A retrospective: Galileo Galilei

Galileo Galilei was born on 15th February, 1564, Pisa, Tuscany, Italy. He became a famous astronomer, physicist and philosopher who was extremely influential to modern science. At the age of six, he and his family moved to Florence where he attended a monastery school at Vallombrosa. In 1581 he moved back to Pisa to study medicine at university, but his heart wasn’t in it, and he favoured the philosophy of mathematics. This is where his studies of motion began, that would occupy him for many years.

In 1585 he left University and got a job as a teacher, and in his spare time he started experimenting with pendulums, balls and other objects to understand motion, and to devise formulas and equations. Many people including Galileo studied Greek philosophers like Aristotle, but rarely did they put their studies into practise by experimenting, and this is why he’s considered as the father of the ‘scientific method’, as he didn’t just accept that something is, or is not, he had to provide a hypothesis.

As well as trying to understand motion, he was also attempting to figure out what gravity was, and what gave an object of mass weight. He did several experiments by dropping things from the tower of Pisa, and despite the weights being different, they landed at the same time, and he needed to know why. Some of his experiments were causing anger with the locals as he was questioning things that they didn’t believe needed questioning. He moved to Padua, where attitudes were considerably more relaxed and he was free to continue his experiments.

In 1609 Galileo became aware of a Dutch invention called the telescope and it fascinated him, and at the time he was studying Copernicus’ views that the Sun was at the centre of the universe, and this was an extremely controversial view as it contradicted texts from the Bible. Galileo studied the telescope and knew that he could improve on it, and over time designed his own version of a refracting telescope so he could monitor the night sky. He soon discovered the phases of Venus, that the Moon was covered in craters and that Jupiter had a number of natural satellites that became known as the Galilean moons:

Io

Ganymede

Europa

Callisto

As well as his planetary discoveries, he found that with the magnification of his telescope what looked like a mist in space, was actually the stars in the Milky Way, and this shocked and baffled the scientific community in equal measure. Whilst being a keen astronomer, he also wrote several books on his discoveries.

In 1616 he was warned by Rome not to write about his theories, but he defied the Church and wrote about the Copernican heliocentrism theory, and he was charged with heresy by the Roman Catholic Inquisition. Heliocentric opinions were outlawed, and upon his views about tides confirming the Earth moves, he was placed under house arrest until his death on the 8th January, 1642. His legacy lives on.

“The sun, with all those planets revolving around it and dependent on it, can still ripen a bunch of grapes as if it had nothing else in the universe to do.” – Galileo Galilei