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Mathematical memories

The Housekeeper and the Professor

  • Yoko Ogawa
. Translated by Stephen Snyder Harvill Secker/Picador: 2009. 192 pp. £11.99/$14 0312427808 9781846552502 | ISBN: 0-312-42780-8

The Housekeeper and the Professor does for number theory what Jostein Gaarder's best-seller Sophie's World (Aschehoug, 1991) did for the history of philosophy, but with a far lighter touch. The narrator, ignorant of mathematics, becomes a surrogate for the average reader as the recipient of a great deal of detailed information. It is indisputably a novel, but it is unapologetically educational.

The Professor is an elderly mathematician whose memory lasts only 80 minutes, as a result of a head injury in a car accident in 1975. Everything that happened before his injury, including his vast grasp of number theory, remains in his mind, but every 80 minutes he has to start all over again.

With his amnesia being understandably hard on the people around him, the Professor is stashed in a cottage on his sister-in-law's property. He has gone through nine frustrated housekeepers by the time the eponymous one is called into service. The Professor's suit is blanketed with hand-written notes to help him navigate the world, the most crucial of which says “My memory lasts only 80 minutes.” Soon, a sketch of the new housekeeper joins the hundreds of other attached scraps, proving useful when she has to introduce herself every morning. Within minutes of their first meeting, the Professor starts to share his love of mathematics with her, and then with her son who joins them after school.

The Housekeeper, who like the Professor remains unnamed throughout the novel, is no ordinary servant. Possessed of intelligence, a keen curiosity and tremendous empathy, she is soon fascinated by her charge and surprisingly receptive to the Professor's lessons, as is her son. It helps that the Professor is an eloquent and skilled teacher. In one memorable scene, he likens the search for very large prime numbers to a quest through the desert wastelands. The Housekeeper has a vivid imagination and personifies the concepts: primes, in resisting division by any number other than zero and one, are “stubborn”; the 'abundant' number 18, whose divisors' sum is greater than itself, “secretly carried a heavy burden”; the 'deficient' number 14, whose divisors' sum is less, “fell mute in the face of its terrible lack”. These tactics help readers to understand the concepts in a creative way, although not everyone will want to follow the strings of equations and diagrams that occasionally invade the prose.

Mathematics inspires a reverence in the Professor. There are repeated references to numbers as mystical entities, existing on the pages of “God's notebook”. And in a world that is constantly being whisked out from underfoot, the Professor is comforted by the predictability of things he can remember: mathematics, of course, but also statistics on baseball cards, or how to predict the position of Venus in the evening sky. A single mother with a dead-end job, the Housekeeper also finds maths a source of clarity: “I needed the sense that this invisible world was somehow propping up the visible one, that this one, true line extended infinitely, without width or area, confidently piercing through the shadows. Somehow, this line would help me find peace.”

The mathematical lessons weave through a narrative that is uneventful but pervaded by a sense of beauty. Although the translation is fresh, and the characters could be of any nationality, there is a Japanese ambience. The language is as precise and graceful as a tea ceremony, and the backstory as sparsely sketched as shodo calligraphy. And if the Housekeeper's newly kindled enthusiasm for numbers sometimes stretches the reader's credulity, the book is so charming that the author is forgiven.

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Rohn, J. Mathematical memories. Nature 460, 461–462 (2009).

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