On This Day

Galileo Galilei

Astronomer and Physicist Galileo Galilei

Profession: Astronomer and Physicist


Biography: Called the Father of Modern Science by Einstein, Galileo was born into a musical family in Pisa. After studying mathematics and natural philosophy he was appointed to the Chair of Mathematics in 1589 before moving to the University of Padua where he made major discoveries in Fundamental and Applied Science. These included a military compass and an improved version of the telescope. With the later he was the first to identify the moons of Jupiter and describe the topography of our Moon.

In Physics Galileo conducted experiments with gravity concluding all objects accelerate at the same rate. In 1633 Galileo was found guilty on heresy charges for supporting the view that the earth orbits the sun and sentenced to house imprisonment. Galileo published many works throughout his life including The Starry Messenger and Dialogue Concerning the Two Chief World Systems. Today the moons of Jupiter are named the Galilean Moons and the Galileo Spacecraft was the first to orbit the planet Jupiter.

Born: February 15, 1564
Birthplace: Pisa, Duchy of Florence, Italy
Star Sign: Aquarius

Died: January 8, 1642 (aged 77)

Articles and Photos

Historical Events

  • 1609-08-08 Venetian senate examines Galileo Galilei's telescope
  • 1609-08-25 Galileo demonstrates his 1st telescope to Venetian lawmakers
  • 1610-01-07 Galileo Galilei discovers the first three moons of Jupiter: Io, Europa & Ganymede
  • 1610-01-08 Simon Marius. a German astronomer, independently discovers the first three moons of Jupiter one day after Galileo
  • 1610-01-13 Galileo Galilei discovers Callisto, 4th satellite of Jupiter
  • 1612-12-28 First observation of Neptune - Galileo observes and records a "fixed star" without realising it is a planet
  • 1616-02-26 Roman Inquisition delivers injunction to Galileo demanding he abandon his belief in heliocentrism, which states the Earth and planets revolve around the Sun
  • 1632-02-22 Galileo's "Dialogue Concerning the Two Chief World Systems" is published
  • 1633-02-13 Italian astronomer Galileo Galilei arrived in Rome for trial before Inquisition for professing belief that earth revolves around the Sun
  • 1633-06-22 Galileo Galilei forced to recant his Copernican views that the Earth orbits the Sun by the Pope (Vatican only admits it was wrong on Oct 31, 1992!)
  • 1737-03-12 Galileo's body moved to Church of Santa Croce in Florence, Italy
  • 1992-10-31 Roman Catholic church reinstates Galileo Galilei after 359 years

Quotes by Galileo Galilei

  • "I do not feel obliged to believe that the same God who has endowed us with sense, reason, and intellect has intended us to forgo their use."