from Paul Graham's Essay "Mind the Gap" http://paulgraham.com/gap.html http://paulgraham.com/gap.html Another approach would be to ask, if you were going back

from Paul Graham's Essay "Mind the Gap" http://paulgraham.com/gap.html http://paulgraham.com/gap.html Another approach would be to ask, if you were going back to the year x in a time machine, how much would you have to spend on trade goods to make your fortune? For example, if you were going back to 1970 it would certainly be less than $500, because the processing power you can get for $500 today would have been worth at least $150 million in 1970. The function goes asymptotic fairly quickly, because for times over a hundred years or so you could get all you needed in present-day trash. In 1800 an empty plastic drink bottle with a screw top would have seemed a miracle of workmanship.