Tuesday, December 14, 2010
The Colors That Make Up the World
The three primary colors are red, yellow and blue. However, the primary colors of light are different. They are green, red and blue. To make yellow, one mixes red and green lights. But to make white, ones mixes red, green and blue. Blue and green mix to make cyan, while red and blue light creates magenta. Who knew? The reason for this is because when two colors of light shine close enough to overlap, the eyes interpret the mixture as one color. An instrument called a spectroscope disperses these by bending through different angles. If you look at yellow through a spectrascope, you will see green and red. (How do people ever conceive these ideas?)
All visible things give off light. They give it off in two different ways. Some objects, like the sun, make their own light. Other objects, like the moon, reflect it. Things that don't give off light are colored by something called color subtraction. When a light falls on them, they absorb some of the color and reflect others. That is why a leaf looks green. It absorbs almost all the colors in the sunlight except for green. The reason blue paint looks blue is because it absorbs all the colors except blue. Black substances are ones that absorb all three. Yellow comes from substances that absorb blue light.