05 March 2010

The Milky Way is already colonized

The universe is about 14 billion years old. The Milky Way is about 13 billion years old. Our solar system is only about 5 billion years old.

If intelligent life appeared elsewhere in the galaxy as well, perhaps many times, it probably happened many billions of years ahead of us.

Ergo: unless all civilizations die off for some strange universal reason, the galaxy is already colonized by others (or their robot descendents). (I doubt you need more than a billion years to colonize the entire galaxy, even without faster than light spacecraft.)