.....................................................................................................................................................................................

 

CURVES AND COLORS - AUGUST 05, 2003

 

Why is the mother of all curves, curved?

 

Rainbows are formed when rays of sunlight enter rain drops and get reflected internally. These rays exit the drop, making roughly a 42 degree angle with the incident rays. Upon entering the rain drop, sunlight, which is white, separates into the different colors of the spectrum. This happens because each color has a different wavelength, and gets bent differently by the rain drop due to refraction. The ray leaves the drops as separate colors.

 

To be able to see a rainbow, an observer must look at the perfect angle to capture the rays that leave the rain drops after refraction and internal reflection. If the sunlight entering the drops is parallel to the ground, then the observer would have to look at roughly a 42 degree angle to see the colored light leaving the drops. The set of all the drops that have the perfect angle with the sun and with the observer will form a curve in the sky. See this figure to better understand the physics behind the curved shape.

 

Compact Discs also display rainbow colors. But the science governing the colors visible on the CD surface is quite different. The slots etched on the surface of the CD form a convenient diffraction grating. Diffraction of white light at those slots causes separation of colors, again due to the difference in wavelengths. What colors are seen on the CD surface depends on the angle of the incident light and the angle of observation. Constructive and destructive interference between different diffracted paths determines the observed colors and patterns.

 

:: :: :: ::

 

The picture shows an interesting color pattern I captured on a CD. It is my entry for this week's Photo Friday.

 

 

 

Quick Links

:: Home

:: About

:: Gallery

:: Archive

:: Wireless

 

 

 

 

 

INTERESTING

:: Fodors

:: YMCA Y-Hikes

:: Roanoke Hikes

 

 

LATEST ALBUM

previous :: NEXT

.....................................................................................................................................................................................

Contact me | 2002 www.shyamal.com. All rights reserved.