PHILIPPE BOULANGER
26 articles published in Tangente
Games and ChallengesN°218Jun 13, 2024The surprising aperitif problem
Where should a platter of canapés be placed to satisfy the guests as well as possible? This seemingly innocuous problem has inspired brilliant developments over the centuries. It also illustrates how individual and collective optimization are often at odds—a seemingly paradoxical result.
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Math for everyoneN°74Apr 17, 2020Wheels and roads to match
Surprisingly, wheel and road profiles can be tailored so that the wheel’s axle remains at a constant height, ensuring maximum comfort for the traveller.
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Math for everyoneNov 21, 2019Paradoxes and self-contradictions
A source of amusement, self-reference also lies behind some famous and profound mathematical paradoxes. Logic, our senses and our certainties are all sorely tested. Reflection then takes over… and often leads to wonder!
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Math for everyoneN°71Jul 10, 2019A point charge
A point charge is a source of mystery, like an electron with charge e in a vacuum.
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KnowledgeN°70Apr 11, 2019Operations in billiards
One of the arts and pleasures of mathematics is finding different ways to represent problems. Some problems in dynamics can profitably be replaced by the study of trajectories on a billiard table, revealing hidden structures—and hence hidden logical beauty.
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CuriosityN°70Apr 11, 2019Knitted surfaces
Knitting is generally used to make clothes. Mathematicians face no such limitations: they are interested in other kinds of surfaces that can be recreated with yarn and a needle. The result? Objects that are at once geometric, educational and… artistic!
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Math for everyoneN°69Jan 21, 2019Finding your position at sea
On Earth, a position is identified by two coordinates: latitude and longitude. Finding your position means determining these two values.
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Games and ChallengesN°182May 17, 2018The ever-surprising curiosities of the harmonic series
The harmonic series is one of the few divergent series that frequently arises in science. In mathematics, naturally, but not only there: it also turns up in a theater, in the guise of an absent-minded spectator who has forgotten his seat number, and in problems involving stacks of sugar cubes.
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Games and ChallengesN°182May 16, 2018When expected value turns paradoxical
Expected payoff is essential to rational decision-making, but tricky to use. Many paradoxes arise from misinterpreting what it represents. Casinos—and the unscrupulous people who encourage you to wager your money—understand this only too well...
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History and CultureN°182Mar 19, 2018Statistics: beware of fluctuations!
Extracting knowledge from a mass of homogeneous data is the province of statistics. Yet it is quite an art: the conclusions must be treated with care! Small fluctuations around the mean can invalidate an entire line of reasoning. Let us learn how to spot them.
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History and CultureN°179Nov 22, 2017Punch-card control: from Jacquard to Hollerith
Interfaces are a defining feature of our culture: the punch-card control system of the Jacquard loom transformed textile manufacturing. But who remembers it today? It was a first step towards the computer, which now governs how we interact with the world.
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Math for everyoneN°177Jul 17, 2017Poets talk to us about math… and vice versa
Mathematics and poetry are two ways of making sense of the world. Worlds apart? Not quite.
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