Fermi paradox


August 14, 2022

The Fermi paradox is a supposed contradiction between the high estimated probability of the existence of extraterrestrial civilizations and the lack of evidence for the existence of such civilizations. The age of the Universe and its vast number of stars suggest that if Earth is a typical planet, extraterrestrial life should be widespread. While discussing this over lunch with colleagues (presumably Ede Teller, Emil Konopinski, and Herbert York) in 1950, physicist Enrico Fermi asked, "Where are they?" - otherwise: "Where are you?" ("Where is everybody?") Fermi raised the question: how is it that if there are many advanced extraterrestrial civilizations in the Milky Way, we have yet to find evidence such as alien spacecraft, alien spacecraft, or radio transmissions. Fermi is credited with greatly simplifying the problem of the probability of extraterrestrial life. However, wider investigation of the topic began in 1975 with Michael Hart, and the theory is sometimes referred to as the "Fermi–Hart Paradox". There have been and are ongoing attempts to resolve the Fermi Paradox, direct or by looking for indirect evidence, as well as setting up theories that state that such life can exist without people's knowledge. Opponents assume that intelligent extraterrestrial life does not exist, or that it is so rare that humans could never come into contact with these life forms. Much scientific work has focused on developing theories about extraterrestrial life and possible models for such life, for the most part, the Fermi Paradox has become a theoretical point of reference. The problem has spawned many scientific treatises that directly discuss it, while various related questions are addressed in fields as diverse as astronomy, biology, ecology, and philosophy. The emerging new field of astrobiology brought an interdisciplinary approach to the questions of the Fermi paradox and the existence of extraterrestrial life.

The basis of the paradox

The Fermi paradox is a contradiction between probabilities that can be assumed based on sizes and other data (highly estimative) and the lack of evidence. A more complete definition could be given as follows: The basis of the paradox is the "argument of dimensions", which can be expressed in numbers: The estimated number of stars in the Milky Way is 250 billion (2.5 × 1011), and this number is 70 trillion (7 × 1022) in the visible part of the Universe. Even if the proportion of intelligent life present on the planets orbiting these stars were negligibly small, there should still be a large number of civilizations even within the Milky Way. This statement presupposes the principle of mediocrity, that Earth is not special, just one planet among many, subject to the same rules, effects, and likely outcomes as any other world. Some estimates of the Drake formula support this claim, although the assumptions behind the calculations are also subject to debate. In Fermi's thought process, he claimed more than this: if we take for granted the ability of intelligent life to solve the problem of finite environmental resources and its tendency to colonize new living spaces, it seems likely that any advanced civilization would sooner or later, in search of new resources, first colonize the own planetary system, then the surrounding ones. So, based on the large number of worlds suitable for life similar to Earth, it can be easily assumed