Galileo The Physicist

Giovanni Benedetti - a court mathematician was very influential. His work on falling bodies, first outlined in 1552, helped lay the basis for the overthrow of Aristotelian physics.

Note: Most of Galileo's work in physics involving theoritical conditions of motion was done between about 1588 and 1592 - his telescopic work did not commence until 1609. The same year that Kelper publishes his first two laws (which we will discuss next lecture)

• In 1595 he comes up with an explanation for tides, which indirectly assumes the Copernican theory is correct. In 1616 he publishes this theory which he also argues that it is proof that the earth moves.

• In 1602 he begins experiments with a Pendulum.

• In 1604 he begins experiments with incline planes. Mathematically proves his results 3 years later. So it took about 20 years for Galileo to truly understand and explain motion, acceleration, etc. But, this explanation is purely empirical.

• 1616: A committee of consultants declares to the Inquisition that the proposition that the Sun is the center of the universe is absurd in philosophy and formally heretical and that the proposition that the Earth has an annual motion is absurd in philosophy and at least erroneous in theology.

  On orders of the Pope Paul V, Cardinal Bellarmine calls Galileo to his residence and administers a warning not to hold or defend the Copernican theory. An unsigned transcript in the Inquisition file, discovered in 1633, states that Galileo is also forbidden to discuss the theory orally or in writing.

• 1620: The Congregation of the Index issued the corrections that must be made in Copernicus's On the Revolutions before it can be read.

• 1624: Galileo goes to Rome where he has six audiences with the Pope Urban VIII and also has audience with a number of cardinals. The Pope assured him that he could write about the Copernican theory as long as he treated it as a mathematical hypothesis.

  Galileo begins revising his treatise on tides (see 1616), which eventually results in his Dialogue Concerning the Two Chief World Systems (1632).

• April 30, 1633: On 30 April Galileo confesses that he may have made the Copernican case in the Dialogue too strong and offers to refute it in his next book.

• June 1633: With a formal threat of torture, Galileo is examined by the Inquisition. The next day he is sentenced to prison at the pleasure of the Inqusition and to religious penances. The sentence is signed by only seven of the ten cardinal-inquisitors.

• 1641: Galileo conceives of the application of the pendulum to clocks.

• Dies in January 1642.