If you're not that familiar with the Fermi Paradox I highly recommend Stephen Webb's book If the Universe is Teeming With Aliens... Where Is Everybody?[0] He covers a basic intro to the problem and then goes through FIFTY proposed solutions in an accessible and entertaining manner. A lot of it explains why "obvious" solutions (including the suggestion in this article and others popping up in this thread) aren't really considered so obvious by field experts who have thought a lot about the problem.

For example, many explanations are of the type "Well, maybe the aliens are all doing X," but it requires every independent civilization to be doing that, with no exceptions, so that we haven't even detected one variant, not even one that needed to escape its star and colonize the galaxy, which many experts find unsatisfying. I found the book to be a fun and quick read that touches on a lot of scientific/comsological/biological/etc concepts.

(Looks like he has a newer editing with 75 explanations...[1] I haven't read that one.)

I see the article also mentions the simulation hypothesis. Personally, I'm intrigued by the overlap between secular simulation hypotheses and religious notions of the universe having a Creator.

[0]https://www.amazon.com/Universe-Teeming-Aliens-WHERE-EVERYBO... [1]https://www.amazon.com/Universe-Teeming-Aliens-WHERE-EVERYBO...

Everyone interested in the possibility of alien intelligence should read about the Fermi Paradox: http://en.wikipedia.org/wiki/Fermi_paradox

It is a collection of theories that try to explain why we haven't been contacted yet by aliens.

There is also a very good book on the subject that elaborates further on the theories of the Fermi paradox. In total there are 50 different theories, from life been too young on the universe and thus we're rather alone, to not be able to communicate because they're using superior technology. http://www.amazon.com/Universe-Aliens-Everybody-Solutions-Ex...