
Happy 550th birthday, Nicolaus Copernicus!
Renaissance astronomer and mathematician Nicolaus Copernicus was born in Torun, Poland, 550 years ago today. At a time when deeply entrenched beliefs placed the Earth at the center of the universe – nested within crystal spheres – he proposed the revolutionary idea that Earth revolves around the sun. Can you picture the leap of imagination required for him to conceive of a sun-centered universe?
Copernicus’ famous book – “De revolutionibus orbium coelestium” (On the Revolutions of the Celestial Spheres) – was published just before his death in 1543. It set the stage for all of modern astronomy.
Today, people speak of his work as the Copernican Revolution.

Ancient Greek views of the universe
Copernicus wasn’t the first to conceive of a sun-centered universe. Early Greek and Mesopotamian philosophers also spoke of it.
It was the Greek philosopher Aristotle, however, who proposed that the heavens comprised 55 concentric, crystalline spheres. He said that celestial objects attached to these spheres.
In Aristotle’s model, Earth lay at the center of these spheres.

Nicolaus Copernicus broke the ‘crystal spheres’
So, Earth lay – fixed and enclosed – until Copernicus published his version of a heliocentric, or sun-centered, universe. Copernicus’s ideas and ground-shaking book moved the Earth and replaced it with the sun.
Read more: Copernicus’ revolution and Galileo’s vision, in pictures.

Bottom line: Today is the 550th birthday of Nicolaus Copernicus, who removed Earth from the center of the universe and set off a revolution.