^Human's ability to control the things around us has progressed
   from pre-history to today. This amazing chart shows the "scale"
   at which humans have been able to control stuff for our use. The
   charts go from pre-history to today. Each chart, at the bottom
   is "tiny" at the top is "large", the left is "light" the right
   is "heavy". It is a "strength-density space" chart. It's a way
   of looking at history you don't usually get taught - not quite
   like this.^