The figure of Galileo Galilei has never gone unnoticed. This great Renaissance thinker and scientist has contributed, with his theories and inventions, to today’s view of the universe, laying the foundations of modern astronomy.

His life was very prolific and he never stopped designing new devices that allowed him to get closer to the authentic nature of the world he lived in. However, it was also for this reason that he had more than one encounter with the Catholic Church.

There are many contributions of Galileo Galilei , but the main ones, widely known, are the ones we are going to see below.

Who was Galileo Galilei?

Galileo Galilei was an Italian mathematician, astronomer, physicist and inventor born in Pisa in 1564. He was one of the great minds of the Renaissance , besides being known for having dared to challenge the court of the Inquisition and the entire Catholic Church by assuring that some ideas that had been well established in the West for centuries were no longer valid.

Although he had to retract many of his discoveries to save his life, living his last years in the shadows and in shame, being considered a liar, today his contributions to science are widely recognized. Its importance has been such that in 1992 the Catholic Church recognized his error , publicly asking for forgiveness of Galilei and rehabilitating him, after 359 years of condemnation.

Main contributions of Galileo Galilei

Galileo Galilei’s work is very extensive, like that of any great Renaissance figure of the stature of Leonardo da Vinci or Michelangelo. However, below we will see his main contributions and inventions, which have helped to shape science in the way it has come down to us today.

1. Microscope

Galileo Galilei is well known for having contributed enormously to the understanding of nature through something as simple as lenses. He made many lenses of all kinds of sizes and curvatures, which allowed him to design a kind of microscope.

Although this instrument was still very rudimentary, called ochiollino, and was not technically a microscope, it allowed him to see objects of reduced size .

However, it can be said that the authorship of the first authentic microscope has been widely discussed, with Zacharias Janssen, Robert Hooke and Anton van Leeuwenhoek among the men who made improvements to this apparatus.

2. Telescope upgrade

Galilei did not invent the telescope but he did manage to make great improvements to this instrument, allowing it to have a better observation of the sidereal phenomena.

The first telescope was known in 1609, but Galilei improved it considerably only a year later , making it up to thirty times better. He managed to manufacture them almost in a chain, having made up to fifty more in a very short time.

3. Geometric compass

This is one of the first inventions of this genius, besides being one of the instruments that allowed him to acquire some fame and, most importantly, money. In addition to selling it, Galileo Galilei was in business teaching how to use it.

Thanks to the geometric compass, it was possible to make geometrical figures more easily and accurately than in the past, and complex mathematical calculations could be made with it. It had a warlike purpose, allowing to calculate the trajectory of the cannon balls.

4. Pendulum

Galileo Galilei studied the movement of the pendulum and its oscillations. He got the idea from observing the movement of the bells of the Cathedral of Pisa, which were swung by the wind.

So, in 1583 he studied the pendulum. He realized that the weight of the ball or object on the pendulum did not matter, what mattered was the length of the cord that held it .

5. Scientific Revolution

His attitude towards the ecclesiastical powers of the time is well known. Although Galileo Galilei had been brought up in the Catholic faith, this did not prevent him from showing his theories and discoveries, which were against the Catholic Church.

At a time when the Earth was thought to be the centre of the Universe, he refuted it , saying that our planet was just another star revolving around the Sun.

This led to his arrest and he was close to being burned at the stake. He had to recant in order to avoid death; however, with his opposition to the beliefs taken for granted, he managed to start a real scientific revolution.

Many great thinkers of the time sided with Galilei, and deepened their theories and hypotheses , shaping science and contributing to it being conceived as we see it today.

6. Contributions to Copernican theory

In relation to the previous point, Galileo Galilei studied the Copernican nicolas’ theories on the movement of the stars , refuting the religious belief that the Earth was the centre of the whole Universe.

Thanks to the improvements of the telescope carried out by this Italian scientist, it was possible to demonstrate with empirical evidence the real movement of the planets.

7. Scientific method

Galileo Galilei is considered the father of the scientific method , which served him to clash with the preconceived beliefs and a thought pulling towards the conservatism characteristic of Renaissance Catholicism.

He tried to be as objective as possible, letting himself be guided by mathematics and rigorous observation of natural phenomena.

8. Law of motion

The first law of motion, raised later by Isaac Newton , was the subject of study by Galileo Galilei.

Through his research, the Italian scientist understood that the mass of the object in the vacuum did not matter, seeing the movement as basically the combination of acceleration and speed of the object itself.

The movement was carried out thanks to the application of a force , which made the object move from a point A to a point B in a certain period of time. If no force was applied to the system, it was at rest.

9. Law of the Fall

Following on from his other studies in the field of physics, Galileo Galilei studied how forces can be responsible for the acceleration of an object, allowing him to understand the forces of gravity.

When an object falls, it accelerates progressively as it falls . This acceleration is due to the force of gravity.

10. Satellites of Jupiter

In 1610 Galileo Galilei discovered the moons of Jupiter . He saw how four luminous points were near this planet, initially thinking they were stars.

However, later, seeing how they moved in the night sky, he concluded that they had to be satellites of Jupiter: Io, Europa, Ganymede and Callisto .

11. Sunspots

Surprising as it may seem, in the Renaissance, many people dared to study the spots of the sun. It must be said that, although Galileo was not the one who made the first discovery, he did know how to take advantage of the work of others.

12. Studies of the Moon

With his studies of the Moon, Galileo Galilei made great advances in the field of astronomy, studying both the movement of the satellite and the time it took for it to be fully lit and fully dark.

He also saw how the Moon had a similar geography to the Earth, with its craters, mountains and valleys.

Bibliographic references:

  • Artigas, M. and Shea, W. R. (2009). The Galileo case. Myth and reality. Encounter.
  • Cheraqui, Y. (1990). I, Galileo, Florentine mathematician and philosopher who, in front of everyone, had the audacity to face the truth of the firmament. Madrid: Anaya.