Just to put Magellan into historical context, here are some events and dates to consider. 1519 was the year Magellan set out on his expedition.
The cosmological belief system at the time was “geocentric.” Complex celestial trigonometry was used to navigate by heavenly bodies which were assumed to be rotating around the Earth.
The Spanish Inquisition is in its 39th year.
March 4th, 1519, Hernando Cortez lands in Mexico. By November he is in Montezuma’s Court in Mexico City, overthrowing the Aztec Empire by intrigue and with the assistance of Dona Marina’s interpretative language skills. “To the victor go the spoils” of gold and silver for Spain and her thugs.
May 4th, 1519 Leonardo da Vinci dies.
June 28th, 1519 Charles I of Spain becomes Charles V, Holy Roman Emperor. The 18-year-old Charles is Magellan’s sponsor and the grandson of Ferdinand and Isabella. Charles rules until 1556.
1519 Martin Luther questions the infallibility of papal decrees.