The basic premise of my book is that the next big revolution on the scale of the farming and industrial revolutions will come from human level artificial intelligence in the form of brain emulations (ems). Yes, because people have asked I’ve estimated that this will happen within roughly a century, but that estimate isn’t central. The key is that even if ems take many centuries, they will still come before achieving human level artificial intelligence via the usual methods (UAI – via hand-coded algorithms including statistics), and before other social disruptions of this magnitude.