February 19, 1473. This is the birthday of Nicolaus Copernicus, a Renaissance astronomer and mathematician who sparked the revolution in cosmology that’s still going on today.
Copernicus was born at a time when people believed Earth lay enclosed within crystal spheres at the center of the universe. Can you picture the leap of imagination required for him to conceive of a sun-centered universe? The publication of Copernicus’ book – De revolutionibus orbium coelestium (On the Revolutions of the Celestial Spheres) – just before his death in 1543, set the stage for all of modern astronomy.
Today, people speak of his work as the Copernican Revolution.
A few years ago, if you searched on the word “Google” on Copernicus’ birthday, you’d have found an animated version of a Google Doodle celebrating a sun-centered cosmos. Google uses Google Doodles to showcase holidays, famous birthdays and so on. Not sure if they’re using this doodle this year or not. Search and see! Or see the video below, which also features the Copernicus Google Doodle. Thank you to EarthSky Facebook friend Kausor Khan in Hyderabad, India, for pointing it out to us.
By the way, Copernicus wasn’t the first to conceive of a sun-centered universe. Early Greek philosophers also spoke of it.
It was the Greek philosopher Aristotle, however, who proposed that the heavens were literally composed of 55 concentric, crystalline spheres to which the celestial objects were attached. In Aristotle’s model, Earth lay at the center of these spheres.
Thus Earth lay – fixed and enclosed – until Copernicus published his version of a heliocentric, or sun-centered, universe.
Bottom line: Nicolaus Copernicus was born on this date, February 19, 1473.
Deborah Byrd created the EarthSky radio series in 1991 and founded EarthSky.org in 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. "Being an EarthSky editor is like hosting a big global party for cool nature-lovers," she says.