One paper on the Fermi Paradox I want to plug is this one by Sandberg, Drexler, and Ord. https://arxiv.org/abs/1806.02404 https://arxiv.org/abs/1806.02404 Mos

One paper on the Fermi Paradox I want to plug is this one by Sandberg, Drexler, and Ord. https://arxiv.org/abs/1806.02404 https://arxiv.org/abs/1806.02404 Most people when doing the Fermi estimate for the number of civilizations in the Galaxy use numbers that tend to result in a lot of them. But different people use very different numbers in different steps. If you look at the ranges of values that different people assign to the different terms then suddenly it doesn't seem very unlikely that intelligent civilizations could be rare.