Today is Friday the 13th, and it is the day a physicist once calculated the human race would run out of room. In a 1960 paper in the journal Science, Heinz von Foerster of the University of Illinois, working with Patricia Mora and Lawrence Amiot, fitted two millennia of population data to a curve and found that growth was accelerating toward a vertical line. Projected forward, the curve hit infinity on 13 November 2026. The paper's title was blunt: "Doomsday: Friday, 13 November, A.D. 2026."
What the paper actually said
Von Foerster's model treated population as a self-reinforcing process. More people meant more people to have children, and the growth rate itself rose with population size. Fitted to historical estimates going back to biblical times, the equation produced a hyperbola, and a hyperbola has a date where it goes vertical. He noted that the world population then was about 3 billion and that the curve implied it would become infinite in 66 years, not merely very large. The paper was not a prophecy of famine or war. It was a warning that the mathematics of the moment could not continue.
Why the math failed
The curve assumed that birth and death rates stay where they were. They did not. Fertility fell across Europe, East Asia and Latin America as incomes rose, women entered the workforce, contraception spread and families moved to cities. Global fertility is now below the replacement level of about 2.1 children per woman. The United Nations projects the world population at roughly 8.2 billion today, with growth slowing and a peak later this century before a gradual decline.
Food and technology also refused to stand still. The Green Revolution lifted grain yields, and the share of people living in extreme poverty fell sharply, though hunger remains a serious problem in parts of Africa and South Asia.
A useful mistake
The Complexity Science Hub in Vienna is marking the date with a conference on end-of-the-world predictions, including a public panel on how to survive doomsdays. The point is not to mock a 66-year-old paper. It is that extrapolating a trend into a cliff edge, while ignoring how people and institutions respond, is the same error made today about AI, debt and climate. Von Foerster's real finding was that growth rates are not constants. The date passed quietly, which is the best outcome a doomsday forecast can have.