Dear Bullshitter,
Why is the sky blue?
This great mystery is easily understood if you imagine the Earth spinning within a rainbow: A
rainbow the size of the whole atmosphere. Rainbows have red and orange toward the outside,
blue and purple toward the inside. When the sun is high in the sky, you're on the part of the
earth facing the sun, and thus in the middle part of the rainbow. That's where you get the blue
light.
"But then why isn't the sky violet or indigo? Aren't those farther inside the rainbow than blue?" you might ask. First of all, indigo doesn't count. You don't even know what indigo is, other than "the color between blue and violet". It was just added so that kindergarteners could pronounce ROYGBIV, and it didn't work. Try it without pronouncing the G as "gee" and you'll see. Either name just the primary and secondary colors in the rainbow, or name ALL of the tertiary colors. And trust me, that would get boring: "Red, red-orange, orange, orange- yellow..."
So what about violet? As seen from space, the sun is red. (It only looks yellow from here due to the Clean Air Act.) Thus, the farthest wavelengths from red will be the least represented. The sun just doesn't put out enough purple light to make a big impression on our sky.
My theory is demonstrated by the fact that, at dawn and dusk, you are positioned right at the outside edge of the Earth (as seen from the sun), and so you briefly get to be under the outside part of the atmospheric rainbow. That's why sunrise and sunset feature red skies.
Now you understand. Screw indigo.
(Ask a Bullshitter is for entertainment purposes only. The Bullshitter promises to never look up the correct answer before writing a column. Any resemblance to actual facts is purely coincidental.)
