A 1960 study that predicted humanity would reach a population “doomsday” on Nov. 13, 2026, is now being debunked by demographic trends that have unfolded very differently from what researchers expected.

The study, titled Doomsday: Friday, 13 November, A.D. 2026, was written by physicist Heinz von Foerster and his colleagues. It used a mathematical model of accelerating population growth to predict that the number of people on Earth would eventually reach an extreme point on the specified date.

The researchers argued that advances in medicine and technology would allow human populations to continue growing at an accelerating rate. Their concern was not simply that the world would run out of food, but that humanity could eventually become so numerous that people would be physically squeezed into an increasingly crowded planet.

The prediction attracted considerable attention at the time and was widely discussed in the media. But the population trend eventually began moving away from the model's assumptions.

Global population growth began diverging from the study's projections around 1993, and fertility rates have continued to decline across much of the developed world. Higher levels of education, improved healthcare, urbanization and changing economic conditions have contributed to smaller families and lower birth rates.

The result is a dramatically different demographic picture from the one envisioned in 1960. Current projections indicate that the global population is likely to peak before declining later this century rather than growing indefinitely toward the mathematical singularity predicted by the study.

The original model also failed to account adequately for the concept of environmental carrying capacity. Populations living on a finite planet cannot expand forever. As resources become more limited, population growth can slow, stabilize or reverse.

The prediction's assumption that technological advancement would continually accelerate population growth also proved particularly flawed. Instead, technological and socioeconomic development has generally been accompanied by declining fertility in many countries.

Nov. 13, 2026, therefore, is not expected to bring the population catastrophe envisioned by von Foerster and his colleagues. What was once presented as a mathematical endpoint for humanity has instead become an example of how dramatically demographic trends can change and how predictions based on extrapolating past growth can fail.

Adding another unusual detail to the story, von Foerster had previously worked as a professional stage magician before becoming a professor and scientist. The date he selected for the supposed population doomsday would also have been his 150th birthday.