Why can't I reflect light infinitely?

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Why can't I reflect light infinitely?

Postby Webb » Wed Nov 02, 2011 10:00 pm

I put a LED night light in the bathroom so I don't have to turn the light on every time I go in there.

I have noticed that the light reflects in the mirror so I can see 2 night lights.

Hmmm, why can't I put mirrors on every wall (other than it would look like a whorehouse) and reflect the light over and over and over again infinitely?

Something tells me there is a basic law of physics that would prevent this - something like laws against perpetual motion.

So college kids (I rank this a little above high school physics and I hope I'm right because I don't remember learning it in high school) - why can't I put mirrors all over the walls and ceiling and magnify a 3w night light into 300 watts?
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Re: Why can't I reflect light infinitely?

Postby Xpand » Thu Nov 03, 2011 3:40 am

There isn't any law that stops you from doing that except for the decay of the light intensity at the square of the distance it travels. So, if you had a very intense light you could light up the room, IF the mirrors you had could scatter the light, otherwise you'd have a laser beam that wouldn't light up anything.
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Re: Why can't I reflect light infinitely?

Postby ozzy72 » Thu Nov 03, 2011 2:39 pm

Photons get tired ;D
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Re: Why can't I reflect light infinitely?

Postby Steve M » Thu Nov 03, 2011 3:38 pm

I think you would need some super magnets like the Large Hadron Collider has. Acme supply has marketed such magnets.
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Re: Why can't I reflect light infinitely?

Postby Bud Greene » Thu Nov 03, 2011 4:41 pm

Hmmm, why can't I put mirrors on every wall (other than it would look like a whorehouse)...

I fail to see the problem here... ;) ;D
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Re: Why can't I reflect light infinitely?

Postby patchz » Thu Nov 03, 2011 4:46 pm

Hmmm, why can't I put mirrors on every wall (other than it would look like a whorehouse)...

I fail to see the problem here... ;) ;D

;D ;D ;D ;D ;D

Best reply!!!!!
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Re: Why can't I reflect light infinitely?

Postby Ang2dogs » Thu Nov 03, 2011 5:47 pm

Hmmm, why can't I put mirrors on every wall (other than it would look like a whorehouse)...

I fail to see the problem here... ;) ;D

;D ;D ;D ;D ;D

Best reply!!!!!


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Re: Why can't I reflect light infinitely?

Postby TacitBlue » Thu Nov 03, 2011 6:44 pm

This has been a very funny thread so far! ;D

But on a serious note, please keep in mind that I'm not a physicist or expert in anything, especially light reflection. BUT, it seems to me that that wouldn't work, because it does not increase the AMOUNT of light, it just redirects it. for example, if you put a mirror on the wall opposite of the LED, then instead some of the light reflecting from the wall (allowing you to see it) and some of it being absorbed by the wall, all of it is reflected and simply redirected to another area where some of it will be reflected and some will be absorbed. It doesn't matter how much you bounce it around, you only have so much light to work with.
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Re: Why can't I reflect light infinitely?

Postby Xpand » Thu Nov 03, 2011 7:00 pm

That's because, in order to iluminate large surfaces you have to diffuse the light using a non-flat surface, like white fabric from shirts.
The only way you could illuminate a whole room with only a source of light is by using the an intense source of light and place it at the center of the room. Then cover the walls in pure white paint with with a cement like rugosity in order to scatter the light.
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you see the paralel incident rays (blue) and the green reflected rays not paralel. That's the secret of diffusion and it allows you to illuminate large surface areas from a smaller light source.
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Re: Why can't I reflect light infinitely?

Postby Steve M » Thu Nov 03, 2011 7:11 pm

::) I'll give this one more shot before I have to turn the lights out. And it agrees with Xpand and Tacit. The only way that light could amplify is with polished convex mirrors directed at each other but still using a source of radiation. Basically a laser, in a whorehouse of course.  ;D
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Re: Why can't I reflect light infinitely?

Postby Webb » Thu Nov 03, 2011 9:35 pm

What a hoot.  I'll have to see if I can come up with more stupid questions (involving whorehouses of course).
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Re: Why can't I reflect light infinitely?

Postby machineman9 » Fri Nov 04, 2011 2:54 pm

Inverse square rule... Mythbusters tested an alternative way of maximum diffusion using mirrors to light an otherwise pitch black room, but it's very hard.

If you double the distance of the light, it quarters its intensity. Incidently, we calculated in physics that you could read your newspaper on Pluto - Because despite the inverse square rule, there is enough light there to be equivalent to being 50cm from a 60W bulb. So now you know!  :P
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Re: Why can't I reflect light infinitely?

Postby Jayhawk Jake » Fri Nov 04, 2011 6:43 pm

I'm willing to bet it also has to do with reflectivity, as in a mirror does not reflect 100% of the light that shines on it.  It's probably close to 100%, but anything off and after a while it will dissipate
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Re: Why can't I reflect light infinitely?

Postby machineman9 » Fri Nov 04, 2011 9:03 pm

[quote]I'm willing to bet it also has to do with reflectivity, as in a mirror does not reflect 100% of the light that shines on it.
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Re: Why can't I reflect light infinitely?

Postby Club508 » Fri Nov 04, 2011 9:55 pm

Oh boy, I'm a science junkie here! ;D
Time to have som e fun explaining my theories in the morninig! ;D
Ya know.... Along with that, maybe I should post some of my random theories that may prove current ones wrong.
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