Laser mythology.....

[Schrecken_Licht]

It's pretty obvious that with all these recent incidents (people pointing lasers at aircraft and the guy here who got beamed in the eye by a cop) that most people haven't a clue about lasers and buy into popular (Hollywood can also be blamed for this) mythology about lasers.

People either vastly underestimate or over estimate the dangers involved. The former is usually the case with potential eye damage, and the latter with other sorts of damage and injury.

Many people seem to think that visible light lasers can cut people in half but are harmless to the eyes....I saw a movie (an old movie) not long ago where a guy was being blasted by what appeared to be a high-powered green laser (that was supposed to be used to kill small animals that might escape a research lab he was working in). Well, the guy manages to duck the beam for the most part, but then he gets hit in the face. The laser is powerful enough to put a nice burn mark on his cheek but, wonder of wonders - he can see just fine! Then he gets hit on the back of the hand - right near his face as he's climbing a ladder! And the laser beam also hits the metal ladder right next to his face...all you see are sparks - but no reflection! Of course as most of us know, any visible light laser potent enough to char skin on contact could easily blind, even from reflections! Worse yet, he has nasty burns that could only be inflicted by a couple hundred watts of laser energy - like a CO2 beam!

I am also guilty of believing laser myths (before I got into lasers) - I didn't think lasers were that dangerous to eyes, and I thought you needed many dozens of watts (visible or otherwise) to do damage to a given target, including skin/flesh! Probably because I worked at that laser shop where they had 5kw CO2 lasers - I knew what they could do, so I guess I figured a few watts were nothing.....


What laser myths did you used to believe, and what gripes you the most about "typical" portrayals of lasers (meaning in movies, tv shows and other fictional media or anywhere else)?

 

[JLSE]

Id say the popcorn scene in Real Genius was one of them. The character Kent’s face was pink from the beam entering the room. His glasses light up, and he just ignores the eye thing and has a bite to eat. :-?

 

[FrothyChimp]

I went to Wright Patterson Air Force Base some time ago to one of their research laser labs and watched a demonstration of a CO2 system (had a really hopped up pumping system) that blasted holes through thick titanium plates. The only problem was the laser system occupied the entire room next door in order to operate.

That's what Hollywood forgets to add when replicating laser effects in movies.

 

[iewed]

When I was younger I always thought that the whole blinding by lasers thing was garbage, my little 5mW keychain couldn't do anything. I'm sure glad I read up on my information about lasers though before I jumped into the Class 3B Laser pool, or I may have been in for some real problems.
I will admit though that lasers are very misunderstood pieces of technology.

 

[keeperx]

I agree that thre are myths.. im new to the hobby but already had a prety good understanding of what a laser is... now i know how they work

My favorite is when people say you need a license to operate them (in the US)
There is no such thing.. only the Health & Safety Executive guide (HSG95) "Controlling the radiation safety of display laser installations"

 

[Ace82]

The only myth I believed was that lasers never diverged, that it would keep the same diameter FOREVER! I thought you could hit the moon although it was too far to see but if you were on it it would be the same size dot.

 

[Helioplasma]

SL : is it andromeda strains (M.Chrichton) ?
OH and I always taught the laser never diverged too, and worse comes too worse I taught class I was more dangerous than class IIIa !!! The media is just dramatizing the facts about lasers, but in some point I have to agree with them, when they told a 125mW laser pointer was used on a helicopter ; while most kids think they are harmless.

 

[john_lawson]

where was it i was watching the Discovery channel and I believe they were saying in one of those famous alien crashes the had found a laser in the wreckage a medical type laser device anyone else see this or was I having a really bad Flashback lol :-?

 

[Schrecken_Licht]

SL : is it andromeda strains (M.Chrichton) ?

Yes - but if you don't want to sit thru the whole movie that part is in the last 10 minutes or so....interesting thing is that in the opening credits it lists "Korad Lasers" (which I believe is the company founded by Theodore Maiman....no longer in existence, though) - usually equipment suppliers are listed in the end of the ending credits. I saw that and thought "cool! there's real lasers in this movie".
I'd imagine the lasers used were green HeNes, as (I could be wrong) I don't think they had any other way to make a CW greenie back then (laser diodes didn't come along until the mid-70's or later) - unless by mixing other laser colors.

 

[Abray]

I think I was a firm believer of the myth that color definitely equaled power. If it was a red laser, it was low powered (I didn't know lasers were measured in power, mW0, and if the laser was green, it was automatically high powered! And Blue was even more high powered than green!

 

[keeperx]

I think I was a firm believer of the myth that color definitely equaled power. If it was a red laser, it was low powered (I didn't know lasers were measured in power, mW0, and if the laser was green, it was automatically high powered! And Blue was even more high powered than green!

Wait .. thats lot true ...
I used tho think the same thing.. nas a matter of fact i always thought that lasers had different effcts other than heat..

 

[Abray]

well I guess the part about blue>green>red is true. Because the wavelength gets smaller, adding more energy to the beam. However, I did not believe it was true for those reasons. I had no idea!!

 

[lordoflasers]

I love how in CSI they use a red laser pointer on a tripod to animate bullet trajectory and their lasers bounce off of every thing, including a yellow painted peice of cement.

And of course in the movie Resident Evil when the blue laser cuts that guy into cubes.

 

[RVB]

I also like the myth that one laser goggle can protect you against just any laser. Believe it or not, but I've even met some high level scientists believing that. :thinking:

 

[rocketparrotlet]

I used to believe in the "color=power" myth, with red being lowest, green being high powered, and blue/violet being amazing killer super bright Star Wars power!

-Mark

 

[Benm]

Movies and lasers... always funny isnt it?

I've always found it surprising that holywood moviemakers think that grids of laser beams are commonly used in expensive security systems, but that they are always built such that you can pass between the gaps with enough acrobatics.

As an extra the beams are sometimes invisible (which would make sense), but can be made visible using only some special glasses, no smoke or anything else.

Another holywood thing are sniper rifle scopes that are the size of a ballpoint, yet produce 5 mm wide spots even a mile away.