Page 1 of 3

Why can't I reflect light infinitely?

PostPosted: Wed Nov 02, 2011 10:00 pm
by Webb
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?

Re: Why can't I reflect light infinitely?

PostPosted: Thu Nov 03, 2011 3:40 am
by Xpand
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.

Re: Why can't I reflect light infinitely?

PostPosted: Thu Nov 03, 2011 2:39 pm
by ozzy72
Photons get tired ;D

Re: Why can't I reflect light infinitely?

PostPosted: Thu Nov 03, 2011 3:38 pm
by Steve M
I think you would need some super magnets like the Large Hadron Collider has. Acme supply has marketed such magnets.

Re: Why can't I reflect light infinitely?

PostPosted: Thu Nov 03, 2011 4:41 pm
by Bud Greene
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

Re: Why can't I reflect light infinitely?

PostPosted: Thu Nov 03, 2011 4:46 pm
by patchz
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!!!!!

Re: Why can't I reflect light infinitely?

PostPosted: Thu Nov 03, 2011 5:47 pm
by Ang2dogs
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!!!!!


This is why I make sure to swallow what I'm drinking before I open a thread, cause you never know what's going to make you bust a gut!  ;D ;D ;D

Re: Why can't I reflect light infinitely?

PostPosted: Thu Nov 03, 2011 6:44 pm
by TacitBlue
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.

Re: Why can't I reflect light infinitely?

PostPosted: Thu Nov 03, 2011 7:00 pm
by Xpand
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.
Image
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.

Re: Why can't I reflect light infinitely?

PostPosted: Thu Nov 03, 2011 7:11 pm
by Steve M
::) 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

Re: Why can't I reflect light infinitely?

PostPosted: Thu Nov 03, 2011 9:35 pm
by Webb
What a hoot.  I'll have to see if I can come up with more stupid questions (involving whorehouses of course).

Re: Why can't I reflect light infinitely?

PostPosted: Fri Nov 04, 2011 2:54 pm
by machineman9
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

Re: Why can't I reflect light infinitely?

PostPosted: Fri Nov 04, 2011 6:43 pm
by Jayhawk Jake
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

Re: Why can't I reflect light infinitely?

PostPosted: Fri Nov 04, 2011 9:03 pm
by machineman9
[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.

Re: Why can't I reflect light infinitely?

PostPosted: Fri Nov 04, 2011 9:55 pm
by Club508
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.