Galileo Galilei to Einstein's special theory of relativity. A biography by Galileo's pupil Vincenzo Viviani stated that Galileo had dropped balls of the same material, but different masses, from the Leaning Tower of Pisa to demonstrate that their time of descent was independent of their mass. This was contrary to what Aristotle had taught: that heavy objects fall faster than lighter ones, in direct proportion to weight. While this story has been retold in popular accounts, there is no account by Galileo himself of such an experiment, and it is generally accepted by historians that it was at most a thought experiment
Galileo Galilei references such as Psalm , , and 1 Chronicles which include text stating that "the world is firmly established, it cannot be moved." In the same manner, says, "the Lord set the earth on its foundations; it can never be moved." Further, Ecclesiastes states that "And the sun rises and sets and returns to its place." Galileo defended heliocentrism based on his astronomical observations of 1609 ("Sidereus Nuncius" 1610). In December 1613, the Grand Duchess Christina of Florence confronted one of Galileo's friends and followers, Benedetto Castelli, with biblical objections to the motion of the earth. According to Maurice Finocchiaro,