According to Wikipedia [1], numbers around 100 billion have been bandied about quite seriously, and much lower estimates have been "debunked as unscientific".

According to Wikipedia [1], numbers around 100 billion have been bandied about quite seriously, and much lower estimates have been "debunked as unscientific". An interesting debate, regardless. I had no idea it could be so hard to calculate. At any rate, as you say, 43 bits would have humanity covered for a long, long time. [1] http://en.wikipedia.org/wiki/World_population#Number_of_humans_who_have_ever_lived http://en.wikipedia.org/wiki/World_population#Number_of_huma...