Nicolaus Copernicus: Biography, and discoveries

Nicolaus Copernicus was likely sick enough not to read the anonymous preface that had been appended to his book.

The 16th-century astronomer Nicolaus Copernicus’ “De revolutionibus orbium coelestium” (“On the Revolutions of the Heavenly Orbs”) challenged the cosmology of Aristotle and Ptolemy, which had ruled since ancient Greece. The Earth was immobile and at the center of the planets rotating in their surrounding orbits, according to the then-dominant universe model proposed by Aristotle and Ptolemy. Beyond them were the stars that travel around the Earth every 24 hours.

Copernicus turned over this theory in his mind and suggested the idea that Venus, Earth, Mars, Jupiter, and Saturn were actually floating around the Sun. By doing this, he started a revolution that would change science forever.

Who was Nicolaus Copernicus?

Nicolaus Copernicus
Nicolaus Copernicus.

Born in Torun, Poland, Copernicus was 10 years old when his father died. His uncle, the church administrator Lucas Watzenrode, undertook the education of Nicolaus, hoping that his nephew would follow the same path as him and become a clergyman. Lucas, now the Bishop of Warmia in the fall of 1491, enrolled Nicolaus at the University of Krakow, where he graduated. It was the best institution in Northern Europe in the field of astronomical studies. Copernicus discovered mathematical astronomy, which he will pursue for the rest of his life, here.

Nicolaus Copernicus started his education in Krakow with literature lessons in which they focused on Latin translations and interpretations of Aristotle’s works. According to Aristotle, the Earth and all natural objects consisted of four elements: earth, water, air, and fire; and the perfect and fixed sphere consisted of a fifth element, ether. Aristotle thought that the objects in the ether sphere moved circularly. Copernicus also took geometry lessons, focusing on the works of Euclid and the simplified geometric astronomical models of Claudius Ptolemy.

Ptolemy’s model for the motion of the planets required two circles. It was assumed that each planet moves along small circles called “planetary circles” (epicycles), while the planetary circle moves around a larger ring called the carrier circle around the Earth. When a planet’s retrograde motion in the planetary circle exceeded its prograde motion in the carrier circle, people on Earth would see the planet moving backward compared to distant stars. The Aristotle-Ptolemy model assumed that the planets were rotating around the Earth, which is fixed in the center of the universe. The revolutionary model of Copernicus would challenge this scheme.

The abbreviated version of Regiomontanus’s 2nd-century book also shows the zodiac signs in Ptolemy’s Almagest.
The abbreviated version of Regiomontanus’ 2nd-century book also shows the zodiac signs in Ptolemy’s Almagest. Colorized later in Venice editions in 1496.

After four years in Krakow, in 1495, Copernicus returned to the town of Frombork, on the northeastern Baltic coast, where the Archdiocese of Warmia and the church of the cathedral were located. When an appointment was opened in the church’s governance, Lucas nominated his nephew. His appointment to the position created controversy, but first, Lucas sent him to the University of Bologna to study church law and learn about church management law. During his time in Bologna, Copernicus became the assistant of a famous astronomer professor, Maria Novara da Ferrara. He brought with him a copy of the Alfonsine Tables, on which he had written his own notes. These tables, made for Alfonso X of Spain in the 13th century, included the necessary data to calculate the location of the Sun, Moon, and planets relative to fixed stars.

Copernicus also provided a 1496 volume of the shortened version of Ptolemy’s Almagest that belonged to the German astronomer and mathematician Regiomontanus (the Latinized name of Johannes Müller von Königsberg), who had died 20 years ago. Copernicus was bothered by the difference between Ptolemy’s ideas about how planets move and Aristotle’s ideas about “geometric perfection.” This difference bothered Ptolemaios I Soter and Arab and Jewish astronomers in Spain in the Middle Ages.

Nicolaus Copernicus left Bologna four years later without a degree again. He spent the next few months touring Rome, where the 1500th anniversary of Christianity was held. The public’s discomfort with Pope Alexander VI’s overspending of Church funds for celebrations soon led to reform actions associated with the German priest Martin Luther. This movement resulted in the departure of the Protestant faith from the Papacy.

In 1501, Copernicus applied to the cathedral council in Warmia with a request to study in Italy for two more years. He promised to use the medical education he received in Padua to treat the bishop and members of the council. In 1503, he returned to Warmia not with a medical degree, but with a doctoral degree in law from the University of Ferrara. He undertook the legal affairs of the church and also worked as a personal secretary and a doctor for his uncle for seven years, until his uncle died in 1512.

Building a solar system model

Copernicus continued to work on Regiomontanus’ Almagest. The German astronomer discovered that Ptolemy was looking for an alternative to the planetary circle to explain the retrograde motion of the planets, from which he showed that the roles of the carrier circle and the planetary circle could always be turned into a decentralized circle, the center of which was always in the direction of the Sun. This lesson introduced Copernicus’ solar-centered solar system model.

Copernicus first developed a system in which every outer planet—Mars, Jupiter, and Saturn—revolved around the Sun, and the Sun in turn revolved around the Earth. When he included the inner planets—Mercury and Venus—in the system, Copernicus had to choose between the idea that the planets revolve around the Sun and the Sun revolves around the Earth or a more uniform motion in which the Earth also revolves around the Sun. In the more uniform model, the Earth would be treated as a planet in motion, so that the retrograde motion of planets and other apparent irregularities in the sky would be proven wrong, as opposed to the dominant idea.

Placing all the planets in orbits around the Sun made it possible for them to determine their distances and rotation times. Both showed a proportional increase in the model. (The Moon was in the circle of the planet around the Earth.) Decades later, in his De revolutionibus orbium coelestium, he defended the Copernicus model by saying that in no other arrangement can we find such a precise link between the size of the orbit and its time of circulation.

The collapse of the 1000-year-old order

atlas coelestis
The Sun-centric Copernican system from Doppelmayr’s Atlas Coelestis compilation and illustration collection was published in Nuremberg in 1741. Atlas also shows the Ptolemaic system in the lower right corner of this page, and other cosmological systems, including Tycho Brahe’s Tycho system, where the Sun and Moon revolve around the Earth and other planets revolve around the Sun.

He was also disturbed by the violation of Ptolemy’s uniform circular motion principle in his planetary theory. He found the solution in planetary motion models that preserve the “uniform circular motion” developed by ancient Arab astronomers associated with the Maragheh Observatory. Historians think that Copernicus’ intellectual breakthrough happened around 1510, when he wrote Commentariolus, a small booklet on the heliocentric (sun-centered) planetary theory that maintains circular motion, which was his interpretation of assumptions on the motion of the celestial bodies.

That same year, Copernicus settled permanently in Frombork. The vast majority of his official church affairs here were financial affairs. These works led him to write an article on the exchange rate and coin printing system. However, as his main intellectual passion, he was still taking time to observe the positions of the planets and the Sun, which would provide the necessary data to revise Ptolemy’s model.

Around 1515, a complete copy of the Almagest was published. When Copernicus saw that the book he used as the base, Regiomontanus, was much more comprehensive than his abridgment, Commentariolus, he understood the magnitude of the work he was assigned to. To get the western world to realize the actual system of how the universe works would take many years of observation and math.

The revolution in the heavens

Over the years, Copernicus’ text has developed, but despite the encouragement of his colleagues, he has made no preparations to have the book published. But in 1539, a young Austrian mathematician, Georg Joachim Rheticus, made a long visit to him. Despite the Edict of 1526, which expelled the Lutherans from Warmia, Copernicus accepted Rheticus as a student. In early 1540, a publisher from Gdansk published Rheticus’ work Narratio prima (First Account), which summarized Copernicus’ theories for academics. Rheticus reviewed the text for the last time with Copernicus, and in 1541 he delivered the work to the printer, Johannes Petreius, in Nuremberg. He made wooden molds for the complex technical drawings by Copernicus.

Within ten months of printing the thick, six-volume book, Copernicus asked for a letter sent by a cardinal to be added to the preface in 1536. In the letter, the cardinal asked Copernicus to share his discovery with astronomy enthusiasts and to send his work on celestial spheres and astronomical tables as soon as possible. He also wrote a foreword dedicated to Pope Paul III, attributing the delay in publishing his work to concerns about how his ideas would be received but emphasizing that he believed they would benefit the “Church community“.

Partial paralysis after a stroke in late 1542 prevented Copernicus from continuing his work. He was able to see a printed copy of his great work on May 24, 1543, the day he died. He was likely sick enough not to read the anonymous preface that had been appended to his book. In this preface, his arguments were called hypotheses. The claim that the Sun-centered model was only useful for mathematical calculations was contrary to Copernicus’ view that the Sun-centered universe was not just for calculations but was reality itself. In 1609, it was clarified that this preface was added by the Lutheran theologist Andreas Osiander, who was revising the corrections for Rheticus.

After Nicolaus Copernicus’ death

The statue of Copernicus, erected in 1853 and located in the astronomer’s birth city of Torun, shows the astronomer holding the armillary sphere (the celestial sphere contains the ecliptic).
The statue of Copernicus, erected in 1853 and located in the astronomer’s birth city of Torun, shows the astronomer holding the armillary sphere (the celestial sphere contains the ecliptic).

In 1543, only 500 copies of De Revolutionibus were printed. But his radical arguments did not cause any impact. In the following years, Johannes Kepler and Galileo Galilei stated that they accepted Copernican cosmology not only theoretically but also factually. However, many clerics objected to the contradiction between Sun-centered cosmology and religious cosmology. In 1616, the Catholic Church included De Revolutionibus in the list of prohibited books. After Isaac Newton’s Philosophiæ Naturalis Principia Mathematica (Mathematical Principles of Nature Philosophy) appeared in 1687, more academics began to adopt the Copernican system, but Copernicus’ book remained on the list of banned books until 1835 (along with Kepler’s and Galileo’s books).

In recent years, both scientists and the Church have rehabilitated the reputation of Copernicus. In 1972, NASA launched the Copernicus satellite before the 500th birthday of the astronomer, and the satellite studied interstellar matter during its eight-year activity. In 2005, an anonymous grave was found on the altar of the Frombork Cathedral with the remains of a man in his seventies. In 2008, Polish archaeologists reported that they had compared the skeleton with the DNA sample of a hairpiece taken from a book used by Copernicus and confirmed that the skeleton belonged to Copernicus. Deprived of fame enough to have his name written on his grave when he died on May 22, 1543, Copernicus was buried again under the altar of the cathedral with a black granite tombstone. In addition to that, the International Union of Pure and Applied Chemistry officially approved the designation of the name “Copernicum” (Cp) for the 112th element on the recommendation of the scientist who found it.

Nicolaus Copernicus quotes

“To know that we know what we know, and to know that we do not know what we do not know, that is true knowledge.”

“Of all things visible, the highest is the heaven of the fixed stars.”

“Finally we shall place the Sun himself at the center of the Universe.”

“I am aware that a philosopher’s ideas are not subject to the judgment of ordinary persons, because it is his endeavour to seek the truth in all things, to the extent permitted to human reason by God.”

“For I am not so enamoured of my own opinions that I disregard what others may think of them.”

“Those things which I am saying now may be obscure, yet they will be made clearer in their proper place.”

“The earth also is spherical, since it presses upon its center from every direction.”

“So, influenced by these advisors and this hope, I have at length allowed my friends to publish the work, as they had long besought me to do.”

“The massive bulk of the earth does indeed shrink to insignificance in comparison with the size of the heavens.”

“Pouring forth its seas everywhere, then, the ocean envelops the earth and fills its deeper chasms.”


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By Jim Collins has Jim Collins on staff as a space writer. Jim is passionate about all things astronomical and space-related and always relishes the chance to explore more.