Rainbows are colorful arcs appearing in the sky when sunlight interacts with water droplets! They're formed because sunlight, which appears white to us, is actually made up of all the colors of the rainbow.
The Magic of Refraction
- Sunlight and Water: Rainbows need both sunlight and water droplets in the air, like after a rain shower. These droplets act like tiny prisms.
- Light Bends: As sunlight enters a raindrop, it slows down and bends (this bending is called refraction). Because different colors of light bend at slightly different angles, the white light separates into its individual colors.
- Reflection and Dispersion: The light then reflects off the back of the raindrop before bending again as it exits. This process, called dispersion, separates the colors even further, making them visible as a rainbow.
Think of it like this: Imagine shining a flashlight through a glass prism – you'll see the light separate into a rainbow of colors! Raindrops do the same thing, but on a much larger scale.
Rainbow Colors
The order of colors in a rainbow is always the same: red, orange, yellow, green, blue, indigo, and violet (often remembered with the acronym ROY G. BIV). Red appears on the outer edge, and violet on the inner edge.
Double Rainbows
Sometimes, you might see a double rainbow! This happens when the light reflects twice inside the raindrops, creating a fainter, secondary rainbow with the colors reversed.
Why We See Rainbows
We only see rainbows when we're positioned between the sun and the rain shower. The angle of the sun and the position of the water droplets have to be just right for the separated colors to reach our eyes. This is why rainbows seem to move as you move!
