One way to feel close to the past is to handle objects upon which ordinary people left their mark. For medieval historians, these objects are often manuscripts in which a writer has recorded personal asides such as complaints about the cold. At its heart, The Light Ages traces the career of one such writer through the traces he left in the books he wrote and used.
He was a 14th-century monk, who I can guarantee you have never heard of, called John of Westwyk. John was a member of the grand abbey at St Albans (pictured), whom we first meet as the author of a manuscript discovered in the library of Peterhouse, Cambridge in the 1950s. It is a guide to a complex astronomical instrument called an Equatorie. There had been a suspicion that it was written by Geoffrey Chaucer himself, but diligent work by a Norwegian scholar, Kari Anne Rand, had unmasked the true writer as John of Westwyk. Rand had toured Europe’s libraries until she found a manuscript with identical handwriting that John had put his name to.
Seb Falk, a historian at the University of Cambridge, uses John’s life as a frame in which to illustrate the scientific achievements of the Middle Ages. For example, we cover medieval medicine because John had the misfortune to be attached to an army besieging Ypres when dysentery afflicted the camp, and we learn about navigation while John nips across the English Channel to Calais. His probable stint as a student at Oxford provides the hook to explain why medieval universities were such remarkable institutions, which had educated perhaps a million young men by 1500.
Falk shares a passion for mathematical astronomy with John of Westwyk, so it is not surprising that this subject occupies the bulk of The Light Ages. Falk’s ambition isn’t just to tell a story: he wants to demonstrate the ways astronomy was practised. He sets out detailed instructions on how to read astronomical tables and the use of a popular instrument called an astrolabe. In the last chapter, he shows us the Equatorie itself: a mechanical computer to determine the position of the planets.
This is complicated stuff and, at one point, Falk admits we might be confused. However, he has made an enormous effort to be as clear as he can be. His writing is straightforward and direct with almost no traces of academic pretension. His aim is to bring to a wider audience the work that scholars, himself among them, have been doing at the coalface.
Knowing where the sun and moon are, as well as a few choice stars, was essential to determine time, date and location. However, the only application for tracking the rest of the planets was astrology. John of Westwyk practised this art as well. Falk is careful not to be judgmental, presenting the various opinions of medieval authors about the efficacy of astrology without taking sides. When he covers medicine, Falk explains that it was based on rational theories and careful observation, rather than quackery or superstition. It was perfectly reasonable for medieval people to think that astrology could predict the future, even though it was not actually true. On the other hand, the mathematical astronomy of the astrolabe works as well today as it did 650 years ago. For this purpose, it doesn’t matter whether the earth is going round the sun or the sun orbits the earth.
Throughout The Light Ages, Falk stays discreetly in the background and lets his material take centre stage. It is only in the epilogue that he steps out from behind the authorial curtain to tell us how he rediscovered a 20th-century replica of the Equatorie that had languished in storage for 50 years. I would have liked to have heard a bit more about his personal experiences – what it is like to handle the polished brass of an astrolabe or leaf through vellum pages.
He also can’t resist the occasional anachronism. The references to the Big Bang and wave/particle duality while he discusses medieval theories of light do jar slightly. And despite the lucidity of his writing, the subject matter of The Light Ages inevitably means it can be heavy going at times. But the rewards are rich: Falk gives us a genuine understanding of how people long-dead saw their world and a respect for their considerable scientific acumen.