Galileo Galilei Timeline
Timeline Description: Galileo Galilei (1564 - 1642) was a famed engineer, scientist, and astronomer who was fundamental in the scientific revolution during the Renaissance. He is most well known for improving the telescope, and his resulting observations that supported heliocentric astronomical theory - the concept that the sun was at the center of the solar system. He is often referred to as "the father of modern science."

Date Event
February 15, 1564 Galileo is born.

Born the son of a famed lutenist and musical theorist, Vincenzo Galilei, Galileo and his brother Michelangelo both became accomplished lutenists themselves. However, the family struggles with financial difficulties, particularly because they support the dowries for Galileo's sisters.
September 5, 1581 Galileo enrolls in the University of Pisa.

Though he considers becoming a priest, Galileo's father pushes him to enroll in medical school, instead. While there, he notices how chandeliers take the same time to swing back and forth, no matter how far they are swinging. He is inspired to start studying physics and mathematics, and eventually convinces his father to let him stop studying medicine and take up mathematics and natural philosophy instead.
1586 Galileo publishes a book on the hydrostatic balance.

Galileo publishes a small book about the design of one of his inventions, a hydrostatic balance, which allows one to weigh objects above and below water. This gains him attention among scholarly circles.
1588 Galileo acquires a position as an art teacher.

Galileo acquires a position as an art instructor at the Accademia delle Arti del Disegno in Florence. While in the position, he starts a lifelong friendship with the painter Cigoli.
1589 Galileo acquires a position as a mathematics chair.

Galileo is appointed to the chair of mathematics in Pisa, for 160 scudi per year. While at Pisa he supposedly demonstrates his conclusions on motion by dropping weights from the Tower of Pisa, although this has never been verified.
1591 Galileo's father dies.

Galileo's father dies in 1591, which leads to him taking responsibility for his brother, Michelangelo. He must also meet the terms of a large endowment bestowed on his sister Virginia.
1592 Galileo acquires a position at the University of Padua.

In 1592 Galileo moves to the University of Padua, where he accepts a position teaching geometry, mechanics, and astronomy. This position allows him time to make great advances in theoretical and practical science, including the improvement of the telescope.
August 13, 1600 Virginia Galilei is born.

Virginia Galilei is born out of wedlock to Galileo and Marina Gamba on August 13, 1600. Galileo, who is a faithful Roman Catholic, cannot see how Virginia, and her sister Livia, born a year later, could be married. Instead, he arranges for them both to join the convent of San Matteo in Arcetri as nuns.
December 1613 Galileo first circulates his theory defending the Copernican system.

In December 1613, Galileo forwards the theory that the ocean tides speed up and slow down according to the rotation of the Earth on its axis and its revolution around the sun, which he says supports the Copernican theory that the Earth goes around the sun. The Catholic Church sees this as a direct challenge to its authority, as it advocates the geocentric theory that the Earth is at the center of the solar system.
February 26, 1616 Galileo summoned before Cardinal Bellarmine.

Pope Paul V orders Cardinal Bellarmine to bring Galileo before him on February 26, 1616. Galileo comes to Bellarmine's residence and is ordered to completely abandon his position about heliocentrism. Under the banner of the Inquisition, Galileo's heliocentric writings are all banned.
October 1623 Galileo publishes The Assayer.

After years of being embroiled in a controversy with Father Orazio Grassi, a Jesuit professor of mathematics, Galileo publishes The Assayer in October 1623. This represents the last word in the conflict, which began over comets but evolved into a conflict about the nature of science. The Assayer is a scathing critique of Grassi, and, while it wins the debate, it also makes an enemy out of the Jesuits for Galileo.
February 1632 Galileo publishes Dialogue Concerning the Two Chief World Systems.

In 1623 a new Pope comes to power, Pope Urban VIII, who is a friend and admirer to Galileo. He and the Inquisition formally authorize Galileo's work, and he publishes Dialogue Concerning the Two Chief World Systems. However, the text embarrasses the Pope and alienates Galileo's biggest supporter.
April 12, 1633 Galileo is put on trial.

Galileo is put on trial by the Inquisition on April 12, 1622, until April 30. He is forced to recant his position on heliocentricism, but he is still sentenced to house arrest, and his work, Dialogue, is banned. Though he is eventually allowed to return to his home near Florence, he stays under house arrest the rest of his life.
July 1638 Galileo publishes Two New Sciences.

While under house arrest, Galileo continues his work. In July 1638 he publishes what is highly regarded as his best work, Two New Sciences, which introduce the studies kinematics and strength of materials. It has to be published in Holland to avoid censorship. The strength of this work often earns him the title "the father of modern physics."
January 8, 1642 Galileo dies.

After receiving continuous visitors nearly to the day of his death, Galileo dies on January 8, 1642. The Pope initially refuses the request that he be interred next to his ancestors in the Basilica of Santa Croce, but eventually his remains are moved to the main body of the Basilica.