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Nicolaus Copernicus: The Astronomer Who Placed the Sun at the Center of the Solar System


My writing interests are general, with expertise in science, history, biographies, and “how-to” topics. I have written over sixty books.

1873 painting titled “Astronomer Copernicus, or Conversations with God” by Jan Matejko. The painted depicts Copernicus atop his tower at Frombork—with the cathedral’s spires in the background—observing the sky with his wooden rulers (right).

1873 painting titled “Astronomer Copernicus, or Conversations with God” by Jan Matejko. The painted depicts Copernicus atop his tower at Frombork—with the cathedral’s spires in the background—observing the sky with his wooden rulers (right).


Nicolaus Copernicus was a groundbreaking mathematician and astronomer who lived during the Renaissance era and contributed to science with a new model of the universe that placed the sun instead of the earth at the center of the universe. Although a similar theory had been formulated centuries earlier by Aristarchus of Samos, Copernicus went much further than anyone before him. A major milestone in the history of science, the publication of his book, De revolutionibus orbium coelestium (On the Revolutions of the Celestial Spheres) in 1543 was a radical act that changed beliefs held for over a thousand years.

Born in Royal Prussia, Nicolaus Copernicus held a doctorate in canon law and was also a classics scholar, governor, diplomat, translator, priest, and physician as well as being an influential mathematician and astronomer. He was a man of many talents, making valuable contributions to varied fields, including economics, where he formulated a principle that would later become Gresham’s law. Copernicus’s daring and novel theories made all former theories about the system of the universe obsolete and put humanity on a new scientific path, leading to the Scientific Revolution.

Childhood and Family

Nicolaus Copernicus was born on February 19, 1473, in Thorn (now Toruń), a small town in the province of Royal Prussia, a Polish territory at the time. His mother was the daughter of a wealthy merchant and city councilor from Toruń. His father was a prosperous copper merchant from Cracow. Both his parents were German speakers, and Nicolaus and his three siblings grew up with German as their native tongue.

Nicolaus’s father was actively involved in politics at a time of great upheaval for Prussia and Poland. He took the role of diplomat in important negotiations meant to keep Royal Prussia within the Kingdom of Poland. His mother was from one of the wealthiest and most influential families in the city. Through the extended family of his mother, Copernicus was related to Polish noble families. Scholars believe that Copernicus spoke Latin, German, Polish, Greek, and Italian, with most of his surviving works in Latin or German.

Courtyard of the Collegium Maius (Latin for “Great College”) dating back to the 14th century at the Jagiellonian University in the historic part of Cracow, Poland.

Courtyard of the Collegium Maius (Latin for “Great College”) dating back to the 14th century at the Jagiellonian University in the historic part of Cracow, Poland.


Copernicus’s father died when he was ten years old, and his maternal uncle, Lucas de Watzenrode, took over the responsibility of raising the young man and supervising his education. Although there are no surviving documents detailing Copernicus’s childhood and early education, he probably attended St. John’s School in Toruń and later the Cathedral School at Włocławek.

Copernicus enrolled at University of Cracow (now Jagiellonian University) in 1491. Cracow was one of the most vibrant cultural cities of Europe at that time. Over the next four years, Copernicus studied in the Department of Arts at the Cracow school of astronomy and mathematics, where he acquired a foundation of scientific and mathematical knowledge. He became a pupil of Albert Brudzewski, a professor of Greek philosophy at the university and taught private lessons in astronomy outside the university. Copernicus studied astronomy as well as arithmetics, geometric optics, computational astronomy, and cosmography. He also acquired an extensive knowledge of philosophy and natural sciences by studying the writings of Aristotle and Averroes. In addition to work at the University of Cracow, Copernicus broadened his horizon by engaging in independent study. He read extensively outside his academic duties and began collecting books on astronomy. During these years he made his first scientific writings.

Copernicus left the University of Cracow in 1495 without obtaining a degree. Meanwhile, his uncle had become Prince-Bishop of Warmia and wanted to place Copernicus in a vacant position in the local canonry (church housing for clerics). This was not to be, and both Nicolaus and his brother, Andrew, who had studied with him at the University of Cracow, were sent by their uncle to Italy. There they were to study canon law with the goal of easing their transition into a career with the Catholic Church. While in Italy, Copernicus enrolled at Bologna University, where he studied for the next three years. Instead of focusing strictly on canon law, he spent much of his time studying humanities and astronomy.

The Italian academic experience was an undeniably valuable for setting Copernicus’s path. He became the disciple and assistant of the Italian scientist Domenico Maria Novara da Ferrara. To expand his knowledge of astronomy, Copernicus read important works by George von Peuerbach and Johannes Regiomontanus. The writings of Regiomontanus were instrumental in the development of Copernicus’s theories. On March 9, 1497, Copernicus verified some of his own ideas on Ptolemy's theory of the moon’s motion by conducting an observation at Bologna. While advancing his astronomical theories, he also read widely, including classic authors such as Pythagoras, Cicero, Plutarch, Heraclides, and Plato. His main goal was to gain deeper insights on the ancient astronomical and cosmological systems. Copernicus spent the year 1500 in Rome, working as an apprentice at the Roman Curia. With his interest in the study of the heavens unabated, on November 5, 1500, he observed a lunar eclipse.

Copernicus made a short visit back to Warmia to accept his post at the canonry and returned to Italy on an extension of leave from the chapter. He then took up medical studies, this time at the University of Padua from 1501 to 1503. Copernicus became familiar with the Greek language and began reading books by ancient Greek authors; many of the ancient astronomy texts were in Greek and there were few reliable translations into Latin or German. In 1503, he passed the final examinations at Ferrara and was granted the doctorate of canon law.

History of Astronomy Part 3: Copernicus and Heliocentrism

Political and Administrative Career

Copernicus was thirty years old when he left Italy and returned to Warmia. He quickly became his uncle’s physician and secretary, residing in the Bishop’s castle at Lidzbark. Although officially he spent his time fulfilling political, administrative, and ecclesiastic duties, Copernicus devoted all his free time to astronomy. He also fulfilled diplomatic duties, accompanying his uncle to sessions of the Royal Prussian court and participating in many important diplomatic events. Meanwhile, he published Latin translations of Greek verses and composed his own poetic works.

After his uncle’s death, Copernicus became magister pistoriae, responsible for administering the economic enterprises of Warmia. The new position allowed him financial independence and he moved to Frombork (Frauenberg), a remote town on the coast of the Baltic Sea. Copernicus was drawn into politics as Frombork was the economic and administrative center and one of the two political poles of the Warmia chapter.

Despite his many duties within the church, Copernicus never neglected his observational activity. Between 1513 and 1516, he conducted various astronomical observations, using instruments assembled after ancient models. More than half of his sixty registered astronomical observations were made here. In addition to observations of Mars, Saturn, and the sun, Copernicus made many important discoveries that helped him revise certain aspects of his system in the years to come.

Between 1516 and 1521, Copernicus lived in Olsztyn Castle, taking a position as administrator of Warmia. He spent his free time working on Locationes mansorum desertorum (Locations of Deserted Fiefs), trying to inspire farmers to populate deserted feudal farmlands and thus bolster the economy of the province. He also continued to act as a political and diplomatic agent, which gave him additional responsibilities during the Polish–Teutonic War. He remained a supporter of the Polish Crown’s interests, and when the Teutonic Knights attacked Warmia, Copernicus fought to save the province from the aggressors.

During his political and administrative career, Copernicus was interested in initiating a monetary reform in Poland. In 1517, he developed the quantity theory of money, a key concept in economics even today. In 1526, he wrote Monetae cudendae ratio (On the Minting of Coin) where he dwelt on the importance of money. He concluded that “bad” or debased (not the full silver or gold value) coins drove out of circulation the “good” or un-debased coins. His theory was later developed more fully by the Englishman Thomas Gresham and received the name of Gresham’s law. Copernicus’s recommendations to stabilize the currency were well received by government officials.

In 1537, Prince-Bishop of Warmia Mauritius Ferber died, and Copernicus was one of four candidates to be appointed his successor. However, the nomination was a pure formality as the decision had been already made in favor of another man. Although records are incomplete, it is believed that Copernicus was ordained a priest. This is thought the case as he participated in the election for the episcopal seat, a position which certainly required ordination. Even after his uncle’s death he remained on friendly terms with the elderly bishops of Warmia, offering them his services as a physician.

Copernicus’ great book Revolutions contains a diagram that overturns all previous conceptions of the Universe. The central position is occupied not by the Earth, but by the Sun (Sol).

Copernicus’ great book Revolutions contains a diagram that overturns all previous conceptions of the Universe. The central position is occupied not by the Earth, but by the Sun (Sol).

The Heliocentric Theory

The writings of the ancient scholars Hipparchus and Ptolemy, which stated that all celestial bodies rotated around the earth, held sway for centuries, even though mathematical calculations and celestial observations never fully supported their theory. From his early study of astronomy, Copernicus had been critical of Ptolemy’s ancient system, which placed the earth at the center of the universe. Ptolemy thought that all the planets, the Sun, Moon, and all the stars rotated around the Earth in circular orbits and the Earth stood still. Around 1507, inspired by the works of the ancient Greek mathematician and astronomer Aristarchus of Samos, who was the first to advance the theory that the earth orbited the sun, Copernicus had the sudden insight that the tables of planetary positions could be calculated more accurately if it were to accept the sun centered theory. This model of the solar system required that the earth itself revolves around the sun. In an unpublished version of Copernicus’s final work, he cited Aristarchus but later removed the reference. Unlike Aristarchus who only advanced the theory, Copernicus was determined to prove it using the rigor of mathematics. Some of the technical aspects of Copernicus’s system also appear in earlier works by the fourteenth century Islamic astronomer Ibn al-Shatir.

Copernicus had completed an outline of his heliocentric theory, Nicolai Copernici de hypothesibus motuum coelestium a se constitutis commentariolus—commonly referred to as the Commentariolus completed around 1514. It was a sketch that provided an early iteration of the hypothesis of a heliocentric system and included a brief description without the mathematical detail. Although lacking in rigorous detail, the work was one of the most revolutionary ever written because it proposed the idea that the earth was a just a planet like any other, revolving around the sun, and not the center of the universe as theology, tradition, and science had so long held. Copernicus shared a few copies of his work with his closest friends and acquaintances, mostly astronomers he had worked with at the University of Cracow. His friends were familiar with his ideas and witnessed his progress over the years. As he gathered more observations, his ideas crystallized, and he gained more support.

Johann Albrecht Widmannstetter, secretary to Pope Clement VII, presented Copernicus’s theory to the Pope in a series of public lectures in 1533. The Pope was satisfied with the discovery and everyone showed an interest in Copernicus and his work. In 1536, a cardinal from Rome, Nikolaus von Schönberg, wrote a letter to Copernicus, urging him to make his discovery known to scholars as soon as possible. When the letter reached Copernicus, his work was nearly in its final form and ready for the scientific community to evaluate.

Copernicus’s great work, On the Revolutions of the Heavenly Spheres.

Copernicus’s great work, On the Revolutions of the Heavenly Spheres.

A Revolutionary Book

Around 1532, Nicolaus Copernicus completed his work on the groundbreaking manuscript of Dē revolutionibus orbium coelestium (On the Revolutions of the Celestial Spheres), which aimed to introduce the world to his heliocentric theory. After the brief overview of the theory provided in Commentariolus, which circulated only among his acquaintances, the final work was supposed to cover thoroughly all the main principles of the theory in a detailed form.

Despite pressure from his contemporaries, Copernicus did not rush to publish the book, perhaps out of fear of religious, philosophical, and astronomical objections. Although many kept pushing him to make his discovery public, Copernicus feared that the novelty and incomprehensibility of his findings would expose him to ridicule. Copernicus probably feared that a theory that removed the earth from the center of the universe would be considered heretical. His fears were justified, considering that many theologians contested him for a very long time and that supporters of the same heliocentric theory, such as Galileo Galilei and Giordano Bruno, suffered persecution for their beliefs decades later. When he eventually decided to publish, Copernicus tried to dampen criticism by dedicating the book to Pope Paul III.

The road to publication was long, and in 1539 Copernicus was still making minor changes to improve De revolutionibus when he received a visit from a twenty-five-year-old mathematician from Austria, Georg Joachim Rheticus. The enthusiastic young man had heard rumors of the amazing theory and wanted to meet Copernicus. Rheticus became Copernicus’s pupil and stayed with him for two years.

During his time in Formbork, Rheticus wrote a book titled Narratio prima (First Account), where he gave an outline of the essential principles of the heliocentric theory. With pressure from Rheticus, Copernicus published some chapters from De revolutionibus in a treatise on trigonometry. Since the overall reception of the work was favorable and Rheticus continued to insist on having the integral work published, Copernicus finally agreed.

Because the manuscript was a six-volume work, comprising complex tables and diagrams, Copernicus and Rheticus decided to use the services of a German printer, Johannes Petreius from Nuremberg. Although Rheticus volunteered to personally supervise the publishing of the book, he left the city before the job was completed and delegated his responsibilities to Andreas Osiander, a Lutheran theologian. Going beyond his duty, Osiander added an introduction in which he put forward the idea that the book was not describing real facts, but only provided a device aimed to facilitate the calculation of planetary tables. Since the preface remained unsigned, it was attributed to Copernicus himself and it ended up weakening the appeal of his book because it negated its own main principle, which was that the earth revolves around the sun. The truth of Osiander’s deception was discovered only in 1609 by the German astronomer Johannes Kepler.

Although Copernicus had formalized his theory by 1510, his major work was thus published only in the year of his death, 1543. The original edition of De revolutionibus included only a few hundred copies. Many of the original books have survived to the present day, including early handwritten drafts. Decades after the publication of Copernicus’s revolutionary book, there were still very few astronomers who fully accepted his theory. Eventually, it became common knowledge that the Copernican system explains the motion of the planets about the sun and other astronomical phenomena with an unpreceded accuracy.

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

— NicolausCopernicus

Final Days

Nicolaus Copernicus died on May 24, 1543, at the age of seventy from a stroke. According to a popular legend, he saw the first copy of his book on his deathbed and died peacefully afterward. After his death, his former pupil, Georg Joachim Rheticus, became his successor and advanced his work. In 1551, eight years after Copernicus’s death, astronomer Erasmus Reinhold published a set of astronomical tables based on Copernicus’s work, which replaced all preceding systems over time.

The bold step taken by Copernicus forever changed mankind’s understanding of his place in the universe.

 Nicolaus Copernicus monument before the Polish Academy of Sciences in Warsaw. Copernicus holds a compass and armillary sphere. The inscription in Polish on the pedestal reades: "To Mikołaj Kopernik [from his] compatriots"

Nicolaus Copernicus monument before the Polish Academy of Sciences in Warsaw. Copernicus holds a compass and armillary sphere. The inscription in Polish on the pedestal reades: "To Mikołaj Kopernik [from his] compatriots"


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© 2019 Doug West