We are alone living in this universe. So far we have not yet detected any civilization other than Earth. But assume that the possibility of having a civilization in a star in the Milky Way Galaxy over 5 billion years is 1 in million. We are going to find the time separation of each civilization if our galaxy has 100 billion stars.
The number of stars in the galaxy
The possibility of stars having civilization
It is not possible to make radio contact with another civilization, because our technology did not come to this far yet.