Laser radiation?

Is it harmful?  My friend and I are having a discussion about laser radiation. He claims that it get absorbed into your body, thus creating bad, perhaps dangerous, hazardous long term effects to someone like myself who is addicted to lasers.  He says some of it passes though your body, and some of it gets absorbed.  This is of coarse relative to the power of the laser as well, the more power, the more harm. Comparing to microwaves, x-rays, uv rays, gamma rays, etc., he says laser radiation is similar.  Of coarse, laser radiation is absorbed to your body via pointing the beam on your flesh.   :-X

I disagree, without much official education, I believe the laser radiation is not of too much harm, except of of coarse for our eyes.   :-?
radiation

Answers?  

Thanks - Peace - Ace

Your friend is an idiot ;D
The worst visible/IR radiation can do is burn your skin like any other hot object would.
The hazardous types of radiation are UV/X-Rays/Gamma. Those can actually damage your DNA leading to mutations and cancer. There are UV lasers but those cost $10,000 or more and are unobtainable by the typical laser hobbyist.

Wavelengths of visible light are not short enough to penetrate your skin and to do damage on a cellular level. Razako is right, with enough power you can of course burn objects including your skin. But that the same kind of burn you would get from any other heat source. Only radiation with a wavelength shorter than or equal to UV can penetrate your epidermis and damage DNA. The shorter the wavelength, the higher the penetration level.

I do not have a degree in physics, but I do work daily with X-rays and had to follow courses in order to become qualified.

so, the type of radiation that is damaging to DNA and causes cancer is ionizing radiation. This is radiation that has a wavelength short enough to photo-ionize atoms, so, it needs to be shorter than visible or less than something in the realm of 400 nm. If you can see the laser, so in other words it is green or red it is the same as any other green or red light. When dealing with high power pulsed lasers there is an extreme radiation hazard, but have to be extremely powerful before they become a radiation hazard. Microwaves are also not a radiation hazard any more than the sun light or light from a light bulb. in fact, since microwaves from a microwave oven are about 2.5 GHz they contain about 1 millionth less energy than green light from the sun (the quantized energy that is). So if you can see the light (green or red laser) it is no different than any other green or red light. If you shoot in into your eye it will blind you because it is very bright, but that is all. Your friend needs to take a physics class before he gets up in arms about "radiation."

What about biophotostimulation or whatever it's called. Those visible low powered lasers have a unique effect on tissue cells.I'm not sure, but I think they use lasers and not ordinary light for a reason.I don't know if you could have a negative effect with a more powerful laser though :-/

If you are talking about the use of lasers in medical science, there are two versions: the regular treatment circuit and the alternative circuit.

The regular treatments include eye treatments and alleviating complaints that come with certain skin diseases.

The alternative treatments like LLLT or photobiostimulation claim that they can do almost anything, from healing muscle pain to nerve/tissue regeneration. It supposedly would even help you with quitting smoking. You can compare it witch chiropractic, acupuncture and homeopathy. Such treatments are not scientifically proven to be effective and are offered by private clinics, you won't find a serious hospital offering one. At least not in the Netherlands.

Laser radiation is really only dangerous to you're eyes, your friend is obviously getting Laser radiation confused with Ionising radiation, such as alpha and beta which cause cancer . Although UV from the sun will also cause damage if you get too much exposure, there is nothing to worry about from Lasers aslong as you have your Laser Goggles on .

And might I add, what is happening with the quick reply ?

Diachi

The only difference between laser light and "normal" light is that it is monochromatic (one-coloured) and coherent (the photons go in pace with each other). So as all of ya already have said, laser light is NOT harmful if the wavelenth isn't other than IR or in the visible spectrum. Yes, Gamma rays and X-rays are also photons, but their much higher frequency make them harmful. So I would recommend you to tell your unknowing friend all we have told you in the replies.

I think the taboo word here is 'radiation'. When people hear that they flip. It is indeed radiation, but the radiation is exactly what you see -- light! All the harmful radiation is part of the electromagnetic spectrum, but so is visible light. So when the electrons in the lasing medium get excited and jump rings, they radiate light, but the wavelength of this radiation is in the visible spectrum which is why we see it. To give you an idea, gamma radiation is defined as anything with a wavelength shorter than 0.001nm. Now that would be one crazy laser  

Thanks all for your input! I just always considered the term "radiation" as energy, but now I know that's not 100% correct. Since the word "radiation" is somewhat vauge when not specified type, I can see how one may be mislead from the word itself. Laser radiation to me means laser light, or laser energy.

I'm thankful for all your guy's input, you learn new stuff everday!

Types of radiation

-Peace - Ace

Gus is right. Ignorance rules when the word "radiation" is unleashed. Lasers are a scientific instrument and thus are afforded scientific descriptions. Radiation in physics is much more general than the common cultural definition. It's easy to see how something so mundane takes on a sinister shadow when John Q. Public gets it in his ignorant head.

Heh. This is the same kind of thing with NMR. NMR stands for Nuclear Magnetic Resonance. An NMR spectrophotometer is the single most important device in determining structures of unknown chemical compounds.

Maybe one or two of you have been in one of these machines before, they are very common in hospitals. Except when in a hospital, they are called MRI machines, or Magnetic Resonance Imaging  

Why? Because people freak out when they hear the word 'nuclear' They think nuclear radiation or bombs and stuff. When in reality, an NMR machine just has 'nuclear' in the title because it works by interacting with the nucleus of the atoms  

In fact, I quote from the wikipedia article on MRI (http://en.wikipedia.org/wiki/MRI ):

"In its early years the technique was referred to as nuclear magnetic resonance imaging (NMRI). However, as the word nuclear was associated in the public mind with ionizing radiation exposure it is generally now referred to simply as MRI."


Anyway, that's just a fun fact that some of you guys may not know

Petrovski said:

Wavelengths of visible light are not short enough to penetrate your skin

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Close your eyes and aim a red laser at your forehead. Then and ONLY then are you allowed to tell me visible light is incapable of skin penetration.

Switch said:

What about biophotostimulation or whatever it's called.

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It's rightful name is psychosomatic nonsense.

Well then there you go...Once again, the power of healing by a laser is reserved only to WL.

And yes, red and IR is being difused disipated pretty well in the skin tissue.I guess it's why a sh*tload of 808nm on your skin won't burn.

Cyparagon said:

Close your eyes and aim a red laser at your forehead. Then and ONLY then are you allowed to tell me visible light is incapable of skin penetration.

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Does my hand also count? Generating heat on your skin with a laser does not imply that it's penetrating it. In fact, that means that your skin is absorbing the light and its energy.

[edit] Or are you referring to the fact that you can see light 'spreading' through your skin? Perhaps I've not been clear enough. Your skin is made out of several layers. Light can obviously penetrate the top layer(s), everybody knows the 'flashlight behind your fingers' red glow. The deeper layers are a different story. I've always learned that visible light cannot go beyond your skin, or in other words: cannot penetrate it as a whole. The tissue behind it is "safe".

That is precisely the point I'm attempting to prove to you is fallacious. I say to you again, Close your eyes and aim a red laser at your forehead - preferably between or slightly above your eyebrows.