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Green Laser Pointers: With Great Power Comes Great Irresponsibility


What’s a good tool that can lead presentations, point out constellations, and occupy cats with perfect precision? Laser pointers, of course! And while they can be really useful, lately it seems like they’re not being used right. They’re getting used to annoy moviegoers in theaters or get kids prison time. Unwise, folks. Now a new study shows that laser pointers — especially the green ones — are even more dangerous than we often assume.

Ever been to a star party? They’re get-togethers for amateur astronomy nerds who don’t have ready access to big observatories. They meet up, peer into binoculars and telescopes, and watch the sky. And possibly make s’mores. They also tend to use handheld laser pointers, which reflect well off atmospheric dust and particles, making them good for people to share what they see.

Laser pointers used right, presumably at a BBQ.

In a recent study, researches at the National Institute of Standards and Technology (NIST) found that 44% of the red laser pointers and 90% of the green laser pointers tested failed federal safety regulations. Why? Because they’re just too damn powerful.

Commercial Class IIIa lasers — which includes many common laser pointers and laser sights for firearms — aren’t supposed to have more than 5 milliwatts (mW) of power. Yet the NIST study showed some to have as much as 66.5mW. Military grade rifle lasers typically have 50 mW, for a comparison.

They’re not exactly light sabers, even if they kind of look like them, but you can be temporarily blinded by one of the 5 mW models at short range and prolonged exposure could be worse, and become permanent if left untreated. Researchers who work around lasers wear protective gear and get routine eye exams.

Of course, one of the worst things you could do is point them at aircraft — which is illegal and will rightfully get you jail time. The incidents have increased thirteen-fold between 2005 and 2011:

So it’s not that they should be banned — that’s overkill. Laser pointers can be useful, but maybe they should get powered down. Which means looking to the manufacturers, not so much the consumers, NIST laser safety officer Joshua Hadler said:

“By relying on manufacturers’ traceability to a national measurement institute such as NIST, someone could use this design to accurately measure power from a laser pointer.”

And if nothing else, perhaps it’s better if we stick to using only the red laser pointers.

Leave green to the professionals.

(Universe Today, images courtesy of NSF/LIGO, David Dickison, Amazon, and

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