The Great Silence
In 1961, Frank Drake wrote an equation to estimate the number of active civilizations (N) in our galaxy. N = R ร fp ร ne ร fl ร fi ร fc ร L
The Variables
- Stars (R): The galaxy is full of them (100 Billion+).
- Planets (fp): We now know almost every star has planets.
- Life (fl): Life seems to start easily on Earth...
- Intelligence (fi): ...but it took 4 billion years to get to humans.
- Communication (L): This is the bottleneck. How long does a civilization last before it destroys itself with nukes or AI?
The Great Filter
We haven't met anyone yet. This implies one of two things:
- Rare Earth: Life is incredibly rare, and we are special.
- The Filter Ahead: Advanced civilizations inevitably commit suicide quickly (The Great Filter), so nobody is out there to talk to.