UC Santa Barbara Journal of Astronomy in Culture
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UC Santa Barbara Journal of Astronomy in Culture Title Discovering Discovery: Chich’en Itza, the Dresden Codex Venus Table and 10th Century Mayan Astronomical Innovation Permalink https://escholarship.org/uc/item/6cr1s6jd Journal Journal of Astronomy in Culture, 1(1) Author Aldana, Gerardo Publication Date 2016 License https://creativecommons.org/licenses/by-nc-nd/4.0/ 4.0 Peer reviewed eScholarship.org Powered by the California Digital Library University of California Discovering Discovery: Chich’en Itza, the Dresden Codex Venus Table and 10th Century Mayan Astronomical Innovation Gerardo Aldana y V. University of California, Santa Barbara Abstract: After centuries of scant attention and even- A new reading of Dresden Codex Page 24, the “Pre- tual repose in the Dresden Library in Ger- face” to the Venus Table, is presented, demonstrating a many, a Postclassic manuscript written in much-improved overall coherence. This reading of hie- Mayan hieroglyphs was brought to the at- roglyphic text, mathematical intervals, and calendric tention of modern scholars during the data specifically identifies the Mayan Long Count dates of the Venus Table’s historical correction. The resulting nineteenth century. Six pages of this man- Long Count placement of the manuscript’s Venus Table uscript, the “Dresden Codex,” have been suggests that it was an indigenous astronomical dis- recognized as relating to the planet Venus covery made at Chich’en Itza, possibly under the patro- since Ernst Förstemann first began work- nage of K’ak’ U Pakal K’awiil — one of the most pro- ing through them in the 1880s. minent historical figures in the inscriptions of the city Förstemann suggested that across these during its “epigraphic florescence.” Revealing the logic pages, a table of dates1 based on multiples underlying the construction of the page, the revised rea- of 584 days were used to track the observ- ding suggests a slightly less-accurate approximation to able period of Venus. Förstemann at- Venus’s synodic period than the traditional interpreta- tion allows, but introduces a justification for the graphi- tempted a translation of the pages (almost cal layout of Page 24 that is more straightforward than a century before the decipherment of the traditional interpretations. script itself) by inferring the meaning from the calendric-astronomical patterns he re- Keywords: Maya, Astronomy, Calendars, covered. Venus, Indigenous Knowledge [W]e find that the [Yucatec scribe] de- Introduction sires to say this: 1 Dates in the Maya Calendar are made up of tropical year. Each of 18 months has 20 days; Long Count and Calendar Round compo- one final “month” is of only 5 days. The month nents. The Long Count is a tally of days con- names are Pohp, Wo, Sip, Sots’, Tsek, Xul, Yaxk’in, ceptually equivalent to the Julian Day Number. Mol, Ch’en, Yax, Sak, Keh, Mak, K’ank’in, Muwan, The differences are only that the Long Count Pax, K’ayab, Kumk’u, Wayeb. A full date would is a modified vigesimal count (base-20) and the be written, for example, as bolon pih bolon wini- “zero date” is different in each case. The Cal- khaab ka haab kan winik waxak k’in ho lamat hun mol endar Round is a combination of the 260 Day and transcribed by modern scholars as Count and the 365 Day Count. The 260 Day 9.9.2.4.8 5 Lamat 1 Mol. Within hieroglyphic Count is a combination of 13 numbers and 20 texts, dates (full or partial) are separated by Day Signs, each advancing on a daily basis. time intervals or “distance numbers” given in The Day Signs are Imix, Ik’, Ak’bal, K’an, Long Count format. A time interval of 4.8 rep- Chikchan, Kimi, Manik, Lamat, Muluk, Ok, Chuwen, resents 88 days. Three hundred sixty-five days Eb, Ben, Ix, Men, Kib, Kaban, Etz’nab, Kawak, would be represented 1.0.5 in Long Count no- Ajaw. The 365 Day Count approximates the tation. Journal of Astronomy in Culture 1(1), 2016, pp. 57-76 Copyright © International Society for Archaeoastronomy and Astronomy in Culture 58 I am here treating especially the peri- would have accumulated, and that they de- ods consisting of five successive Venus veloped a means for correcting their Table years, bringing them into harmony accordingly over very long spans of time. with the solar year and the [260 Day His interpretation was consolidated and Count]2. … [E]ach individual Venus extended by Eric Thompson at mid-cen- year [is] divided into four unequal tury, who argued that Postclassic Mayan parts, which appertain to the east, astronomers had access to an ephemeris north, west, and south and are ruled for Venus accurate to “within one day in by certain deities, which I can mention six thousand years” (1978:63). only in part, owing to lack of space. This, I suggest, is where the historiog- Lastly, I would add that each of the raphy of the Dresden Codex Venus Table five Venus years of a period is domi- takes an interesting turn. Without an abil- nated as a whole by a deity, and the ity to read the hieroglyphic text in the Ta- signs of these I give here (1894:443). ble, scholars were left at mid-century to make an argument for the Venus ephem- Förstemann’s work of over a century ago eris mainly through its purported accuracy goes a long way toward capturing the un- in predicting observable phenomena. This derstanding still current in the contempo- trope then dominated the academic con- rary literature (Aveni 2001; Bricker and sideration of the Venus Table: the better Bricker 2007; Lounsbury 1983). the accuracy it could attribute to the Ta- In the 1920s John Teeple, a chemical ble, the stronger the modern interpretation engineer turned Mayan calendar enthusi- was considered to be (Thompson 1978; ast, followed Förstemann and Eduard Lounsbury 1983, 1992; Bricker and Seler’s interpretive work to focus on the Bricker 2007). mathematical subtlety of the Venus Table. In particular, two forms of accuracy Teeple found that a sequence of four ‘un- have controlled this discourse. The first conventional’ time intervals on Page 243 of has to do with the placement of one of the the manuscript—which confounded Calendar Round dates recorded in the Ve- Förstemann (1894)— actually served as nus pages with respect to a historically re- “corrected” multiples of the 584-day ca- constructed first morning visibility of Ve- lendric period of Venus (Thompson nus (fmv).4 The second concerns how well 1978:224). These intervals suggested that the table could be re-cycled to minimize Mayan astronomers kept track of the dif- the accrued error between prediction and ference between their calendric progres- observation. In 1983, Floyd Lounsbury sion based on a Venus Round of 584 days graphically depicted his and Thompson’s and the 583.9214-day synodic period of approaches to both measures as shown in Venus. Teeple argued that these astrono- Figure 1. mers quantified the amount of error that 2 Förstemann here used the term tonalamatl, 4 Scholars in the past turned to the Tuckerman which is the Nahuatl name for the 260 Day Tables to look up idealized observations for the Count. See footnote 1. Mayan area (Lounsbury 1983:5); now it is com- 3 The apparent non-sequentiality of the Pref- mon for archaeoastronomers to utilize software ace and the Table is accidental only. The man- such as EZCosmos (Freidel, Schele, and Parker uscript had fragmented, and it was numbered 1993) or Planet’s Visibility (Bricker and Bricker out of order. In its original form, the Preface 2007:116). Either way, a Calendar Correlation immediately preceded the Table. is necessary for these studies. See footnote 5. Aldana, G. 59 Figure 1. Reconstruction of Lounsbury’s “mean error” graph of Venus observations against hypothetical Dresden Codex predictions. Lounsbury followed Thompson’s ap- work, modifying it slightly by changing the proach to matching the long-term correc- Calendar Correlation5 by two days and ar- tion of the table, but changed the starting guing that the ephemeris was more strictly point; both models synchronize at a warning table. This move slightly altered 10.10.11.12.0 1 Ajaw 18 K’ayab, which Bricker and Bricker’s inherited notion of they assigned to October 25, 1038 A.D. accuracy since now they want a table that Lounsbury engaged the first aspect of the strictly anticipates fmv; the constraint, of Venus Table’s ‘accuracy’ by noting that his course, is that it cannot come so early that reconstruction placed the 1 Ajaw 18 the prediction overlaps with last evening K’ayab of 10.5.6.4.0 exactly on a (histori- visibility—a rather small range of possibil- cally reconstructed) first morning visibility ity over the long run, given that inferior of Venus (mean error of ‘0’). He claimed conjunction varies and can be as short as that this fmv corresponded to a conjunc- half a day. tion of Venus and Mars—in his view, a Nonetheless, the reconstructions by particularly noteworthy event (Lounsbury these scholars ascribe an impressive accu- 1983:12). racy to Mayan Venusian astronomy and in Harvey Bricker and Victoria Bricker its fundamentals create an interpretation (2007) agreed with most of Lounsbury’s 5 The Calendar Correlation is an arithmetic GMT = JDN. The GMT includes “variants,” constant used to link the Maya Long Count to however, that compensate for the prioritization the Julian Day Number. (See footnote 1) The of different data sets by the scholars utilizing it GMT is the most commonly used Correlation (cf. Aldana 2010, 2015). Constant, where GMT = 584,283 and LC + JAC, Vol. 1, No. 1, 2016 60 that has been universally accepted by Ma- also resolve the complications of the tradi- yanists since the early twentieth century tional model with respect to the anchor (Morley 1975; Thompson 1972; Sharer and the Correction Intervals.