Franco Rossi was studying an old wall in Guatemala when he noticed something no one had ever seen before — a Maya mathematician's signature, buried for more than 1,200 years. Rossi, a researcher at the Massachusetts Institute of Technology, was examining a small building at the ancient Maya city of Xultun when he and his team uncovered more than 50 mathematical and astronomical texts scrawled on its walls. Hidden among the calculations was a name: Sak Tahn Waax, which translates to "White-chested Fox." It was the first time anyone had identified the individual behind Maya astronomical work.
For centuries, historians had found signatures on Maya pottery and stone carvings, but never on mathematical work. The scholars who calculated complex calendar dates, predicted eclipses, and tracked the movements of Venus and Mars remained completely unknown — until now. "While artists' and sculptors' signatures for painted ceramic vessels and carved monuments have been identified, the scholars behind computational timekeeping have remained anonymous," Rossi said.
The wall contained 11 hieroglyphs forming a full mathematical formula, along with the phrase "so says" followed by Sak Tahn Waax's name. The calculations connected several cycles of time: the 260-day ritual day-count used in Maya ceremonies, the solar year, and the movements of both Venus and Mars. Co-author David Stuart, an epigrapher (someone who studies ancient inscriptions) at the University of Texas at Austin, explained that the math showed a unique understanding of patterns between these cycles — a completely new way of tracking planetary movement that had never been seen in Maya texts before.
The building where the discovery was made, labeled Structure 10K-2, held what researchers called "rough draft" calculations — essentially working notes left by an 8th-century astronomer. Co-author Heather Hurst, who led the San Bartolo-Xultun Project, compared it to finding an early sketch of a famous painting. "This fills out an important dimension of Classic Maya life," she said. The Classic Maya period ran from 250 to 900 CE, a time when mathematics and astronomy shaped everything from building monuments to crowning kings.
The discovery connects modern people to an actual individual from one of the ancient world's great intellectual traditions. Rossi noted that scholars in India, Iraq, China, and Greece were doing similar astronomical work during the same era, and their achievements are credited to named individuals. "We can now add Sak Tahn Waax to such thinkers," Rossi said, "highlighting the great Indigenous astronomy and calendrical traditions of the Americas." The findings were published in the journal Antiquity.