Period (MY = million years) | Number of great ideas | Landmarks |
| 2.5 MY BC - 1.4 MY BC | 4 | Genus Homo |
| .5 MY BC - 30,000 BC | 10 | Archaic H. sapiens |
| 30,000 BC - 10,000 BC | 5 | Modern H. sapiens |
| 10,000 BC - 0 | 12 | Ancient civilization |
| 1000 AD - 1800 AD | 9 | Dawn of Industrial Age |
| 1801 AD - 1930 AD | 10 | 2nd billion people |
| 1931 AD - 1973 AD | 4 | to 4 billion |
| 1974 AD - present | 1 | to 6 billion |