3 ms·
Would make for an interesting scify novel. What if humanity came on the scene hundreds of millions of years earlier and U235 was at 1%.
by crb002 12y ago
Would make for an interesting scify novel. What if humanity came on the scene hundreds of millions of years earlier and U235 was at 1%.
- iwwr 12y agoHundreds of millions? It depends precisely what number. Terrestrial macroscopic life is barely 500mil years old and 100mil years earlier the atmosphere would have been too low in oxygen to breathe. Land animals with larger brains are rather recent too, just 250mil years or so. But that still leaves a large margin for sentient life to develop.