I always find this statistic about the number of people who ever lived to be incredible. It means that 6.5% of everyone who ever lived is alive right now. For me, that fact helps explain the incredible pace of change observable in every facet of civilization. There is an awesome amount of our humanity's intelligence on display at this very moment.<p>Then, when you consider how a lot of the 6.5% live (i.e. with extreme poverty and hunger), we are not even remotely reaching our collective capacity. The pace is going to get even faster as we achieve the Millenium Development Goals.
There is considerable debate over when the first Homo sapiens sapiens appeared, but the consensus is that it was much longer ago than 50 000 years. 200 000 would be considered a fairly conservative number these days. This obviously skews the math a little.
They used to tell children that people turn into stars when they die. Isn't it interesting then that the number of dead people is of the same order as the number of stars in a galaxy! :-)
"Out of all the people that ever were, almost all of them are dead. There are <i>way</i> more dead people. ... You're just dead people that didn't die yet."<p>It's a bit from a Louis CK routine, and the numbers appear to back him up.
Given the average lifespan of a human on earth today (around 67), and the average population growth rate (somewhere between 1 and 2%), it causes an acceleration in the number of humans living and being born.<p>The notion that this growth is unsustainable is scare mongering. 1.5% growth per year is sustainable indefinitely to colonize the galaxy, if we can just keep the resources needed to support that growth flowing. At some point we will need to create a Dyson sphere around the sun to capture most of its energy, and harvest the raw materials in the asteroid belt between mars and Jupiter. As for living space, it will be superstructures orbiting the sun in the habitable zone.