All of these HN alternate explanations are listed and explained by Tim Urban here: http://waitbutwhy.com/2014/05/fermi-paradox.html http://waitbutwhy.com/2014/0

All of these HN alternate explanations are listed and explained by Tim Urban here: http://waitbutwhy.com/2014/05/fermi-paradox.html http://waitbutwhy.com/2014/05/fermi-paradox.html