Tuesday, April 22, 2008

Laser pointers, bans, and stupidity

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New South Wales just passed a law banning the use of high power laser pointers without a permit. See here. However, the effectiveness of law is already being questioned. See here and here. NSW is not the first place to put in place such a ban.

The ban was prompted by some recent misuse of laser pointers, where beams were flashed at the cockpits of aircraft that were taking off and landing. Let's make no mistake. There is simply no excuse for intentionally targeting aircraft (or any vehicle) with a laser. To do so is 1st degree stupidity at best.

Update: It turns out that the idiots pointing lasers at aircraft aren't the only stupidity in this story.

The real question is will the ban be effective? And by this I mean, are we going to see a meaningful reduction in the kinds of incidents that provoked this ban? Politicians seem to love to ban things. More often than not these kinds of bans are ineffective theatre designed to let them say they are taking action.

Such incidents are also not unique to Australia, they have been recorded in the US and Canada and there are incidents dating back to around 2003. See here and here.

Understandably the pilots union supports a ban on these devices. Thankfully they were open to legitimate uses such as astronomy.

Laser pointers can be invaluable for teaching astronomy to small groups of people. They can also be annoying to other astronomers if used carelessly. Like many issues, finding a balance can be challenging.

Incidents such as these are a natural consequence of technology, any technology, becoming inexpensive and widespread. I have a hard time believing that these could be accidents. How many of these incidents were fuelled by anger, alcohol, or drugs? How many were poorly thought out pranks?

Banning high powered laser pointers and requiring a permit will raise the bar for people getting these devices. Essentially there are three groups of people to consider. Those with a legitimate need that will go through the bureaucratic hoops to continue using one. Those that do not will circumvent the system with intent. And those in the middle that don't have a legitimate need or the determination to get a permit. A ban is really only going to affect the middle group.

Handheld lasers exceeding 500 mW are for sale! Also, there are widely videos showing you how to build your own high power laser using surplus CD and DVD lasers (specifications vary from 30 mW to 300 mW with 100-150 mW being common)!

The problem is not the inexpensive laser pointers available in dollar stars. They aren't very powerful, typically under 1 mW, and can be used for presentations and entertaining pets. While I doubt these would have any effect on pilots at range, I would err on the side of caution and not want to test the assumption.

Laser pointers used for astronomy are something else all together. For starters the human eye responds poorly to red and blue light compared to green. A green laser should give you the best visibility with the least power. But how much power?

A number of factors affect visibility. The thickness of the beam. The moisture in the air. Even light pollution.

Over the years I've borrowed a few of these devices to use as star pointers. The smallest was a 5 mW green laser. This just didn't cut it. It was only really barely visible on moist nights with dark skies. On the other end of the spectrum, was a 55 mW class IIIb green laser. This one seems to be visible in just about all nighttime conditions. While this is a far cry from the 500 mW ones I've seen advertised, it is still over powered for star pointing. I've had discussions with others that suggest a 15 mW laser should be adequate for star pointing. But what I'd really like to see is something with variable power so that you can get just what is needed and no more.

Safety with these lasers is a matter of awareness, attitude and responsibility. When I was a Scout, I learned to shoot a rifle. We were taught never to point a gun at anything we did not intend to shoot. Never under any circumstance. The same applies to a laser pointer. When I use one, I follow a few simple rules:
  • Keep control of the laser at all times yourself. Avoid rapid and wide movement. Don't let children use the laser.
  • Never point the laser at anything that might be an aircraft (or vehicle). Avoid moving objects and flashing lights.
  • If you need to point at a moving object, trail behind it. Do this even if you're sure it's not an aircraft. During Earth Hour, I was pointing out the International Space Station. Even though I was 99.99% sure it was the ISS and the laser couldn't affect the people on it, I still trailed the laser behind it.
  • Be aware, look around carefully before pointing.
  • Be respectful of other groups around you.
A NSW man was recently sentenced to three years in prison for shining a laser pointer at a police helicopter. See here. Others have been similarly convicted in other jurisdictions.

Now what will bans like these actually do?
  • It will probably raise awareness of the risks.
  • It may make it harder to obtain and use powerful laser pointers. Although without importation bans this will be less effective.
  • Fewer people will seek to own such devices. (probably)
  • Conversely by banning them, more people may want to own these devices.
  • It may promote more responsible behaviour from laser owners. More likely it will slow the growth of irresponsible owners.
  • And adds to the possibility of stiff penalties for abuse. Although, other laws can be used for this purpose and stiff penalties have already been handed out.
  • It may not even help police track down abusers, because you can't simply stop looking after you've checked out all the permit holders. The abuser probably won't have a permit.
  • It may criminalize people unfairly if not carefully applied (probably).
Will bans like this reduce such irresponsible incidents? That remains to be seen; but, I suspect that it will be less effective than its' authors hope. It also raises a lot of questions about what is considered "legitimate use" and who will be legitimate users. Lastly, I'm concerned about overzealous enforcement.

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