defendgalileo2

         Galileo also did work with infinity. He wrote that the points of infinity on a line, is

greater than the points of infinity on a shorter line. He also said that there are just as many

squares 1,4,9,16... as there are natural numbers 1,2,3,4.... even with the squares being

included in the natural numbers.

          Possibly the field that Galileo’s mathematical knowledge contributed to the most

was astronomy. Galileo used an objective lens on his telescope to discover the moons of

Jupiter, which he christened the “Medicean Planets” after one of his patrons. Galileo also

had a great interest in the heliocentric Copernican System which stated that the sun was

the center of the universe, making it the center of the rotational movements of the planets.

          In 1604 Galileo had seen a supernova and used it to challenge the Aristotle idea in

several of his public speeches. Aristotle had a geocentric philosophy, meaning he thought

that the earth was the center of the universe and that all celestial bodies revolved around

the earth. He later wrote a work comparing the two systems entitled Dialogue on the

Two Chief World Systems.

          In the summer of 1609, Galileo built his first three powered spyglass. Later that

year he presented an eight powered telescope to the Venetian Senate, and turned a

twenty powered telescope to the heavens. He observed the moon and resolved nebular

patches into stars. Due to his remarkable invention he made numerous celestial

observations from 1609-1610. During this time he made his famous discovery of Jupiter’s

satellites.