Ban of Handheld Lasers within 10k of airports

[digits_]

Would Joe Laser who thinks he has the perfect laser point it near his kids or anybody else if he had any reasoning power between his ears? To believe they weren’t potentially dangerous he’d have to have gone through life never seeing a science fiction movie, never read a book, a newspaper, never watched tv, never heard of eye surgery or any of the thousands of other mentions of lasers in society.
[...]
So he knows they can damage yet he points them at aircraft anyway.

Did you even read my post? Half of it deals exactly with question. It's about the probability of hitting someone with the perfect laser. In summary: close by, in the eyes: almost guaranteed hit, dangerous. At 7000 ft away: practically impossible to hit someone in the eye. See the gun analogy.

Sure digits_, educate them. That’s what Garneau’s announcement was supposed to do by telling them what will happen when they’re caught. Now let’s see if it works.

Here’s a thought experiment of your own. How many people go to court not knowing what they did was illegal and all they really needed was “education”?

They might know it is technically illegal, but if you don't tell them WHY or how dangerous it actually is, chances are people will ignore it. There are so many safety regulations and laws all around us, that some (most?) people have a habit of ignoring a lot of them if they don't understand why it is important.

[Rockie]

As I said, would you point a laser anywhere near your kid even if you thought there was little chance it might hit their eye? I'm guessing you wouldn't. But not everyone is as smart as you obviously. Pointing it at an aircraft is worse because of the very slight angular difference between the middle of the plane and the cockpit. Unless you have a foolproof gyrostabilized aiming system I'd say the chance of the beam crossing to the windows is even greater than up close. The proof is in how many reports there are of that exact thing happening. It happened to me so I'm not inclined to accept your supposition.

They might know it is technically illegal, but if you don't tell them WHY or how dangerous it actually is, chances are people will ignore it.

As I also said, unless you've been living in a cave cut off from the modern world your whole life it simply is not possible to not know lasers of any kind are potentially dangerous. People who get lasers play with them and very quickly discover the beam diverges and diffuses, most of the pointers do so within a room. Yet people still shine lasers at airplanes. Educate sure, but put some muscle behind it for the really slow learners of which there are many.

[digits_]

As I said, would you point a laser anywhere near your kid even if you thought there was little chance it might hit their eye? I'm guessing you wouldn't. But not everyone is as smart as you obviously. Pointing it at an aircraft is worse because of the very slight angular difference between the middle of the plane and the cockpit. Unless you have a foolproof gyrostabilized aiming system I'd say the chance of the beam crossing to the windows is even greater than up close. The proof is in how many reports there are of that exact thing happening. It happened to me so I'm not inclined to accept your supposition.

Well yes, that's the whole point: people are using laser B which makes it way easier to hit the plane, but they THINK they are using laser A which would be harmless. There is a discrepancy between what they THINK they are doing, and what they are actually doing. At short distance, the effect of laser A and laser B is the same, so they don't shine into their kids eyes. What happened to you was with laser B, not laser A, because laser A doesn't exist.

They might know it is technically illegal, but if you don't tell them WHY or how dangerous it actually is, chances are people will ignore it.

As I also said, unless you've been living in a cave cut off from the modern world your whole life it simply is not possible to not know lasers of any kind are potentially dangerous. People who get lasers play with them and very quickly discover the beam diverges and diffuses, most of the pointers do so within a room. Yet people still shine lasers at airplanes. Educate sure, but put some muscle behind it for the really slow learners of which there are many.

I am not disputing that lasers are dangerous, nor that they don't know that lasers are dangerous. Again, read my gun analogy.

Also, not sure what you mean with "the beam diffuses"?

[Rockie]

Also, not sure what you mean with "the beam diffuses"?

Does the light from a laser get refracted and reflected by moisture and other particles in the atmosphere?

[trey kule]

The penalties are the maximums. Not what has appeared so far in case law.

This is Canada. Brought before a judge, and found guilty, our laser pointer will, for the most part simply be told not to do it again. And if they do...well they will be told again, not to do it again.
Instead of 8 months, one or two well publicized 5 year sentences and a huge fine might offer a deterrent
I understand in the US this activity is taken much more seriously.

One of these boneheads will eventually bring down a plane and then we will see some judicial action occur.

[AuxBatOn]

What's the NOHD for such lasers?

A 2mm aperture, 200mW, 0.8 mRad beam divergence laser has roughly a 125m NOHD. You may be blinded by light but your eyes should be fine

[Posthumane]

A few years ago a friend of mine bought a 1W blue laser online for about $100, so they are quite accessible and easy for laymen to get. There weren't any controls on the site to keep minors from ordering it, as in most countries (at the time) buying high power lasers was perfectly legal. I don't have the specs on that particular laser, but it was able to light a piece of paper on fire from several metres distance. The divergence of course varies with the quality of the optical elements within the system - cheap laser pointers that you get from the dollar store do have enough that it's noticeable across the room, but with higher quality ones you might not be able to tell any difference in beam size until it got several hundred metres away (In fact some of the lasers tested at my workplace have a large aperture and convergent optics, focused for specific distances).

There are actually many cases of people going down to the park or other public places and shining these lasers at people passing by, including children. I used to get a weekly newsletter related to various weapon incidents, and at one time there were several instances a week within the US and Canada. They didn't typically make the news as often there was no physical harm done, although the potential was there. As AuxBatOn implies, the distance to cause permanent eye damage is not nearly as great as the distance where it poses a problem for pilots due to the dazzling/distracting effect of a bright light. The perpetrators in these cases were rarely caught and prosecuted.

There are definitely lots of people out there who like to intentionally cause harm, but I think there are many more (like digits points out) that really have no idea how dangerous these things can be. Do any of the non-technical people who buy these know why a blue laser is more dangerous to the eyes than a red laser? I think many of them don't, and probably don't care.

[B208]

Also, not sure what you mean with "the beam diffuses"?

Does the light from a laser get refracted and reflected by moisture and other particles in the atmosphere?

It gets reflected, refracted and absorbed by particles in the atmosphere, collectively known as "blooming". Even in a perfect vacuum it will start to diffract slightly when it leaves the appeture.

[photofly]

Coherent means that the wavelengths of the light are in phase. This is important for data transmission applications and lots of experiments. For our "blind the pilot" task, this is irrelevant (unless you are trying to beam updated SOPs through his retinas )\

Actually coherence is very relevant when it comes to stopping people seeing things. A coherent light source generates nothing but interference patterns with itself when it shines on objects, which makes it impossible to use it as a source of illumination for vision.

However, the coherence length of hand held lasers is short, in the tens of metres. Beyond that distance the laser is effectively no longer coherent.

[AirFrame]

One of these boneheads will eventually bring down a plane and then we will see some judicial action occur.

Sadly this is unlikely even if someone does bring down a plane. First off, the only way we'll know that a laser was the cause is if the pilot has time to make a call to someone and report the strike. Second, as with drones, finding the perpetrator on the ground has proved difficult if not impossible. And that's when they can play dumb and say "oh, well, nobody was hurt, see, my drone is back here in one piece". When they see an airplane hit the ground after the laser hit the airplane, they're going to be scared sh*tless and you'll never see them.

[B208]

Coherent means that the wavelengths of the light are in phase. This is important for data transmission applications and lots of experiments. For our "blind the pilot" task, this is irrelevant (unless you are trying to beam updated SOPs through his retinas )\

Actually coherence is very relevant when it comes to stopping people seeing things. A coherent light source generates nothing but interference patterns with itself when it shines on objects, which makes it impossible to use it as a source of illumination for vision.

However, the coherence length of hand held lasers is short, in the tens of metres. Beyond that distance the laser is effectively no longer coherent.

What you have written makes no sense. Just for reference, I have a minor in physics and used to teach physics.

[B208]

Just a thought here guys; Nothing says we can't peruse both education and enforcement. We make an effort to help people understand just how dangerous lasering an aircraft is and then we use thumbs screws on the ones that go ahead and do it anyways. I. am. brilliant.

[Rockie]

Just a thought here guys; Nothing says we can't peruse both education and enforcement. We make an effort to help people understand just how dangerous lasering an aircraft is and then we use thumbs screws on the ones that go ahead and do it anyways. I. am. brilliant.

Precisely what I've been saying. Educate with muscle for the slow learners.

[photofly]

What you have written makes no sense. Just for reference, I have a minor in physics and used to teach physics.

Look up laser speckle. Coherent light from parts of a rough surface that at your eye subtend an angle smaller than your eye's resolution yet whose distance from the source differ by more than a small part of a wavelength cause destructive interference (dark) and constructive interference (bright) patterning, which is not related to the "brightness" of the part of the object you're looking at if viewed under non-coherent radiation.

Just for reference, you don't scare me. I have a degree in physics, and I did too. So what? Neither is a guarantee of correctness.

https://www.rp-photonics.com/speckle.html

[rookiepilot]

Just for reference, you don't scare me. I have a degree in physics, and I did too. So what? Neither is a guarantee of correctness.

That and a buck and change will get you a Tim's, too.

[B208]

Look up laser speckle. Coherent light from parts of a rough surface that at your eye subtend an angle smaller than your eye's resolution yet whose distance from the source differ by more than a small part of a wavelength cause destructive interference (dark) and constructive interference (bright) patterning, which is not related to the "brightness" of the part of the object you're looking at if viewed under non-coherent radiation.

Now, that makes sense.

Just for reference, you don't scare me.

I've been working on making myself more approachable and less intimidating. I'm glad to hear that it's working.

[digits_]

Coherent means that the wavelengths of the light are in phase. This is important for data transmission applications and lots of experiments. For our "blind the pilot" task, this is irrelevant (unless you are trying to beam updated SOPs through his retinas )\

Actually coherence is very relevant when it comes to stopping people seeing things. A coherent light source generates nothing but interference patterns with itself when it shines on objects, which makes it impossible to use it as a source of illumination for vision.

However, the coherence length of hand held lasers is short, in the tens of metres. Beyond that distance the laser is effectively no longer coherent.

Won't your eyes get damaged either way if the beam hits you?

[photofly]

Permanent eye damage is caused by (as far as I know) retinal heating, which is caused by a high power per unit area of the direct beam hitting your eye. Lasers are topical for this because a laser beam is highly collimated, it doesn’t spread out quickly, the laser power stays concentrated for a considerable distance. To cause damage the laser must damage your retinal cells in the time before you blink, the blink reflex protecting your eye from sudden bright light. Anything under 1mW is unable to do that even close to the source where the beam is most concentrated.

I do read however that even a severely hazardous Class IV 1.5W laser of typical beam parameters is considered eye-safe after about 1000 feet.

Your retina can’t be damaged by laser light reflected off objects close to you: once the beam hits a rough object it spreads out and the power delivered to the area of your cornea (which is focused onto the retina) is very small.

Similarly, you can’t look at the sun without burning your retina but you can look at objects illuminated by the sun.

Now, infrared lasers - they’re really nasty. You can’t see the beam, so no blink will shield your eyes.

This page is interesting:

http://www.laserpointersafety.com/safet ... index.html

[B208]

Permanent eye damage is caused by (as far as I know) retinal heating, which is caused by a high power per unit area of the direct beam hitting your eye.
.....

Your retina can’t be damaged by laser light reflected off objects close to you: once the beam hits a rough object it spreads out and the power delivered to the area of your cornea (which is focused onto the retina) is very small.

Don't forget wavelength. A sufficiently short wavelength, (near the U.V. end of the spectrum), will break the chemical bonds in the molecules of the rods and cones of the retina. This applies to both direct and reflected light.

[photofly]

Permanent eye damage is caused by (as far as I know) retinal heating, which is caused by a high power per unit area of the direct beam hitting your eye.
.....

Your retina can’t be damaged by laser light reflected off objects close to you: once the beam hits a rough object it spreads out and the power delivered to the area of your cornea (which is focused onto the retina) is very small.

Don't forget wavelength. A sufficiently short wavelength, (near the U.V. end of the spectrum), will break the chemical bonds in the molecules of the rods and cones of the retina. This applies to both direct and reflected light.

Ultraviolet light does cause retinal damage, which is why you should wear only good quality UV filtering sunglasses, but laser pointers being nearly monochromatic (which is the point of a laser after all) produce radiation that's visible light and not ultraviolet. So I don't think that is a danger in circumstances of lasers being shone at aircraft.