Thursday, April 24, 2008


Les laser-pointers dangereuses

Reuters tells us about a law proposed in Australia this week that would make possession of handheld lasers illegal, at least in the state of New South Wales (home of the city of Sydney). We’re not just talking about science-fiction ray guns, but those regular pen-sized or key-fob-sized laser pointers that people use when they’re making presentations.

Here’s more detail from the Sydney Morning Herald (emphasis mine):

The proposed legislation, which has been modelled on NSW knife laws, will also make it an offence to carry any kind of laser in public without a reasonable explanation.

Under the proposed legislation, high-powered lasers — category 3 and 4 devices — will be classed as prohibited weapons, and possessing one without a permit will be an offence punishable by up to 14 years in jail.

Police will also be able to frisk anyone suspected of carrying a laser, and anyone unable to provide a lawful excuse for possessing one could face two years’ jail and a $5,000 fine.

NSW Premier Morris Iemma said the laws were in response to a spate of incidents in which aircraft were targeted with lasers.

“Make no mistake,” says Premier Iemma, and Police Commissioner Andrew Scipione agrees, “they are lethal weapons.”

I would think that the risk would be minuscule, vanishingly small, certainly so small as not to be worth making laws about. How easy do you think it’d be to aim a tiny laser pointer at an airplane cockpit from a distance? And hit the pilot in the eye. When the plane is moving at takeoff speed. And is it powerful enough to really do anything? Incredible, no?

But it seems very trendy to do it, and it’s actually been enough of a demonstrated problem — not just a theoretical one — that the Australians have decided to take action:

Lasers have become a serious problem for aircraft in Sydney. In the most recent incident, a beam was pointed at an ambulance helicopter at the weekend.


Earlier this year, six planes landing at Sydney Airport were diverted to a different runway because of laser attacks. Last year, a helicopter carrying a critically ill brain surgery patient could not land after the pilot was targeted by a beam.

Catching the culprits can be expensive: late last year, police used two helicopters as well as ground officers in a fruitless search for a laser in Bondi.

I wonder, though, whether the problems have been caused by more powerful lasers, and it’s just easier to ban everything than to try to sort them out.

Teachers and others who use the pointers in lectures and presentations are worried:

Bob Lipscombe, the deputy president of the NSW Teachers Federation, said enforcement of the new bans should focus on people who posed a threat. “We don’t think teachers would pose a threat,” he said.

Well, never mind: I’d personally love to see them banned, but not because of pranksters who target airplanes. I’m more bothered by the other kind of “laser lunatic”: most people who use them to point at the screen during a presentation seem to have learnt the technique from the cameraman of The Blair Witch Project.

There are times when you do need to point at a portion of a chart or photo. There are times. But not most of the time. And there’s seldom a need to point at the bullet you’re talking about now. If you feel that’ll be necessary, create your slides accordingly (have a set of slides with the same list, each highlighting the next bullet, in turn).

Do not turn around to face the screen, taking your focus away from your audience, and point a wobbly beam vaguely in the direction of the current item, letting the beam bounce and bobble dizzyingly. You will lose your hold on the audience. I will start checking my email and reading blogs.

Whether violators deserve jail time for this is, of course, open to question.

So it might be an overwrought law that nevertheless helps....


lidija said...

I am quite sure laser pointers are not category 3, 4 lasers (laser categories stem from how much power they put out) but with academic fashion accessories like the green laser being oh-so-last-decade, I hear there are blue laser pointers around, so the wavelength will matter a little. But I think it would have to be category...4... to severly hurt someone on the spot. But weaker ones could hurt the retina IF one is totally oblivious to staring at a bright light spot longer than your reflex will make you blink and turn away... which nobody is. Which, again, is not immediate danger to anyone. Baby and the bathwater approach...

I like your "Blair Witch" comparison :)))

briwei said...

Actually, laser pointers are typically Class 3A, which is the weaker of the class 3 lasers. The difference is a combination of wavelength and power level. The hazard risk is low, but not zero.

A class 3A hazard comes from direct intra-beam viewing although reflection can also be a hazard. Diffuse viewing is still safe at this power level.

FYI, my knowledge comes from having been a department safety coordinator at a company that manufactures high powered lasers.

lidija said...

Yes, wow. I just looked up and I guess class 3 is a pretty wide power range (I really only worked with 3's and 4's in the lab so I assumed they wouldn't be pointers). So basically it's a general protection issue, not just a pilot will crash issue. Them crazy Aussies.