The Housekeeper and the Professor

Memory and maths in the modern world


In 2003 the Japanese writer Yoko Ogawa published The Housekeeper and the Professor, translated into English in 2009 and released as a film entitled The Professor and His Beloved Equation in 2006. The protagonist of the novel is a retired professor of mathematics whose memory lasts only 80 minutes.

Professor_HousekeeperThe consequences of the car accident that led to the professor’s impairment are told through the eyes of his new housekeeper, who is charged with taking care of the professor, his home and his unusually challenging day-to-day life. For the professor and his limited memory, the housekeeper is new every day. Every object that has been moved for more than 80 minutes results in a frantic search. Everything the professor has to remember is jotted on a post-it note and attached to his jacket with safety pins. The oldest and easiest to reach note reminds him that his ‘memory lasts only 80 minutes’.

There are very few characters in the drama, and the most important one is not an actor but the great, almost obsessive love, of the professor. His mathematics. In fact, his amnesia does not prevent him, after getting acquainted every day with the new old housekeeper, from tackling new formulas and trying to prove new theorems. Soft lead pencils and paper are consumed at a furious pace, in the knowledge that in 80 minutes he will have to start all over again. Inside the drawers of his desk one can find more or less recent awards and prizes for his publications. These the professor will forget every time the drawers remain closed for longer than the span of his memory.

Paul Erdös with a young Terence Tao

Paul Erdös with a young Terence Tao.

In the book, the most evident contrast is between the impossibility of building any meaningful human relationship and the professor’s successful activity in the field of mathematics, despite his lack of memory and almost autistic behaviour. In the novel’s development, it is impossible not to notice similarities with the mathematicians André Weil, Srinivasa Ramanujan or Paul Erdös. Indeed, it is suggested that the professor was based on the latter.

Alongside the plot of this sad and delicate novel stands the beauty and mystery of mathematics, which will affect the work of the housekeeper and shape the future of her 10-year-old son, who the professor calls Root. But at the end of the novel, the question remains: is it possible to do maths, and publish groundbreaking work, with a memory that lasts only 80 minutes?

Memory seems to be fundamental for human survival. It often seems to be the key ingredient in passing exams as students and applying memorised solutions as professionals. For some modern philosophers, such as Henri Bergson, memory is a synonym for the spirit itself. Is it not true that a perfect memory of every event of our past, studied in detail, would open doors that are otherwise sealed? Even more so in mathematics, where the ability to recall in an instant every formula and strategy studied in order to apply the correct one to a particular problem would surely lead to ever greater success?

The artificial creation of this sort of memory has been made possible in the integrated electronic circuits of today, but computer and human memory remain radically different, both in its capacity and the way in which they process data. The table below, proposed by David Kriesel, summarises their differences in storage methods, time requirements and type of processing unit.


Modern attempts to simulate our learning processes and even our neural structures through machine learning algorithms may not be as tolerant to errors and as able to generate unusual associations as we are. This is especially true in situations different from the ones in which they have been specifically programmed.

Despite these differences and the known impossibility in implementing the human mind in a computer (in rare occasions, the opposite has successfully been achieved), the best approximation of infinite memory is always at everybody’s fingertips. Google is on our side. It has all the answers (even the wrong ones). It remembers everything, but how many times has its silicon memory alone solved a problem on which we were working?

The romantic figure of the professor and his very existence, albeit fictitious, is perhaps meant to represent the elusive working of the human mind, even when every day (or every 80 minutes) everything has to be started all over again. Even when the results we obtained in one particular scenario are not immediately valid in situations only slightly different. The challenges that mathematics poses are not just about the acquisition of new memories. In fact, they ask to be approached with new eyes every time.  They ask and instruct us to turn aside from old, well-worn paths. They ask us to forget.

[Pictures: Banner adapted from TextureX, Flickr and deradrian, Flickr under creative commons license CC BY-SA 2.0; Paul Erdös and Terence Tao by Terence Tao, creative commons license CC BY-SA 2.0.]

Sebastiano is a PhD student in medical imaging and biomedical engineering at UCL, where he works on the image registration problem. When he’s not struggling with diffeomorphic transformations between MRI scans, he is likely to be wandering aimlessly around London, playing electric bass or reading some popular classic book.

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