![Cedric in his office](https://www.telegraph.co.uk/multimedia/archive/03221/SUMM_A3A8435-HD_3221687b.jpg?imwidth=680)
Fields Medal winner Cédric Villani: 'the human brain is not designed for maths'
The flamboyant mathematician, whose semi-autobiographical book is published this week, reveals his pet dinosaur, teaching methods and mysterious love of spiders
![Cedric in his office](https://www.telegraph.co.uk/multimedia/archive/03221/SUMM_A3A8435-HD_3221687b.jpg?imwidth=680)
Professor Cédric Villani, 41, is a French mathematician who focuses chiefly on the theory of partial differential equations and mathematical physics. After winning the Fermat and Henri Poincaré prizes in 2009, he was awarded the prestigious Fields Medal – described as the ‘Nobel Prize for Mathematics’ – in 2010 for his work on optimal transport and kinetic theory. Villani, who is a household name in France, is director of the Institut Henri Poincaré in Paris and a professor at Lyon University; his part-autobiographical book, Birth of a Theorem: A Mathematical Adventure (Bodley Head, £18.99), was published this week. Villani lives in the Parisian suburbs with his wife, Claire, 40, a biologist, and their two children.
Routine Since becoming well known, normal days have all but disappeared for me, so I rarely find consistency. If I am at home, however, I will usually rise at 7am, the same time as my children. I breakfast on warm milk, preferably full-fat and unpasteurised, with jam and crispbread, before heading into Paris for work.
Signature style I wear a three-piece suit, velvet cravat, pocket watch and brooch every single day, even if I am at home. I began to dress like this as an experiment when I was president of my university’s student union, but it soon stuck. People often think I am a poet or musician, so it is a nice conversation-starter. My body has adapted to it, and I even dress this way when I work in central Africa. The only times I do not are for sleeping and exercise, though I do little of the latter now I have given up competitive table tennis.
![dinosaur](https://www.telegraph.co.uk/multimedia/archive/03221/_A3A8363_3221697c.jpg?imwidth=680)
PHOTO: Baudouin
Dinosaur
My great love as a child was dinosaurs, and I think I read everything on the subject below professional level. When I moved to Paris for school, aged 17, I bought this toy dimetrodon, named Philibert. He is not technically a dinosaur, of course, since dimetrodons became extinct before the Triassic period, but he looks it. Philibert was my buddy: I would keep him in my bag and leave the zip open so he could breathe, and when I left the room I made sure a maths book was in front of him so he wasn’t bored. Years later I read that
did the same with his teddy bear at university.
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PHOTO: Baudouin
Spiders I have been wearing large spider brooches as part of my look for the past 10 years, but I do not tell anybody why. There was an incident, and that is all I say. It is my one secret, and I believe everybody should have a mystery about them. I have more than 30 in my collection now, from all over the world, and most are made or commissioned for me. In my office I also have a taxidermy tarantula.
Pets At home we have eight rabbits, five hens and one cat. My wife takes care of the garden with our children, who love learning about the animals. They are particularly fascinated by the processes of life, reproduction, survival and so on, which is brilliant because it is so important for children to see these things first hand. The hens lay eggs for us every morning.
Rubik’s cube Many people ask me if my children have inherited a gift for mathematics, and I hate this question. I myself am the son of two literature professors, so you never know what children will be interested in; you need to let them discover it. Truthfully, my children, who are 14 and 11, are far better with their hands than me. Currently they both obsess over Rubik’s cubes.
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PHOTO: Baudouin
Mask I was given this half of a dramatic mask as a gift from Lad’AM, a benevolent academic sect based in Paris, which uses literature and maths in public stunts across the city. On it is written the number 284, while the other half, which they have, has 220. Those are the two lowest ‘amicable numbers’ – meaning that the sum of their proper divisors is equal to the other number – which is very rare. The Pythagoreans thought this was a sign of friendship in the numerical world, so it is a nice reminder about the start of maths, when people were just looking for patterns in numbers.
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PHOTO: Baudouin
Snark-capturing kit One of my heroes is Lewis Carroll, who as well as being a wonderful writer was also very interested in mathematics and made great advances in the presentation of logic. Any literature that constructs absurdity from reason is appealing to me, like anagrams and puns, so Carroll’s nonsense verse is a particular favourite. I can still recite the whole of Jabberwocky, having learnt it as a child. Shortly after graduating, I made a kit based on Carroll’s poem The Hunting of the Snark. The craftsmanship is rudimentary, but within it contains samples of everything a snark hunter is said to need: thimbles, care, smiles and soap, railway-shares, forks and a bit of hope.
Teaching The human brain is not designed for maths, but it is made for language and stories. When I am doing my public lectures and teaching people, I always begin with a story and weave the maths in. If one can explain how a bat finds its food through maths, for instance, it is more likely people will be interested. This is why my talks are full of references to songs, history and film. I am also co-creating a comic book this year with a French graphic artist, in which one of the characters is Alan Turing. It is so important we study and keep understanding mathematics, especially in the age of computers.
Africa I only discovered Africa rather recently. It’s funny, there is a perception in the West that Africa is in need of our help, but in fact my career was helped initially by a mathematician from Benin, who teaches in Atlanta. I am also the son of Algerian refugees, but had rarely been to the continent. Five years ago that Beninese colleague invited me to lecture in a summer school. I have returned every year since. It is where I bought this mask of a man blissfully kissing [pictured], which was a particularly enjoyable sale as I love haggling the price. The happiness and children’s enthusiasm for learning in Africa is far better than in the West, and I am now heavily involved in promoting mathematics through various projects across Senegal, Cameroon, Nigeria and Benin.
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PHOTO: Baudouin
Fields Medal Winning the Fields Medal is in the back of any mathematician’s mind, but I did not think it was possible for me until just a few years before I did. The ceremony is held every four years in a different city, and the medal awarded to up to four different people, all under the age of 40, by the International Congress of Mathematicians. I won in Hyderabad in 2010, when I was 36, so it was my last chance. The medal itself [pictured] is 8ct green gold, plated with 24ct gold, and features Archimedes on one side. Winning has opened so many doors, as I was invited to speak all over the world, from universities to TED talks.
![Gomboc](https://www.telegraph.co.uk/multimedia/archive/03221/_A3A8353_3221695c.jpg?imwidth=680)
PHOTO: Baudouin
Gömböc This funny-looking object is called a gömböc. It is remarkable because it has only two points of equilibrium: one stable and one unstable, meaning that however it is placed on a surface, it will always right itself. Its existence was only proved in 2006 by Hungarian scientists, and it has very little practical application (though does go some way towards explaining how tortoises get back on their feet). It is, then, just research for the sake of maths itself, like beautiful art.