When gazing at shallower angles, all droplets within this line of sight direct violet light to one's eye, while the red light is directed out of the peripheral vision and downward at one's feet. (The other color wavelengths exit these drops at more shallow angles, and thus, pass overhead.) This is why red appears at the top of a rainbow. So when one looks at a steep angle, the red light from the higher drops travels at the correct angle to meet one's eyes. In a previous diagram, we see that red light refracts out of the water droplet at steeper angles to the ground.

To find out why this is, let's consider raindrops at two levels, one above the other.

As the light (still separated into its range of colors) exits the water droplet, it speeds up as it travels back out into the less dense air and is refracted (a second time) downward to one's eyes.Īpply this process to a whole collection of raindrops in the sky and voilá, you get an entire rainbow.Įver noticed how a rainbow's colors (from outside edge to inside) always go red, orange, yellow, green, blue, indigo, violet? The light continues traveling through the drop until it bounces (reflects) off the back of the droplet and exits the opposite side of it at a 42° angle. So, when a ray of light enters a raindrop and bends, it separates into its component color wavelengths. When any of these things happen, the different color wavelengths are separated and can each be seen. Light travels in a straight line unless something reflects it, bends (refracts) it, or scatters it.Visible light is made up of different color wavelengths (which appear white when mixed together).This causes light's path to bend or 'refract.'īefore we go any further, let's mention a few things about light: As the light rays from the sun strike and enter a water droplet, their speed slows down a bit (because water is denser than air). The rainbow-making process begins when sunlight shines on a raindrop.

Raindrop promise ring