Hal Green - Academia.edu (original) (raw)

Papers by Hal Green

During the past two decades, systematic documentation of architectural orientations and horizon a... more During the past two decades, systematic documentation of architectural orientations and horizon alignments in large areas of Mesoamerica has significantly increased the corpus of reliable data on which interpretations of the use and meaning of these orientations and alignments can be based. When dates reported to be marked by architectural orientations of civic and ceremonial structures at 106 sites throughout the Maya lowlands are analyzed within the ranges of date error derived from reported Interval Error, and interpreted in a manner consistent with fundamental principles of Maya worldview, including duality, intervallic patterning and preoccupation with cosmic order, a calendrically symmetrical pattern of marked dates emerges, defining a region-wide horizon reference system that enabled the tracking of time for all purposes. Subterranean chambers and other constructed devices throughout Mesoamerica, including in the Maya lowlands, enabled precise determination of the dates of those zenith passages which served as the fundamental reference pole of this horizon reference system.

This is a revised version of a Draft paper posted on academia.edu in 2020. It embodies two significant changes: (1) date error has been derived directly from reported Interval Error (rather than indirectly form reported azimuth and declination error) and (2) orientations have been identified that mark mirror opposite date pairs at the horizon that occur 20 days before/after the 260-day band nadir passages and 20 days after/before the 260-day band zenith passages.

E Group assemblages, considered to be the earliest form of monumental architecture in the central... more E Group assemblages, considered to be the earliest form of monumental architecture in the central Maya lowlands, were once thought to be “observatories” of the solstices and equinoxes. However, when the dates reported to be marked at the horizon by the axial alignments of 71 of E Groups in the central Maya lowlands (systematically documented by Šprajc 2021) are adjusted within applicable date error ranges, they define a horizon reference system that enabled precise tracking of time for all purposes. Patterns related to these astronomically and calendrically significant marked dates, especially those marked by the north and south lateral axes of the E Groups, establish the intentionality of this system, the fundamental reference poles for which are the zenith and nadir passages of the latitudinal band where the interval between the zenith passages is uniquely equal to 260 days, numerically equal to the pan-Mesoamerican divinatory calendar. During the transition between the Late Preclassic and Early Classic periods, axial alignments of E Groups were transferred to the architectural orientations of civic and ceremonial structures of other type as E Groups ceased to be constructed.

When interpreted in light of established principles of Mesoamerican worldview and stated date err... more When interpreted in light of established principles of Mesoamerican worldview and stated date error, systematically documented architectural orientations of civic and ceremonial structures at 63 sites in Oaxaca, the Gulf Coast, and the West and North of Mesoamerica provide increased support for the conclusion that the 260-day divinatory count is directly related to the 260-day interval between the two solar zenith passages that occur within a narrow latitudinal band just south of 15° North latitude. Pre-Hispanic inhabitants of these four culturally diverse regions tracked the most important days of the solar cycle by means of a horizon reference system defined by the dates of those 260-day band zenith passages, the mirror opposite nadir passages and other calendrically significant solar events of the 260-day band. This system of marked dates, similar to those established by architectural orientations in central Mexico and the Maya lowlands, enabled the use of local horizon calendars at most sites that, because of the calendrical symmetry of the region-wide horizon reference system of which they were a part, enabled calendar specialists to reconstruct the complete system from the locally marked dates for the precise tracking of time for all purposes.

Speculations that the Mesoamerican 260-day divinitory count may have a direct relationship to the... more Speculations that the Mesoamerican 260-day divinitory count may have a direct relationship to the 260-day interval between solar zenith passages that uniquely occur within a narrow latitudinal band just south of 15° north latitude (the “260-day band”) are supported by evidence from extensive and systematic documentation of architectural and horizon orientations at sites throughout Central Mexico. Sites were located and important structures within those sites were oriented from as early as the early 3rd century BC in accordance with a horizon reference system defined by the dates of the zenith and nadir passages and related calendrically significant solar events of that 260-day band. Subterranean chambers and other constructed devices in Central Mexico have been identified that enabled precise determination of the actual dates of those zenith passages. Calibration of the horizon reference system using the actual zenith passage dates from one solar cycle to the next would maintain concordance with the tropical year. In these respects, the zenith sun of the 260-day band was an organizing principle of the constructed space and calendrics of Central Mexico.

Unresolved questions of Mesoamerican calendrics are whether counts were maintained in concordance... more Unresolved questions of Mesoamerican calendrics are whether counts were maintained in concordance with the tropical year and, if so, how this was done. Extensive and systematically documented orientations throughout Central Mexico establish that a horizon reference system, used to locate sites, to orient important structures within those sites, and to track the position of the sun at the horizon on significant dates of the solar year, is defined by the dates of the zenith passages (and related calendrically significant solar events) occurring within a narrow latitudinal band just south of 15° north latitude. Only there within Mesoamerica is the interval between these two zenith passages 260 days, numerically equal to the tonalpohualli, the 260-day count of Central Mexico. Subterranean chambers and other devices at Teotihuacan, Xochicalco, Monte Alban and Tajin enabled precise determination of the actual dates of these zenith passages. When tonalpohualli dates are used for the zenith passages and related 260-day band solar events in the horizon reference system, a calendrical symmetry results that enabled calibration of that system from one solar cycle to the next to maintain the tonalpohualli and the horizon reference system in concordance with the tropical year without intercalation of leap days.

During the past two decades, systematic documentation of architectural orientations and horizon a... more During the past two decades, systematic documentation of architectural orientations and horizon alignments in large areas of Mesoamerica has significantly increased the corpus of reliable data on which interpretations of the use and meaning of these orientations and alignments can be based. When dates reported to be marked by architectural orientations of civic and ceremonial structures at 106 sites throughout the Maya lowlands are analyzed within the ranges of date error derived from reported Interval Error, and interpreted in a manner consistent with fundamental principles of Maya worldview, including duality, intervallic patterning and preoccupation with cosmic order, a calendrically symmetrical pattern of marked dates emerges, defining a region-wide horizon reference system that enabled the tracking of time for all purposes. Subterranean chambers and other constructed devices throughout Mesoamerica, including in the Maya lowlands, enabled precise determination of the dates of those zenith passages which served as the fundamental reference pole of this horizon reference system.

This is a revised version of a Draft paper posted on academia.edu in 2020. It embodies two significant changes: (1) date error has been derived directly from reported Interval Error (rather than indirectly form reported azimuth and declination error) and (2) orientations have been identified that mark mirror opposite date pairs at the horizon that occur 20 days before/after the 260-day band nadir passages and 20 days after/before the 260-day band zenith passages.

E Group assemblages, considered to be the earliest form of monumental architecture in the central... more E Group assemblages, considered to be the earliest form of monumental architecture in the central Maya lowlands, were once thought to be “observatories” of the solstices and equinoxes. However, when the dates reported to be marked at the horizon by the axial alignments of 71 of E Groups in the central Maya lowlands (systematically documented by Šprajc 2021) are adjusted within applicable date error ranges, they define a horizon reference system that enabled precise tracking of time for all purposes. Patterns related to these astronomically and calendrically significant marked dates, especially those marked by the north and south lateral axes of the E Groups, establish the intentionality of this system, the fundamental reference poles for which are the zenith and nadir passages of the latitudinal band where the interval between the zenith passages is uniquely equal to 260 days, numerically equal to the pan-Mesoamerican divinatory calendar. During the transition between the Late Preclassic and Early Classic periods, axial alignments of E Groups were transferred to the architectural orientations of civic and ceremonial structures of other type as E Groups ceased to be constructed.

When interpreted in light of established principles of Mesoamerican worldview and stated date err... more When interpreted in light of established principles of Mesoamerican worldview and stated date error, systematically documented architectural orientations of civic and ceremonial structures at 63 sites in Oaxaca, the Gulf Coast, and the West and North of Mesoamerica provide increased support for the conclusion that the 260-day divinatory count is directly related to the 260-day interval between the two solar zenith passages that occur within a narrow latitudinal band just south of 15° North latitude. Pre-Hispanic inhabitants of these four culturally diverse regions tracked the most important days of the solar cycle by means of a horizon reference system defined by the dates of those 260-day band zenith passages, the mirror opposite nadir passages and other calendrically significant solar events of the 260-day band. This system of marked dates, similar to those established by architectural orientations in central Mexico and the Maya lowlands, enabled the use of local horizon calendars at most sites that, because of the calendrical symmetry of the region-wide horizon reference system of which they were a part, enabled calendar specialists to reconstruct the complete system from the locally marked dates for the precise tracking of time for all purposes.

Speculations that the Mesoamerican 260-day divinitory count may have a direct relationship to the... more Speculations that the Mesoamerican 260-day divinitory count may have a direct relationship to the 260-day interval between solar zenith passages that uniquely occur within a narrow latitudinal band just south of 15° north latitude (the “260-day band”) are supported by evidence from extensive and systematic documentation of architectural and horizon orientations at sites throughout Central Mexico. Sites were located and important structures within those sites were oriented from as early as the early 3rd century BC in accordance with a horizon reference system defined by the dates of the zenith and nadir passages and related calendrically significant solar events of that 260-day band. Subterranean chambers and other constructed devices in Central Mexico have been identified that enabled precise determination of the actual dates of those zenith passages. Calibration of the horizon reference system using the actual zenith passage dates from one solar cycle to the next would maintain concordance with the tropical year. In these respects, the zenith sun of the 260-day band was an organizing principle of the constructed space and calendrics of Central Mexico.

Unresolved questions of Mesoamerican calendrics are whether counts were maintained in concordance... more Unresolved questions of Mesoamerican calendrics are whether counts were maintained in concordance with the tropical year and, if so, how this was done. Extensive and systematically documented orientations throughout Central Mexico establish that a horizon reference system, used to locate sites, to orient important structures within those sites, and to track the position of the sun at the horizon on significant dates of the solar year, is defined by the dates of the zenith passages (and related calendrically significant solar events) occurring within a narrow latitudinal band just south of 15° north latitude. Only there within Mesoamerica is the interval between these two zenith passages 260 days, numerically equal to the tonalpohualli, the 260-day count of Central Mexico. Subterranean chambers and other devices at Teotihuacan, Xochicalco, Monte Alban and Tajin enabled precise determination of the actual dates of these zenith passages. When tonalpohualli dates are used for the zenith passages and related 260-day band solar events in the horizon reference system, a calendrical symmetry results that enabled calibration of that system from one solar cycle to the next to maintain the tonalpohualli and the horizon reference system in concordance with the tropical year without intercalation of leap days.