“That’s a misconception, Lennie. The sky is everywhere, it begins at your feet.” -Jandy Nelson
There are all sorts of explanations that people give for why the sky is blue. Some say that it’s because of the fact that oxygen is a light blue gas. Others contend that the sky reflects the blue ocean, giving it a comparably blue color. Still others place the blame on sunlight itself, alleging that it’s naturally slightly blue in color. All of these science-y sounding explanations, compelling though they might be, are way off the mark. If they were correct, after all, you wouldn’t have reds during sunrise and sunset!
Instead, it’s a combination of three factors that make the sky blue for us:
- Sunlight is made of many different wavelengths of light.
- The small atmospheric molecules scatter that light, but scatter short-wavelength light more efficiently.
- And the human eye has three types of cone (and one type of rod) that allow our brains to interpret color.
Put them all together, and a blue sky is the net, inevitable result.