The Sky's Dark Labyrinth: A Novel

  • Stuart Clark
Polygon: 2011. 272 pp. £12.99 9781846971747 | ISBN: 978-1-8469-7174-7

Somewhat eclipsed in popular culture by his great Italian contemporary Galileo Galilei, Johannes Kepler is finally achieving the iconic status he has long held in science. In 2009, the seventeenth-century German astronomer was the subject of an opera by US composer Philip Glass (Nature 462, 724; 2009). Now, Stuart Clark's novel — the first in a trilogy about famous astronomers — puts fictional flesh on the bones of Kepler's life and times to enjoyable effect.

Astronomer Johannes Kepler in his final decade. Credit: INTERFOTO/ALAMY

Only 60 years or so after Copernicus provided the idea of the heliocentric Universe, Kepler worked out the orbits of the planets. The story told in The Sky's Dark Labyrinth, which takes its name from a phrase in Galileo's 1623 book Il Saggiatore (The Assayer), is well known. Kepler assisted aristocratic court astronomer Tycho Brahe in Prague, taking over Tycho's precise observations of Mars and its changing position in the sky. From these studies, Kepler deduced his three laws of planetary motion, the first two of which he published in Astronomia Nova (The New Astronomy) in 1609, the same year that Galileo first pointed his telescope skywards.

Clark depicts the clash of two strong personalities: the haughty Tycho, and Kepler, whose confidence in his own mathematical abilities never wavered. He draws, too, on the interaction of each with Rudolph II, the Holy Roman Emperor, who became Kepler's patron and whose name is commemorated in the Rudolphine Tables (1627). These were produced by Kepler using the laws of planetary orbits, which he derived on the basis of Tycho's observations. Working with these 'planetary tables', Kepler accurately predicted that transits of Mercury and of Venus would occur in 1631. The first of these was observed in Europe, but he did not realize that there would soon be a second transit of Venus, in 1639. (The next transit of Venus will be visible from Earth on 5–6 June 2012, depending on the observer's location; the following one is not until 2117.)

The author paints the conflicts between Lutherans and Catholics that drove the Lutheran Kepler from Graz to Prague, and that helped govern how Pope Urban VIII treated Galileo. Clark describes the blood that literally flowed during the internecine warfare between Rudolph II and his brother, Matthias, as the latter's troops attacked while Kepler and his family cowered in the city — evoking parallels with battles today.

The fun of reading plausible words from the mouths of Kepler and Galileo overwhelms objections to invented conversations.

My wife and I have made several astronomy-related pilgrimages: to Prague to see the plaque over Kepler's lodgings and his joint statue with Tycho; to dine at the Golden Griffin where Tycho lodged for a time, now a restaurant and hotel; to visit a monument (we found it defaced) to Kepler in Regensburg, Bavaria, possibly near where his bones were originally buried until they were lost; and to see the house in Regensburg where Kepler died in 1630, now a museum. I was also able to help the Houghton Library at Harvard University in Cambridge, Massachusetts, acquire the only known copy of Kepler's 1603 almanac.

As Clark emphasizes, 1603 was thought to be particularly auspicious at the time. Rudolph II is quoted as saying, “Eight hundred years earlier, Charlemagne founded Europe; eight hundred years before him, Christ was born.” Soon thereafter, Kepler saw a supernova — the last seen in our Galaxy and now named after him.

I could all but smell the streets and markets of seventeenth-century Prague in this novel. In one memorable passage, Clark describes Kepler taking the path to the castle, across the Stone Bridge, where in 1611 he wrote his little book on the snowflake, recently republished to celebrate its 400th anniversary.

Clark also brings to life interesting minor characters and conjures up Kepler's eventful family history, including the joys of parenthood, his difficult mother (whom he had to clear of suspicions of witchcraft), and the tragic deaths of his children and first wife, Barbara. Thoughtfully crafted dialogues reveal the tension between Kepler's rationalism and the 'magical' beliefs of others.

Interspersed among the chapters about Kepler are several about Galileo's time in Padua, Florence and Rome. In these, Kepler endorses the veracity of Galileo's reports of seeing new 'stars' around Jupiter through his newfangled optical tube. And Galileo's lack of response to a letter from Kepler is explained as a result of religious rivalry: the Catholic church in Rome feared that lapsed-Lutheran Kepler would side with their Protestant enemies.

Today, in an age when Vatican astronomers have telescopes in Arizona and host summer schools on cosmology at the Pope's summer residence at Castel Gandolfo near Rome, it is hard to evoke the mood of the early seventeenth century. Clark manages it.

Just as Shakespeare's inventions about the lives of kings give us too much pleasure to resist his playing fast and loose with history, the fun of reading plausible words from the mouths of Kepler, Galileo and their contemporaries overwhelms petty objections to invented conversations. I am less fond of Clark's minor chronological adjustments and his invented character, Cardinal Pippe.

The Sky's Dark Labyrinth deserves a broad readership. I look forward to Clark's forthcoming novel on Isaac Newton and Edmond Halley, and the final part of the trilogy, on Albert Einstein, Edwin Hubble and Georges Lemaître.