Rainbows

If you see a rainbow with some friends, is it the same rainbow for each of you?

This is a variation of the old question "If a tree falls in the forest and nobody's around, does it still make a sound?" The answer is: no. A falling tree may move some air around, but we need air pressure differentiators to translate the air movement into the electro-chemical reactions we experience as sound.

The same is true for a rainbow. To experience a rainbow, three things are required: a light source, moisture in the air, and a specific angle of refraction. If any one of these is missing, there is no rainbow. If you take away the light, of course there's no rainbow. If you take away the water droplets in the air, then there’s no rainbow. Remove the necessary angle of refraction (implied by the positions of you and your friends juxtaposed to the moisture in the air), then there’s no rainbow. Of course, the final required ingredient is the viewer!

A rainbow seems to be an objective experience because any number of people looking out after a rainstorm may agree to seeing a rainbow—but it’s really a subjective experience. There’s no single definitive rainbow. Each person is seeing his or her own version of the colors refracted by the water droplets (a rainbow) because each person is responsible for his or her own angle of refraction.

This is not true just for rainbows. This is true of everything. Rainbows are just an excellent example of this idea because the three factors are easily discerned. Thinking of a rainbow this way helps you realize that YOU are actually a critical component of the rainbow.

This isn’t true for rainbows only-- you’re the critical component of everything you see, feel, and hear around you. For example, when you pick up a rock, you never actually pick up the “objective” rock. You pick up your own personal version of the rock—in just the same way you see your own personal version of a rainbow. Though there are more perceptual factors involved, the principle is the same.