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A technological rainbow – finding the visible spectrum in a CD

There are seven wavelength ranges within the visible spectrum that each correspond to a different color. The colors fall in an order red, orange, yellow, green, blue, indigo, and violet.

Compact Disc (CD) surface enlarged 500 times

I placed a microscope with LED lights on the surface and enlarged it 500x. Twisting and turning the microscope resulted in some fascinating and artsy pictures:

Why does a CD reflect rainbow colors?

Like water drops in falling rain, the CD separates white light into all the colors that make it up. The colors you see reflecting from a CD are interference colors, like the shifting colors you see on a soap bubble or an oil slick.

You can think of light as as being made up of waves-like the waves in the ocean. When light waves reflect off the ridges on your CD, they overlap and interfere with each other. Sometimes the waves add together, making certain colors brighter, and sometimes they cancel each other, taking certain colors away. (Source: quora.com)

By hoyd

Communication Adviser at Norwegian Centre for Space-Related Education, a part of Andøya Space Center.