It’s related to the number of total internal reflections inside a raindrop. The 2nd rainbow is actually inverted, colour wise. The 3rd inverts again, and so is normal. Each reflection loses more light however, so it gets dimmer. 3 is the practical limit in the sky, with our eyes. In the lab version, at least 18 rainbows can be detected, even by undergraduate level students!
Ok this is crazy. I have a picture I took a few years ago of a double rainbow. Never noticed it was inverted, but I went to look and sure enough it is. Now I’m wondering how I didn’t notice before.
It’s related to the number of total internal reflections inside a raindrop. The 2nd rainbow is actually inverted, colour wise. The 3rd inverts again, and so is normal. Each reflection loses more light however, so it gets dimmer. 3 is the practical limit in the sky, with our eyes. In the lab version, at least 18 rainbows can be detected, even by undergraduate level students!
Ok this is crazy. I have a picture I took a few years ago of a double rainbow. Never noticed it was inverted, but I went to look and sure enough it is. Now I’m wondering how I didn’t notice before.