WHITECROW BORDERLAND

Mayan Astronomy

Note 16: Classic and Modern Period Eclipse Sequences in the Dresden Codex. 8/18/99

The Dresden Codex Eclipse Table has both a structure and a content. The structure of the table is the same today as it was 1300 years ago. The content, however, if time were allowed to pass from then to now, would more than likely not be the same as it was when the Mayas composed it. Reconstructing an eclipse sequence, using Maya calendrical day-names from the almanac and modern eclipse positions from contemporary eclipse tables, becomes possible under two sets of circumstances that are reasonably accessible. First, one must have a suitable base-day eclipse that establishes a sequence of events which exactly matches the prescriptions of the Dresden Codex's structural limitations. That eclipse (lunar) must be followed by a second and third event after additions of 177 days each, as the Classic Period structure demands, before a third addition of 148 days occurs to reach the third lunar eclipse in the sequence. After that, 9 additions of 177 days each must be counted before the next "picture" interval of 148 days in the text is reached. A sequence of eclipses which matches that structure and is consistent through the entire length of the table, specifying 69 eclipse position to recover the base-day beginning of a second table, was reported and described in detail in "A Dresden Codex Eclipse Sequence: Projections for the Years 1970-1992," Latin American Antiquity 4 (1), 1993, 74-93. That report does not contain data from the beginning to the end of the sequence, as much to conserve space as for any other reason, and has been confirmed to reach its proper conclusion by subsequent observation. That additional data will be reflected in what follows here.

The second necessary component of writing a contemporary Dresden Codex eclipse sequence requires a suitable list of almanac day-names, other than the ones used originally by the Classic Period Mayas themselves, to express a reasonable facsimile of the original structure. The method employed to establish the day-names for the contemporary sequence was somewhat complex but essentially straightforward. Using an ancient sequence of eclipses, beginning with a lunar eclipse on June 29, 698 A. D. as the base-day for the Classic Period sequence, one which exactly matches the Dresden Codex structure, a zero base-day for the Maya Long Count notation was established in strict adherence to Classic Period practice at precisely 1,412,848 days prior to the location of the base-day eclipse. This number of days exactly matches the Long Count position of 9.16.4.10.8 12 Lamat 1 Muan, which is the accepted base-day of the Dresden Codex Eclipse Table and counts back exactly to the zero base-day recorded as 13.0.0.0.0 4 Ahau 8 Cumku. That day is April 29, 3171 B. C. or Julian Day #563334. Counting forward then from that position, the end of the Long Count, 1,872,000 days after the beginning of its sequence, occurred on August 14, 1955 (Julian Day #2435334). The lunar eclipse for the base-day of the contemporary sequence occurred on May 25, 1975 (Julian day #2442558), or 81 days less than twenty years after the terminal point of the Classic Period Long Count notation.

Assuming that the Mayas would have simply continued the count for the next 13-Baktun period without alterations from what had gone before, which may or may not be a reasonable assumption, the next zero base-day would have been identified by the Long Count notation of 13.0.0.0.0 4 Ahau 3 Kankin on August 14, 1955. The base-day for the contemporary eclipse sequence would have been written as 1.0.1.4 13 Kan 7 Yax because it occurred 7,224 days after the contemporary zero base-day of a second Long Count notational system (counted from August 14, 1955). This notation, then, would have been the formal designation for the base-day of the contemporary Eclipse Table had the Classic Period Mayas reached this point in time and were still using their calendrical system as we understand it now.

Several curious facts emerge from this exercise. The interval from the base-day lunar eclipse on June 29, 698 A. D. and the one designated here for the beginning of the contemporary sequence is equal to 466,376 days. This interval is just 64 days short of registering an even number of Maya eclipse tables (39 total) from the base-day eclipse in the ancient sequence to the one in the contemporary list. It may also be significant that 39 is a multiple of 13, which has been shown to carry considerable weight in other contexts when discussing principal features of Maya astronomy. 64 itself is just one day less that the multiple of 13 (65) which functions to quarter the 260-day almanac (4 X 65 = 260). The effects of this numerical structure over time, which may or may not be a mere coincidence, are clearly visible in the comparison of day-name triads from the original table to the one that is generated by the contemporary sequence of eclipses. Near repetitions (one day differential) in almanac coefficients and of actual triads of day-names from one table to the next because of this numerical structure may suggest that the contemporary Eclipse Table was very nearly predictable from 1300 years ago in the Classic Period. What is certain, of course, is that Maya astronomers, had they simply survived as such to the present day, would have been perfectly at home with the day-name sequence generated by the eclipses of the last quarter of the twentieth century.

An initial problem one encounters in the Dresden Codex sequence is the fact that the required interval of 177 days to move forward from the base-day position to the first eclipse in the sequence does not agree with the triad of day-names that are listed in the table. 10 Cimi, which occupies the first day-name position in the triad in the 69th position of the table, the base-day position, is the 166th day of the almanac. When the count is extended 177 days to the next, or first eclipse position, of the table, the day-name 5 Akbal should be reached since it is the 83rd day of the almanac sequence. The Mayas, however, and for reasons which are not clear, wrote the day-name 6 Kan, the 84th day, in that position and followed it, appropriately, with 7 Chicchan (85th) and 8 Cimi (86th). An interval of 178 days, which the Mayas used occasionally in the table's structure, would have carried forward to the day-name position as it was recorded. There is no credible explanation for this discrepancy other than to suggest that the scribe who copied the table wrote the wrong value, 177 instead of 178, in that row of the table's structure. A more likely explanation than scribal error is the possibility that the discrepancy was meant to express a fact or concept of the table's use which no one now understands.

One significant astronomical feature encountered at the first eclipse position in the lunar sequence concerns the fact that the full moon rose at Palenque on November 18, 1975 at 17:31 PM. One minute before that, at 17:30 PM, Alcyone in the star cluster Pleiades also crossed the eastern horizon and remained relatively close to the moon as it entered the earth's shadow. While this conjunction of moon and star does not necessarily prove anything conclusive about the validity of the modern eclipse sequence relative to the Maya Classic Period, connections between the sun, the moon, the planets, and the Pleiades have been shown to be quite significant in the context of the Dresden Codex Venus Table when using the same correlation employed here. Work toward establishing precisely where the Venus Table sequence of day-names might stand in the modern period has not yet reached completion but is in progress.

The table which follows, like the Dresden Codex itself, lists only the almanac day-names for each triad for the 69 eclipse positions in the structure. Page and column numbers and letters for the location of each position are also included along with the interval specified to reach the next eclipse.

As this table demonstrates, every first-day in each of the 69 triads occupies an almanac day-name position equivalent to 196 days prior to the one that follows it when moving from the ancient sequence to the modern sequence. This structure is necessitated by the fact that the interval of time separating the two base-days (June 29, 698 A. D. and May 25, 1974 A. D. ) is equal to 466,376 days, or 1793 X 260 + 196 days. The reason this might be significant, of course, concerns the fact that the remainder from an even number of almanacs from one base-day to the next is one day longer than three-quarters of the almanac interval itself (195 days). Also true at the same time, since 11960 is an even number of almanac intervals (46), is the fact that this period of time expresses 38 Dresden Codex Eclipse Table intervals with a remainder of 11896 days, or 64 days less than the number of days necessary to complete the 39th Eclipse Table in the extended sequence from then to now. As noted earlier, this may not prove anything substantial about Maya knowledge of modern eclipse sequences from the Classic Period to the present day, but it does suggest that elements of their calendrical astronomy, in terms of its inherent internal structures, may have a natural capacity to anticipate event occurrences of certain kinds over long periods of time. There are certain considerations involving the Dresden Codex Venus Table, when it is carried forward to the modern period in the same way that the Eclipse Table has been done here, which may make it possible to argue that Classic Period Maya astronomers were actually able to predict this sequence of eclipse day-names as early as 670 A. D. That material, because of its complexity, will be presented in a different context.

To reach [Note 1]; [Note 2]; [Note 3]; [Note 4]; [Note 5]; [Note 6]; [Note 7]; [Note 8]; [Note 9]; [Note 9a]; [Note 10]; [Note 11]; [Note 12]; [Note 13]; [Note 14]; [Note 15]; [Note 17]; [Note 18] in this series of thoughts.

To return to Index click X in the upper right-hand corner of the page.

To view the Myth of Eden Index click here.

---