Commonly known by his Latin name, Nicholas Copernicus, Mikolaj Kopernik is regarded as "The Father of Astronomy". Nicholas Copernicus, born February 19, 1473, was the first astronomer to formulate a scientifically based heliocentric cosmology that displaced the Earth from the center of the universe. While a student at the University of Kraków, he discovered several logical contradictions in the existing astronomical system taught at that time, which put the earth at the center of the universe. Later when studying medicine and religious law at Bologna University, Kopernik pursued further investigations of the movements of celestial bodies, especially the moon. His direct observations, coupled with research based on various Greek and Latin astronomical writings, prompted him to originate the Copernican system of the structure of the universe. This theory placed the sun at the center of the solar system and the earth in orbit around it. Kopernik's most famous written work, De Revolutionibus, which laid the foundation for modern astronomy, was completed in 1530, after fifteen years of painstaking observations and calculations, often with instruments of the astronomer's own making. Although deeply convinced of the truth of his heliocentric system, Kopernik did not actively seek to publish this work because of its controversial nature. He did, however, manage to catch a dimmed glance at the first printed copy moments before his death on May 24, 1543.

Kopernik Monument This is a photo of the Kopernik monument located on the "Torun Triangle" at the intersection of 18th Street and the Benjamin Franklin Parkway in Philadelphia. It was erected by the proud Philadelphia Polish Community and depicts Kopernik's discovery of the Earth's rotation around the Sun. The "Torun Triangle" on the parkway is a salute to Philadelphia's Sister City - Torun, Poland.

When The Earth and Sun Were Moved 450 Years Ago Nicholas Copernicus Changed the World The Revolution of Heavenly Spheres, written by Polish astronomer Mikolaj Kopernik, well known by his Latin name Nicholas Copernicus, was written over 450 years ago. This manuscript, printed in 1543, described for the first time in history the correct position of the sun as the center of the solar system with the earth and other planets revolving around it. Copernicus' book formed the basis for modern astronomy and is considered to have caused the greatest revolution in science in the last two thousand years. Copernicus put an end to the belief that the earth was the center of the universe by properly placing the planet earth in orbit around the sun, revolving once around the sun each year while rotating on its axis once every twenty-four hours. Until Copernicus the teachings of the Greek astronomer Ptolemy were considered to be correct. Ptolemy, who lived in Alexandria in the second century after Christ, taught that the earth was round and calculated its circumference with surprising precision. The Ptolemaic system, however, taught that the earth was the stationary center of the universe and that the sun, moon, planets, and stars revolved around it. Nicholas Copernicus was born in Torun, Poland, on February 19, 1473, of a well-to-do merchant family. He attended St. John's School in Torun and also studied canon law at the University of Krakow from 1491 to 1495 and then studied at the Universities of Bologna and Padua between 1496 and 1503. During his studies at the University of Krakow, he discovered several contradictions in the system then used to calculate the movements of celestial bodies. This discovery led to his monumental work which was published over 450 years ago. The citizens of Torun are proud of their native son and erected a monument in front of city hall to honor "Mikolaj Kopernik", the citizen of Torun who moved the earth and stopped the sun. The Nicholas Copernicus University in Torun also honors the Father of Modern Astronomy with a quality institution of higher learning.