Calculation of the Probability of Extraterrestrial Life in the Universe

Undoubtedly, in the world, we are human beings who came after the early humans, and according to the history, it can be said that the 20th century is the peak of the prosperity of today's humanity, and it can be said that there was no such progress in the previous thousand years of history. In the 21st century It can be expected that many unanswered questions will be completely answered. If we expand this issue in the universe, there were definitely civilizations before us for billions of years, which according to the time of development, it can be expected that their technological progress was superior than us and considering the possibility of the existence of stars and galaxies it can be said that tens, hundreds and thousands of extraterrestrial civilizations can be expected. Considering that the Milky Way galaxy has about two hundred billion stars, if we assume the probability of advanced life to be one billion, even advanced or super advanced civilizations can be expected.