Oldest known book of the Americas points to how Mayans precisely recorded the movement of Venus

Dresden Codex. Credit: NOVA/PBSDresden Codex. Credit: NOVA/PBS

The Dresden Codex (also known as the Codex Dresdensis) is a Maya codex from the pre-Columbian era of 11th-12th century; and as such is considered as a copy of an older, original document that was possibly compiled in 8th century AD. In spite of the ‘derivative’ feature, the Dresden Codex is the oldest book written in the Americas known to historians, with its fascinating content of astronomical tables, including the Lunar Series and Venus table. Pertaining to the latter mentioned part, while the Venus table has intrigued researchers and historians over the years, the scope of its analysis has been mostly limited to numerology denominations. But this time around, researcher Gerardo Aldana, a professor of anthropology at UC Santa Barbara, has made a new case for the table, and his study links the astronomical and historical attributes of the Venus table that were possibly achieved by an early Maya scientist. In essence, the table might have alluded to an incredible astronomical discovery related to Venus more than a thousand years ago.

To that end, Aldana made use of epigraphy (study of hieroglyphics) combined with archaeology and astronomical records, and this ambit hints at how a correction in the ancient text relates to to the movements of Venus. The equation was probably made during the period between 8th-10th century (also known as Terminal Classic period) in the Mayan city of Chich’en Itza, (possibly) under the patronage of K’ak’ U Pakal K’awiil, the ruler/high-ranking official of the settlement. Aldana has this to say about the scribe who made this change in the Venus table –

This is the part that I find to be most rewarding, that when we get in here, we’re looking at the work of an individual Mayan, and we could call him or her a scientist, an astronomer. This person, who’s witnessing events at this one city during this very specific period of time, created, through their own creativity, this mathematical innovation.

Now the ‘correction’ in question here, referred to as the ‘mathematical subtlety’ by Aldana, was already known by many researchers. In simple terms, the ‘mathematical subtlety’ stood as a correction for Venus’s irregular cycle, which is 583.92 days. So much like the leap years of our conventional Gregorian calendar, without the correction, a calendar based on days would have allowed some error to creep in (over the passage of years). But while scholars were already aware of the ‘mathematical subtlety’, most academic studies have not really revealed the actual purpose of such a correction. As Aldana put forth his queries –

But the question is, what does it mean? Did they discover it way back in the 1st century BC? Did they discover it in the 16th? When did they discover it and what did it mean to them? And that’s where I come in.


Aerial view of Chich’en Itza.

So by the employing the aforementioned methods of epigraphy and other avenues, the UCSB anthropologist came across an interesting anomaly in the Venus table. This entailed the use of the key Mayan verb, k’al, which traditionally means “to enclose’, but was used in a different context in the text – being more oriented towards a historical and cosmological purpose. Now while there is no doubt about the accuracy of the correction (pertaining to Venus’s irregular cycle) made in the table, most scholars assumed (till now) that it was based on numerology. However Aldana put forth his different conjectural route –

So what I’m saying is, let’s step back and make a different assumption. Let’s assume that they had historical records and they were keeping historical records of astronomical events and they were consulting them in the future — exactly what the Greeks did and the Egyptians and everybody else. That’s what they did. They kept these over a long period of time and then they found patterns within them. The history of Western astronomy is based entirely on this premise.

To bolster his conjecture into a credible theory, Aldana made a visit to the impressive Mayan archaeological site of Copán in Honduras. Boasting its own record of Venus, the city’s table was found to precisely match with that of the Dresden Codex. In other words, it boosts the probability that beyond numerology, the observations of Venus were related to historical records. But in spite of this variance in interpretation, the question still remained – why exactly did the Mayans historically record such astronomical observations. Aldana explained his hypothesis –

They’re using Venus not just to strictly chart when it was going to appear, but they were using it for their ritual cycles. They had ritual activities when the whole city would come together and they would do certain events based on the observation of Venus. And that has to have a degree of accuracy, but it doesn’t have to have overwhelming accuracy. When you change that perspective of, ‘What are you putting these cycles together for?’ that’s the third component.

Connecting all the dots, the possibility arises that during the heydays of Chich’en Itza, the astronomer-extraordinaire of the temple observed the movements of Venus and made the necessary changes in the table to counter any error creeping into the calendar. This was done to ‘correctly’ set the yearly ritual events, thus alluding to a broader cultural context, as opposed to just a small numerology exercise. In essence, this Mayan scientific achievement is of a much larger scope than previously thought. But sadly, the name of the scribe/scientist who made the necessary corrections is still lost to history. As Aldana said –

I don’t have a name for this person, but I have a name for the person who is probably one of the authority figures at the time. It’s the kind of thing where you know who the pope was, but you don’t know Copernicus’s name. You know the pope was giving him this charge, but the person who did it? You don’t know his or her name.


The Mayan observatory of Chich’en Itza.

The study was originally punished in the Journal of Astronomy in Culture

Source: UCSB

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