Galileo Galilei

As I pointed out earlier in the post on Copernicus, Galileo (1564-1642) advocated Copernicus' worldview, the heliocentric model, and got imprisoned for it by the Vatican. Despite this Stephen Hawking has said that Galileo was perhaps the most important person for the development of modern science. Albert Einstein called him the "father of modern science". His work overlapped somewhat that of Johannes Kepler (1571-1630).

Galileo was born in Pisa but moved aged 8 to Florence. He first went to school at the monastery Camaldolese at Vallombrosa. Seriously he considered priesthood but at his father's urging enrolled for medical studies at the University of Pisa. He studied mathematics instead and got a professorship at Pisa in 1589 at age 25. He did however not advance mathematics but is mostly known for his work in astronomy and physics. He was, however, probably the first person that used mathematics for describing physical events and thus predated Newton on this issue.

In 1592 he moved to the University of Padua teaching geometry, mechanics and astronomy until 1610 when he published the first scientific work performed with a telescope The Starry Messenger. In 1590 he had discovered Copernicus publication from 1543 De Revulotionibus Orbium Coelestium.

Although a pious Roman Catholic Galileo fathered three children out of wedlock with Marina Gamba and since marriage is a sacrament in the Catholic Church this proved that he was more a man of faith than a dogmatic.

Galileo made his career in astronomy with the tool of a 30X telescope which he built himself from the description of the first practical telescope invented in Holland 1608 by Hans Lippershey. He obtained information that expanded the knowledge greatly of astronomy at the time and which confirmed the heliocentric theory.

Retrospectively Galileo got beaten by Kepler on the theory of the tides. He called Kepler's idea that they are caused by the moon for "useless fiction", an idea which of course was very clever since it contains a feel for gravitation. He also did not believe in Kepler's correct elliptical orbits either but instead argued for the classical perfect circle.

In physics Galileo developed the concept of inertia, mathematically described it, and introduced the idea of frictional force. His work later went into Newton's first law.

The Galileo affair with the Catholic Church has just recently ended when the Vatican in 2008 decided to erect a statue of him inside the Vatican walls.