be a monster rather than a man.’ Nevertheless, despite its radical contents, the pamphlet caused no ripples among the intellectuals of Europe, partly because it was read by so few people and partly because its author was a minor canon working on the fringes of Europe.
Copernicus was not dismayed, for this was only the start of his efforts to transform astronomy. After his uncle Lucas died in 1512 (having quite possibly been poisoned by the Teutonic Knights, who had described him as ‘the devil in human shape’), he had even more time to pursue his studies. He moved to Frauenburg Castle, set up a small observatory and concentrated on fleshing out his argument, adding in all the mathematical detail that was missing in the Commentariolus.
Copernicus spent the next thirty years reworking his Commentariolus, expanding it into an authoritative two-hundred-page manuscript. Throughout this prolonged period of research, he spent a great deal of time worrying about how other astronomers would react to his model of the universe, which was fundamentally at odds with accepted wisdom. There were often days when he even considered abandoning plans to publish his work for fear that he would be mocked far and wide. Moreover, he suspected that theologians would be wholly intolerant to what they would perceive as sacrilegious scientific speculation.
He was right to be concerned. The Church later demonstrated its intolerance by persecuting the Italian philosopher Giordano Bruno, who was part of the generation of dissenters that followed Copernicus. The Inquisition accused Bruno of eight heresies, but the existing records do not specify them. Historians think that it is likely that Bruno had offended the Church by writing On the Infinite Universe and Worlds, which argued that the universe is infinite, that stars have their own planets and that life flourishes on these other planets. When condemned to death for his crimes, he responded: ‘Perchance you who pronounce my sentence are in greater fear than I who receive it.’ On 17 February 1600, he was taken to Rome’s Campo dei Fiori (Field of Flowers), stripped naked, gagged, tied to a stake and burned to death.
Copernicus’s fear of persecution could have meant a premature end to his research, but fortunately a young German scholar from Wittenberg intervened. In 1539, Georg Joachim von Lauchen, known as Rheticus, travelled to Frauenburg to seek out Copernicus and find out more about his cosmological model. It was a brave move, because not only was the young Lutheran scholar facing an uncertain welcome in Catholic Frauenburg, but also his own colleagues were not sympathetic to his mission. The mood was typified by Martin Luther, who kept a record of dinner-table conversation about Copernicus: ‘There is talk of a new astronomer who wants to prove that the Earth moves and goes around instead of the sky, the Sun and the Moon, just as if somebody moving in a carriage or ship might hold that he was sitting still and at rest while the ground and the trees walked and moved… The fool wants to turn the whole art of astronomy upside-down.’
Luther called Copernicus ‘a fool who went against Holy Writ’, but Rheticus shared Copernicus’s unshakeable confidence that the route to celestial truth lay with science rather than Scripture. The sixty-six-year-old Copernicus was flattered by the attentions of the twenty-five-year-old Rheticus, who spent three years at Frauenburg reading Copernicus’s manuscript, providing him with feedback and reassurance in equal measure.
By 1541, Rheticus’s combination of diplomatic and astronomical skills was sufficient for him to obtain Copernicus’s blessing to take the manuscript to the printing house of Johannes Petreius in Nuremberg for publication. He had planned to stay to oversee the entire printing process, but was suddenly called away to Leipzig on urgent business, and so handed responsibility for supervising publication to a clergyman by the name of Andreas Osiander. At last, in the spring of 1543, De revolutionibus orbium cælestium (‘On the Revolutions of the Heavenly Spheres’) was finally published and several hundred copies were on their way to Copernicus.
Meanwhile, Copernicus had suffered a cerebral haemorrhage at the end of 1542, and was lying in bed, fighting to stay alive long enough to set eyes on the finished book that contained his life’s work. Copies of his treatise reached him just in time. His friend Canon Giese wrote a letter to Rheticus describing Copernicus’s plight: ‘For many days he had been deprived of his memory and mental vigour; he only saw his completed book at the last moment, on the day he died.’
Copernicus had completed his duty. His book offered the world a convincing argument in favour of Aristarchus’ Sun-centred model. De revolutionibus was a formidable treatise, but before discussing its contents it is important to address two perplexing mysteries surrounding its publication. The first of these relates to Copernicus’s incomplete acknowledgements. The introduction to De revolutionibus mentioned several people, such as Pope Paul III, the Cardinal of Capua and the Bishop of Kulm, yet there was no mention of Rheticus, the brilliant apprentice who had played the vital role of midwife to the birth of the Copernican model. Historians are baffled as to why his name was omitted and can only speculate that crediting a Protestant might have been looked upon unfavourably by the Catholic hierarchy which Copernicus was trying to impress. One consequence of this lack of acknowledgement was that Rheticus felt snubbed and would have nothing more to do with De revolutionibus after its publication.
The second mystery concerns the preface to De revolutionibus, which was added to the book without Copernicus’s consent and which effectively retracted the substance of his claims. In short, the preface undermined the rest of the book by stating that Copernicus’s hypotheses ‘need not be true or even probable’. It emphasised ‘absurdities’ within the Sun-centred model, implying that Copernicus’s own detailed and carefully argued mathematical description was nothing more than a fiction. The preface does admit that the Copernican system is compatible with observations to a reasonable degree of accuracy, but it emasculates the theory by stating that it is merely a convenient way to do calculations, rather than an attempt to represent reality. Copernicus’s original handwritten manuscript still exists, so we know that the original opening was quite different in tone from the printed preface that trivialised his work. The new preface must therefore have been inserted after Rheticus had left Frauenburg with the manuscript. This would mean that Copernicus was on his deathbed when he first read it, by which time the book had been printed and it was too late to make any changes. Perhaps it was the very sight of the preface that sent him to his grave.
Figure 10 This diagram from Copernicus’s De revolutionibus illustrates his revolutionary view of the universe. The Sun is firmly at the hub and is orbited by the planets. Earth itself is orbited by the Moon and is correctly located between the orbits of Venus and Mars.
So who wrote and inserted the new preface? The main suspect is Osiander, the clergyman who took on responsibility for publication when Rheticus left Nuremberg for Leipzig. It is likely that he believed that Copernicus would suffer persecution once his ideas became public, and he probably inserted the preface with the best of intentions, hoping that it would assuage critics. Evidence for Osiander’s concerns can be found in a letter to Rheticus in which he mentions the Aristotelians, meaning those who believed in the Earth-centred view of the world: ‘The Aristotelians and theologians will easily be placated if they are told that … the present hypotheses are not proposed because they are in reality true, but because they are the most convenient to calculate the apparent composite motions.’
But in his intended preface, Copernicus had been quite clear that he was willing to adopt a defiant stance against his critics: ‘Perhaps there will be babblers who, although completely ignorant of mathematics, nevertheless take it upon themselves to pass judgement on mathematical questions and, badly distorting some passages of Scripture to their purpose, will dare find fault with my undertaking and censure it. I disregard them even to the extent of despising their criticism as unfounded.’
Having finally plucked up the courage to publish the single most important and controversial breakthrough in astronomy since the ancient Greeks, Copernicus tragically died knowing that Osiander had misrepresented his theories as nothing more than artifice. Consequently, De revolutionibus was to vanish almost without trace for the first few decades after its publication, as neither the public nor the Church took it seriously. The first edition did not sell out, and the book was reprinted