The Copernican Revolution – Thomas Kuhn


“To describe the innovation initiated by Copernicus as the simple interchange of the position of the earth and sun is to make a molehill out of a promontory in the development of human thought. If Copernicus’ proposal had had no consequences outside astronomy, it would have been neither so long delayer nor so strenuously resisted.” —Thomas Kuhn, in The Copernican Revolution

One of the pivotal moments in science —or should I say, the pivotal moment in science— gives us great clues into understanding in more depth the pursuit of truth humanity long-ago embarked in. How did it happen? Why did it happen? Why Copernicus?

Before adopting the Copernican cosmology, humanity was very immersed in Aristotelian thought. Aristotle, being the great mind and philosopher that he was, had devised his theories in a way that everything from physics and astronomy to the meaning of life and theology were deeply intertwined, and the concept that the earth stood still at the center of the universe was fundamental.

“Man does not exist for long without inventing a cosmology, because a cosmology can provide him with a world-view which permeates and gives meaning to his every action, practical and spiritual” —Thomas Kuhn, in The Copernican Revolution

“We’re all to a certain extent prisoners of the mind-set of our culture and time in ways so inherently part of us that none of us can discern exactly how we and our science are influenced.” —Kitty Ferguson, in Fire in the Equations

However, from the time of Aristotle (4th Century BC) to the time of Copernicus (16th Century) a great deal of things changed. For instance, during the middle ages the church when through a period of obscuring science, and it wasn’t until much later that they were deemed pro-scientific. Another example is the usefulness of the knowing of astronomy, during Aristotle’s time understanding the skies was not particularly useful, but then with the invention of calendars and the incorporation of sky-related devices to the mainstream public, understanding the skies was a useful tool.


So it was when Copernicus, trying to simplify Ptolemy’s monstrously complex and very flawed system of cosmology, came to the realization that a system where to sun stood still at the center was much more beautiful. What is impressive is that De Revolutionibus Orbium Coelestium, Copernicus’ masterpiece, was not a revolutionary text under any measure, it was not an improvement over Ptolemy’s system in the sense that it was equally flawed, but what made all the difference were two things: that it was much more beautiful, and that the historical context was ready for a paradigm shift.

Beauty and harmony seem a strange basis under which to argue, but time and time again, science has been proved to fall upon their enchantment. The Copernican Revolution was due then, not to pragmatic motivations, but aesthetic. Scientists preferring his model over Ptolemy’s was a matter of taste purely, but so many quickly acquired it that it was not long until the new sun-centered model was heavily worked-on and much improved.

“At this latitude I’m spinning 836 miles an hour round the earth’s axis; I often fancy I feel my sweeping fall as a breakneck arc like the dive of dolphins, and the hollow rushing of wind raises hair on my neck and the side of my face. In orbit around the sun I’m moving 64,800 miles an hour. The solar system as a whole, like a merry-go-round un- hinged, spins, bobs, and blinks at the speed of 43,200 miles an hour along a course set east of Hercules.” —Annie Dillard, from Pilgrim at Tinker Creek