Nicolaus Copernicus

Nicolaus Copernicus
Nicolaus Copernicus; German: Nikolaus Kopernikus; 19 February 1473 – 24 May 1543) was a Renaissance mathematician and astronomer who formulated a model of the universe that placed the Sun rather than the Earth at the center of the universe. The publication of this model in his book De revolutionibus orbium coelestiumjust before his death in 1543 is considered a major event in the history of science, triggering the Copernican Revolution and making an important contribution to the Scientific Revolution...
NationalityPolish
ProfessionScientist
Date of Birth19 February 1473
CountryPoland
The two revolutions, I mean the annual revolutions of the declination and of the centre of the Earth, are not completely equal; that is the return of the declination to its original value is slightly ahead of the period of the centre. Hence it necessarily follows that the equinoxes and solstices seem to anticipate their timing, not because the sphere of the fixed stars moves to the east, but rather the equatorial circle moves to the west, being at an angle to the plane of the ecliptic in proportion to the declination of the axis of the terrestrial globe.
More stars in the north are seen not to set, while in the south certain stars are no longer seen to rise.
The strongest affection and utmost zeal should, I think, promote the studies concerned with the most beautiful objects. This is the discipline that deals with the universe's divine revolutions, the stars' motions, sizes, distances, risings and settings . . . for what is more beautiful than heaven?
Since, then, there is no objection to the mobility of the Earth, I think it must now be considered whether several motions are appropriate for it, so that it can be regarded as one of the wandering stars. For the fact that it is not the centre of all revolutions is made clear by the apparent irregular motion of the wandering stars, and their variable distances from the Earth, which cannot be understood in a circle having the same centre as the Earth.
I therefore took this opportunity and also began to consider the possibility that the Earth moved. Although it seemed an absurd opinion, nevertheless, because I knew that others before me had been granted the liberty of imagining whatever circles they wished to represent the phenomena of the stars, I thought that I likewise would readily be allowed to test whether, by assuming some motion of the Earth's, more dependable representations than theirs could be found for the revolutions of the heavenly spheres.
In the first book I shall describe all the positions of the spheres, along with the motions which I attribute to the Earth, so that the book will contain as it were the general structure of the universe. In the remaining books I relate the motions of the remaining stars, and all the spheres, to the mobility of the Earth, so that it can be thence established how far the motions and appearances of the remaining stars and spheres can be saved, if they are referred to the motions of the Earth.
In the center of all rests the sun. For who would place this lamp of a very beautiful temple in another or better place that this wherefrom it can illuminate everything at the same time? As a matter of fact, not unhappily do some call it the lantern; others, the mind and still others, the pilot of the world. Trismegistus calls it a "visible God"; Sophocles' Electra, "that which gazes upon all things." And so the sun, as if resting on a kingly throne, governs the family of stars which wheel around.
Of all things visible, the highest is the heaven of the fixed stars.
Moreover, there is no difference between the earth's centers of gravity and magnitude.
To be sure, heretofore there has been virtually unanimous acceptance of the belief that the middle of the universe is the earth.
Every observed change of place is caused by a motion of either the observed object or the observer or, of course, by an unequal displacement of each.
Near the sun is the center of the universe.
The earth also is spherical, since it presses upon its center from every direction.
Yet if anyone believes that the earth rotates, surely he will hold that its motion is natural, not violent.