If we assume that other universes, like ours, exist, why are we not?
Think of it ike this: Imagine the country you live in as being our near universe with each city and town a place that has intelligent life. YOU are the alien. How many of the cities and towns in your country have YOU visited in your life? Even in your immediate state. Have you visited EVERY city and town? Now think of your entire word as being our entire universe. Same question. How many cities and towns in the entire world have YOU visited? Theres life all over the world. Why havent you visited each and every city and town in it? Once an intelligent species learns that the universe is teaming with life and once it explores enough to realize the basic concept of evolution of life, theres really no reason to continue exploring. The chance of happening upon life that could annihilate your own species increases with each new contact. Why risk it?