The Fermi Paradox: A 10 Step Guide To Finding Aliens

4. Behind Us

If TGF is behind us, then it means that we are one of the rare and lucky few that have survived it. This provides an explanation as to why there are no other aliens knocking about the place. Where exactly behind us TGF is key to figuring out what life in the universe looks like.

Professor Robin Hanson sets out nine stages of evolution, number one being the right planet around the right star, number nine being space colonisation, and any of the nine could be TGF. They are as follows:

The right star system (including organics) Reproductive something (e.g. RNA) Simple (prokaryotic) single-cell life Complex (archaeatic & eukaryotic) single-cell life Sexual reproduction Multi-cell life Tool-using animals with big brains Where we are now Colonization explosion

If it is right at the beginning of life itself, it might mean that we really are alone in the universe. If it is shortly after the beginning of life, at the prokaryotic stage, it could mean that the universe is crawling with simple, single-celled organisms, but nothing with a face, let alone a space ship. If it is number nine, however, it's pretty bad news.