A navigator can know the latitude of his ship by observing the location of stars, where the sun rises in the morning and sets in the evening, and what time of year it is.
VOA: special.2010.07.14
And it does not use hot fusion, the union of hydrogen atoms into larger elements that powers thesunandstars.
The Mayan calendar is based on the position of the heavenly bodies -- thesun, the moon andthestars -- and was meant to tell the Mayan people about agricultural and economic trends, said archeologist Alfredo Barrera.