Astronomical phenomena in Dresden codex

Abstract

The relationship between Maya and our calendar is expressed by a coefficient known as ?correlation? which is a number of days that we have to add to the Mayan Long Count date to get Julian Date used in astronomy. There is surprisingly large uncertainty in the value of the correlation, yielding a shift between both calendars (and thus between the history of Maya and of our world) to typically several hundred years. There are more than 50 diverse values of the correlation, some of them derived from historical, other by astronomical data. We test here (among others) the well established Goodman-Mart?nez-Thompson correlation (GMT), based on historical data, and the B?hms? one (B&B), based on astronomical data decoded from the Dresden Codex (DC); this correlation differs by about +104 years from the GMT. In our previous works we used several astronomical phenomena as recorded in the DC for a check. We clearly demonstrated that (i) the GMT was not capable to predict these phenomena that really happened in nature and (ii) that the GMT predicts them on the days when they did not occur. The phenomena used till now in the test are, however, short-periodic and the test then may suffer from ambiguity. Therefore, we add long-periodic astronomical phenomena, decoded successfully from the DC, to the testing. These are (i) a synchrony of Venusian heliacal risings with the solar eclipses, (ii) a synchrony of Venus and Mars conjunctions with the eclipses, (iii) conjunctions of Jupiter and Saturn repeated in a rare way, and (iv) a synchrony of synodic and sideric periods of Mercury with the tropical year. Based on our analysis, we find that the B&B correlation yields the best agreement with the astronomical phenomena observed by the Maya. Therefore we recommend to reject the GMT and support the B&B correlation.