Imagine a world where the Earth is immobile at the centre of the Universe, a world where all the heavenly bodies – including the Sun – turn around our planet. This was how most people saw the Universe until the end of the Middle Ages.
Four hundred and seventy-five years ago the Earth lost its privileged position. That year, Nicolaus Copernicus – a Polish astronomer, physician and canon – published, just before his death, a book that would transform our way of seeing the Universe.
Who was Copernicus?
Born in 1473, Copernicus was raised by his uncle, who took pains to offer him a quality education. During his studies he was introduced to various disciplines, including mathematics, medicine and Greek. But the area that easily excited him the most was astronomy, where he would carve out an enviable reputation for himself.
Back in Poland after his schooling, Copernicus was appointed canon at his uncle’s diocese, where he helped out with administrative tasks. He would hold that position all his life.
His knowledge of Greek allowed him to delve into the work of ancient authors such as Aristarchus of Samos, who had postulated in the third century B.C.E. that the Earth turned around the Sun. Copernicus in the early 1510s wrote a short treatise, the Commentariolus, where he set out his ideas on a heliocentric system. In that system it was the Sun that was at the centre of the Universe. The Earth was a planet like the others, spinning around and orbiting the Sun. That text would not be published until the 19th century.
Revolutions of the celestial spheres
It was in 1530 that Copernicus finished his major work, known as On the Revolutions of the Celestial Spheres. Nevertheless, Copernicus refused to publish the text immediately: he was a meticulous, perfectionist astronomer, and wanted to be sure of the accuracy of all his calculations before releasing them.
It was finally in 1543, the year of his death, that the work would be printed and distributed in Europe. Legend has it that Copernicus got to hold a copy of his book just before his death, on May 24, 1543.
The text was well received at the beginning. However, the development of ideas about heliocentrism by followers like Galileo, Bruno and Kepler drew the anger of the Church to Copernicus’s text, and the book was placed on its List of Prohibited Books in 1616.
The Copernican revolution
Before Copernicus, a few philosophers had advanced the hypothesis that the Sun was at the centre of the solar system, but none of them had succeeded in really establishing the concept. Copernicus would be the first to develop a theory sufficiently elaborated as to comprise a complete system. This would trigger a major scientific revolution around the world: the Copernican revolution.