First where? Universe? Supercluster? Local group? Galaxy? It does seem unlikely that we are the first. But if it takes the average galaxy 20 billion years to e

First where? Universe? Supercluster? Local group? Galaxy? It does seem unlikely that we are the first. But if it takes the average galaxy 20 billion years to evolve stable interstellar life, we may never hear from the others - even if there are millions of other civilizations in the universe. The question here isn't the odds of interstellar life evolving. The question is how frequently interstellar life evolves in neighboring regions of space at similar times while displaying mutually recognizable signs of intelligence.