Most people have heard of Galileo but what who was he and what did he do?

Galileo Galilei was an Italian astronomer, scientist and mathematician who lived between 1564 and 1642.

Galileo was described by physicist Steven Hawking as perhaps being responsible more than any other single person for the birth of modern science.

Born in 1954 in Pisa, Italy Galileo was the first of six children, his farther Vincenzo Galilei was a well known lute (basically any stringed instrument with a neck that is played by plucking) musician and composer.

Aged 11, Galileo was sent to a Jesuit Camaldolese monastery to study, there he became intrigued by religion to the point a few years later where he wished to become a monk himself.

However this was not the life Galileo’s father had planned for him, Vincenzo had long intended his first son to study then practice medicine. Age 17, Galileo was now sent to the University of Pisa in order to begin these studies, it was however at this point he first became interested in the science of mathematics.

In 1885, after eventually convincing his father to let him study what he was now focused on, mathematics, Galileo left the university before earning a degree, choosing instead to earn a living by teaching mathematics.

Galileo’s work now truly began as he started work on gravity and motion, publishing a number of papers on the subject. In 1589 he was appointed to the position, professor of mathematics at Pisa University.

Then in 1592 he moved to the University of Padua where he would teach astronomy, mechanics and geometry right up to 1610.

In 1609 the now well respected scientist heard news from the Netherlands about the invention of the telescope. In typical fashion he chooses to build his own and even improves on the original. It is with this new method of observing celestial objects in the night sky that Galileo makes perhaps his most famous discovery.

Many people know Galileo as the man who first discovered the four biggest moons of Jupiter: Europa, Io, Ganymede and Callisto. Having observed those four moons orbiting the planet Jupiter the professor quickly concluded that not everything orbited the Earth. Therefore Earth was not the centre of the universe with everything else orbiting us as many believed at the time.

Galileo’s other significant contributions to the world of astronomy included observing our moons surface to be rough and cratered instead of smooth as was believed at the time, he was also the first to discover sun spots.

His opinion that our planet in fact orbited the sun and not the other way around is called the Copernican view. This heliocentric theory was originally put forward by Nicolaus Copernicus around 1543 in his book “On the Revolutions of the Celestial Spheres” shortly before his death. Despite this seeming obvious to us nowadays, back in 17th century Italy these beliefs did not go down well.

Even though Galileo had still been a religious man his new beliefs appeared to go against many of the Churches teachings. Despite Galileo claiming the theory of heliocentrism didn’t go against certain religious passages, in 1616 the matter was taken so seriously he ended up being put on trail for heresy.

Although he was eventually acquitted of the charges, Galileo had been forbidden to teach his views ever again.

Then a number of years later in 1632 he published “Dialogue Concerning the Two Great World Systems” (Ptolemaic and Copernican), here Galileo discussed the two theories. Prior to publishing this work Pope Urban VIII had asked Galilei not to advocate heliocentrism but instead put forward arguments for and against it.

The now controversial scientist choose not to do this which then led to a second trail, in 1633 Galileo Galilei was found guilty of heresy. In 1634 the elderly and now blind in one eye Galileo returned to his home in Arcetri near Florence. There he continued his research up until his death, aged 77 on the 8th of January, 1642.

Although at that time Galileo’s reputation had been severely tarnished, further scientific research and discoveries since then have now vindicated his work and beliefs. To many, Galileo Galilei is considered the father of modern science and astronomy.