consider how much damage someone can to with a car I think you will find causing damage for the lulz is not really that common.
- ikuygtyuiouy 16y ago
  A gun runs out of ammunition - with this you can stand on a freeway overpass and silently blind everybody that drives under it.
  - Retric 16y ago
    Just how long do you think you can target someones eyes in a moving car? I am not saying a pilot or driver is not going to notice, but to cause actual harm would be really hard.
    - ikuygtyuiouy 16y ago
      At one watt the safe exposure limit is 10micro-secs. That's 0.000010s - I think I can hold it on a car for that long
      - Retric 16y ago
        car != someones eyes in a car. First off the front windshield is going to act as a beam splitter and cut off 1/2 the power or less considering how dirty and scratched up the glass is). Second, safe exposure to the full beam for 0.000011s is not going to cause noticeable short term damage. These things are vary dangerous to friends playing in the backyard, but once you start taking about poeple at a distance in moving cars it really comes down to luck. PS: At 60mph it takes 370 microseconds seconds to travel 1 cm. If you stuck one of these at the side of a subway tunnel facing the people inside (at eye level) at most you could cause mild short term damage. Trying to nail peoples eyes on cars on the freeway without some sort of tracking system would be really difficult. And obvious that something was happening.
- 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

lutorm 16y ago

A 1W handheld laser is amazing. I remember back in the early nineties, we got our hands on a, IIRC, 400mW Argon laser. I thought that was powerful, and it was a ~6"x6"x2ft box with a huge fan and a power cord. To have that sort of power in a battery-powered, pocket size package is... well, I'm amazed. FYI, in Sweden, what's called "Class 4" lasers (>0.5W, basically) are regulated (or at least back in those days they were.) You need a permit to operate one, and you need to implement strict safety arrangements to avoid exposure. (I got a waiver for my 10W home-built CO2 laser, but that's a different story... ;-)

Retric 16y ago

It's still far less dangerous than a gun. The problem is people don't view in that category. "It's just a flashlight" vs "This is dangerous and if I use it improperly I can go to jail for a long time". PS: When you consider how much damage someone can to with a car I think you will find causing damage for the lulz is not really that common.

ikuygtyuiouy 16y ago
A gun runs out of ammunition - with this you can stand on a freeway overpass and silently blind everybody that drives under it.
- Retric 16y ago
  Just how long do you think you can target someones eyes in a moving car? I am not saying a pilot or driver is not going to notice, but to cause actual harm would be really hard.
  - ikuygtyuiouy 16y ago
    At one watt the safe exposure limit is 10micro-secs. That's 0.000010s - I think I can hold it on a car for that long
    - Retric 16y ago
      car != someones eyes in a car. First off the front windshield is going to act as a beam splitter and cut off 1/2 the power or less considering how dirty and scratched up the glass is). Second, safe exposure to the full beam for 0.000011s is not going to cause noticeable short term damage. These things are vary dangerous to friends playing in the backyard, but once you start taking about poeple at a distance in moving cars it really comes down to luck. PS: At 60mph it takes 370 microseconds seconds to travel 1 cm. If you stuck one of these at the side of a subway tunnel facing the people inside (at eye level) at most you could cause mild short term damage. Trying to nail peoples eyes on cars on the freeway without some sort of tracking system would be really difficult. And obvious that something was happening.
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