A 66-year-old scientific paper went viral this week with claims that Friday, November 13, 2026, was mathematically destined to be "the end of the world" — and even though the date has now passed without incident, the panic it sparked online was real.

The claim traces to a 1960 paper published in the journal Science titled "Doomsday: Friday, 13 November, A.D. 2026," by physicist Heinz von Foerster and two co-authors. The paper modeled historical human population growth and found that if the trend continued unchecked, the global population would approach a mathematical infinity on that exact date, according to IFLScience.

Von Foerster never claimed the world would literally end — the paper described a mathematical singularity in a growth curve, not a scheduled apocalypse, and population growth slowed well below that trajectory decades ago. One account notes von Foerster later acknowledged the date was picked tongue-in-cheek, in part because it happened to be his own birthday.

Still, "the world is ending in 2026" claims circulated online for much of the year, prompting fact-checkers to repeatedly knock them down. The date came and went Friday without any unusual event, and commenters online spent the day joking about bills, work and ordinary Friday-the-13th plans instead.