Announcements• Exam 1 will be returned Monday?

• Exam 2 is scheduled for Monday March 31 (a month away). Tentatively will cover the rest of Chapter 5 (Kepler, Galileo and Descartes), all of Chapters 6 & 7 and some of 8.

• 1st Project Presentations will be next Wednesday (March 5)

• For next time: start reading Chapter 6

Galileo Galilei1564 – 1642

Born in Pisa, his family moved to Florence when he was 8

At 17 he begins study as the University of Pisa

Originally he studies medicine but is unhappy with it so he changes to mathematics. In 1589 he is

appointed chair of mathematics at the university

In 1592 he moves to the University of Padua to teach math, geometry

and astronomy

While at Padua he performs numerous physics experiments

Early on he is not yet a committed Copernican but he isn’t happy with

Ptolemy either

Vs

He considers Tycho’s model a bastardization of Ptolemy and not worth bothering with

In the summer of 1609 he hears about a new invention: the telescope

Invented by Hans Lippershey of Zeeland in 1608, word quickly spread across Europe to Galileo

After making refinements

to the design,

Galileo turns his

telescope to the heavens

His first major discovery

concerned the planet Jupiter

Over a week long period in January 1610 he makes observations that prove the existence of four moons orbiting Jupiter.

His observations of the moon showed it to have topography

similar to Earth

He publishes his first observations in the Starry Messenger

Published in March 1610. He calls the moons of Jupiter the Medicean stars after his patrons

Simon Marius claimed to have observed the moons before Galileo but didn’t publish his findings until after Starry Messenger came out

His next significant observations are of the Sun

By tracking sunspots across the face of the Sun he deduces the rotation of the Sun. While he does make observations and sketches, his studies of the Sun are not as detailed as other observers of the time.

Another observation that supports his new Copernican views was the

phases of Venus

He observes the rings of Saturn but never understands what they are

He first observes it in July 1610. By 1612 the rings were edge-on and became invisible only to reappear by 1616

In December 1614 Father Tommaso

Caccini preaches against the

Copernican view

The sermon is directly aimed at Galileo and is meant to incite ferment against the Copernicans

In 1615 Galileo is called to Rome to defend his views before

Cardinal Bellarmine

In 1616 the Church formally bans De Revolutionibus

Cardinal Bellarmine explicitly warns Galileo not to hold or espouse the Copernican view.

Galileo publishes more observations in The Assayer in

1623He also attacks other astronomers that still hold to the Ptolemaic view.

In 1623 Galileo’s friend, Cardinal Barberini, becomes Pope Urban VIII

Emboldened by discussions with Pope Urban VIII,

Galileo defies the Inquisition and publishes Dialogues in

1632

By late 1632, Dialogues is banned and Galileo is put on trial

By June 1633 he is found guilty and sentenced to prison. After recanting

his views, his sentence is commuted to house arrest

While under house arrest, he finally publishes the results of his

physics experiments

Discourses and Mathematical Demonstrations Relating to Two New Sciences lays the foundation for kinematics and dynamics

He dies while still under house arrest, on January 8, 1642

If you have time…