Among the influential figures that shaped the scientific revolution during the Renaissance, the figure of Galileo Galilei stands out (Rubio, n.d.). This Italian mathematician, physicist, and scientist made a significant contribution to science and changed the paradigm regarding the position of the Earth in the Universe (Rubio, n.d.). As expressed by Cajal (n.d.), due to all the aforementioned and his tireless work in the development of the scientific revolution and the scientific method, he is considered the father of modern science.
Biography
Galileo Galilei was born on February 15, 1564, in Tuscany, more precisely in the city of Pisa (Cajal, n.d.). His parents, Vincenzo Galilei, a mathematician and musician from Florence, and Giulia Ammannati di Pescia, from a family of artisans, took charge of his education until he turned ten (Cajal, n.d.; Rubio, n.d.). However, the family had to move to Florence, and unable to care for Galileo, they delegated his education to a neighbor named Jacobo Borhini, a man of deep religious faith (Rubio, n.d.; Cajal, n.d.). According to Cajal (n.d.), it was precisely Borhini who arranged for Galileo's entry into the convent of Santa Maria Vallombrosa in Florence.
The news was not well-received by Galileo's father, who was not particularly religious (Rubio, n.d.). Therefore, he decided to withdraw his son from the monastery, and in 1581, enrolled him in the University of Pisa to study medicine (Rubio, n.d.). However, four years later, he left the university without a degree but with a solid understanding of Aristotle (Fernandez & Tamaro, 2004). This experience allowed him to discover his true vocation: physics (Farias, 2021). At the age of twenty, he began conducting experiments in mechanics, catching the attention of several professors (Rubio, n.d.). His self-taught knowledge in mathematics was so extensive that at the age of twenty-five, he secured a position as a mathematics instructor at the University of Pisa. According to Rubio (n.d.), in 1592, he moved to Padua and began working as a professor at the university, teaching subjects such as astronomy, mechanics, and geometry.
During the eighteen years he spent in Padua, until his departure in 1610, he made most of his discoveries (Rubio, n.d.). Despite the omnipresent threat of the Spanish Inquisition in Europe, Padua was a metropolis distant from religious repression (Cajal, n.d.; Rubio, n.d.). This allowed him to conduct his experiments in complete tranquility, without feeling threatened by this oppressive institution (Cajal, n.d.; Rubio, n.d.). During his time in Padua, he formulated the law describing the accelerated motion of objects, observed the stars, verified the operation of the water pump, built the precursor to the thermometer, and studied magnetism (Rubio, n.d.). In fact, according to Rubio (n.d.), a milestone in his professional career occurred there in 1609 when he perfected the telescope and could observe the night sky in a way that no one had seen before, acquiring the knowledge that allowed him to challenge the geocentric theory.
Through his observations, he concluded that the Sun, and not the Earth, is the center of the galaxy (Rubio, n.d.). This conclusion was based on the scientific method, not beliefs or assumptions. Simultaneously, by recognizing that the Earth was not the center of the Universe, he also acknowledged that the planet was in motion. With this, he confirmed the premise formulated years earlier by Nicolaus Copernicus, who claimed that the Earth was not the center of everything. Additionally, according to Rubio (n.d.), his telescope observations helped him demonstrate that celestial bodies did not revolve around the Earth, but rather planets orbited the Sun.
In 1611, he embarked on a journey to Rome with the purpose of presenting his discoveries (Rubio, n.d.). His opposition to the model that had been accepted in Renaissance society until then attracted the attention of several researchers, as well as the disapproval of most ecclesiastical authorities. Asserting that the Earth was not the center of everything was an attack on one of the fundamental pillars of the Church and Christian religion. The censorship was immediate, and in 1616, the Spanish Inquisition prohibited him from defending, disseminating, teaching, and promoting the heliocentric theory. Despite the repression against his science, he continued researching and developing his studies, as well as publishing works. To circumvent censorship, instead of "defending" heliocentrism, he presented this idea as a hypothesis, which technically did not defend it but described it. According to Rubio (n.d.), this was a clever and subtle nuance that allowed him to continue publishing for some time.
Over the decades, perhaps a bit tired of presenting a scientific fact as a mere hypothesis, he openly defended the heliocentric theory in 1632 in a work titled "Dialogues on the Two Chief World Systems" (Rubio, n.d.). This time, the Spanish Inquisition quickly realized and began investigating the situation as heresy. One year later, at the age of sixty-nine, he was accused in Rome of violating the 1616 censorship, treating it as an infringement and threatening him with torture. He was ultimately forced to retract the heliocentric theory and his findings. After rejecting his ideas, his sentence was reduced to house arrest, which, though unjust, was preferable to being tortured by the more sophisticated inquisitorial means. According to Rubio (n.d.), legend has it that upon leaving the court, he muttered "Eppur si muove," alluding to the fact that the Earth would continue moving as he had observed.
House arrest lasted from 1633 to 1638, during which he became blind (Rubio, n.d.). Realizing that Galileo had become blind, the Spanish Inquisition showed some Christian mercy and allowed him to move to a residence near the ocean. There, he continued working with several of his students, including Evangelista Torricelli and Vincenzo Viviani (Cajal, n.d.). Finally, he died on January 8, 1642, at the age of seventy-seven (Rubio, n.d.). According to Rubio (n.d.), he died rejected by his followers, who did not forgive him for yielding to inquisitorial pressure, and was seen as a heretic by the Holy Church, an institution that acknowledged its mistake in condemning him in 1992.
Scientific Method
Galileo Galilei is recognized for introducing an innovative approach to research, supported by the scientific method (Cajal, n.d.). The development and implementation of the scientific method were crucial for the advancement of true science (Farias, 2021). For Galilei, hypotheses were essential and would be accepted or rejected based on empirical observations. However, according to Farias (2021), what should be avoided was adopting Church truths and absolutizing them without subjecting them to the scientific method.
Heliocentric Theory
Galileo Galilei is acknowledged for his heliocentric theory, which led him to face the Inquisition's tribunals (Rubio, n.d.). This contribution is considered a crucial moment in the separation between Church and science. Through his observations, he strengthened the Copernican theory, asserting that the Earth revolves around the Sun and not the other way around (Rubio, n.d.). This heliocentric theory was one of the most significant scientific revolutions in the history of science, changing the previous paradigm and making people realize they were not the center of the cosmos but part of a celestial body, among others, revolving around a star. However, it's important to note that he was mistaken in thinking the Sun was the center of the Galaxy (Rubio, n.d.). Indeed, according to Rubio (n.d.), the Sun is the heart of the Solar System, but today it's known that the Sun orbits around larger celestial objects, and its position in the Milky Way is rather peripheral.
Telescope Improvement
Galileo Galilei is often incorrectly credited with inventing the telescope (Redd, 2017). He did not invent the telescope from scratch since similar devices with lenses that magnified objects already existed (Rubio, n.d.). However, according to Rubio (n.d.), it was Galileo Galilei's insight that made it possible to optimize these devices, giving rise to the first telescope as known today, an instrument capable of magnifying celestial bodies up to 30 times.
Observations of the Sky
Thanks to the development of his telescope, Galileo Galilei is recognized for having observed the sky in a way that no one had achieved before (Rubio, n.d.). He pioneered the observation of lunar craters, sunspots, the four largest satellites of Jupiter, the phases of Venus, and other astronomical phenomena and bodies (Rubio, n.d.). Finally, in line with Cajal (n.d.), the telescope revealed that the cosmos contained a much greater number of stars than those visible to the naked eye.
Laws of Motion
Galileo Galilei is acknowledged as an inspiration and precursor to the laws of motion, later formulated by the English physicist and mathematician Isaac Newton (Rubio, n.d.). Galilei concluded that all bodies, regardless of their size or mass, accelerate at the same rate (Cajal, n.d.). Similarly, he developed the concept of motion in terms of velocity by implementing inclined planes. Additionally, he formulated the concept of force as the cause of motion and established that the natural state of an object is either at rest or in uniform motion. For example, objects always have a velocity, and sometimes this velocity has a magnitude of zero, equivalent to being at rest. Finally, according to Cajal (n.d.), Galilei postulated that objects resist changes in motion, a concept known as inertia.
Development of Mathematics
During his adolescence, Galileo Galilei had a deep love for mathematics and believed that they could describe the laws of how the world worked (Rubio, n.d.). Mathematics were a fundamental tool for understanding nature because the world was governed by numbers. Therefore, according to Rubio (n.d.), he was one of the first scientists to base his research on mathematics, using numbers as tools to analyze and understand natural phenomena.
Precursor of the Thermometer
Galileo Galilei is credited with the creation of the precursor to the thermometer, known as the thermoscope (Rubio, n.d.). This device consisted of a tube ending in a large sphere, filled with water or alcohol (Aguirre, 2019). It used hot air to move the water through the tube, marked with a range of temperatures. According to Aguirre (2019), this discovery was the basis for the development of modern thermometers, making it a highly significant finding.
References
Cajal, A. (s.f.). Galileo Galilei: biografía, aportes y obras. Lifeder. Recuperado 16 de noviembre de 2021, de https://www.lifeder.com/aportaciones-galileo-galilei/
Farias, I. (2021). Principales aportaciones de Galileo Galilei a la ciencia. Psicocode. Recuperado 16 de noviembre de 2021, de https://psicocode.com/ciencia/aportaciones-galileo-galilei/
Fernández, T., & Tamaro, E. (2004). Galileo Galilei. Biografías y Vidas. Recuperado 16 de noviembre de 2021, de https://www.biografiasyvidas.com/monografia/galileo/
Redd, N. T. (2017). Galileo Galilei: Biography, inventions & other facts. Space.Com. Recuperado 17 de noviembre de 2021, de https://www.space.com/15589-galileo-galilei.html
Rubio, N. M. (s. f.). Galileo Galilei: biografía y aportes a la ciencia de este investigador. Psicología y Mente. Recuperado 16 de noviembre de 2021, de https://psicologiaymente.com/biografias/galileo-galilei
