An ancient Maya astronomer finally has a name

A once-anonymous Maya scientist now has a name.

Sak Tahn Waax, or “White-Chested Fox,” is credited as the author of a calendrical formula painted in Maya glyphs on the wall of a ruin in Guatemala, researchers report July 14 in Antiquity. The table of dates and calculations, recorded more than 1,200 years ago, lays out relationships among the cycling positions of Venus and Mars and several cycles of the Maya calendar over an eight-year span.

While the names of other Maya luminaries are known — rulers are often named in writings and on monuments, and some artists signed their works — this is the first known name of a Maya mathematician-astronomer. Maya texts related historical events and natural cycles, and “individuals like Sak Tahn Waax were not only observing these cycles but linking them with each other,” says MIT archaeologist Franco Rossi. “It is frankly surprising that more such signatures haven’t turned up.”

The name and table were discovered at Xultun, an archaeological site near Guatemala’s borders with Mexico and Belize. They consist of an inverted L-shape of 11 blocks of elaborate Maya glyphs: The top nine blocks record five Maya calendar dates and the intervals between them, and the last two are the “signature” of Sak Tahn Waax — a presentation that implies White-Chested Fox claimed credit or was being credited for the work, Rossi and his colleagues say.

The dates span 2,920 days — five cycles of Venus, which takes 584 days to return to the same position relative to the sun as seen from Earth, and eight 365-day Haab years. Within that span, the table also incorporates shorter Maya calendrical cycles: the 20-day Uinal, or Maya month; the 260-day Tzolkin ritual count; and the 360-day Tun, a yearlike interval. The researchers interpret one inferred 1,560-day interval as two 780-day cycles of Mars. Such calculations, which linked astronomical and calendrical cycles, underpinned Maya almanacs and divination.

The first glyphs are damaged, so the researchers reconstructed the most likely starting date from the others: November 11, 781, in the Gregorian calendar. They say the table was probably devised in or near that year. The glyphs at Xultun list specific dates, but the method embodied in the table could perhaps have been reused for other 2,920-day spans.

The glyphs were found in a room the researchers think was a workspace for making Maya codices — painted books of bark folded like an accordion.

More than 50 “rough drafts” of calculations and tables appear on the walls, most painted and a handful incised, suggesting the room was used for intellectual work and perhaps for training astronomers. The glyphs were identified as astronomical when the room was discovered in 2010, but they were fully deciphered only recently, revealing the final calendrical formula.

“These ‘rough draft’ calculations and tables are akin to finding an early version of a well-known manuscript, or a sketch of a great artwork,” Rossi says. “This positions us to better understand the inner workings of Classic Maya mathematics and astronomy.”

Astronomer E.C. Krupp, director of the Griffith Observatory in Los Angeles, says the formula reconciled Maya calendrical and planetary cycles centuries before comparable tables appeared in surviving Maya codices. Krupp, who was not involved in the study, says that Sak Tahn Waax can now be added to the roll of great astronomers: “Maya astronomy has been personalized by this discovery.”