Copernicus lived about one hundred years before Galileo, whose name is so prominent in connection with the fixing of this theory in the mind of man. This was the time when the great Christopher Columbus lived.

Nicolas Copernik was the name of our hero, but he is best known under the Latin form of his name—Copernicus. He was born in Polish Prussia in 1473, and although his birthplace, Thorn, was then in Poland, it is now in Prussia. We know practically nothing of his parents except that his father was a merchant.

When we learn that Copernicus was taught Latin and Greek at home, we might suppose that his father must have been an accomplished scholar, but as his father died when Copernicus was only ten years of age it is probable that these languages were acquired after his father's death. This is very probable, for the boy was then taken care of by his uncle, who was a Bishop. At the age of seventeen Copernicus went to the University of Cracow, which town was the old capital of Poland.

His uncle, the Bishop, desired that Copernicus should enter into Holy Orders, but he proved an unsuccessful candidate for a Canonry, and was sent to Rome to study. There he became very friendly with an illustrious astronomer, who obtained for him the professorship of Mathematics in Rome.

Copernicus made great progress in the study of Astronomy. He soon rivalled his distinguished friend and master. After several years of successful teaching of Mathematics in Rome, Copernicus returned to his native land and settled down in the position of Canon of one of the principal churches in Poland. Here he passed a quiet life, devoting one part of each day to the duties of his holy office, another part to giving free medical advice, and the remainder of his working day to study. At this time he would be about thirty-five years of age. He had no desire to make a great reputation for himself, nor did he care to enter into controversy, and so he worked away on his own account, trying to establish the theory that the Sun, and not the Earth, was the central body. He kept his manuscript to himself, revising and re-revising it year after year. It is quite possible that Copernicus knew that the Church would not favour his theory, and so his best plan was to prepare his book upon the subject. This book, De Revolutionibus Orbium, was his life-work, and was not completed until he was fifty-seven years of age. But even then he did not seek to publish it. The MS. lay dormant until a few years before his death, and only owing to the pressure of his friends did he agree to publish it. That would be about twelve years later. In the meantime the idea had been severely criticised by many of those who heard of the work. The great German Reformer Martin Luther, who was then living, thought Copernicus a fool to hold such opinions. He was even ridiculed on the stage at a public performance.

While Copernicus was a scholarly student, and devoted great care to plotting out the motions of the planets, and to the Mathematics of Astronomy, we must remember that Science had been dead for many centuries and was only beginning to be revived. Hence many of the arguments used by Copernicus, although they passed for logic in these days, would seem quite ridiculous nowadays. For instance, Copernicus adopted the same "argument" as Aristotle did, that the planets must move in regular circles because the circle was the most perfect and only natural form. For the same reason the Earth was spherical. Then his idea of the motion of the planets was similar to the ancient conception of the heavenly bodies being fixed in gigantic crystal spheres which, in his theory, circled around the Sun. However, he was the first to prove that the Earth is really a planet flying through space just as Jupiter, Saturn, and the other planets are. Pythagoras had suggested this, but he had offered no proof of his theory.

It is difficult for us to realise what a complete of man's ideas this theory required. Indeed, man's position had been very much like that of the little child to whom everything seems centered around itself. Everything that takes place in the Baby's world has special reference to the Baby. Man had imagined for ages that he was on a firmly fixed Earth, around which all the heavenly bodies danced attendance. Now he was asked to believe that this great big world of his was in reality a mere speck in the Universe; that he was on the surface of a comparatively small planet continually flying through space.

This great awakening did not come really during the lifetime of Copernicus. Indeed, he never saw his great book published. The first copy is said to have been placed in his hand when he was on his death-bed, but it is very doubtful if he could realise what it was. Then we must remember that a book which was practically a technical treatise, written in Latin, was not read by the general public. A hundred years later Galileo wrote upon the same subject in the vulgar tongue (Italian) instead of in Latin. The reason which Galileo gave was that, although people might have "a decent set of brains, yet not being able to understand things written in gibberish, take it into their heads that in these crabbed folios there must be some grand hocus pocus of logic and philosophy much too high up for them to think of jumping at. I want them to know, that as Nature has given eyes to them just as well as to philosophers for the purpose of seeing her works, she has also given them brains for examining and understanding them." But that was a century later than Copernicus. It took the Church a long time to realise that this theory was the beginning of a great revolution of thought.

Immediately preceding Galileo there came one Tycho Brahé, who did not adopt the theory of Copernicus, but whose great astronomical observations, as we shall see in the succeeding chapter, led on to the establishment of the Copernican System by Galileo.