The Mayan people invented complex and highly accurate calendars based off astronomical readings. They are also believed to have discovered the technique of vulcanization, a process that strengthens rubber by adding other materials.
Through studying celestial bodies such as stars and planets, the Mayan people had the ability to predict solar eclipses and plan for proper harvesting and crop rotation techniques. They used a calendar that took two different cycles into account, involving a secular and sacred year. The sacred year was 260 days long, while the secular year was 365 days long. Days in the sacred calendar received a name and number, and days in the secular calendar received a number and month name. The cycle followed by the calendar would automatically be reset after 52 years. This cycle was known as the Calendar Round.
The Mayan people also used their astronomical understanding to build architecture designed to display the beginning of the fall and summer equinoxes, such as the pyramid of Chichen Itza in Mexico. They also made colorful paint mixtures from the mineral mica, as well as complex types of cloth. The strengthened rubber they discovered was used to make balls intended for sports, as glue and bindings and as a water-resistant material.