Part 1 of 5 · freeIntroduction
Over a 75-year life, we sleep for nearly 25 years. For a long time sleep was thought to be no more than a pause. In fact it is active work, as vital as drinking or eating.
Science still does not have every answer about “why” we sleep. But it knows very well what happens when we do not, and what the night quietly repairs.
The rest is in the Sophia app.The remaining parts, the open-book quiz and the full glossary. Free to start; Premium unlocks everything.
- 2What sleep loss reveals
- 3At night, the brain cleans house
- 4Who sleeps how much, and how
- 5The internal clock and blue light
Open-book quiz9 questions whose answers are in the text.
Glossary13 terms explained in a tap.
30 languagesThe same course, from French to Japanese.
