All about flooble | fun stuff | Get a free chatterbox | Free JavaScript | Avatars    
perplexus dot info

Home > Science
What is quicker than the eye? (Posted on 2004-03-04) Difficulty: 5 of 5
As you probably know... a given color of light can generally, be described by one number (e.g., the frequency of its wave length).

The color white, however, has no associated frequency; it is composed of equal amounts of all the (visible) frequencies of light. Black, of course, is the absence of light. And various shades of grey are generally composed of various intensities of white (as you lower the overall intensity of white, the grey gets darker and approaches black).

The question is: why is light (optically) additive? More specifically, why is it that when we add Red and Green together we get Yellow; Green and Blue together, we get Cyan; Red, Green, and Blue together, we get white?

(Please don't confuse this with the subtractive quality of pigments/paints, where as we add more colors, particularly more of the primary colors red, yellow, and blue, we approach black.)

Could we use three (or more) different colors and achieve the same result?

No Solution Yet Submitted by SilverKnight    
Rating: 3.7000 (10 votes)

Comments: ( Back to comment list | You must be logged in to post comments.)
easy on the eye | Comment 4 of 14 |
Objects do not have color. They are only coated with a substance that reflects light of a certain wavelength. Assuming they are illuminated with white light, coating (A) will reflect red light stronger than the other wavelengths, which are still present in varying degrees, but overpowered. Coating (B) green. A mixture of both coatings will be seen to reflect yellow because of destructive interference.The red wavelengths cancel out the green, leaving yellow as the strongest remaining reflective wavelength. Using lasers for illumination in our experiment, this is not the case. A red helium-neon laser, and a green argon laser mixed together will not produce yellow light. So light is not additive after all.
  Posted by john on 2004-03-05 02:10:43
Please log in:
Login:
Password:
Remember me:
Sign up! | Forgot password


Search:
Search body:
Forums (0)
Newest Problems
Random Problem
FAQ | About This Site
Site Statistics
New Comments (8)
Unsolved Problems
Top Rated Problems
This month's top
Most Commented On

Chatterbox:
Copyright © 2002 - 2017 by Animus Pactum Consulting. All rights reserved. Privacy Information