Galileo Galilei was born in 1564 in the city of Pisa. His father was a accomplished musician and Galileo would himself, become one under the tutelage of his father. He became a pivotal figure in the Renaissance Period that was slowly taking on the established teachings in Europe of the time.
The city of Pisa was one of the centres of the Renaissance Period and so was a place of rigorous intellectual activity. Galileo’s early environment installed in him a mind of with Renaissance curiosity and creativity, undoubtedly influenced his voracious appetite for knowledge.
He contributed to numerous fields in science in particular astronomy and physics. He supported the Copernican theory of a heliocentric, or Sun centred Universe. In physics, his insights into motion laid the groundwork for what would be later refined by Sir Isaac Newton.
Galileo is often mentioned as inventing the telescope. This however was not true. The first practical telescope was developed by Hans Lipperhey who patented one in 1608. Lipperhey is not credited for the telescope invention either. There is no record of anyone inventing the telescope, particularly in Europe but there are references that the Chinese knew of the principle around the same time.
Galileo heard of this telescope and decided to build one of his own. He developed it further. The telescope he developed became the first refracting telescope.
In January 1610 he turned his telescope to the night sky and observed Jupiter. He noted that it was accompanied by three ‘small stars’. On subsequent nights he made observations of Jupiter noting that these small stars were joined by a fourth. He concluded from his observations that these ‘small stars’ were in fact moon’s of Jupiter. These moons were later named the ‘Galilean Moons’ in his honour.
Galileo continued to make observations of the planets. In 1610 he observed Saturn and noted it did not show a disk as did the other planets. Instead it appeared as three ‘blobs’. This confused him. He later observed Saturn with its rings open which further confused him. He was actually watching Saturn’s Ring System opening and closing during its 29 year orbit around the Sun.
Galileo laid the foundations for modern Astronomy. His work was built upon by later Astronomers like Sir Isaac Newton.
Galileo’s legacy to Astronomy and Physics cannot be understated.