Visible Light and Why We See Colors

There is such a variety of colors in our lives; from the reds, oranges and yellows to the greens, blues and purples, and every shade in between. Life would be very dull without all the beautiful colors.

Visible light is the electromagnetic waves of light visible to the human eye. When all are present, we see white light. When white light shines through a prism it is broken into the colors of the visible light spectrum. Water vapor in the atmosphere can also break apart wavelengths. That’s why we see rainbows.

Lengths of light waves starting with the longest and proceeding to the shortest: red (650 nm), orange (590 nm), yellow (570 nm), green (510 nm), blue (475 nm), indigo (445 nm) and violet (400 nm). A nanometer is the unit of measure used to describe wavelengths. One nanometer is equal to one billionth of a meter which is 39.37 inches. So we are talking about very small lengths.

An object may absorb some of the waves and reflect others. We see only the ones it reflects. If it absorbs all of the wavelengths we will see black. If it is reflecting all of the wavelengths, we will see white. All of the other colors are combinations of reflected/absorbed wavelengths and how the receptors in our eyes capture them and how the brain interprets them.

Color enriches our lives in so many ways. It can set a mood, tell us if our food is ripe, and lets us express ourselves with our clothing or our home decorating. It helps us appreciate the beauty of our planet.