This pdf book is available *free of charge* here (37 Mo), or on Arxiv, or on the website of ENS Éditions.

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 Oztürk, Ahmet Feyzioglu and Arkadas Ozaki 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.