A postcard summary of life, the universe, and everything could go as follows.
In a universe that was doubling in size about every ten billion years, life and animals appeared on Earth. The largest animal brains then doubled in size every thirty million years. About two million years ago humans achieved important brain innovations, and the number of humans then doubled every quarter million years. About ten thousand years ago we learned to farm instead of hunt, and the human sphere then doubled every thousand years. Finally the industrial revolution occurred, and the world economy has since been doubling every fifteen years.
Our history has thus been a sequence of steady exponential growth modes, with sudden transitions between them. Could yet another new mode appear soon, growing even faster?
Looking at the number of doublings each previous mode experienced before the next mode showed up suggests that a new mode should appear sometime in the twenty-first century. Since each mode grew over one hundred times faster than the previous mode, the next economic mode should double every week or two. And since each transition has taken less time than the previous doubling time, the next transition would take less than fifteen years.
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