BERTRAND HAUCHECORNE
179 articles published in Tangente
Math for everyoneN°80Nov 16, 2021Some examples of groups
The first examples that spring to mind are groups of numbers. But groups crop up in every area.
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History and CultureN°202Oct 13, 2021Schwarz's theorem
From Euler to Cauchy, via Clairaut, no one doubted that reversing the order of partial differentiation left the result unchanged. Hermann Schwarz overturned this belief with a superb counterexample.
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Math for everyoneN°202Oct 12, 2021The Parisian origins of Nicolas Bourbaki
A plaque honoring the Bourbaki group at the site of its first meeting in a Paris café.
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KnowledgeN°202Oct 12, 2021From intuition to rigor:
From Cauchy to Weierstrass, rigor steadily took hold in analysis throughout the 19th century. A variety of counterexamples swept away mistaken beliefs and forced mathematicians to define the relevant concepts more precisely. Some "monstrous" functions were introduced, fascinating to some and repellent to others.
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History and CultureN°202Oct 12, 2021The exception that does not prove the rule
A persistent belief holds that counterexamples are primarily a source of amusement. Yet they play a fundamental role in several areas, both as mathematical proofs and as teaching tools—not to mention their entertaining, or even artistic, side, depending on how one looks at them.
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History and CultureN°79Aug 23, 2021When Poincaré is being ironic
Henri Poincaré regarded experience and intuition as essential to the foundations of mathematics. He was therefore often ironic, even caustic, toward those who relied on abstract logic to provide a foundation for arithmetic
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History and CultureN°200Jun 15, 2021A driving force for innovation in education
Tangente reaches a great many teachers and is also available in secondary-school libraries across France and the French-speaking world. Alongside its initiatives aimed directly at teaching, its support for more diverse approaches to learning has proved extremely valuable. Experts attest to this.
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History and CultureN°200Jun 15, 2021Tangente, a catalyst for mathematical culture
A magazine devoted to mathematical culture—that is sure to surprise more than a few people! When Tangente arrived in 1987, it transformed the way mathematics was viewed. It inspired some readers to pursue a path they had never considered and others to embark on initiatives to popularize mathematics. Many prominent figures bear witness to this.
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Math for everyoneN°78May 19, 2021Through Euclid's eyes
Two postulates in Euclid's Elements embody the ideal conception of the straightedge and compass inherited from Plato's realm of Ideas. The Alexandrian scholar built much of plane geometry—and the constructions he bequeathed to us—on these two postulates.
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History and CultureN°199Apr 19, 2021László Lovász and Avi Widgerson, 2021 Abel Prize winners
This year, the Norwegian Academy of Science and Letters has put theoretical computer science and graph theory in the spotlight.
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Math for everyoneN°199Apr 13, 2021The Mercator projection
The best-known maps are based on the famous Mercator projection, named after its Flemish creator, who worked in the early Renaissance. Yet this projection relies on mathematical concepts developed well after the scholar’s death! So how could he have constructed his world map?
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N°77Feb 18, 2021“A better understanding of how the brain works”
Dr Christophe Habas is a neuroradiologist. He heads the medical imaging department at the Quinze-Vingts Hospital in Paris. His work combines hospital practice, research and university teaching. He has an in-depth understanding of the role mathematics plays in medical techniques, which he kindly agreed to share with us.
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