Considerations on the Fifth Parameter

Unlike the fourth Drake parameter, which we calculated around 0.5 (probability of 50%) over a period of 100 million years in the previous section, the fifth Drake parameter is just above 0.01 (probability of 1%) over a period of 1500 million years (excluding GOE and NOE), therefore significantly lower. This does not surprise us because, after all, H. sapiens is the only successful attempt among an infinity of species that have appeared on the planet. Moreover, the subdivision of the calculation into three macro intervals has highlighted two things: