Enrico Fermi, is the apparent contradiction between the lack of evidence and high probability estimates, e.g. those given by the Drake equation, for the existence of extraterrestrial civilizations. The basic points of the argument, made by physicists Enrico Fermi (1901–1954) and Michael H. Hart (born 1932), are:
- There are billions of stars in the galaxy that are similar to the Sun, many of which are billions of years older than Earth.
- With high probability, some of these stars will have Earth-like planets, and if the Earth is typical, some might develop intelligent life.
- Some of these civilizations might develop interstellar travel, a step the Earth is investigating now.
- Even at the slow pace of currently envisioned interstellar travel, the Milky Way galaxy could be completely traversed in about a million years.
In a recent follow-up to their video about the Fermi paradox, design studio Kurzgesagt offers a few possible solutions to the problem of why, if the Universe is so vast, humans have yet to contact alien life. The video also looks at ways advanced civilizations could contact each other, and why they may choose not to.