The Italian astronomer Galileo Galilei, one of the most innovative figures in the history of science, made groundbreaking advances that would change the accepted view of the cosmos. In 1611, he presented his first telescope, which he had created himself, to the papal court, thus ushering in a new era in astronomy. However, his relationship with the Church became strained due to discoveries and theories that challenged established dogma. With this telescope, Galileo discovered celestial bodies never before seen, such as the moons of Jupiter, the phases of Venus, and irregularities on the lunar surface, demonstrating that the heavens were not immutable as had been previously believed. But what truly ignited tension was his support for the Copernican theory, which argued that the Earth was not the center of the universe, but rather revolved around the Sun.
Galileo and his discovery of the astronomical telescope
In 1609, Galileo built his first telescope based on descriptions of an instrument used in Holland to observe distant objects. Although he did not invent the telescope, Galileo was the first to use it to observe the sky and draw scientific conclusions. This invention allowed him to make important astronomical discoveries. On January 7, 1610, Galileo observed Jupiter’s moons for the first time, contradicting the geocentric model that all celestial bodies revolved around the Earth. Four months later, he published his work. Sidereus nuncius (The Starry Messenger), where he described the moons of Jupiter and lunar craters, thus refuting the beliefs of Aristotelian astronomy.
The Church’s first warning in 1616
By 1616, the Church already viewed Galileo’s discoveries with suspicion, as they supported Copernicus’s heliocentric model, according to which the Earth and the planets revolved around the Sun. The Copernican theory directly conflicted with certain biblical interpretations, and that year Galileo was summoned to Rome to appear before the Inquisition. Although he was not condemned on this occasion, he was ordered to abandon his defense of heliocentrism. Galileo agreed not to teach this theory publicly, though he never ceased to believe in its scientific validity and continued his research privately.
The conflict reaches its climax: 1632 and the Dialogue on the two greatest systems in the world
In 1632, Galileo published his best-known work, Dialogue on the two greatest systems in the worldWritten in the form of a conversation between three characters, one defended Ptolemy’s geocentric system, another Copernicus’s heliocentric system, and a third acted as an impartial mediator. Although Galileo claimed the work was impartial, the character defending the Ptolemaic model, named Simplicius, was portrayed as inept and irrational. This book unleashed the fury of the Church, and in 1633, Galileo was summoned again before the Inquisition.
Galileo’s trial by the Inquisition
At his trial in 1633, Galileo was accused of heresy, primarily for violating the order not to defend heliocentrism. Although he was threatened with torture, he was never subjected to it. Ultimately, to avoid a harsher punishment, Galileo was forced to publicly recant his views. It is said that after his abjuration, Galileo uttered the famous phrase “Eppur si muove” (“And yet it moves”), although there is no historical evidence to support this claim. Following the trial, Galileo was sentenced to house arrest, a sentence he served at his villa in Arcetri, near Florence.
His final days and his legacy
During his last years of life, Galileo continued to write while under house arrest. Despite the blindness that affected him in his later years, he completed his work Speeches and mathematical demonstrations about two new scienceswhere he developed the foundations of modern physics. He died in 1642, but his legacy as a scientist continued to grow over time, and today he is considered one of the founders of the modern scientific method. In 1979, Pope John Paul II commissioned a review of Galileo’s trial, and in 1992 the Church officially acknowledged the errors made in his conviction. Galileo’s case has been a source of controversy for centuries, and in many ways it symbolizes the conflict between science and religion. However, over the years, both science and the Church have learned from this incident, and today the Vatican promotes science through its own Astronomical Observatory. Throughout his life, Galileo faced numerous challenges, but his perseverance and unwavering commitment to the pursuit of truth changed the course of history. Today, he is remembered as a pioneer of modern science and a key figure in the relationship between religion and science.