2025 Tangente Book Prize: three books making mathematics accessible and captivating
The Tangente Book Prize, whose 2025 winners were announced at the Salon jeux et culture mathématiques (Mathematics Games and Culture Fair) on Saturday, June 14, is awarded each year to a book for the general public that inspires readers to learn more about one or more areas of mathematics. This year, the prize was awarded to Le Rulpidon sous toutes ses coutures by Sylvie Benzoni-Gavage, professor at the Institut Camille Jordan1 . The books Matheuses. Les filles, avenir des mathématiques (Matheuses: Girls, the Future of Mathematics) and Pourquoi est-on penché dans les virages ? Le sport expliqué par les sciences en 40 questions (Be A Champion: 40 facts you didn't know about sports and science) received honorable mentions.
- 1CNRS/École centrale de Lyon/INSA Lyon/Université Claude Bernard/Université Jean Monnet
The Rulpidon from every angle
In the courtyard of the Maison Poincaré in Paris stands a 300-kilogram sculpture measuring 2 meters on each side, made of steel plates: the Rulpidon. Depending on the angle, this work by Ulysse Lacoste appears as a square, a circle, or more or less elongated ovals. This hybrid is a Steinmetz solid, named after the mathematician Charles Proteus Steinmetz, although it was previously described in detail by Count Léopold Hugo, Victor's nephew, under the name “equidomoïde à base carrée” (square-based equidomoïde).
Fascinated by this geometric curiosity, mathematician Sylvie Benzoni sets out to investigate. Combining insatiable curiosity with mathematical reasoning, Sylvie Benzoni takes us into the strange world of topology, a branch of mathematics that studies the properties of geometric objects.
- For more information: “Le Rulpidon sous toutes ses coutures” (The Rulpidon in all its glory): three holes, nine colors, and one unknown | Le Monde
Matheuses. Girls, the future of mathematics
At age 17, one in two French girls no longer studies mathematics, compared to only one in four boys. These inequalities raise many questions among teachers, families, scientists, and teenagers. How can we get more girls into mathematics? How can we support them in the classroom? How can we encourage our daughters to study maths when we ourselves gave up? How can we change the way maths is taught so that it is no longer exclusive? Finally, how can we feel less alone when we are a girl who loves maths?
This book, written by Clémence Perronet, a sociologist at the Centre Max Weber2 , Claire Marc, from the Méduse Communication agency, and Olga Paris-Romaskevich, a mathematician at the Institut Camille Jordan3 , is as much a book about math as it is a math book, and aims to provide the broadest possible answers to these questions. It presents the results of a sociological survey and gives a voice to 45 teenage girls, while inviting readers to discover original math problems at their own pace.
- For more information: Matheuses: Girls, the future of math is a meeting between three worlds: women, mathematics, and sociology | CNRS Mathematics
Be A Champion. 40 facts you didn't know about sports and science
Why do sprinters slow down before the finish line? Why do golf balls have dimples? Why do we swim better slightly below the surface of the water? Why are we more stable on a bike when we go faster? Why do we clench our arms when we do a pirouette? Is there a law governing the evolution of records?
Amandine Aftalion, a mathematician at the Laboratoire de Mathématiques d'Orsay4 , answers 40 questions using concepts from physics and mathematics, presented in a simple and enjoyable way, giving us a better understanding of sports. At a time when big data is invading sport, we discover that predictive and deterministic equations remain the basis for analyzing athletic performance. An accessible book for anyone who plays or watches sports and asks themselves, “But why?”
- For more information: “Be A Champion: 40 facts you didn't know about sports and science,” a book that combines mathematics, physics, and sport | CNRS Mathematics
Les prix Tangente
The Tangente club was founded in 2013 by fourteen authors from the mathematical culture magazine Tangente with the aim of promoting mathematical culture to the general public. Each year, the Tangente Book Prize is awarded to a book that has inspired a wide audience to learn more about one or more areas of mathematics. Another prize, called the Tangente High School Prize, aims to bring a different perspective to mathematics and combat the “scientific” versus “literary” labels in high schools. This year, it was awarded to the comic book Laurent Schwartz, les engagements d'un médaillé Fields (Laurent Schwartz, the commitments of a Fields Medal winner).