#Science At Home: This is a #BlueJay #feather.

Did you know that Blue Jay feathers, although they are bright #blue, contain no blue pigment? This is easily proved by holding it up to a bright light.

This phenomenon is called "structural color". It is caused by microscopic lines that reflect or #diffract #colors in different ways, causing the light waves to interfere, strengthening some colors and weakening others.

This is also how blue eyes get their color. Humans have no blue pigment.