If we woke up tomorrow and...
pg: Despite the generally frivolous answers, this is an interesting question and one I often wonder about.  What turns out to take up all the time if we want to reproduce where we are now?  Presumably the optimal plan is to spend practically all your effort on machine tools.It would be interesting to be able to figure out what would be the best benchmark of progress.  Would it be the precision with which you could machine metal?  That might do up to about 1900.It might turn out that most of the time was spent on something nontechnical, like moving stuff from place to place before you'd developed fast ways of doing that.  So maybe in practice the most important benchmark would be how fast you could move stuff.Reproducing where we are now would in some ways be harder than getting here was.  E.g. the most accessible coal and mineral deposits used to be sitting right on the surface, but now those are gone.