Can probability predict our extinction?

Apocalyptic predictions often focus on physical threats or societal collapse indicators. A mathematical doomsday argument instead uses probability laws and a single data point: the total number of humans who have lived. The argument is illustrated with two ticket drums containing 1 to 100 tickets or 1 to a billion tickets. Drawing ticket 14 strongly favors the smaller drum because low numbers are extremely unlikely from a much larger set. Replacing tickets with humans, being around the 117 billionth human ever born makes it more likely that humanity is near the beginning of a much larger future only if the total number of humans is enormous. Otherwise, the birth rank suggests extinction is relatively close, with timing depending on assumptions about key variables.

"Most doomsday scenarios hinge on an analysis of physical threats or indicators of societal collapse. Some researchers, however, have mounted a purely mathematical argument that suggests our time is running out. Their eerily simple doomsday argument relies solely on the laws of probability and a single data point: the total number of humans who have lived to date."

"Imagine you're blindfolded and face two giant spinning drums. Each drum contains tickets numbered 1, 2, 3, and so on. One of them contains 100 tickets total, and the other contains a billion. You put your hand into one of the drums and pull out ticket number 14. Do you think you picked from the 100-ticket or billion-ticket pool? The 100-ticket bin feels much more likely because the chances of pulling such a low number out of a billion are astronomically small."

"Now let's play the same game but replace the tickets with people. You are roughly the 117 billionth human ever born. What's more likely: that you are an extreme statistical anomaly living at the absolute dawn of what will become a multitrillion-person galactic human empire, or that you're an average, run-of-the-mill human living somewhere near the middle of the pack? The first answer is akin to drawing 14 from a drum of a billion tickets. The second predicts an uncomfortably close extinction."

"Just how close depends on how we estimate certain variables. On supporting science journalism If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today. Consider another way to look at this argument, which would be to line up every pers"

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