Science & People

Nicolaus Copernicus | Biography, discoveries, and quotes

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. According to the then prevalent universe model suggested by Aristotle and Ptolemy, the Earth was immobile and was at the center of the planets rotating in the surrounding orbits. 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?

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. Here Copernicus met with mathematical astronomy, which he will pursue with a lifetime passion.

Nicolaus Copernicus started his education in Krakow with literature lessons in which they were 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, 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 that is fixed in the center of the universe. The revolutionary model of Copernicus would challenge this scheme.

Copernicus's education period

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

After four years in Krakow, in 1495, Copernicus returned to the town of Frombork without any academic degree, 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 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 to 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–where he had his own notes on the pages. These tables, made for the 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 disturbed by the contradiction between the planetary orbits of Ptolemy and the Aristotelian "geometric perfection" ideals that disturbed both Ptolemaios I Soter and medieval Arab and Jewish astronomers in Spain.

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 over-spending 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. The undertook the legal affairs of the church, and also worked as a personal secretary and a doctor of 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 teaching was an introduction to Copernicus's Solar-centered Solar system model.

Copernicus first developed a system in which every outer planet–Mars, Jupiter, Saturn–revolves around the Sun, and the Sun circularly revolves 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, 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 distance and rotate 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, 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

Sun-centric Copernican system. Doppelmayr's Atlas coelestis compilation and illustration published in 1741 in Nuremberg.
The Sun-centric Copernican system from Doppelmayr's Atlas Coelestis compilation and illustration collection, 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 believe that Copernicus's intellectual breakthrough took place around 1510, peaking with Commentariolus (his interpretation of assumptions on the motion of the celestial bodies), a small booklet on Heliocentric (sun-centered) planetary theory that preserves uniform circular motion.

That same year, Copernicus settled permanently in Frombork. His vast majority of 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 he saw that the book which 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. Convincing the western world to change the cosmological system it had been connected to for more than 1,000 years would require decades of observation and calculations.

The revolution in the heavens

Over the years, Copernicus's 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's work Narratio prima (First Account), which summarized Copernicus's 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 of Copernicus.

Within ten months of printing the six-volume thick 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 the enthusiasts of the subject and to send his work on the celestial spheres along with the astronomical tables at the earliest. He also wrote a foreword dedicated to Pope Paul III, attributing the delay in publishing his work to the concerns about how his ideas would be received, but emphasizing that he believed they would benefit the "Church community".

Partial paralysis with 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 see the anonymous Preface had been appended in the 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's view that the Sun-centered universe was not just for calculations but it was the 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's death

The statue of Copernicus, erected in 1853, located in the astronomer's birth-city of Torun, shows the astronomer while holding the armillary sphere (the celestial sphere contains the ecliptic).
The statue of Copernicus, erected in 1853, located in the astronomer's birth-city of Torun, shows the astronomer while 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's book remained in the list of banned books until 1835 (along with Kepler's and Galileo's books).

In recent years, both scientists and the Church rehabilitated the reputation of Copernicus. In 1972, NASA launched the Copernicus satellite before the 500th birthday of the astronomer, and the satellite studied the interstellar matter in 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 have 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 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."
  • "Although all the good arts serve to draw man's mind away from vices and lead it toward better things, this function can be more fully performed by this art, which also provides extraordinary intellectual pleasure."
  • "In the midst of all dwells the Sun. For who could set this luminary in another or better place in this most glorious temple, than whence he can at one and the same time brighten the whole."
  • "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."
  • "Those who know that the consensus of many centuries has sanctioned the conception that the earth remains at rest in the middle of the heavens as its center, would, I reflected, regard it as an insane pronouncement if I made the opposite assertion that the earth moves."
  • "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."
  • "I can easily conceive, most Holy Father, that as soon as some people learn that in this book which I have written concerning the revolutions of the heavenly bodies, I ascribe certain motions to the Earth, they will cry out at once that I and my theory should be rejected."
  • "Pouring forth its seas everywhere, then, the ocean envelops the earth and fills its deeper chasms."