Fermi's paradox is a paradox that arises from the apparent contradiction between the high probability that extraterrestrial civilizations exist and the lack of evidence for their existence. It is named after physicist Enrico Fermi, who is said to have first posed the question in the 1950s.
The basic idea behind Fermi's paradox is that the universe is very big and very old. This means that there should be many other planets in the universe that are similar to Earth and that have conditions suitable for the evolution of intelligent life. If this is the case, then it seems logical to assume that some of these civilizations would have developed the technology to travel to other planets or even to other star systems.
However, despite the fact that we have been looking for evidence of intelligent life from other planets for many years, we have not yet found any definitive proof of its existence. This leads to the question: if the universe is as big and old as we think it is, and if many other conditions for the evolution of intelligent life are present, then why haven't we seen any evidence of intelligent life from other planets?
There are many different explanations that have been proposed to try to resolve Fermi's paradox. Some of these explanations focus on the limitations of our own technology and our ability to detect signs of intelligent life from other planets. Other explanations focus on the possibility that intelligent life is rare or that it may not exist at all.
Overall, Fermi's paradox is a fascinating and complex topic that continues to be a source of debate and discussion among scientists and philosophers.