Spheres of influence.

Heavenly Intrigue: Johannes Kepler, Tycho Brahe, and the Murder Behind One of History's Greatest Scientific Discoveries, by Joshua Gilder and Anne-Lee Gilder (Doubleday, 304 pp., $24.95)

WHILE every culture has developed myths and legends about the stars and planets, the systemic, controlled investigation of the night sky stands as a recent and exclusively Western phenomenon. Joshua and Anne-Lee Gilder's Heavenly Intrigue focuses on the tortured relationship of two men who originated this scientific study of the heavens: Johannes Kepler and Tycho Brahe. Their efforts laid the groundwork for the modern quest to explain and understand astronomy in terms of repeatable experiments and quantifiable laws. Brahe and Kepler jointly researched the heavens for about 18 months at the dawn of the 17th century. Their collaboration ended, however, when Brahe died suddenly after returning home from a banquet. In this new book the Gilders--he a novelist and former White House speechwriter, she a German-born TV journalist--present convincing evidence that Kepler murdered Brahe.

Their finding proves particularly stunning when one considers Kepler's sterling historical reputation. He was arguably both the first great European scientist born outside the aristocracy and the first to recognize that heavenly bodies follow complex, mathematically describable laws rather than the commands of supernatural powers. Although Nicolaus Copernicus first proposed a heliocentric model of the solar system, Kepler's studies (based upon Brahe's data) made the sun-centered planetary constellation useful. The Copernican model, which postulated that planets move in divinely ordained perfect circles, has almost no utility for predicting planetary motion; but modern astronomers and physicists still need to understand Kepler's laws of planetary motion. Historians of science can draw an almost straight line between Kepler's studies of laws of planetary motion and Isaac Newton's revolutionary explanation of gravitational forces.

In the Gilders' book, however, Kepler emerges as a distinctly unsympathetic character. He was the son of downwardly mobile tradespeople; his own Self Analysis (a private memoir) depicts him as a depressive, mendacious, self-loathing, self-aggrandizing borderline agoraphobic with morals "similar to a dog's." Brahe, on the other hand--a larger-than-life aristocrat who sometimes wore a pure-gold nose to cover a dueling scar--emerges as generous, kind, and literate.

In short and readable chapters, the Gilders trace the two men's careers from late adolescence through Brahe's death. Born to the top ranks of Danish nobility, Brahe studied in Germany and returned home to a life of luxury and ease (he was one of the wealthiest men in Denmark). He married for love, built an enormous castle as a base for his observations, conducted the best pre-telescopic observations of the heavens, and performed a wide variety of alchemical experiments. After a hostile new regime came to power, Brahe fled to Prague (leaving behind nearly all of his wealth), where he found an agreeable patron in the form of the crazed but generous Holy Roman emperor Rudolph II. Kepler, on the other hand, scraped his way into higher education by sheer force of will but found himself turned away--for a variety of political, theological, and personal reasons--from the religious studies and well-paid teaching posts he desired. Eventually invited to serve as Brahe's assistant (the Gilders show that he almost certainly wasn't the aristocrat's first choice), he worked with the older man for 18 months. Kepler did not like the work: He wanted to conduct his own research, and the position reduced him to the reasonably comfortable but utterly boring life of a well-compensated lab assistant.

In his letters, some of which the Gilders translate themselves, Kepler continually demands access to Brahe's observational data in between his whining requests for fewer responsibilities and greater perquisites. Generous to a fault with material goods, Brahe steadfastly refuses to share his data. Too nearsighted and impatient to conduct his own systematic observations, Kepler believes that the trove of observations could prove his own theories. This lust for the data, the Gilders contend, ultimately led Kepler to murder his boss.

The evidence certainly points in that direction. Based on new tests of hair samples taken from Brahe's remains, the Gilders provide evidence that he died from intentional mercury poisoning. A study of the hair appears to prove that he ingested a massive dose of mercury, and the Gilders, with the assistance of Johns Hopkins professor Lawrence Principe, provide a new translation of Brahe's drug recipe that shows he couldn't have accidentally overdosed on a mercury drug, as some scholars have contended. Kepler, who had ready access to the Brahe household and a discernible motive for murder, emerges as the most likely culprit.

Although the Gilders correctly credit Kepler with his important discoveries, the form of the book tends to overstate Brahe's historical importance and understate Kepler's. Kepler's later life, when he built the first accurate and useful model of the solar system, gets covered only in a hurried chapter that seems like an afterthought. Kepler may have been a terrible character but he remains a scientific giant who transcended his age. Brahe, who never gave up on the idea that the sun revolved around the earth, was a bright and keen observer whose scientific discoveries stand in the shadow of Kepler's great works. The Gilders' obvious affection for Brahe may lead them to let him off too easily for his refusal to share data with Kepler: They compare him to a modern academic guarding his data from rivals before publication. But today, as in the 17th century, junior scientists work with their elders for few material rewards specifically so they can gain access to senior scientists' data. Brahe's refusal to share his data with Kepler, therefore, isn't quite as innocent as the Gilders imply. It should be needless to say, however, that a bit of academic selfishness hardly justifies homicide.

This minor quibble aside, the Gilders have produced a brilliant, readable, and original historical work that ought to convince readers that one of history's greatest scientists committed a cold-blooded murder.

Mr. Lehrer is an associate fellow of the Sagamore Institute.