Subterranean observatories, dark chambers and solar telescopes

Abstract

Our field investigations, carried out for more than three decades in about twenty under­ground observatories located in caves and inside pre-Hispanic buildings in Mesoamerica, led us to question whether the ideas that were formulated by Paollo del Pozzo Toscanelli, in the fifteenth century, and by Galileo Galilei at the beginning of the 17th century, and that conducted them to invent a modern object for scientific research (the solar telescope), could have arisen among the Mesoamerican peoples more than ten centuries before. The two oldest underground observatories in Mesoamerica were found between 1980 and 1995 in Teotihuacán and have been dated to the 4th century AD, followed by the one found inside Building P in Monte Albán, Oaxaca. Despite having been built years later (VII-VIII centuries AD), the Xochicalco Observatory has proven to be the most accurate and best preserved of all those we have studied in these three decades. In recent field and cabinet studies, we have retaken his research under the light of new archaeological discoveries highly significant about ceramic objects, that we called"astronomical discs." They led us to take,as a referent of this type of early astronomical observational instruments, to the Xochicalco Observatory, which was especially used in relation with the apparent move­ments of the Sun at the time of its passage through the meridian of a site. This paper pro­poses that two cultures separated by time and space, in America and Europe, in indepen­dent ways, achieved the invention of an instrument that gave similar solutions to scientific questions that probably were, in some ways, of different nature. Despite the different way in which knowledge was applied and interpreted at each time and place, the instruments created are enormously similar, to the extent we can propose that in Mesoamerica, around the 8th century AD, if not earlier, was created a complex solar observation instrument that allowed the recording of positions of this celestial body that had considerable precision. The characteristics of the Mesoamerican underground observatories, that we formulate here, based on archaeological and empirical evidence, allow us to propose that they were instruments for measurement and scientific experimentation, whose characteristics lead us to compare them with dark chambers and solar telescopes invented in other latitudes centuries later.