Have you ever seen a rainbow after a rainstorm and wondered if the sky was showing off its favorite outfit? Some people even joke that rainbows are the sky’s way of smiling after crying. Rainbows may look magical but they are really a mix of science and a little bit of weather fun. There was a time, not so long ago, where people didn’t understand the science behind the colorful event so they made up stories to explain rainbows. In Irish folk tales leprechauns hid their gold at the end of the rainbow. In some Native American legends rainbows were seen as bridges between the earth and the spirit world. The real explanation behind rainbows is found in science and it may not be as fun as the ancient beliefs, but it is still rather amazing.

A rainbow forms when sunlight shines through raindrops. Each raindrop acts like a tiny prism bending or refracting the light. A prism is a clear glass or plastic shape usually with flat sides that can split white light into its many colors. You may be thinking light is white how can it turn into colors, but the white light you see is not really white, but a mix of all the colors of a rainbow. A prism bends light because light slows down when it moves from air into glass or water. When sunlight enters a raindrop, the part of the light that hits first slows down while the rest keeps moving, so the whole beam bends. Each color of light slows down by a different amount, and that is why the prism spreads the colors apart, showing the rainbow hidden inside the sunlight.

Every rainbow always shows the same seven colors in the same order: red, orange, yellow, green, blue, indigo and violet. That can be a lot to remember so scientists came up with a fun helper. The name Roy G Biv works like a rainbow superhero who carries all the colors in his cape. If you can remember his name you will always know the rainbow’s secret order.

So, the next time you see a rainbow you will know the science behind it but you can also smile at the magical stories people once believed. Rainbows are proof that nature can be both beautiful and scientific at the same time.