Very interesting post. Thank you very much for sharing. This is something that has fascinated me ever since I saw Terminator 2 as a kid. Are you familiar with the Fermi paradox? Among other things it talks about probability and how based solely on probability there should be other civilizations even more advanced than our own. One of the things it postulates though is that perhaps civilizations have an expiry date and maybe they terminate themselves at a certain point of technological development. My point being that maybe we are approaching our moment in history. I hope not. If you don't know about the fermi paradox check out this video: