In 1960, physicist Heinz von Foerster and his colleagues predicted global "doomsday" for November 13, 2026, when they calculated the human population would reach infinity. Today, as that date approaches, the world's population is approximately 8.3 billion, a number far from their infinite forecast.

This unfulfilled prediction demonstrates how human behavior and societal changes, including improved living standards and education, can alter even highly cited scientific models and reshape humanity's demographic future [intro]. It highlights the dynamic nature of population models and their sensitivity to societal shifts.

What the records show

The 1960 paper, "Doomsday: Friday, 13 November, A.D. 2026," by Heinz von Foerster, Patricia M. Mora, and Lawrence W. Amiot from the University of Illinois Urbana-Champaign, observed a consistently shortening doubling time for human population since 400 BCE. Using an equation based on historical population estimates, they projected that if this accelerating trend continued, the world's population would exceed 25 billion by 2020 and approach infinity by late 2026. They termed this point "doomsday," asserting that humanity would be "squeezed to death". The November 13, 2026, date was chosen by von Foerster, falling within his formula's range and coinciding with his birthday.

The timeline

Von Foerster's model was widely cited in textbooks on genetics, ecology, and demography throughout the 1960s, 1970s, and 1980s, its predictions considered accurate for decades [intro]. The global population's annual growth rate peaked in 1963 at 2.28%. However, by approximately 1993, population growth began to fall behind the model's forecasts [intro]. The world population reached 8 billion in November 2022 and 8.2 billion in 2025. As of October 12, 2026, the population is estimated at 8.32 billion, with an annual growth rate of about 0.83%. United Nations projections indicate the global population will peak around 10.3 billion in the mid-2080s before a gradual decline.

What changed and for whom

The divergence from the 1960 prediction is attributed to shifts in human reproductive patterns [intro]. Declining birth rates are linked to improved living standards, increased education for women, and urbanization [intro]. Rising prosperity often changes perceptions of the costs and benefits of raising children, reducing family size [intro]. Higher educational attainment for women correlates with lower fertility rates, as it often leads to career opportunities, increased income, and delayed marriage and childbearing [intro]. Urbanization also contributes, as urban populations typically have better access to healthcare, education, and employment, influencing smaller families [intro].

What the subject has said publicly

Upon the paper's publication, demographers expressed skepticism, pointing out perceived flaws. Public health expert Harold Dorn commented in Science two years later that the article would swiftly prove unreliable. The authors of the 1960 paper intended their work as a "thought experiment and a warning," aiming to show that a finite planet cannot sustain infinite growth.

What we could not confirm

We could not confirm if Heinz von Foerster or his colleagues Patricia M. Mora and Lawrence W. Amiot made any specific public statements about their model's accuracy after the early 1990s, when global population growth began to fall behind their original forecasts [intro].