The Google Doodle - the sylised Google logo - on Google's homepage, honouring mathematician and astronomer Nicolaus Copernicus
To mark the 540th birth date of Polish Renaissance mathematician and astronomer Nicolaus Copernicus, Google has created an animated doodle on its homepage depicting the solar system as described in his seminal work, De Revolutionibus Orbium Coelestium (On the Revolutions of the Celestial Spheres).
The theories presented in this book turned astronomy on its head in the 16th century. Previously, it was believed that the Earth was the centre of the universe and that other celestial bodies, including the sun, orbited our stationary planet. This idea of geocentrism was first established by the Greek philosophers Plato and Aristotle back in the 4th century BC but it was Hellenistic astronomer Claudius Ptolemaeus that refined what became a widely accepted theory from the 2nd century onwards.
That was until, of course, De Revolutionibus Orbium Coelestium, in which Copernicus described the universe in mathematical rather than Aristotelian terms and proposed a heliocentric model wherein the sun was at the centre, orbited by Earth and all other planets.
Google’s animated doodle illustrates this heliocentric model showing the known planets of Copernicus’ time – Mercury, Venus, Earth (and its moon), Mars, Jupiter and Saturn (without its rings, which weren’t first observed until much later by Galileo Galilei).
Copernicus was born on 19 February 1473 in what was then Royal Prussia in the Kingdom of Poland. De Revolutionibus Orbium Coelestium was published just before his death at age 70 in 1543. In fact, it is said the first printed copy of the book was handed to him on his death bed.
Copernicus first began working on his heliocentric model in the early 16th century and had produced a first draft of his theories by around 1514. However, fearing incomprehension and condemnation, he was reluctant to publish them until later in life.
Though the book wasn’t banned outright, it was placed on the Catholic Church’s Index of Forbidden Books in 1616 and apparently its availability was limited only to qualified scholars by special request. Nevertheless, the heliocentric model sparked the Copernican Revolution and, over the years that followed, other prominent astronomers across the world contributed to the theory, including Galileo Galilei, and the revolution was arguably completed in 1687 when physicist Isaac Newton provided a consistent physical explanation that showed that the planets are kept in their orbits by the force of gravity.
In turn, the Copernican Revolution is considered one of the starting points of the 16th-century Scientific Revolution and the dawn of modern science.
