Evolution
- First microorganisms emerged from alkaline hydrothermal vents: 4 × 10⁹ years ago
- Single-celled photosynthetic microbes: 3.5 × 10⁹ years ago
- Cyanobacteria (solar energy: CO₂ + H₂O → O₂ + others): 2.5 × 10⁹ years ago
- New complex organisms (algae): 1.2 × 10⁹ years ago
- Ediacaran (first moving organisms): 600 × 10⁶ years ago
- Four-legged animals: 4 × 10⁶ years ago
- Homo (extrasomatic energy → fire for cooking, comfort, safety): 10⁵ years ago
- Civilization (crop cultivation → controlled photosynthesis): 10 × 10³ years ago
- Inanimate prime movers:
- Sails: 5 × 10³ years ago
- Water wheels: 2 × 10³ years ago
- Windmills: 10³ years ago