A star-crossed partnership

Margaret Wertheim is the author of "The Pearly Gates of Cyberspace: A History of Space From Dante to the Internet."

Tycho & Kepler

The Unlikely Partnership That Forever Changed

Our Understanding of the Heavens

Kitty Ferguson


Walker & Co.: 402 pp., $28


Ever since the breakaway success of “Longitude,” Dava Sobel’s charmingly told story of an 18th century clockmaker who solved one of the great technological conundrums of his day, science writers and their publishers have been looking for the next big science-history hit. Essential to the plan is a charismatic, and preferably eccentric, leading man; to my knowledge, there have been no women in the genre so far. Chief among the many contenders have been Simon Winchester’s “The Map That Changed the World,” the story of the orphaned son of a blacksmith who became the founder of modern geology; and “The Invention of Clouds,” Richard Hamblyn’s finely spun tale about an amateur meteorologist who named and classified the numinous forms of our atmosphere. Yet for all the richness of their prose, none of these books has come close to “Longitude’s” success.

The peculiar alchemy of the bestseller may well be present in Kitty Ferguson’s “Tycho & Kepler,” in which we encounter not one but two charismatic and deeply eccentric protagonists -- Tycho Brahe and Johannes Kepler. Between them they forged a new foundation for our understanding of the heavens, paving the way for the cosmological synthesis of Isaac Newton a century later. Tycho the observer and Kepler the theoretician constitute one of the most dramatic partnerships the scientific world has seen.

By far the more famous of the two is Kepler, the man who discovered the laws of planetary motion. When Newton said, “If I have seen further it was by standing on the shoulders of giants,” he referred to no one more than Kepler, for it was on the basis of Kepler’s planetary laws that Newton built his own law of gravity. But this story begins, as many a scientific revolution must, with the observation of anomalous facts, and the giant on whose shoulders Kepler stood was Tycho Brahe, the greatest observational astronomer of the pre-telescopic era.

In every way Tycho Brahe was larger than life. At the age of 20, he lost part of his nose in a duel and fashioned for himself a cosmetic replacement made of silver and gold. Born in 1546, Tycho was the scion of a noble Danish family, and he was expected to take up the duties of a knight and courtier. Yet in his early teens Tycho became entranced by the stars; by 16 he was keeping a logbook of his own astronomical observations. For a gentleman of the Renaissance, astronomy was an acceptable hobby but hardly a way of life. King and country called. Tycho’s passion was of the type, however, that not even money and social position was going to be allowed to stand in the way. Where most tales of triumph over adversity are about overcoming the pitfalls of poverty, in Tycho’s case we witness the unusual spectacle of a man evading the sinkholes of wealth.

Tycho had been born in the same decade that Copernicus died, and the latter’s sun-centered system was a considerable source of speculation among astronomers of his day. Contrary to popular opinion, Copernicus was not the first to have thought up this arrangement of the heavenly bodies, and neither were astronomical tables based on his system significantly better than those based on the older Ptolemaic model. At the time it was not in fact possible to distinguish empirically between an Earth-centered and a sun-centered system. Tycho decided that his life’s mission was to reform astronomy, to amass a collection of observations accurate enough to finally determine the true system of the heavens.

For this monumental project he would need a set of instruments far more precise than anything constructed before. Fortunately, Denmark’s king was sympathetic to the cause and bestowed upon Tycho the island of Hven. On this rocky outcrop in the Danish oresund he built a fantastical observatory, an extravagant pastiche of architectural, technological and aesthetic innovation, which he named Uraniborg.


In the 16th century, there was no such thing as a pure research institute. Uraniborg was also Tycho’s home, and he based the entire construction on the new architectural fashion inspired by Andrea Palladio. Building and gardens alike were designed around a suite of geometric symmetries, metaphorically referencing the divine mysteries above; turrets sprouted from the roof, an elaborate fountain splashed in the courtyard, hundreds of rare fruit trees were imported, a luxury deeply resented by the local peasants, who were forced into service as laborers. Running water was piped through the building, an elaboration that not even the queen of England could boast. On the upper levels Tycho installed his instruments, including a giant armillary sphere and the vast mural quadrant, while in the basement he built an extensive alchemical laboratory.

Tycho fulfilled his astronomical dream, leaving as a legacy a set of observations of unprecedented rigor. But what to make of these figures? Tycho could not bring himself to accept the Copernican system -- as indeed, could few at the time -- and he formulated his own hybrid cosmological model halfway between the Earth-centered and the sun-centered systems. He hoped that his data would eventually confirm this peculiar arrangement. The man to whom he entrusted the job of interpreting his empirical treasure -- imploring to him from his deathbed, “Let me not seem to have lived in vain” -- could not have differed more from Tycho himself.

Kepler came from a family of dissolutes and drunks, and it is hard to imagine a less promising start to a great career in science. His parents were so poor that at times they could not afford his school fees, and Kepler spent several years of his childhood laboring on a farm. Into the bargain he was small and sickly and perpetually plagued by insecurity. On one thing only could he match the magnificence of Tycho Brahe: his intense passion for stars.

Kepler had originally intended to enter into the church, but astronomy became for him a new kind of theology, a never-ending confirmation of God’s greatness. Above all, Kepler saw the divine hand reflected in the mathematical harmonies he discerned in the motions of the planets. After struggling fitfully with his own calculations from his home in Graz, he joined the master’s entourage in 1600. Based on Tycho’s data, Kepler discovered dozens of mathematical relationships in the planets’ dance. History celebrates three of them, including the radical fact that the paths of the planets are not circles but ellipses. For 2,000 years, astronomers had insisted that only the perfection of the circle was worthy of the heavenly bodies; Kepler’s discovery of elliptical orbits stands as one of the seminal advances of modern science. He was the first real astrophysicist.


In “Tycho & Kepler,” we are given the sense of science as a quintessentially human activity, conducted not by disembodied spirits squirreled away in ivory towers but by living, breathing and distinctly idiosyncratic subjects. In reality we have two books here -- and one of them is an absolute triumph. It is clear that in her intertwined tales Ferguson’s heart lies chiefly with Tycho. He is her pole star, the man whose character broke across the chasm of years to speak to her directly, and it is this book that rivals “Longitude.” Yet with Kepler, Ferguson is sometimes struggling to connect. Though his science is vividly rendered, his soul evades her. This is strange because few people have inspired such passion among professional historians of science. In Fernand Hallyn’s masterpiece, “The Poetic Structure of the World,” a rigorously academic though profoundly lyrical work, one is utterly seduced by this fissiparous intellect, who built in the end what Hallyn calls a vast metaphysical wonder-cabinet of a cosmology.

I also have one minor quibble: Dazzled as I was by Ferguson’s multivalent portrait of life in the late Renaissance, at times I felt a little overwhelmed by the detail. One of the primary virtues of “Longitude” was surely its shortitude, and it’s a pity that more of Sobel’s followers have not taken this lesson on board. It’s a small point amid a wealth of strengths; “Tycho & Kepler” will certainly be among the best science books of the year.