- The Italian scientist built the strongest telescope of his time and made discoveries that challenged and changed what people thought they knew
- The Church denounced his theories and placed him under house arrest, though Pope John Paul II would apologise centuries later
Galileo Galilei was born on February 15, 1564 in Pisa, Italy, to Vincenzo Galilei, a famous musician, and Giulia Ammannati, a housewife.
The eldest of six children, he went to school in a monastery and thought about becoming a monk himself.
But his father wanted him to become a doctor. Galileo started studying medicine, but changed his studies when he became fascinated with mathematics and philosophy.
The famous Galileo used to be pictured on Italian currency.
In 1585, he left the university without a degree. But he built up his reputation, and wasselected as the chair of mathematics at the University of Pisa at the age of 25.
When he was 28 years old, Galileo became a professor of mathematics at the University of Padua, where he taught geometry, mechanics and astronomy. But many of his teachings went against the beliefs of the Roman Catholic Church, which was extremely powerful at the time. The Church believed Earth was the centre of the universe, but Galileo would eventually prove otherwise.
A moving earth
Galileo soon developed the strongest telescope the world had ever seen, and would prove the Church wrong. Though he had many breakthroughs in physics, it was his observations of the sky that changed the world.
After years of gazing at the night sky with his telescope, he published a book, The Sidereal Messenger, about what he’d seen, such as moons circling Jupiter. He reached the conclusion that Earth circled the sun, and not the other way around.
Putting truth on trial
Armed with his discoveries, Galileo converted to Copernicanism, the thoughts of Polish astronomer Nicolaus Copernicus (1473-1543), who had proposed that the sun was the centre of the universe and that the Earth travelled around it.
In 1615, the Church pronounced that the Copernican theory went against its ideas, and told Galileo to treat the theory hypothetically.
But the Italian scientist was put on trial in 1633 for writing about the forbidden ideas in a way that made them seem true. He spent the rest of his life under house arrest.
This painting depicts the trial of Galileo in Rome.
Death and legacy
Galileo’s followers continued to visit the Italian scientist until his death on January 8, 1642, in a villa near Florence, Italy. He died aged 77, due to fever and heart palpitations (abnormal heartbeat).
On October 31, 1992, Pope John Paul II, the head of the Roman Catholic Church at the time, expressed regret about how past theologians had handled Galileo’s case. The pope acknowledged the Church had been wrong.
In December 2008, Pope Benedict XVI, John Paul II’s successor, praised Galileo’s contributions to astronomy during events to mark the 400th anniversary of the scientist’s telescope, and to show that faith and science could be bridged.