Copernicus, by placing the sun at the center of the planetary universe, was able to reduce the number of epicycles from eighty-three to seventeen.

That such deficiencies existed within Ptolemy's theory was not discovered de novo by Copernicus.

* Nicholas Copernicus by Bertel Thorvaldsen

Copernicus himself was mainly motivated by technical dissatisfaction with the earlier system and not by support for any mediocrity principle.

A great breakthrough in astronomy was made by Polish astronomer Nicolaus Copernicus ( 1473 – 1543 ), who proposed in 1543 the heliocentric model of the solar system.

Galileo, however, felt that the descriptive content of the technical disciplines warranted philosophical interest, particularly because mathematical analysis of astronomical observations — notably the radical analysis offered by astronomer Nicolaus Copernicus concerning the relative motions of the Sun, Earth, Moon, and planets — indicated that philosophers ' statements about the nature of the universe could be shown to be in error.

Furthermore, Copernicus continued to use as a point of reference the center of the earth's orbit rather than that of the sun, as he says, " as an aid to calculation and in order not to confuse the reader by diverging too much from Ptolemy.

However, his mockery of the idea of a round earth was criticised by Copernicus as " childish ".

In the Galileo affair, the acceptance, from 1616 to 1757, of the Greek geocentric model ( Ptolemaic system ) by the Roman Catholic Church, and its consequent opposition to heliocentrism, was first called into question by the Catholic cleric Copernicus, and subsequently disproved conclusively by Galileo, who was persecuted for his minority view.

The idea that the earth moved around the sun, as advocated by Copernicus, was to most of his contemporaries doubtful.

The two largest of these hospitals, recently run by the voivodeship, are to be taken over by Nicolaus Copernicus University and run as its clinical units.

Alternatively, he may have proved the heliocentric theory by determining the constants of a geometric model for the heliocentric theory and by developing methods to compute planetary positions using this model, like what Nicolaus Copernicus later did in the 16th century.

As noted by Copernicus himself, the suggestion that the Earth rotates was very old, dating at least to Philolaus ( c. 450 BC ), Heraclides Ponticus ( c. 350 BC ) and Ecphantus the Pythagorean.

* Possible date-Nicolaus Copernicus begins to write Commentariolus, an abstract of what will eventually become his heliocentric astronomy De revolutionibus orbium coelestium ; he sends it to other scientists interested in the matter by 1514.

** Nicolaus Copernicus ' De revolutionibus is placed on the Index of Forbidden Books by the Congregation of the Index of the Roman Catholic Church.

* October 7 – The first biography of Nicolaus Copernicus ( d. 1543 ) is completed by Bernardino Baldi.

This value was improved by 28 seconds in 1525 by Nicolaus Copernicus, who appealed to the estimation of Thabit ibn Qurra ( 826 – 901 ), which had an error of + 2 seconds.

It was more accurate than later measurements by Copernicus and Tycho Brahe.

Copernicus did not question it, Ptolemy could not.

If in any one calculation Ptolemy had had to invoke 83 epicycles all at once, while Copernicus never required more than one third this number, then ( in the sense obvious to Margenau ) Ptolemaic astronomy would be simpler than Copernican.

Kepler's laws and his analysis of the observations on which they were based, the assertion that the Earth orbited the Sun, proof that the planets ' speeds varied, and use of elliptical orbits rather than circular orbits with epicycles — challenged the long-accepted geocentric models of Aristotle and Ptolemy, and generally supported the heliocentric theory of Nicolaus Copernicus ( although Kepler's ellipses likewise did away with Copernicus's circular orbits and epicycles ).

* c. 1350 – Ibn al-Shatir anticipates Copernicus by abandoning the equant of Ptolemy in his calculations of planetary motion, and he provides the first empirical model of lunar motion which accurately matches observations

" The Eye of Heaven: Ptolemy, Copernicus, Kepler.

Johannes Kepler ( 27 December 1571 – 15 November 1630 ) was the first to closely integrate the predictive geometrical astronomy, which had been dominant from Ptolemy to Copernicus, with physical concepts to produce a New Astronomy, Based upon Causes, or Celestial Physics .... His work led to the modern laws of planetary orbits, which he developed using his physical principles and the planetary observations made by Tycho Brahe.

Various 16th-century books based on Ptolemy and Copernicus use about equal numbers of epicycles.

As a measure of complexity, the number of circles is given as 80 for Ptolemy, versus a mere 34 for Copernicus.

Written in Greek by Claudius Ptolemy, a Roman era scholar of Egypt, it is one of the most influential scientific texts of all time, with its geocentric model accepted for more than twelve hundred years from its origin in Hellenistic Alexandria, in the medieval Byzantine and Islamic worlds, and in Western Europe through the Middle Ages and early Renaissance until Copernicus.

In 1632, shortly after the publication of Galileo's Dialogues of the New Science, Torricelli wrote to Galileo of reading it " with the delight [...] of one who, having already practiced all of geometry most diligently [...] and having studied Ptolemy and seen almost everything of Tycho Brahe, Kepler and Longomontanus, finally, forced by the many congruences, came to adhere to Copernicus, and was a Galileian in profession and sect ".

In this respect it differed from the epicyclic and eccentric models with multiple centers, which were used by Ptolemy and other mathematical astronomers until the time of Copernicus.

He described objectively three systems: Ptolemy, Copernicus and of Tycho Brahe without taking sides.

The celestial spheres, or celestial orbs, were the fundamental entities of the cosmological models developed by Plato, Eudoxus, Aristotle, Ptolemy, Copernicus and others.

* Copernicus, Nicolaus On the Revolutions of the Heavenly Spheres, in Great Books of the Western World: 16 Ptolemy Copernicus Kepler Encyclopædia Britannica Inc 1952

* Kepler Epitome of Copernican Astronomy ( Bks 4 & 5 ) published in Great Books of the Western World: 16 Ptolemy Copernicus Kepler Encyclopædia Britannica Inc 1952

Two anthologies of his essays have been released, The Great Copernicus Chase and Other Adventures in Astronomical History from Cambridge University Press and The Eye of Heaven: Ptolemy, Copernicus, Kepler in the American Institute of Physics.

* Owen Gingerich: The Eye of Heaven: Ptolemy, Copernicus, Kepler.

To Riccioli the question was not between the geocentric world system of Ptolemy and the heliocentric world system of Copernicus, for the telescope had unseated the Ptolemaic system ; it was between the geo-heliocentric world system developed by Tycho Brahe in the 1570s ( in which the sun, moon, and stars circle an immobile Earth, while the planets circle the sun – sometimes called a " geo-heliocentric " or " hybrid " system ) and that of Copernicus.

As Copernicus ( following Ptolemy ) wrote,

** Celestial spheres, fundamental entities of the cosmological models developed by Plato, Eudoxus, Aristotle, Ptolemy, Copernicus and others

There is a haunting resemblance between the notion of cause in Copernicus and in Freud.

We talk about national character in the same way that Copernicus talked of the compulsions of celestial bodies to move in circles.

Historical records indicate that Copernicus was unaware of the fundamental aspects of his so-called ' revolution ', unaware perhaps of its historical importance, he rested content with having produced a simpler scheme for prediction.

Solving astronomical problems requires, for Copernicus, not a random search of unrelated tables, but a regular employment of the rules defining the entire discipline.

Copernicus required a systematically integrated, physically intelligible astronomy.

Without abandoning too much, Copernicus sought to make orthodox astronomy systematically and mechanically acceptable.

These wonders are important achievements of society, science, culture and defense, ranging from the Pyramids and the Great Wall in the Ancient age, to Copernicus ' Observatory and Magellan's Expedition in the middle period, up to the Apollo program, the United Nations, and the Manhattan Project in the modern era.

In physical cosmology, the Copernican principle, named after Nicolaus Copernicus, states that the Earth is not in a central, specially favored position.

Since the 1990s the term has been used ( interchangeably with " the Copernicus method ") for J. Richard Gott's Bayesian-inference-based prediction of duration of ongoing events, a generalized version of the Doomsday argument.

Hermann Bondi named the principle after Copernicus in the mid-20th century, although the principle itself dates back to the 16th-17th century paradigm shift away from the Ptolemaic system, which placed Earth at the center of the Universe.

Copernicus demonstrated the motion of the planets can be explained without the assumption that Earth is centrally located and stationary.

In fact, although the Copernican heliocentric model is often described as " demoting " Earth from its central role it had in the Ptolemaic geocentric model, neither Copernicus nor other 15th-and 16th-century scientists and philosophers viewed it as such.

The work of Copernicus, Kepler, and Galileo set aside the old notion that the earth was the center of the universe.

* 1473 – Nicolaus Copernicus, mathematician and astronomer ( d. 1543 )

Researchers at Case Western Reserve University and Copernicus Therapeutics are able to create tiny liposomes 25 nanometers across that can carry therapeutic DNA through pores in the nuclear membrane.

* 1543: Nicolaus Copernicus.

In 1543, astronomer Nicolaus Copernicus from Toruń ( Thorn ) published his work De revolutionibus orbium coelestium and became the first person to formulate a comprehensive heliocentric cosmology that displaced the Earth from the center of the universe.

File: Nikolaus Kopernikus. jpg | Nicolaus Copernicus ( 1473 – 1543 )