Dr. Livio explains how developments in astronomy have altered our sense of human uniqueness. He describes the “Copernican Principle” that suggests that we humans are not especially unique. And scientific discoveries, including evolution, other planets and galaxies, have led to the expectation of other intelligent life in the universe –and indeed, even the notion of multiple universes. But scientists have also discovered that the conditions necessary for complex life may be rare. Here, we learn what we might expect.