My Mind Is Copernican, but My Heart Is Ptolemaic: Perception Is Reality

By Gene Wilburn

1660 or 1708 by Pieter

“The Sun Also Rises” — Ecclesiastes 1:5

The Ptolemaic System

For over a millennium the science of astronomy subscribed to the Ptolemaic System, formulated by the Greek philosopher and astronomer Claudius Ptolemy of Alexandria around 150 CE. It described a cosmos with the earth as the centre of the universe while the sun, moon, stars, and planets (and the Zodiac) revolved around it, in perfect circles. We now call this the geocentric view of the heavens.

We shouldn’t dismiss Ptolemy and subsequent astronomers out of hand, for they were excellent observers and recorders of the night sky which, in their time, wasn’t obscured by city lights. Their observations were as accurate as they could make them without telescopes. What they could see with their naked eyes was their reality.

To account for the apparent retrograde motion of the planets, they developed a set of complex, but circular, epicycles to explain these motions.

The Ptolemaic view of the heavens held sway for the next 1300 years. It had staying power, and, moreover, it was also accepted and approved by the early and medieval Church.

Near the end of the Middle Ages when new learning started spreading across Europe in the Renaissance, a new theory turned the cosmos upside down. The Polish astronomer, Nicolaus Copernicus, published De revolutionibus orbium coelestium in 1543. To say its publication caused an uproar is an understatement. It totally flipped our understanding of the cosmos.

The Copernican Revolution

What Copernicus brilliantly proposed, using only his naked eyes, was that the sun was the centre of our solar system, and that all the planets, including earth, circled around the sun. The Church didn’t much like this, nor did many of the astronomers of the time, but the Copernican system prevailed because it fit better with later observations of the night sky, after the invention of the telescope.

The Copernican Revolution shifted us from a geocentric to a heliocentric view of our solar system. As an existential side effect, it displaced mankind from the centre of the cosmos.

But as successful as the Copernican system was, it still had a few scientific rough edges and it, too, used the concept of epicycles to explain some of the retrograde movement of the planets.

English astronomer and mathematician Edmund Halley, bothered by these discrepancies, coaxed Isaac Newton to publish his ideas and his newly invented mathematics to assist with refining the Copernican model. This resulted in Philosophiæ Naturalis Principia Mathematica, 1687, in which Newton’s laws of motion and law of universal gravitation were presented, along with the mathematical framework of early calculus.

Finally the problematic epicycles were eliminated from the Copernican view, based on Newton’s physical forces and the ability to calculate orbits that turned out to be ellipses rather than perfect circles.

The universe was still relatively small in Newton’s time. It took us until the 1920s to realize that many of the nebulae we could see with new, more powerful telescopes were actually galaxies, like our own Milky Way galaxy — not only that, but that there were a large number of them. Through red shift/blue shift spectroscopic analysis, it could also be seen that most of them were receding away from us.

As telescopes became yet more powerful, it became apparent that the number of galaxies in the cosmos numbered in the millions, then billions, and maybe even trillions, and that they were, for the most part, all expanding away from each other.

If they were all expanding, the question arose: “What was their starting point?” This led, through much research and debate, to the Big Bang Theory of the universe, which, by scientific consensus, happened about 13.7 billion years ago. And with better dating methods, it appeared that our earth was formed about 4.5 billion years ago. Most recently, images and measurements from the JWT (James Webb Telescope) space observatory provide a hint that the Big Bang might have even happened further back in time than we currently think, but that is still up for debate.

This is heady stuff, and as a science lover from early childhood I bask in the wonder of it all. But there is one problem: Despite its scientific inaccuracy, I still live Ptolemaically.

Perception is Reality

For most of us, the day starts at sunrise and ends at sunset. Few of us think, or say, “what a beautiful rotation of the earth this evening” instead of “what a beautiful sunset.” Likewise, our perception is that the moon rises and sets, and the stars (including the bright planets) circle overhead during the night. This has been mankind’s perception of reality since probably before we descended from the trees and started living on the savannas.

We may be an insignificant speck in the universe, but most of our perceptions and goals are mundane in the etymological sense of the word: “of the earth.” We don’t wonder about being a speck in the cosmos nearly as much as we wonder who will be the next U.S. President, and if devastating local world conflicts will ever be resolved. In other words, our main focus is on “us” and “now” and “earth.”

As a species we have tried out, and endured, many different ways of organizing ourselves into social units that we call, variously, tribes, counties, cities, countries, coalitions of countries — the building blocks of “civilization.”

On a personal level, once we get beyond the lower levels of Maslow’s Hierarchy of Needs (Maslow’s Pyramid), and have enough food, shelter, and the absence of immediate threats, we begin to concentrate on personal relationships, education, careers, raising families, and pursuing any number of entertainment, academic, craft, or artistic pursuits. This is the reality most of us live by, from sunrise to sunset, and on moonlit nights.

As more recent neuroscience explains: It’s complex, but the brain is constantly generating predictions about the world, and our perceptions are influenced by our unique expectations and internal narratives. While our perceptions play a significant role in shaping our reality, they are not a perfect reflection of the objective world.

We perceive see the night sky as Ptolemaic. Although we might know that sunsets are misnamed, it’s a perception and a bias that most of us happily live with. Although I love the astronomical accuracy of a Copernican system, I perceive sunrises and sunsets as Ptolemaic.

I wouldn’t have it any other way. As wonderful as science is, it’s a poor poet. And as the poet e.e. cummings wrote: “I’d rather learn from one bird how to sing than teach ten thousand stars how not to dance.”