Back in school in our science class, when we pointed white light toward a triangle glass prism, it came out of the prism in the form of a rainbow. Light of different colours bends, or refracts, by different amounts. This separation of colours is called dispersion, creating the rainbow colours. Not only does this occur in a prism, but dispersion is also caused by ice crystals and what we are more familiar with, water drops in the form of rain. In the last two cases, the light is coming from the sun. Helping to create much bigger rainbows, but the colours are the same. With a rainbow, the colours are in this order: red, orange, yellow, green, blue, indigo and violet. Red is on the outside of the rainbow.
Under the right conditions, some of the light does not come out of the raindrops to form the primary rainbow. This light repeats the process to form a secondary rainbow. But this time the colours are reversed thanks to an extra reflection in the rain drops. Red on the inside and so on. Since more of the light came out on the first opportunity, the secondary rainbow is much fainter. By this process we can get third and fourth rainbows. But each would be fainter and harder for our eyes to see. Inside the primary rainbow where all colours come back to our eyes at the same angle, we see bright white light. Between the primary and secondary rainbows, where no light comes toward our eyes, we get darkness. And if the sun is not behind you and trillions and trillions of water droplets not in front of you, and all not at a particular angle to your eyes. Then you just see the rain.
For this rainbow, which lasted more than half an hour, I saw it forming from home. I saw where the sun was and how fast the clouds that were dropping water were moving. I thought I had a good chance of getting out and getting a better picture than the one I would get from home. But due to the location of the sun and the rainbow, I was not able to get a picture of the whole rainbow. Plus, for the middle section of the rainbow, there was not enough rain for the colours to stand out. So I decided to get a closer look at a section of the rainbow. You can still see the order of the colours of the primary rainbow and also the images show the inside is lighter than the outside area of the rainbow.
