Part 1 of 5 · freeIntroduction
The observable universe holds about 2 trillion galaxies, vast gatherings of stars, each one with hundreds of billions of stars. On the numbers alone, potentially habitable planets should be beyond counting. Yet since modern astronomy began, we have not had a single confirmed contact.
This contradiction has a name: the Fermi paradox, after the physicist Enrico Fermi. The question is no longer only science fiction. It belongs to Exobiology, the science of how life might appear elsewhere and how we could detect it.
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 life seems to need
- 3Oases in the solar system
- 4The great silence
- 5How we search today
Open-book quiz9 questions whose answers are in the text.
Glossary20 terms explained in a tap.
30 languagesThe same course, from French to Japanese.
