Laser'ed on Landing

[Ty Webb]

What kind of spectacular effect would a car bomb have? Part of everday life in the Middle East, I believe here it would have a devastating effect to the national psyche.

Sure the first, and second, and third ones might. But we are a very resilient people, and the end result result would be a strengthening of resolve against the terrorists, and probably a call for the expulsion of most foreign-born Muslims, unless the Muslim community gets off its collective ass and started a huge effort to start policing themselves.

Why it hasn't been attempted, I cannot speculate. Perhaps it has been, it was never revealed with the perp cooling his jihadi heels in sunny Gitmo.

Agreed, and agreed, and agreed again.

 

[rumpletumbler]

They wouldn't want to mess up their free convenience store for every, man, woman and child.....

In other news...........


Morris man was 'playing' with laser Lawyer: Parsippany resident wasn't trying to distract pilot

By Michael Daigle and Rob Seman, Daily RecordPARSIPPANY -- The attorney of a Lake Parsippany resident questioned by authorities about his suspected use of a laser light said Saturday her client was in the "wrong place at the wrong time." David Banach was showing his daughter a common laser pointer that he had purchased on the Internet, said attorney Gina Mendola Longarzo. Longarzo said she met with Banach on Saturday.

"At one moment he was in the backyard playing with his daughter," said Longarzo, "and 10 minutes later 12 police cars descended and he was whisked away by authorities and interrogated until 4 a.m."

Banach was taken from his Pitman Road home Friday by state, local and federal authorities investigating the shining of green lasers onto aircraft flying over the region.

Longarzo said once authorities fully investigate the incident, her client will be exonerated. He has not been charged, she said.

[font=helvetica,arial][/font]Jay Patel, who lives across the street from Banach, said Banach often buys many toys for his two young children. Patel said Banach was not doing anything sinister.

"I don't think he was doing it purposely," Patel said.

No one was home at the Banach residence later Saturday.

On Friday FBI agents, police from the Port Authority of New York and New Jersey and a federal terrorism task force were seeking the source of green lasers that were aimed at separate aircraft flying over Morris County in the last several days. The local incidents were among several being investigated nationwide.

A Port Authority helicopter was marked by a similar laser Friday during the search and authorities targeted the Lake Parsippany area for a possible source.

Several people have been questioned in connection with the incidents, which involved a corporate jet and a Port Authority of New York and New Jersey police helicopter. No arrests had been made Saturday, according to an FBI spokesman.

"It is an ongoing investigation," FBI Special Agent Steve Kodak said. "Nobody is in custody and there have been no arrests."

He said that the appropriate statutes relate to interfering with the safety of an airplane in flight. While the terrorism task force was called in to help with the search, a common practice, Kodak said, federal officials do not consider the incidents terrorism related.

Last month the FBI and the Homeland Security Department sent a memo to law enforcement agencies saying there is evidence that terrorists have explored using lasers as weapons.

In New Jersey last week, both aircraft were targeted by the lasers in the vicinity of Teterboro Airport.

On Wednesday night, a pilot preparing to land the jet at Teterboro reported seeing three green laser beams about 11 miles from the airport.

Port Authority spokesman Steve Coleman said that plane was a corporate-owned Cessna with 13 passengers.

In addition to the Teterboro incidents, federal agents are looking into recent reports of lasers being shone at aircraft in Colorado Springs, Colo., Cleveland, Washington, Houston and Medford, Ore., according to law enforcement and transportation officials, some of whom spoke to The Associated Press on condition of anonymity.

In some cases lasers locked onto aircraft several thousand feet up as they approached airports, federal officials said.


http://www.dailyrecord.com/news/articles/news2-laser.htm

 

[anjinoo7]

REALLY? A police officers LIDAR is enormous in spread? I guess that's why they aim it at your license plate or head light assembly when they attempt to determine your speed. I guess the next time I get nailed by a LIDAR equipped cop, I'll defend myself by saying it was the car next to me.

Yes you are correct, the beam spread is quite significant relative to the exiting beam from the gun. For example a beam width of 3.5 millradians becomes 1.75 Feet in diameter at 500 feet. An example of the calculation is provided at http://copradar.com/preview/samform/sf6d3d1.html since you like radar detector websites that utilize cop science. I really would not reference Valentine radar's website to validate my scientific opinion.

You do know that police helicopters are equipped with FLIR equipment...only the poor police departments have observers using NVG. I would expect that NYPD choppers have the latest in onboard FLIR equipment...especially since 9/11. That's why they knew that a laser was being pointed at them and that's how they knew where the laser came from...they saw it on their FLIR.

Yes I know they have FLIR pods on them however that does not mean they can see across the entire spectrum from far UV light to far IR. No one makes or manufactures such a product that is capable of this feat yet. There tends to be problems with cooling, resolution etc. In order for them to have actually seen an IR laser, it would have to operate within the wavelengths the FLIR could see in. Not impossible but highly improbable. Here is another link for you and a quote from that sight. "The entire electro-magnetic spectrum includes gamma rays, x-rays, ultraviolet radiation, visible light, infrared radiation, microwaves, and more. Each band is differentiated by its wavelength. The infrared radiation band is a portion of the overall electro-magnetic spectrum, and is divided into three smaller bands. Near-IR spans from .7(m to 3(m. Light intensifiers such as night vision goggles are sensitive to electromagnetic radiation in these wavelengths and in the visible wavelengths. Beyond Near-IR is the Mid-IR band (3(m to 6(m) and the Far-IR band (6(m to 14(m). In general IR imagers operate well in one or the other, but not both." http://www.mantech.com/contracts/5506P_prodDesc.asp

Your average Joe doesn't really have a use for these types of lasers but they can get them. The military uses them to target STATIONARY targets such as building bridges etc. I have not seen a weapon system yet that employs a laser to target a MOVING object like an airplane.

In fact, your argument would portend that no one saw the laser, so how would they have known they were being lased?

The laser was visible to the naked eye?? Perhaps operating in the wavelengths of 416nm to 694nm??

Cheers

 

[Nocturnal1]

Just saw this:
FBI: No terror link in lasers aimed at aircraft
By Kevin Johnson and Alan Levin, USA TODAY
WASHINGTON — A string of incidents around the country involving laser beams aimed at aircraft aren't linked to terrorism and are more likely the work of mischief makers, the FBI said Sunday.
The FBI attributed eight incidents in the past 10 days to pranks or accidental acts that tagged aircraft in Ohio, Texas, Oregon and New Jersey. Pilots reported that powerful laser beams apparently had been aimed at them during takeoffs and landings.

Lasers have been a growing concern in the aviation community. Laser pointers, devices the size of a pen that are used by public speakers, have enough power to cause vision problems in pilots from a distance of 2 miles, according to the Federal Aviation Administration. A pilot hit by a laser also could become distracted.

The Homeland Security Department issued a bulletin to law enforcement agencies in November warning that terrorist groups have expressed an interest in using them.

In the latest laser-flashing case, a police helicopter investigating an earlier laser incident near the Teterboro, N.J., airport was hit Friday evening by a beam coming from a neighborhood in Parsippany. Potential witnesses were being questioned Sunday by the FBI.

No one has been arrested or charged. But an attorney for a Parsippany man said her client was questioned by the FBI.

Attorney Gina Mendola Longarzo said David Banach was playing with his daughter on the deck of their home Friday evening when they waved a handheld laser pointer in the air. Longarzo said Banach was aware that a helicopter was in the area but did not think the beam was powerful enough to reach the helicopter. Within minutes, Longarzo said, police and federal agents swarmed Banach's home.

"There is no connection to terrorism here," Longarzo said. "This is a man who has never had a parking ticket."

FBI spokesman Stephen Kodak said the investigation was continuing and that "several people" were being questioned. He said there is no evidence linking the New Jersey incidents to terrorism.

 

[Flylo]

Another one?

Channel 5 in Nashville is reporting a United Express airplane was hit with a laser at 7:30 last night during takeoff from BNA.

http://www.newschannel5.com/content/news/8697.asp


.

 

[Singlecoil]

With all this talk about lasers, I'm starting to wonder if that's what happened to me several years ago. I think I was flying the Seattle-Medford run and was climbing out when my left eye started to burn and go blurry. I don't remember any flash of light or anything like that but I do remember being very puzzled and concerned. My left eye stayed completely useless for about 30 minutes, then gradually got better. I never mentioned it to anyone except the FO because I was worried about medical issues down the road with the FAA. This part I remember very clearly, however. As we were flying along and I was wondering what the he11 was going on, I noticed I also had a burn on my left forearm about as big around as a cigar. Now I'm feeling like a moron for not putting two and two together, but at the time I thought it was some weird nervous system deal like shingles or something and didn't want to attract any attention.

 

[spngbobsqrpilot]

The military uses them to target STATIONARY targets such as building bridges etc. I have not seen a weapon system yet that employs a laser to target a MOVING object like an airplane.

Leave it to battlefield opportunity..

An F-15 on a counter-SCUD mission shot down a hovering Iraqi helo with a laser-guided bomb.

http://www.history.navy.mil/wars/dstorm/dsfeb.htm

OK, so it was officially "hovering". But was there any wind, and if so, isn't this considered "moving"?

 

[Philso]

Most car bombs don't have drivers. The IRA invented the car bomb and they never used it as a guided/suicide weapon. (Matter of fact, the IRA taught the methods to Middle East terror organizations many years ago.) In an open society, such as ours and the UK, there was never a need for a suicidal driver.

But there were the proxy car bombs. The IRA used to hold a family hostage while a member of the family drove a car or van full of homemade explosives to the local security base or another target. Sometimes the driver made it back alive, other times they didn't.

 

[Philso]

Car bombs just don't have the spectacular effect.

Location, location, location.

A car bomb in the heart of London was "worth" more to the IRA than 10 car bombs in Belfast, in terms of fund raising and publicity. The last one outside the BBC was on television for over 2 weeks and was covered on CNN and MSNBC

 

[TDTURBO]

Guess what's this months special on Vrotate?

http://vrotate.com/specials.htm

 

[FN FAL]

Guess what's this months special on Vrotate?

http://vrotate.com/specials.htm

Yea, but those aren't the special "invisible" LASERS that can't be seen by police helicopters...like the super secret ones the terrorists have been using to shine airliners.

 

[anjinoo7]

Yea, but those aren't the special "invisible" LASERS that can't be seen by police helicopters...like the super secret ones the terrorists have been using to shine airliners.

Your attempt at sarcasm relating to IR lasers and the technological limits of your SUPER DUPER POLICE HELECOPTERS with the ALL SEEING EYE is lost on folks who actually completed a science course or 2. Edumicate yourself cause you look like an ass.

Cheers

 

[TDTURBO]

Yea, but those aren't the special "invisible" LASERS that can't be seen by police helicopters...like the super secret ones the terrorists have been using to shine airliners.

Ya, I know, it just struck me as funny seeing it after reading this thread.

 

[FN FAL]

Ya, I know, it just struck me as funny seeing it after reading this thread.

It's no laughing matter TDT...the radially dioscoptic hectobars of translucent pulsating illumination generated by the types of lasers the terrorists have been using to attack airliners, exceed the angular parsec defibrulation range of most tangiometric optical positioning and ranging devices. Generally speaking, desmodromic interlobicular diode devices have not been useful to authorities in locating these terrorists and neither have their counterparts, the phased locked loop copraphasic multi-conducting silicon based semi-conductors. It will require patients, to conduct more experiments...so only time will tell.

 

[TDTURBO]

It's no laughing matter TDT...the radially dioscoptic hectobars of translucent pulsating illumination generated by the types of lasers the terrorists have been using to attack airliners, exceed the angular parsec defibrulation range of most tangiometric optical positioning and ranging devices. Generally speaking, desmodromic interlobicular diode devices have not been useful to authorities in locating these terrorists and neither have their counterparts, the phased locked loop copraphasic multi-conducting silicon based semi-conductors. It will require patients, to conduct more experiments...so only time will tell.

Good One FN FAL!
LMAO!!!

 

[EagleRJ]

It's no laughing matter TDT...the radially dioscoptic hectobars of translucent pulsating illumination generated by the types of lasers the terrorists have been using to attack airliners, exceed the angular parsec defibrulation range of most tangiometric optical positioning and ranging devices. Generally speaking, desmodromic interlobicular diode devices have not been useful to authorities in locating these terrorists and neither have their counterparts, the phased locked loop copraphasic multi-conducting silicon based semi-conductors. It will require patients, to conduct more experiments...so only time will tell.

LOL!

That's what it's like watching a Star Trek episode!

 

[laser]

Knuckelhead in NJ Charged.

Man Charged With Aiming Laser at Aircraft
January 04, 2005 12:24 PM EST
NEWARK, N.J. - A man who initially claimed his daughter aimed a laser at a helicopter was charged after he told federal agents that he pointed the light beam at two aircraft, authorities said Tuesday.

David Banach of Parsippany faces charges of interfering with the operator of a mass transportation vehicle and making false statements to the FBI. He is scheduled to appear in U.S. District Court on Tuesday afternoon.

The aircraft were targeted by the lasers near Teterboro Airport.

On Wednesday night, a pilot preparing to land a chartered jet with 13 people aboard reported seeing three green laser beams about 11 miles from the airport. On Friday, a helicopter carrying Port Authority detectives was hit by a beam as they surveyed the area in an attempt to pinpoint the origin of the original beams.

The two incidents were among a rash of recent reports of lasers allegedly aimed at aircraft, raising fears that the light beams could temporarily blind crew members and lead to accidents. Last month the FBI and the Homeland Security Department sent a memo to law enforcement agencies saying there is evidence that terrorists have explored using lasers as weapons, though federal law enforcement officials have said there is no evidence of any terrorist plot in the current incidents.

According to court papers, under questioning Banach admitted lying and said he shined a laser beam at both the jet and the helicopter. He has not been charged in the helicopter incident.

His lawyer, Gina Mendola-Longarzo, did not immediately return a phone call seeking comment Tuesday.

The chartered jet was flying at about 3,000 feet when the pilot and co-pilot saw a green laser beam strike the windshield three times, according to court documents filed Tuesday. The flash blinded the two temporarily, but they were later able to land the plane safely.

After the helicopter crew also reported seeing laser beams, FBI agents canvassed Banach's neighborhood trying. Banach told the agents it was his daughter who shined a beam at the helicopter, according to court papers. He denied the laser was in use when the jet had passed nearby. But later, Banach submitted to a lie detector test and eventually said he shined the laser beam at both aircraft, according to the court papers. The papers did not give any alleged motive. END


I thought this was a simple laserpointer. Anjinoo, I can't understand most of the stuff you've written so far. Make it simple. Was the pointer this guy had strong enough to "temporarily blind" the crew (at 3000'), or is this probably media embellishment?

 

[wrxpilot]

I thought this was a simple laserpointer. Anjinoo, I can't understand most of the stuff you've written so far. Make it simple. Was the pointer this guy had strong enough to "temporarily blind" the crew (at 3000'), or is this probably media embellishment?

What a tool... Blames his daughter after getting caught?? He should do time just for that. And being stupid enough to be tripped up by a lie detector test! Dumbass all around...

 

[anjinoo7]

I thought this was a simple laserpointer. Anjinoo, I can't understand most of the stuff you've written so far. Make it simple. Was the pointer this guy had strong enough to "temporarily blind" the crew (at 3000'), or is this probably media embellishment?

It is a simple laser pointer. Probably this one for $99.95, check out the pictures section

http://www.thinkgeek.com/gadgets/lights/5a47/action/20fb225/

. No more blinding or harmful at 3000 feet AGL than someone shining a real bright flashlight in your eyes sitting right next to you. What do you do when that happens, use your blink reflex and close your eyes. Laser safety is a factor of many things, power of the laser, wavelength or the frequency, atmosphere, beam diameter and DWELL TIME or how long you stare at it. In order for these lasers to do some sort of harm to you, you must stare at it for some time at a fairly close range.
Lets take a hypothetical situation and maybe I can explain better. You are flying in the pattern at some airport and lets say your at 4000ft agl, straight and level in a CJR. First thing we talk about is range here. The actual distance from your eyes to the ground where the dumbass is who has the laser is not 4000ft because you can't see right below the A/C, it is probably somewhere on the order 1.5 times the distance or slant range. The slant range is the hypotenuse of the triangle represented by the altitude of the airplane and the distance between the dumbass with laser and the airplane's ground track (the point on the Earth at which it is directly overhead). More distance decreases power or effect. As a laser safety officer, we have to calculate Nominal Ocular Hazard Distance or the distance at which a laser is hazardous and not hazardous. If we look at our green laser from the site above we can see that it is classified as a IIIA type laser. The ANSI standard for a higher power IIIB is defined as this: In general, Class IIIB lasers will not be a fire hazard and are not generally capable of producing a hazardous diffuse reflection except for conditions of intentional staring done at distances close to the diffuser. Again your blink reflex protects you. Next thing we talk about beam divergence or the increase in beam diameter with distance from the aperture from which the beam emerges. Distance makes the beam grow larger, so right next to the laser it may be 1.5 mm in diameter and by the time it gets to 6000ft it may be the size of a Volkswagen. Bigger diameter decreases power but may give your cockpit a green glow. The other factor is the atmosphere. The atmosphere disrupts the beam and what may start as a perfect circle ends up at the plane as a something akin to a funky blob because of atmospheric distortion. The easiest way to explain is to picture looking over a hot parking lot and you can see the air shimmering as it rises. Well this happens all the time at all altitudes but increases closer to the ground because the air is denser. This causes mucho power loss. The other aspect is how long are your eyes exposed to the beam. Damage occurs when the Maximum Permissible Exposure is exceeded. MPE is defined as: The level of laser radiation to which a person may be exposed without hazardous effects or adverse biological changes in the eye or skin . Well or natural reaction to bright light is to close our eyes or turn away. In either case you are able to quickly close your eyes or turn away long before your MPE is ever reached. The next difficulty for the dumbass it to train the laser on the cockpit for an extended of time while the plane is moving at long distances. Not impossible to hit the plane and flash the cockpit but very difficult to train on a small window for extended periods of time. In almost all the situations, that the media reports pilots saw the cockpit light up a funky color, or may have even been directly hit in the eyes. In any event not any more harmful to ones eyes that a stupid friend hitting you in the eyes with the beam of his mag light as a joke. You temporarily lose your night vision and see a spot but you then regain your vision however, no other hazards occur.
My whole point in all of this is to hopefully allay fears and take what you read in the paper with a grain of salt. Believe it or not they want to sell some papers or advertising and to do that you gotta sensationalize a little bit. As we can see from the latest arrest he was a dumbass who thought it would be cool to lase a plane. I will happily answer any questions anyone has but I don't tend to give into mass histaria concerning these lasers because I have worked around both lasers and planes , primarily by putting a very large laser on a very large plane

http://www.boeing.com/defense-space/military/abl/flash.html

 

[fastandlow]

anjinoo7 - I think you and Vik were talking about two different things. You can't see the light from any laser unless it shines directly into your eye or reflects off something. In the atmosphere - that would be dirt, water, smoke. Clear atmosphere, no reflection, no visible beam. But you're right - when it reflects, it would have to be in the visible range to be seen.

These green lasers are probably commercial types (surveying maybe). As for the little red pointers, I just about guarantee I could shine one into a cockpit at 500-1000' for a moment. No $100k tracking equipment needed. You can see these reflecting off highway signs from nearly 1/2 mile away at night, could easily flash one into an airplane if you were standing in the right spot.

 

[anjinoo7]

anjinoo7 - I think you and Vik were talking about two different things. You can't see the light from any laser unless it shines directly into your eye or reflects off something. In the atmosphere - that would be dirt, water, smoke. Clear atmosphere, no reflection, no visible beam. But you're right - when it reflects, it would have to be in the visible range to be seen.

Fast, this is what I tried to point out in my last post that I provided a link on, you can see a green lasers beam. Here are some pictures that are not directly pointed at the camera and the beam is visable.

http://www.thinkgeek.com/gadgets/lights/5a47/action/210cd9d/
http://www.thinkgeek.com/gadgets/lights/5a47/action/21046eb/
http://www.thinkgeek.com/gadgets/lights/5a47/action/21033ff/

These green lasers are probably commercial types (surveying maybe).

Here is another link to a $99 GREEN laser.
http://www.thinkgeek.com/gadgets/lights/5a47/

With regard to atmosphere, the air of the atmosphere is constantly in turbulent motion. Light from a star is refracted in random directions over time periods of tens of milliseconds, by rapidly-moving pockets of air of varying densities and temperatures. For this reason images twinkle and are blurred to our eyes. The same has an effect on the performance of a laser; it blurs it and makes it not so focused. Dust, vapor, and smoke are other factors however, the primary reason is these rapidly moving pockets of air, much as you see coming off a hot parking lot.

 

[Corona]

There was an article in the paper about the laser used in the NJ case. Here's the home page for the laser:

http://www.bigha.com/sky/index.php

The manufacturer was disappointed someone was using it irresponsibly. The lasers apparently have a range up to 5 miles (!), depending on atmospheric conditions.

I remember when the first handheld (red) lasers came on the market several years ago. I bought one in a pen for 5-6$. Some articles came out in the newspapers about how malls and other public places were banning them because of abuses by the inbred. Looks like we're back to that.

C

 

[fastandlow]

With regard to atmosphere, the air of the atmosphere is constantly in turbulent motion. Light from a star is refracted in random directions over time periods of tens of milliseconds, by rapidly-moving pockets of air of varying densities and temperatures. For this reason images twinkle and are blurred to our eyes.

Yep - and the starlight photons you are seeing are coming *from* the star and directly *into* your eye - diffused, refracted or not. If a laser photon is travelling from a laser to your eye, you'll see it (if it's in the visible band). Otherwise, if there's nothing for the photons to bounce off of (dust, water), you won't detect the photons with your eye! This all applies to relatively low power light. Course the last time I took a physics class was about, oh 20 yrs ago...

 

[rumpletumbler]

It's no laughing matter TDT...the radially dioscoptic hectobars of translucent pulsating illumination generated by the types of lasers the terrorists have been using to attack airliners, exceed the angular parsec defibrulation range of most tangiometric optical positioning and ranging devices. Generally speaking, desmodromic interlobicular diode devices have not been useful to authorities in locating these terrorists and neither have their counterparts, the phased locked loop copraphasic multi-conducting silicon based semi-conductors. It will require patients, to conduct more experiments...so only time will tell.

LOL!......

 

[FN FAL]

Who knew pointing could be so much fun?

I'm against banning things or activities, but pointing is rude.

It's bad enough we have the midget cars with excesively loud exhaust laying rubber all the time in our neighborhood, the fat middle aged office nerds and their Harleys that sound like they don't have a muffler, people who drive in the left lane of interstates next to semi-trucks for five miles while gabbing on their cell phones and car stereos so loud as they drive by they rattle the dishes in our cupboards and the pictures hanging on the walls...but now we have to have our privacy interupted with light beams.

Like I said, I'm not for banning something like this...but I think laser owners need a wake up call and this fat guy getting his but hauled into federal court under the Patriot Act, is it.

If I get one of these things "pointed" at me from another car, while I'm driving my car...those people better have their freeking seatbelts on.

 

[bigD]

Shaun of the Dead!

 

[FatesPilot]

MFR laser attack

A couple sentences on NBC nightly news tonight (12/30) about pilots reporting a laser being shinned in the cockpit. Has anyone see this first hand?

Yes, me and my crew flying into Medford, OR on Christmas night at 8pm.
http://www.foxnews.com/story/0,2933,142867,00.html
http://www.mailtribune.com/archive/2004/1230/local/stories/02local.htm

It was a clear VMC night with partial moonlight and 30+ miles of visibility. We were around 6,000 AGL when I (the PIC) was momentarily flash blinded by a high power green laser which appeared to be 2 inches in diameter. The laser was tracking us 8 miles from MFR on the LOC 32 and continued to track us until we passed over it, lasting about a minute. I saw five refractions in the cockpit. It was disorienting and I felt personally violated. Several passengers saw refractions in the cabin as well. I don't think anyone can appreciate how powerful a green laser can be until it happens to them. This is something very serious. The Jackson County Sheriff is investigating along with the FBI and the FAA.

I had a digital scan of my retina and there is no permanent damage. My doctor believes it would take several seconds of exposure to burn the retina. However, once laser light enters the eye it is magnified by a power of ten. There are cases of pen lasers degrading vision from 20/20 to 20/60 with several seconds of exposure.

Keep this in mind. Whoever did this to us was doing it with malicious intent. Green lasers are expensive to obtain, and not something a kid would purchase. This was an attempt to blind us. It tracked our plane for over a minute in continuous moderate turbulence. Is the fact this happened a week after the FBI warning a coincidence?

Side bar: I wonder if that Jasper astronomy laser could appear to be 2 inches in diameter from a mile away. Can someone do the math on that for me? I think that's the most plausible explanation so far, since the source was in an urban part of town.

 

[rumpletumbler]

I felt personally violated.

LOL! Ok...sorry...I'm feeling insensitive this morning.

 

[Full of Foehn]

Ease up on the guy.

Learn before you post, anything within 694nm to 416nm is VISIBLE to the naked eye. Incidentally, a majority of the lasers available to the public are in the visible spectrum. Anything higher than 694nm gets into the near infrared and far infrared, anything below 416nm gets into the ultraviolet spectrums. Please educate yourself before making smart-ass posts.

I think what he meant was that you cannot see the beam unless there is particulate, vapor, or colloidial matter in the atmosphere to scatter the light. Of course, whatever the laser is pointed at will be illuminated, depending upon its density and tranparency.