2009-05-19 00:18:26
Everything revolves around us, it’s obvious, the Sun moves from East to West every day and, like it, most of the stars do, except -something worth mentioning- the Polar star, which persists in remaining immobile . There is nothing special about that, the sky is a huge sphere that revolves around the Earth and the Polaris is right on the axis. What is clear is that the Universe is spherical and we, who are so important, are in the center. This is how those who lived in ancient times thought, including great Greek sages, such as Parmenides, Plato or Aristotle.
These observations gave birth to a new science, Astronomy. The most observant discovered that not all the stars move equally in the sky. The Moon revolves around us following a rhythm different from that of the fixed stars, the Sun does its own and a series of “wandering stars” (that means in Greek “esters for the planet“, hence the name “planets”) rotate following strange movements that come and go across the sky, as if their spheres stopped at a given moment, reversed, and came back again.
The Universe seemed to work that easily, but when astronomers began to design a model that would allow them to predict eclipses, the phases of the moon, the movement of the planets or the appearance of stars on the horizon, things got complicated. . The Greek sage Eudoxus, a student of Plato, needed 27 spheres of different radii to describe the movements of the sky. Some semi-transparent spheres that moved at different rates pulling the Sun, the Moon and the planets. Aristotle perfected the model by adding more spheres, no less than 55, and he did it with such mastery and beauty that he managed to convince the world for many centuries, despite being wrong.
The model was adjusted by Ptolemy, in the 2nd century AD. He proposed such a number of spheres, one inside the other, eccentric, large, small, that the model lost the symmetry and aesthetics of Aristotle but, more or less, gave results to the time to make predictions. That “more or less” allowed the survival of the system, but it was so complex that some openly protested. They say that King Alfonso X the Wise, upon being informed of the Ptolemaic model, said: “if this is really how God has built the universe, I could have advised him better”.
In every society there is a “black sheep” and in Greek society it was a mathematical genius named Aristarchus of Samos. When he was young, he dared to say that the Sun was bigger than the Earth, a dangerous thing to say, because the great sage Anaxagoras had been banished for much less, suggesting that the Sun was as big as the Peloponnese. The fact is that in Aristarchus’s head the idea that something much larger than the Earth was forced to revolve around it did not fit, it was as if a shot putter could easily throw a body a hundred times heavier than himself. With these premises, against the current, one thousand seven hundred years before Copernicus, Aristarchus elaborated a system of the Universe that displaced the Earth from its position and placed the Sun in the center of the Universe. Unfortunately the book in which he developed his theory has been lost and we only know of his existence thanks to the comments of Archimedes and some writers like Plutarch.
The history of science tiptoes through the dark centuries of the Middle Ages and shines again with the arrival of the Renaissance. Looking back to the great thinkers of the past, and the invention of the printing press, which put long-forgotten works into the hands of many, sparked an unprecedented cultural revolution. It is said that Nicolaus Copernicus looked more at the books than at the stars. This was how he was able to check Ptolemy’s mistakes and, possibly, he heard of Aristarchus’s ideas. His great talent allowed him to develop a new vision of the Cosmos with the Sun at the center, the heliocentric theory, a revolution that forever dethroned the human being from the center of the Universe.
We invite you to listen to the biography of Nicolás Copernicus. It begins with these words:
The chronicles say that in May 1543 a messenger knocked on the door of the canon of Fraunburg, in Poland, with express mail. He brought the first copy of a book just off the printer and wanted to deliver it to the author in his own hand. After much hesitation, they let him in and he found an old man already dying on his deathbed. Careful not to disturb the patient, the messenger placed the volume on the bed and concluded his mission. He suspected that NICOLAS COPERNICO would die without being aware of that unexpected visit… but it was not like that.
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