In Part One of this article we established that we are intelligent, but are likely relative newborns compared to any other intelligent life in the Galaxy. That is, of course, if there _are_ other intelligent lifeforms in the Galaxy.
What are the chances that we ar the only game in town, and that the universe is as big as it is to support one example of intelligent life? Astronomers through history tend to get in trouble for making presumptions of eminence.
First we were displaced from the center of the Solar System, then we find out we are not at the center of the Milky Way, or of the Universe either.
Eventually we work out that we are situated in a minor suburb of one of the spiral arms of the Milky Way, about one-half to two-thirds out from the center. Will we ever see the rest of our Galaxy, close-up?
Using current chemical fuel-based technologies, it will take 120,000 years to travel to the nearest star alpha-Centauri out of an estimated 300,000,000 stars! Instead of getting down about it what if, given time, WE become powerful?
What I mean is, what if we decide to travel fast? There are schemes for how to do this which have had a great bit of U. S. government expenditure. For example, in a program called Project Orion we learn that if one million standard nuclear bombs could be used as a means of propulsion, then we could arrive at alpha-Centauri in about 100 years. What would we do there?
Well, we would build units to live in, kind of like the 'hamster' modules envisioned for colonizing Mars. Then, perhaps after living on this new planet orbiting alpha-Centauri for about a century we could launch an expedition to the next-nearest star. That would take about another 100 years of flight time.
At this point, we would have humans living permanently on Earth, on a planet orbiting alpha-Centauri, and on a planet orbiting another nearby star. We would continue this process until after about 10 million years we would colonize the whole Galaxy.
In this so-called 'coral' model of colonization, we would be moving bit-by-bit, and humbly compared to any scenarios envisioned by the movies we watch on the topic.
If we can already think in this direction, and if other civilizations have up to a 7 billion year advance on us, then this Galaxy colonization should have happened, and it should have happened already. This is the meat of the Fermi Paradox: where are they?
Is it really too hard to travel between the stars? Or is there really an advanced civilization and we are like bacteria to them? Finally, what if we are the only game in town? We must look after ourselves, as it may be that intelligence is precious and scarce in the Galaxy.