Who was Galileo Galilei?

Galileo Galilei lived in Italy during the Renaissance, a period of the awakening of new ideas in Europe. His father wanted him to be a doctor, but the rebellious Galileo got caught up in the chaos of mathematics, physics and astronomy - and the rest is history  

Written by: Ariel Kers

of: Young Galileo, issue 200 September 2020

Everyone knows that Galileo was an important scholar, physicist and astronomer, a pioneer scientist who understood in many fields, formulated mathematical laws for natural phenomena, studied the craters of the moon and the moons of Jupiter and fought stubbornly for his scientific truth. But what kind of person was he? How did his innovative world views develop? What was it like to live in Renaissance Florence and study at the University of Pisa?  

Galileo's youth

Galileo Galilei was born in the city of Pisa in Italy on February 15, 1564, the eldest son of Julia and Vincenzo Galileo. Vincenzo was a musician who contributed a lot to the development of musical theory in his time. To this day, pieces of music he composed are performed in concerts. Vincenzo was also a mathematician, so Galileo had someone to learn from to develop his original thought.

Galileo was named after his grandfather, who was a very respected man in Pisa. When he was eight years old, his family moved to Florence, the capital of the province of Tuscany, where his father made a living by selling wool. Galileo was sent to the Camaldoli monastery to study and become a priest. The monastery is located in an area called Orrezzo, in a forest at the top of the Apennine mountain range. The monks in the monastery grew a botanical garden, worked in the laboratory in the monastery and developed medicines from medicinal plants they cultivated in the garden or collected in the forest. It is said that their traditional prescriptions and concoctions are still used today in the Tuscany region.

Galileo was influenced by the long stay in the monastery and wanted to become a monk, but his father thought that his wise son should find a decent living, and what is more decent than being a doctor? The father sent the young Galileo to study medicine at the University of Pisa.

The rebellious lecturer

Medicine is certainly a respectable profession and a good living for him, but Galileo did not like studying at the university. However, what is not done to please father, who paid a handsome sum for the studies? Galileo spent four years studying medicine, and finally he got fed up. He switched to studying mathematics, where he found his true field of interest.

He studied and taught and became a professor of mathematics at the University of Pisa, later the most famous and important lecturer at this university, where many other important scholars worked. It is said that even as a lecturer he was rebellious and did not like the manners of the ceremony: he did not adhere to the formal dress required of lecturers at the University of Pisa, mocked the traditional customs, and even composed a long mocking poem in rhymes about it. For his rebelliousness he was punished many times with reprimands and fines.

Galileo the conservative

When we think of Galileo, we envision an innovative, original and rebellious scientist who does not follow the same path and breaks new ground. It is interesting to know that Galileo's views at the beginning of his career resembled those of his contemporaries. Even Galileo, one of the wisest scientists who ever lived, initially had a hard time digesting Copernicus's ideas, according to which the Earth, like the other planets, revolves around the Sun (the heliocentric view: helio - sun, centrum - center; the sun is in the center, and the earth surrounds her). Galileo wondered: Could it be that Copernicus was right? Does the earth go around the sun and not the other way around?

The earliest manuscript of Galileo that has been found was written around the time he left the University of Pisa, when he was 21 years old. The manuscript does not yet show his original and revolutionary thought, he strongly rejects the ideas of Copernicus, and does not dispute the accepted and ancient principles of Aristotle's physics, formulated at a time Many before the scientific revolution and most of them were wrong. In Galileo's essay "De Moto", written in Pisa, he also agreed that the Earth is the center of the universe!

I wonder what made Galileo change his mind. These were probably the scientific proofs he collected - it is possible that when he examined the facts to formulate a theory, he realized that his predecessors were wrong and Copernicus was really right. To Galileo's credit, he was open enough to change his mind and base himself on new facts that became known to him.  

Of course, we have almost no records of Galileo's daily life as a young man. One can only imagine him wandering the streets of the city of Florence or among the buildings of the University of Pisa, absorbed in thoughts about the movement of bodies and the earth orbiting the sun, planning scientific experiments or sitting with friends in a restaurant on a side street in the city and joking with them about the haughty lecturers at the university.

Science during the Renaissance

Galileo and his scientific work were a very important part of the Renaissance in Europe. The Renaissance period (Renaissance - rebirth) is a general name for the emergence of new ideas in European culture. Revolutionary ideas that influenced commerce, economics, art, architecture, science, philosophy and even religion. Florence, the city where Galileo lived, was a very important cultural, economic and scientific center in those days.

Today's Florence is a tourist city - everyone wants to visit the beautiful city, which has extraordinary art treasures, wonderful architecture and heritage. In Galileo's time, everyone wanted to get to Florence because it was a vibrant center of activity, art, commerce and revolutionary new ideas. The Renaissance heralded the beginning of the modern era in Western culture.

In Galileo's time there was no clear distinction between science and art. Important artists such as Leonardo da Vinci were also scientists and inventors. But the most important development of the Renaissance was apparently the arrival of the scientific method.

Galileo and his contemporaries invented a revolutionary way of learning about the world. They claimed that all natural phenomena can be explained through physics. With the help of mathematics and the use of empirical evidence (that is, results and proofs obtained through repeated experiments that can be refuted), one can better understand the world. This scientific method seems to us today an obvious and everyday matter, but in Galileo's time it was an innovation that completely changed fields such as astronomy, physics, biology and anatomy, and even the attitude to faith and religion.

The belief that the earth is in the center

The astronomy of the late Middle Ages in Europe was based on the model of an ancient Greek scholar named Ptolemy (Ptolemy), who claimed that the Earth was at the center of the universe and all the heavenly bodies revolved around it. You can't blame Ptolemy - this is how it looks to people living on Earth: the sun rises in the morning, moves across the sky and sets in the evening, and at night the stars make the same rotation. Why not believe what we see?

But the astronomers of the Renaissance proved that Ptolemy was wrong and that his theory, which lasted for about 1,500 years, was wrong. It turned out that the earth does not stand still, but rotates every day on an imaginary axis, so we see that the sun rises in the morning in the east and sets in the west.

On top of that, it turned out that the earth orbits the sun, which is, among other things, the reason for the change in the seasons and the angle of the sun in the sky. A comprehensive change of perception was needed. If ordinary people and even learned scientists find it very difficult to change their minds, they should be shown the facts. For this, Galileo realized, one needs to study nature, conduct experiments, prove the claims and then present them to the people.

Galileo makes science accessible

To prove the facts that Galileo discovered, he used a telescope. Ptolemy did not have a telescope, and it is possible that if he had such a device he would have formulated a more accurate theory about the nature of the universe. In 1609, Galileo built his first telescope - an excellent telescope with much better sharpness and magnification than those available at the time.

It takes a long time to build a telescope, especially with the technologies of the Renaissance, but Galileo was a very hardworking man. He built more than 100 different telescopes! The best of them had a magnification of 30 times, much more than any other telescope invented up to that time. Using the telescope he developed, Galileo was able to see the four large moons of the planet Jupiter, and these were named after him - the Galileo moons.

Galileo was not satisfied with making discoveries, it was important for him to present them to people. He allowed them to look through his telescope at the moons of Jupiter or the craters of the moon, that is, he provided them with the facts and made scientific discoveries accessible to them.

On top of that, Galileo wrote his important book "On the Two Methods of the World" in the language of the people (Italian), not in the language of the scholars (Latin). It can be said that he was the father of popular science. This was his way of explaining scientific ideas to the masses who did not know Latin and Greek, the languages ​​of science.

For example: What do you think of when you hear the words "Felis Sylvestris Catos"? Maybe it sounds like a Harry Potter magic spell to you, but I'm not sure you've thought about your cat - because you don't know Latin! This is the Latin name of the domestic cat.

To this day, when scientists want to explain their discoveries to people interested in science, they write popular science books in relatively simple language that even non-scientists can understand. In fact, the issues of Young Galileo that you read are full of articles in the popular science genre, thus we are continuing the path of Galileo Galilei!

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More of the topic in Hayadan:

• 400 years since the first observation through a telescope by Galileo Galilei
• Did Galileo Galilei ignore observations?
• Debate between the church and scientists in Italy - is it permissible to take DNA samples from Galileo's body