Static discharge using Lasers.

[LaserSteve]

Its not an  IR laser in a common non-contact thermometer. 

 A Pyroelectric detector is used to determine the temperature by looking at the 8 to 12  Micron  wavelength FAR IR emission from the object being measured. With some mathematic  corrections applied, its intensity is somewhat proportional to the object's temperature.

 A red aiming  laser is used to show the user where the center of the instrument's  field of view is located.

Steve

[wiss]

That's what I thought
No way this is related to the 5 mW diode laser.

[Wim_L]

I agree such a small laser isn't likely to cause that.

Do you notice significant airflow where you are standing? If that's ionised air, it could be charging insulators (such as the plastic parts of the thermometer).

[B.B.Bubby]

I agree such a small laser isn't likely to cause that.

Do you notice significant airflow where you are standing? If that's ionised air, it could be charging insulators (such as the plastic parts of the thermometer).

There could have been a sheltered area that allowed a big build up of ionized air - My memory fails me though.

I'm not dismissing ideas like this, as on face value they are probably the most logical

It's just that in all of my 20+ years working around industrial machinery that processes paper / plastic webs I've never had a random shock caused from static - except for when i took those two stupid temp measurements. I am sure the static discharge occurred the very moment the laser trigger was pulled. 

Anyway - why is some photo electric affect involving a low power laser (low power but still relatively high light intensity transmitted in a tube / conduit shape) so unbelievable ?   We are not talking about shedding electrons from a metallic source, but rather shedding electrons from already heavily charged organic molecules or dust particles. I'm quite sure science backs this up. (i'm not a scientist's / physicist's arse hole, I just google stuff) 

I'll do the experiment. If i can repeat the results, cool, if not, meh....  I can only prove the effect exists not that it doesn't 

I'll post a video either way.

Cheers
Simon

[LaserSteve]

Let me put it this way.  The US Department of Defense, The Russian MOD, The UK MOD, Big Defense Contractors, Lots of Inventors, No doubt the Aussie MOD, and Evil Minions everywhere have put Hundreds of Millions of Dollars, Rubles, Pounds, Yuan, etc into attempting laser guided electrical discharges.   

 None of them have ever published results using a CW laser of low power.   If they could have, they would have, and we civilians would have known about it by now.


Steve

[Ian.M]

Which of course doesn't actually rule it out, it just makes it vanishingly unlikely, a bit like the odds of someone flying for the first time finding the only winning ticket to a British national lottery rollover on the floor of the Aukland airport transit lounge after their plane was diverted there due to an in-flight emergency.   Long odds, stacked up many times in a row . . . .

[B.B.Bubby]

Which of course doesn't actually rule it out, it just makes it vanishingly unlikely, a bit like the odds of someone flying for the first time finding the only winning ticket to a British national lottery rollover on the floor of the Aukland airport transit lounge after their plane was diverted there due to an in-flight emergency.   Long odds, stacked up many times in a row . . . .

You can travel around the universe with that sort of logic 

https://en.wikipedia.org/wiki/Technology_in_The_Hitchhiker's_Guide_to_the_Galaxy#Infinite_Improbability_Drive

[schopi68]

What type of  laser IR temperature probe has this been? Almost every one i know has an isolated plastic case, so this devices do not have a direct ground path or many isolating barriers between the laser-diode and earth.

[B.B.Bubby]

What type of  laser IR temperature probe has this been? Almost every one i know has an isolated plastic case, so this devices do not have a direct ground path or many isolating barriers between the laser-diode and earth.

Yeah, just a mid range generic plastic unit.

[B.B.Bubby]

Another laser phenomenon that may have been a contributing factor -  http://www.chem.scphys.kyoto-u.ac.jp/nonnonWWW/watanabe/studies/photophoresis/index.html.en

Getting motivated to start experimenting.

Any one got a van de graff generator I can borrow? 

[Wim_L]

Another thing to consider is this: if you were grounded on a metal walkway, and there is highly charged material passing nearby, you will have a strong field between you and that material. If you extend your arm towards the charged material to point the thermometer at it, you'd focus the field at your hand and can get some strong field gradients there.

[abebarker]

I met a guy that said he and some class mates observed, pretty much, the same phenomena. I don't know how reliable of a source the guy is but I found the report interesting and have really wanted to test it.

The guy said they had a Tesla coil in their class when they shone a laser pointer of 633nm next to it, the discharges would be conducted down the beam. They had other laser pointers of different wavelength but only the 633nm laser would work.

Again, I don't know how credible the story is. I do find the idea intriguing though.

[B.B.Bubby]

Another thing to consider is this: if you were grounded on a metal walkway, and there is highly charged material passing nearby, you will have a strong field between you and that material. If you extend your arm towards the charged material to point the thermometer at it, you'd focus the field at your hand and can get some strong field gradients there.

Yeah I can see how that would work, I've been over that walkway hundreds of times - but only twice did i reach over the railing with a thermometer gun in my hand doing really bad Danny Glover impersonations. 

[B.B.Bubby]

I met a guy that said he and some class mates observed, pretty much, the same phenomena. I don't know how reliable of a source the guy is but I found the report interesting and have really wanted to test it.

The guy said they had a Tesla coil in their class when they shone a laser pointer of 633nm next to it, the discharges would be conducted down the beam. They had other laser pointers of different wavelength but only the 633nm laser would work.

Again, I don't know how credible the story is. I do find the idea intriguing though.

Can you remember any more about the conversation?

[Ian.M]

Running the numbers on the maximum possible surface power density in the laser spot, I get 1.59KW/sq m, which is only about 50% more than the power density of tropical noon desert sunlight.  This makes the observed discharged vanishingly unlikely to be a electrooptical effect as unless its highly frequency sensitive or requires a coherent light source, such behaviour would be common knowledge, and a known design issue for above ground HV electrical distribution systems.

[schopi68]

I am shure, if it would work to discharge static electricity via a laser beam, humans would no longer have trouble with thunderstorms. 

[Ian.M]

Actually, you can (at least theoretically) trigger lightning 'on demand' by laser provided the correct type of charged culminonimbus cloud  is overhead.  See: http://iopscience.iop.org/1367-2630/4/1/361/fulltext/

However they used a 50MW pulsed UV laser not a 5mW continuous visible red laser . . . .

[B.B.Bubby]

Running the numbers on the maximum possible surface power density in the laser spot, I get 1.59KW/sq m, which is only about 50% more than the power density of tropical noon desert sunlight.  This makes the observed discharged vanishingly unlikely to be a electrooptical effect as unless its highly frequency sensitive or requires a coherent light source, such behaviour would be common knowledge, and a known design issue for above ground HV electrical distribution systems.

Except for some important differences...

We are talking about a beam of light not randomly scattered wide area lighting (day light)
a beam provides a conduit for the effect (if it does exist) ie: if particles can become trapped in this beam, they're all in a line and can interact and behave very differently than a mass amount of randomly scattered particles, it doesn't matter how bright that light is.. just the shape of this light.

Could also have something to do with the monochromatic nature of the laser?

There's at least one other bloke in the world who may have observed the effect...

Cheer
Simon

[B.B.Bubby]

Actually, you can (at least theoretically) trigger lightning 'on demand' by laser provided the correct type of charged culminonimbus cloud  is overhead.  See: http://iopscience.iop.org/1367-2630/4/1/361/fulltext/

However they used a 50MW pulsed UV laser not a 5mW continuous visible red laser . . . .

Different things, I'm talking about a small 5mW laser being able to trap already ionized particles in its beam and use these particles as a discharge path.  or the small laser is able to shed electrons from already heavily ionized air / dust / organic matter particles, this shedding could start an avalanche / chain reaction along the beams length, maybe instigated at millions of points simultaneously.

Well that's what i think is happening - not that a 5mW laser can ionize normal air to create the discharge - but if the atmospheric (charge) conditions are right, with the right sort of particles in it,  than yeah maybe it can provide a discharge path, indoors, short range etc.

[wiss]

Normal 5 mW lasers are less intense than sunlighy, after the the colimating lense.

[TerraHertz]

Another laser phenomenon that may have been a contributing factor -  http://www.chem.scphys.kyoto-u.ac.jp/nonnonWWW/watanabe/studies/photophoresis/index.html.en

Getting motivated to start experimenting.

Any one got a van de graff generator I can borrow?

No, but I do have a 0 to 200KV regulated power supply. SouthWest Sydney area.
I've been trying to get around to setting up the Faraday cage it needs around it (to be safe to use in my small workshop) so I can try some experiments related to something else (that LED sparkle ball thing from another thread.) The cage will be soon; I'm not doing anything fancy, probably just chicken wire (ha ha very appropriate.)

What occurred to me to try, related to your laser scenario, is to put two sphere electrodes spaced JUST far enough to not ark over in air. One of them with a small hole through it, so a laser can be shone between the two at closest distance. So, a relatively short distance, like 6 inches to a foot will do for the experiment. 200KV - can do.

The idea being if the air gap is only just not quite arcing, then any tendency of the laser at all to initiate an arc actually will. If it does, the spheres can be moved apart till nothing happens. That will show what degree of effect the laser has.

Only guessing about mechanism, but if it does work I think it will be due to the laser stimulating photoelectric emission from the surface, (in the high E field). Excess ions near a point on the surface will accelerate in the field, and form a leader cascade 'point', concentrating the field more as the leader point extends. Possibly with the laser beam assisting further ionization at the point, since there there's a zone where the air is reaching breakdown point anyway, and any extra energy (the photons) will kick it over. So there'll be a kind of guiding effect. The laser couldn't do it by itself, but it can steer the much greater energy available in the electrostatic field.

I'd guess it will only work in E field gradients not far below arc-over levels.
Your moving film/paper might build up charge to just below arc-over level, but self-limit there due to volume corona effects draining the charge before it gets to breakdown at any point. Until someone shines a laser at it...

[abebarker]

I met a guy that said he and some class mates observed, pretty much, the same phenomena. I don't know how reliable of a source the guy is but I found the report interesting and have really wanted to test it.

The guy said they had a Tesla coil in their class when they shone a laser pointer of 633nm next to it, the discharges would be conducted down the beam. They had other laser pointers of different wavelength but only the 633nm laser would work.

Again, I don't know how credible the story is. I do find the idea intriguing though.

Can you remember any more about the conversation?

There isn't much more to tell. He said they would shine the laser across the room onto a wall. The Tesla coil was closer to the wall than it was to them. The discharges from the coil would travel down the laser beam toward the wall. He was adamant that the discharges would only travel down the 633nm laser beam and not the beam of other wavelengths.

I believe he said he went to school in Tooele Utah (pronounced TOO-WILL-AH). He said that he was a Cobra pilot in Desert Storm but that is irrelevant.

[B.B.Bubby]

Another laser phenomenon that may have been a contributing factor -  http://www.chem.scphys.kyoto-u.ac.jp/nonnonWWW/watanabe/studies/photophoresis/index.html.en

Getting motivated to start experimenting.

Any one got a van de graff generator I can borrow?

No, but I do have a 0 to 200KV regulated power supply. SouthWest Sydney area.
I've been trying to get around to setting up the Faraday cage it needs around it (to be safe to use in my small workshop) so I can try some experiments related to something else (that LED sparkle ball thing from another thread.) The cage will be soon; I'm not doing anything fancy, probably just chicken wire (ha ha very appropriate.)

What occurred to me to try, related to your laser scenario, is to put two sphere electrodes spaced JUST far enough to not ark over in air. One of them with a small hole through it, so a laser can be shone between the two at closest distance. So, a relatively short distance, like 6 inches to a foot will do for the experiment. 200KV - can do.

The idea being if the air gap is only just not quite arcing, then any tendency of the laser at all to initiate an arc actually will. If it does, the spheres can be moved apart till nothing happens. That will show what degree of effect the laser has.

Only guessing about mechanism, but if it does work I think it will be due to the laser stimulating photoelectric emission from the surface, (in the high E field). Excess ions near a point on the surface will accelerate in the field, and form a leader cascade 'point', concentrating the field more as the leader point extends. Possibly with the laser beam assisting further ionization at the point, since there there's a zone where the air is reaching breakdown point anyway, and any extra energy (the photons) will kick it over. So there'll be a kind of guiding effect. The laser couldn't do it by itself, but it can steer the much greater energy available in the electrostatic field.

I'd guess it will only work in E field gradients not far below arc-over levels.
Your moving film/paper might build up charge to just below arc-over level, but self-limit there due to volume corona effects draining the charge before it gets to breakdown at any point. Until someone shines a laser at it...

0-200kV  power supply     

I'm half way through building a 40cm van de graaff
Hopefully I can start trying out a few things in the next few days.

[B.B.Bubby]

I met a guy that said he and some class mates observed, pretty much, the same phenomena. I don't know how reliable of a source the guy is but I found the report interesting and have really wanted to test it.

The guy said they had a Tesla coil in their class when they shone a laser pointer of 633nm next to it, the discharges would be conducted down the beam. They had other laser pointers of different wavelength but only the 633nm laser would work.

Again, I don't know how credible the story is. I do find the idea intriguing though.

Can you remember any more about the conversation?

There isn't much more to tell. He said they would shine the laser across the room onto a wall. The Tesla coil was closer to the wall than it was to them. The discharges from the coil would travel down the laser beam toward the wall. He was adamant that the discharges would only travel down the 633nm laser beam and not the beam of other wavelengths.

I believe he said he went to school in Tooele Utah (pronounced TOO-WILL-AH). He said that he was a Cobra pilot in Desert Storm but that is irrelevant.

Thanks mate, weird how they didn't follow up on it.

[TerraHertz]

I'm half way through building a 40cm van de graaff
Hopefully I can start trying out a few things in the next few days.

Pity about those flanges on your top ball... uh, two bowls. Those will corona discharge away and cut your top achievable voltage down a lot.
Where are you? If Sydney, I have a few spare metal donuts if you want one.

Last year I found a tossed out exercise treadmill. The track is about six foot long, big rubber belt with motor drive, rollers, etc.
I grabbed it thinking wow, possible huge Van de Graph generator. But I haven't come up with anything insulating (I can find for free) to replace the steel side frames. Needs to be solid. Big fat fiberglass bars, or something like that. Wood is not suitable. PVC piping not strong enough. Though, now I come to think of it, *large* PVC pipe would probably work.
Hmm. Also I could slit the belt and use a narrow width. That would fit inside a large tube. Also it would give me spare belts.