How long and in what capacity did Joachim Rittstieg study a system of calenders used in pre-Columbian Mesoamerica?
Joachim Rittstieg Joachim Rittstieg (born February 23, 1937 in Berlin, died May 27, 2014 in Rendsburg) was a secondary school mathematics teacher who had travelled in Mexico, Guatemala, Belize, Honduras and El Salvador, and had studied the Mayan calendar system as a 40-year hobby.
Metallurgy in pre-Columbian Mesoamerica The emergence of metallurgy in pre-Columbian Mesoamerica occurred relatively late in the region's history, with distinctive works of metal apparent in West Mexico by roughly AD 800, and perhaps as early as AD 600. Metallurgical techniques likely diffused northward from regions in Central or South America via maritime trade routes; recipients of these metallurgical technologies apparently exploited a wide range of material, including alloys of copper-silver, copper-arsenic, copper-tin and copper-arsenic-tin.