Nathalie Braun
5 articles published in Tangente
History and CultureN°225Aug 18, 2025A short history of flexagons
Popularized by Martin Gardner, flexagons are geometric curiosities that sparked huge enthusiasm among the general public. Although their mathematical study began in the 1940s, they have not yet given up all their secrets.
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History and CultureN°221Dec 17, 2024Against slavery
In his Réflexions sur l’esclavage des nègres (Reflections on Black Slavery), published in 1781 under the pseudonym Pastor Joachim Schwartz ("black" in German), Condorcet opposed slavery, which he regarded as a fundamental violation of human rights, and denounced the contradictions and injustices bound up with the enslavement of Black people.
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Math for everyoneN°92Dec 04, 2024Pentagonal architecture
The pentagonal tower has stood since the 14th century in Castellane, a fortified town and subprefecture of Alpes-de-Haute-Provence.
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Math for everyoneN°92Dec 04, 2024Pentacles and pentagrams
The pentagram, also known as the star pentagon, is a non-convex pentagon formed by joining every other vertex of a regular pentagon. It has journeyed through the ages and across civilizations, always shrouded in mystery.
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History and CultureN°89Feb 20, 2024Descartes' way
How can fractions be handled geometrically? At the beginning of his most famous work, Descartes shows us how.
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