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Reflecting Red Laser
Why we cant see red laser pointer beam (we have to use smoke to reflect the beam)?
but we can see green laser beam without smoke. Is that because of power , if so could someone explain in details it.
Actually, you can only *see* the laser beam when the laser light scatters off air molecules or air particles and the scattered light goes towards your eye. So, when you add more particles, like smoke, there are more chances for the light to scatter toward your eye.
Now that we we've discussed how you *see* a laser beam, I can answer your question about red versus green light. Laser light comes in different wavelengths, the shorter the wavelength the more blue the light looks, and the longer the wavelength, the more red the laser light looks to us. How well laser light scatters off air molecules depends on it's wavelength. The shorter the wavelength, the better it scatters light. This is called Rayleigh scattering, and it is proportional to 1/(wavelength)^4. So where is this all going? The green laser beam emits light of a shorter wavelength than the red laser does, so it scatters off just the air well enough for you to *see* the beam.
Your question about power also is relevant. If the power emitted by the red and green lasers was the same, then what we discussed about Rayleigh scattering would apply. If you increase the power of the laser, you increase the number of photons of emitted (the quantitized packets of light, if you haven't heard of these before, don't worry about it, but you can think of them as tiny particles of light). When you increase the number of photons, you increase the chance that enough photons will scatter off the air molecules so that you can *see* the laser beam.
Hope this helps! Let me know if you want to know more!
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JF Lazartigue - Color Reflecting Hair Conditioners (Deep Red) - Beauty $26 Zappos.com is proud to offer the JF Lazartigue - Color Reflecting Hair Conditioners (Deep Red) - Beauty: Enhance your natural color or give your hair a darker tint while nourishing and conditioning the hair. These gentle conditioners contain no ammonia or peroxide, so they're great for all hair types. ; Vegetable protein restores hair's shine and luster. ; Does not lighten hair. ; After shampooing, towel dry hair. Apply product all over using provided gloves. Comb through and leave on for 5 to 30 minutes, depending on the level of intensity desired. Rinse thoroughly. ; For less intensity, mix Colour Reflecting Hair conditioner with Vita-cream with milk proteins. ; 3.4 fl. oz. |
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LS650 Red laser Sight $24.94 The brilliant red beam of the laser sight finds your target quickly and precisely. Cables with momentary pressure pads that allow you to activate the laser with push button ease, are also included. |
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AU11590 Red Laser with Flashlight $59.99 BARSKA Red Laser w/160 Lumen Flashlight w/Quick Release Mount. Keep your target in sight with BARSKA’s new 5mw red laser with an integrated 160 lumen flashlight. Designed to quickly attach/detach from most Picatinny/Weaver style rails. Only 3¾” in length and weighs 4.2 oz. Three different target acquisition methods: flashlight, laser, and flashlight and laser together. Includes batteries and momentary on/off long cable switch. |
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laser reflecting off mirror
I think a sniper almost shot me?
So i was in the living room w/ my sister talking about stuff, and all of a sudden, the sliding glass-door that led to the back of the house was saturated by red. In my perspective, it was a huge red circle beam on the glass - probably due to refraction and whatnot - but in my sister's perspective, the red beam was a perfect small circle, the type you see in movies.
I'm trying to explain this as best as possible. I was facing the glass sliding door and it would have been impossible to see the red beam but the beam had to get through the glass to get to me, so i saw it reflected on the glass. My sister was facing me and was turned away from the glass door so she saw the circle around my head region.
My question is, is this a sick prank by some guy, or was this serious because i honestly doubt those pen laser things can reach that far. Should i call the police? Thank you.
Oh o.k, i feel much better knowing laser pens can do that.
Some asshole neighbor kid was likely just screwing around with a common red laser pointer, maybe a couple hundred feet away, at most. Do you have any specific reason to believe that you have enemies who are willing to go so far as to hire an assassin?
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