A 1960 study predicted population doomsday on Friday, November 13, 2026

In November 1960, three University of Illinois researchers gave a paper in the journal Science an alarming title: "Doomsday: Friday, 13 November, A.D. 2026." On that date, which happens to be Friday the 13th, they calculated, human population "will approach infinity" if it kept growing the way it had for 2,000 years.

Sixty-six years later, how did that prediction hold up? The U.S. Census Bureau's population clock showed about 8.22 billion people in the world on November 10, a number rising by about 2.2 people a second.

The paper's lead author was Heinz von Foerster, an Austrian-born physicist on the university's electrical engineering staff, writing with Patricia M. Mora and Lawrence W. Amiot. November 13 also happened to be von Foerster's birthday.

The team collected 24 estimates of world population, running from the time of Christ almost to 1958, and fit a curve through them. Most population models assume growth slows as a species crowds its environment. The authors argued that humans are different because we communicate and form what they called coalitions, so a larger population could make life better and speed up growth even more. In their model, the growth rate rose along with the population.

That assumption produced a simple formula: 179 billion divided by the number of years left until doomsday, with that number raised to the power of 0.99. Ten years out, the formula gives 18.3 billion people. One year out, it gives 179 billion. With about five weeks left, it gives 1.75 trillion. When the years left reach zero, the math breaks and the answer goes to infinity. The authors put that moment at the year 2026.87, give or take 5.5 years, which is how they arrived at November 13, 2026.

They also had some fun with it. If Charlemagne had known the formula, they wrote, he could have predicted doomsday within 300 years. Their warning was grim all the same: "our great-great-grandchildren will not starve to death. They will be squeezed to death."

Time and The New York Times covered the paper, and it inspired a run of Pogo comic strips, according to Western University historian Alan MacEachern. Mathematicians and demographers wrote to Science calling the work "ridiculous" and "manifestly absurd," and the authors defended their math. Some readers took the paper as a joke.

For three decades, the formula ran a little below the real numbers. Then it shot past them, because the trend it depended on had already ended. World population growth peaked at 2.28 percent a year in 1963, three years after the paper appeared. By 2023, it was down to 0.87 percent growth.

The world's fertility rate reached 5.3 children per woman in 1963 and fell to 2.25 by 2023. The authors had called for almost exactly that. They wrote that avoiding doomsday would mean "cutting the birth rate to about half its present value," or shrinking the average family "to just a little above two children." They also listed other proposals then in circulation, including heavy taxes on families with more than two children and space travel. It was "only unfortunate," they wrote, "that no re-entry permit to earth can be given these space-trotters."

The authors had assumed that better living conditions would keep speeding up growth. In practice, the improvements that came actually helped slow it. Our World in Data points to three main reasons birth rates fell: women gained more access to school and paid work, fewer children died young, and children became more expensive to raise as child labor declined. It calls the first two the most important in most places.

When many children die, parents tend to have more children, and fertility follows falling death rates "after a lag of some years." In 1950, about one in four newborns worldwide died before age 15. By 2020, about 4 percent did. Access to family planning also played a part, and the change could happen fast. Iran went from more than six children per woman to fewer than three in 10 years, and China did it in 11. The same drop took the United States 82 years and the United Kingdom 95.

Where world population is headed now

Today's projections look nothing like a curve racing to infinity. The Census Bureau's International Database shows the world growing from about 8.2 billion in 2026 to about 10.6 billion in 2090, then slipping slightly by 2100. The United Nations expects a peak of about 10.3 billion in the mid-2080s.

The worries have changed along with the numbers. In the bureau's data, 136 of 227 countries and areas, with about 71 percent of the world's people, already have fertility below 2.1, the level needed for a population to replace itself over time. And 93 of the 227 are projected to have fewer people in 2100 than today.

China is projected to fall by more than half, from 1.41 billion to 663 million. South Korea would lose 61 percent and Japan 46 percent. Those countries face the problem of supporting growing older populations with fewer workers.

The opposite problem is concentrated in Africa. Nigeria is projected to grow from 250 million to 623 million by 2100, the Democratic Republic of the Congo from 125 million to 580 million, and Tanzania from 71 million to 301 million. In those three countries, women average more than four children, and growth that fast raises its own questions about schools, jobs, and housing.

The United States falls between those extremes, with the bureau's database projecting growth of about 8 percent by 2100. Our look at the U.S. population in 2050 covers the nearer term, and the U.S. population since 1900 shows how far the country has come.

Sources

Heinz von Foerster, Patricia M. Mora, and Lawrence W. Amiot, "Doomsday: Friday, 13 November, A.D. 2026," Science, November 4, 1960. U.S. Census Bureau, Population Clock, accessed November 10, 2026, and International Database, November 2026 update, world totals summed from 227 countries and areas. Our World in Data, based on United Nations World Population Prospects, population and growth rates, fertility rates, the global decline in fertility, and child mortality. United Nations, Population. Alan MacEachern, The Conversation, September 30, 2026. Von Foerster's birth date is from Wikipedia. Formula values use the paper's Equation 11 at the start of each year, with doomsday at 2026.87. The 2026 actual figure is the bureau's midyear estimate.