The Italian scientist Galileo made several scientific discoveries and inventions, but his most famous invention, his telescope, was actually no invention at all.
Introduction to Galleo
Galileo Galilei, who lived from 1564 to 1642, is considered one of the founders of modern geometry and physics. Although he developed many important scientific theories and made many critical observations of the solar system, he is not credited with many original inventions. He did contribute to many inventions and improve upon many others.
Heliocentric Model of the Solar System
One of Galileo's most famous "inventions" was his confirmation that the sun is the centre of our solar system, a theory first put forward by Nicolaus Copernicus. Galileo confirmed the theory partly through his observation of the phases of the planet Venus as it reflected light from the sun while orbiting the star. This was revolutionary at the time because most of the world still believed Earth was the centre of the universe. The Catholic Church arrested Galileo as a heretic for this.
Although the telescope was invented in 1608 by Dutchman Hans Lippershey, Galileo built his own in 1609, without ever having seen Lippershey's, and he improved it over time from 3X magnification to about 30X. He built his first telescope based on descriptions he had heard. He was the first to use a telescope to observe the heavens.
In 1597, Galileo invented a geometric compass, a scientific instrument with two arms that can be used for making calculations and geometric measurements. Galileo also is credited with inventing a microscope with two lenses at either end of a hollow tube.
Contributions to Other Inventions
Galileo also contributed to the invention of several other pieces of technology for which there is no acknowledged single inventor. For instance, in he built an early thermometer in the 1590s, which used the expansion and compression of air to lift and lower water in a tube.