Types of civilizations:

1. Planetary – can store and use energy on it's own planet
2. Stellar – can harvest and use energy within it's solar system
3. Galactic – can control energy at the scale of it's entire host galaxy

The [[../www/The Great Filter]] is a hypothetical event that hinders life to progress from type 1 to type 3

topic:: [[../www/Cosmology]] related:: [[../www/The Great Filter]]