A Mayan Copernicus: Venus Table may have been a major mathematical innovation
Ancient Mayan astronomers were far more advanced than previously thought, new analysis of an ancient document suggests.
Key points:
- Mayans were able to track the movement of Venus
- They wanted to be able to time events so they coincided with its appearance
- The "elegant" mathematical equation they devised shows how advanced their culture was
The Venus Table of the Dresden Codex — the oldest existing Mayan manuscript — tracks the observable phases of the planet, and has historically been admired as a curiosity that was used mainly for astrology.
But professor of anthropology and Chicano studies at UC Santa Barbara, Gerardo Aldana, has offered a new interpretation of the Venus Table in a paper published in the Journal of Astronomy in Culture, arguing that it instead represents a major Mayan innovation in mathematics and astrology.
"What my article intends to do is really change how we understand what [the Venus Table] means within ancient Mayan culture itself," he told the ABC.
"We've known for a long time that ancient Mayan astronomers were tracking Venus and we know that they developed a model for projecting their predictions into the future.
"But we haven't had a good sense of precisely when that intervention occurred. When did they figure this whole thing out? And where did it take place?"
Analysis driven by new reading of single hieroglyphic
Critical to Professor Aldana's reinterpretation of the Venus Table was his introduction of a new reading of a specific hieroglyphic term.
"There have been interpretations that the Mayans feared Venus, that they saw it as a malevolent deity and so they would have to do certain kinds of rituals to protect themselves from Venus," he said.
"That's a misinterpretation and, in part, it's resulting from a misreading of a hieroglyphic text."
This, Professor Aldana said, changes our understanding of the Venus Table from being based in numerology to instead being used to set the timing of large-scale ritual events.
"They're much more festival, ritual, events that involve large communities or large groups of society, and in this case they wanted it to be timed by the visibility of Venus," he said.
"This is why I make the comparison to Copernicus, because Copernicus was worried about how good their astronomical models were so that they could do things like set the timing of Easter.
"It's the same thing in Mayan civilisation during the Terminal Classic. They were interested in these large-scale events and they needed good astronomical models to set those appropriately."
It has also long been known that the Venus Table contains a mathematical "correction" to account for the Mayan Calendar's irregular cycle, which Professor Aldana likens to a "leap year".
He said he believed that correction was developed at the city of Chichen Itza during the Terminal Classic period (AD 800-1000).
"There's one specific date that's an anchor to the whole table ... but for the most part it's been taken as a numerological fiction," he said.
"It's been taken as a convenient date because it satisfied numerological constraints [but] I'm arguing that's not its purpose.
"It was actually used as a historical record that the first time some Mayan astronomer observed Venus [and] made a record of it. That record was preserved ... until finally it got to Chich'en Itza and the astronomer used it to create this new mathematical calendric innovation."
'One, really elegant, mathematical equation'
Professor Aldana compared the "calendric innovation" to the Gregorian calendar's leap year.
"Our calendar is based on just 365 days, but the length of the tropical year is a little bit more than that — it's 365.2422 days — so we need to take into account over long periods of time, at least four years, that extra time period," he said.
"What the calendrics are doing here in the Dresden Codex is finding ways of accommodating for the fact that there's a difference between ... their Venus round, which is 584 days, and the actual observation of Venus cycles, which is 583.92 days.
"That extra eight-one-hundredth of a day, it adds up when you talk about projections into the future or you look back at historical records.
"What this astronomer found when he or she was sitting at the top of this building at Chichen Itza and watching Venus, relative to their calendar, they're seeing the pattern and trying to make it fit with the historical records they have and they come upon this one, really elegant, mathematical equation that allows them to tie it all together."
Professor Aldana points to the rising popularity of Quetzalcoatl, a deity with strong ties to Venus, during the Terminal Classic period as corroboration of his suggested timing of the Venus Table correction.
"If you get into the time period that I'm pointing at as the moment of this discovery, it's also the time period when Quetzalcoatl, [known as] Kukulkan [to the Mayan people], becomes a very important figure," he said.
"This whole time that [Quetzalcoatl] is taking root as this new religious figure is the same time as this discovery of Venus — and it makes sense, because this Quetzalcoatl figure is tied to the planet Venus."
Popular culture 'misrepresents' the Mayan people
Professor Aldana said this interpretation put the Mayan tradition more in line with other ancient civilisations.
"If you talk about the earliest Greek astronomers that we know of, they were doing the same kind of things," he said.
"They kept records and by looking at these records over very long periods of time, you find patterns.
"Those patterns drive your model and they drive your interpretations and I'm saying that's what we're seeing here with the Dresden Codex ... so in that way they're more alike than different."
Professor Aldana said he hoped his analysis would help people see the Mayans "as something other than a monolithic society".
"We talk about 'the Maya' as though that's a meaningful term — how can you capture all these millions of people with one phrase?" he said.
"Popular culture has misrepresented the Mayan [people] in so many ways that we have to almost excavate or peel away that stuff to get at their experiences and what they tried to do and what they recorded.
"We have to get through all that in order to see this rich discovery that they made, and it's worth the effort when we do take that on."