Tweakers' Asylum

RE: Light absorbs light?

72.66.45.88

geoffkait

M

In Reply to: RE: Light absorbs light? nt posted by oldmkvi on April 25, 2010 at 07:20:50

Well, only a specific color (wavelength) light absorbs light of a certain color (wavelength). Blue-green is the "complement" of red so blue-green light will absorb red light (or near red).

Pop Quiz 1: what color light would be used for a Blu-ray player to absorb stray scattered light?

Pop Quiz 2: Why doesn't the blue-green light absorb the primary laser light as well, such that the data cannot be read (no pun intended)?

Follow Ups:

You bring darkness to man's minds. - rick_m 10:00:29 04/25/10 (1)
"Well, only a specific color (wavelength) light absorbs light of a certain color (wavelength)."

Earlier this morning I was enjoying the sunny, clear morning, the white-crowned sparrows hopping around under the Red Rhody blossoms and the green of the lawn that needs mowing. But I guess it was all a faith-based illusion. After reading your posts I looked again but there was only a murky darkness, not totally dark, vague areas of dimness appeared randomly and then dissipated. Sigh. It figures, a nation given to glorifying football and eschewing physics is doomed to live in darkness.

I'm hoping that towards dusk when the effective blackbody color temperature of the sun shifts more out of the eye's passband that there will be less cancellation and I'll be able to see at least dim outlines, meantime I'm stuck with darkness at noon, a veritable visual gulag... Thanks!

With apologies to Arthur Koestler,

Rick
- You can go back to sleep in your recliner, old timer. nt - geoffkait 10:13:30 04/25/10 (0)
  nt
RE: Light absorbs light? - oldmkvi 07:35:25 04/25/10 (2)
I understand , but it seems like a solid object would absorb, not other light. I could be wrong!
- RE: Light absorbs light? - Ray Moth 16:23:19 04/26/10 (0)
  You're right. A solid object is not an active radiator, it simply reflects radiation that falls upon it and that it cannot absorb. A light source is an active radiator and can interfere/interact with light from another active radiator. This is "addition" of light. E.g. red, blue and green light added together give white (as in color TV).
  
  However, white light filtereed through red, blue and green colored filters give no light at all = black. This is "subtraction" of light.
- RE: Light absorbs light? - geoffkait 07:50:59 04/25/10 (0)
  The color of a solid object we see is actually the color of the *light* the object reflects. An orange appears Orange to us because it reflects the color (wavelength) Orange and absorbs all other colors of light (wavelengths).

Post a Followup:

FAQ

Post a Message!

Forgot Password?

Moniker (Username):
Password (Optional):
	Remember my Moniker & Password (What's this?) Eat Me
E-Mail (Optional):
Subject:

Message:	(Posts are subject to Content Rules)

Optional Link URL:
Optional Link Title:
Optional Image URL:
Upload Image:
E-mail Replies:	Automagically notify you when someone responds.

To view your new posting or follow-up, click on the RELOAD or REFRESH button on your browser.

This post is made possible by the generous support of people like you and our sponsors:

Sonic Craft