This pdf book is available *free of charge* here (37 Mo), or on Arxiv, or on the website of ENS Éditions. Check this review by Serge Tabachnikov, from the Math Intelligencer (2018), here the review by Damien Mégy, from the Gazette des mathématiciens or by Fernando Gouvea from the Mathematical Association of America.

The LaTeX source files can be downloaded here (170 Mo).

A printed version is available for sale at ENS Éditions (27 €).

This book is published under a Creative Commons CC0 license.

I am very proud that a Turkish translation is available. Warm thanks to Betül Tanbay, Ferit Öztürk, Ahmet Feyzioǧlu and Arkadaş Özakın and to the Turkish Mathematical Society.

A stroll in the mathematical world. This is neither an elementary introduction to the theory of singularities, nor a specialized treatise containing many new theorems. The purpose of this little book is to invite the reader on a mathematical promenade. We pay a visit to Hipparchus, Newton and Gauss, but also to many contemporary mathematicians. We play with a bit of algebra, topology, geometry, complex analysis, combinatorics, and computer science. Hopefully, motivated undergraduates and more advanced mathematicians will enjoy some of these panoramas.