There are few things as breathtaking as a Californian sunset. And there are few better places to be than in the ocean when that sun disappears each day. Some people believe the crazy orange, pink, red and purple skies are just a beautiful result of the ugly reality of living in highly populated (and polluted) places. It’s all explained by a phenomenon known as Rayleigh scattering, which tells us that when the sun is directly overhead at noon its light has the shortest distance through the atmosphere and to your little eyeballs, giving you a bright and often blue sky to look at. But when that sun is setting the same light has further distances to travel. All the colors and wavelengths of light are still scattered, but not equally. Colors with shorter wavelengths are scattered the most: violet, blue, green and so on until we reach the warmer hues of yellow, orange and red, which all come together to give us these brilliant sunsets. What you’re watching in awe is the scattering of light as it bounces off of and through particles in the air. And yes when that sky happens to exist over a busy city like San Francisco, where humans are creating a lot of extra particles that float into the atmosphere, you’re going to get some pretty vibrant colors.
Whether all that science talk bums you out or not really isn’t the story though. It’s safe to guess anybody lucky enough to catch these sunsets with a front row seat in the Pacific Ocean isn’t studying which scientific process is at play. They’re just enjoying one hell of a view in The City By The Bay.
