Part 1 of 5 · freeIntroduction
Looking up at a blue sky is so ordinary that we forget to ask why it is blue. The atmosphere, the layer of gas wrapped around the Earth, has no color of its own. That shade comes from a very precise meeting between sunlight and the gas molecules floating around us.
Understanding this blue means understanding how light travels and scatters, that is, how it bounces off in every direction instead of running straight ahead. And here is the bonus: the same effect turns the sky red and orange at sunset.
The rest is in the Sophia app.The remaining parts, the open-book quiz and the full glossary. Free to start; Premium unlocks everything.
- 2White light hides every color
- 3Scattering: why blue wins
- 4So why not violet?
- 5And the red of evening?
Open-book quiz8 questions whose answers are in the text.
Glossary4 terms explained in a tap.
30 languagesThe same course, from French to Japanese.
