@28f03eb2 On Fermi Paradox/no evidence,... Problem is that we are looking for other us. When we see it it will hit us on the head... Physical principles do not require DNA based carbon life, not even carbon based life, not to mention infinite possibilities within DNA carbon life itself. Then "societal" and technological evolution over it, godzilion possible paths. Other us may be rare, none to be seen just like a baby rabbit searching first time out of the hole for another in a dark forrest 

 @c45edd90 aren't we looking for things like wormholes or Dyson spheres though? Things that act and look different than other stars in the sky?