Galileo is perhaps the first scientist, at least since the Greek Archimedes, to be well known to the general public.
He is famous partly for his real achievements in physics and astronomy, partly for legendary achievements (such as dropping cannon-balls off the Leaning Tower of Pisa), and partly for having been tried for heresy by the Inquisition and compelled
to recant his belief, now universally accepted, that the Earth moves in space.
Only in the last few years has the Catholic Church officially "reversed" his conviction. Yet his ideas, in spite of the violent controversy they stirred and the official condemna-tion they brought him, came to be generally accepted by educated opinion within a few years after his trial. Why were these ideas, though pronounced heretical, so widely and quickly accepted?
The reason for this swift acceptance, it will be suggested, is that Galileo's theories and observations, radical though they were, were badly needed by people who were trying to make sense of the physical world. The orthodox physics and astronomy of Aristotle and his successors, though hollowed by tradition and authority, as already--before Galileo's time--being severely strained on several theoretical and observational fronts.
Attempts to "save the appearances"--to fix up the traditional physics and astronomy so that they could continue to adequately explain the observed world--were becoming ever more elaborate, shaky, and inelegant.
There are two sciences with which Galileo is associated: astronomy and physics. We will consider his work in physics
--his principal concern for most of his career (Drake 15)--first. Ancient Greek science made great progress in statics; Archimedes' theory of displacement and flotation is still a valid model for these phenomena. In dynamics, or the physics
of motion, however, the Greeks were much less successful.
Aristotle proposed two "laws of motion:" first, that objects tend to ...