This Week in H’burg is a weekly column featuring photos and fun facts from local photographer Pierre Ratté. Each week we’ll feature a new photo from Ratté along with a fact about the subject matter of the photo.
Rain and Rainbows. You see a rainbow when the sun is behind you and rain is in front of you. If light strikes at exactly a 48 degree angle, it refracts a spectrum of light off the back of the raindrop. Because the light is refracted by spherical drops it causes an arch, with rays of longer spectrum red appearing toward the top of the arch, and shorter spectrum blue towards the bottom. Think of it this way, the longer wavelength forms the longer arch – red; the shorter wavelength forms the shorter arch – blue. In a double rainbow, light refracts off the inside of the drop a second time causing a more faint arc, which is always higher in the sky. That higher arc will have reds on the bottom and blues on the top because the light spectrum is reversed, just as you see your imaged reversed in a mirror. In Eastern culture, a double rainbow is a sign of good fortune. The first rainbow signals good outcomes in the material world, and the second rainbow in the spiritual world.
Pierre Ratté posts a daily picture on Instagram, Facebook and TodayinHburg.com. He can be reached at pj*****@ic****.com. His book “100 Days Sheltering-In-Place” can be purchased at Levin’s and Copperfield’s bookstores, TodayinHburg.com or Amazon.com.
