2012: The Maya calendar correlation problem pt 1

I have now read Gerardo Aldana’s essay ”The Maya calendar correlation problem” that I mentioned in an earlier blog post. It is also a long essay and I will make it into two or three blog posts. Although the essay does not concern the 2012 phenomenon as such I file it under that category on this blog since it shows that the correlation problem still is with us. John Major Jenkins, one of the main proponents for an “alternative” interpretation of the Maya calendar, has commented on Aldana’s research but without actually reading the essay. Not only is Jenkins’ critique missing the whole issue that Aldana raises, but Jenkins (and other “2012ers”) will for sure not give up their beloved winter solstice alignment. That would be devastating to their business.

 

Eric Thompson

The essay takes a history of science approach and “examines the individual histories of Mayanist considerations of the Dresden Codex Venus Table, the Landa equation, the Katun sequence in the Chronicle of Oxkutzcab, and a subset of the calendric data in the Books of Chilam Balam” (p. 2). I highly recommend everyone to read the essay as it shows how some issues can become “black boxed” in the Latourian sense. Aldana shows that “critical aspects of the problem’s genealogy […] have been buried within the literature, and so rendered invisible to late 20^th and early 21^st century scholarship” (p. 2). The main focus is set on Eric Thompson and Floyd Lounsbury and their formulation and solution of the problem. It turns out that Thompson still affects Mayanist research, 35 years after his death.

 In this first post I basically mention the various calendars and astronomical data that are under discussion in Aldana’s essay. The Calendar Round (CR) consists of a 260 day long cycle generally called tzolkin (chol qiij) and a 365 day long cycle generally called haab (haab’). Together these cycles form the greater CR of roughly 52 years. The CR appears to have been the same at all known sites throughout the lowlands during the Classic period. However, there were changes in practice sometime between the early Postclassic period and the late Colonial period as can be seen in the so-called Yearbearers which are different in later periods. Hence, there were some slippage between the tzolkin and the haab. During Classic times the CR were often combined with Long Count (LC) dates. Thus, the aim of the correlation issue is to match the CR and LC dates with equivalent dates in the Julian calendar (not the Gregorian calendar since it was introduced in 1582). This is the Ajaw equation and it is expressed as: LC + X = JD. X is the Ajaw constant and JD is the Julian Day number.

During the Terminal Classic the Maya began to use a Katun Count (aka the Short Count) that named a katun (a 20 years long period) after the final day in the tzolkin calendar. Hence 9.4.0.0.0 13 Ajaw 18 Yax was called a Katun 13 Ajaw. However, sometime between the late Terminal Classic period and the early Colonial period the Maya changed this system from being part of the larger Baktun count of the LC to simply become a cyclical format with 13 katuns in each cycle (the may cycle in Prudence Rice’s model). Thus, can we be sure that there is strict continuity through these changes in calendar practices? Can there even be a maintained synchrony across the Maya area without the LC? It is doubtful in my opinion.

During the Classic period the LC was accompanied by the Lunar Series. These are fairly consistent from site to site and most of the moon ages were probably derived from observation. Hence, any proposed calendar correlation must predict the moon ages within the Lunar Series. What is needed then is the recording of moon ages and calendar dates in later Maya documents, such as the Dresden Codex. Unfortunately there is no recognizable historical eclipse within the Eclipse Table of the Dresden Codex. The table only appears to record possible events or warning dates, not observed moon ages with a known historical anchor.

It is the Venus Table in the Dresden Codex that has played a crucial role in the correlation issue. The Venus Round (VR) is given as 584 days in the Dresden Codex. It counts them off for roughly 104 years. However, the true synodic period of Venus is 583,9214 days. This discrepancy is believed to have been corrected by the use of correction intervals in order to make up for the accumulating error. Many Mayanists have proposed schemes for “integrating correction intervals with uncorrected VR in idealized schemes, but for the most part, these proposals rely on the invocation of a specific calendar correlation…” (p 11). It is here where the problems begin and Aldana shows how people have twisted and bended the empirical data in order to fit their own correlation constant. To be continued…