Everyday Math
Applied mathematics to everyday life: elections, sport, music, road traffic, weather, computer science, finance
A mathematical critique of liberalism | Tangente
In our "modern" and "civilized" societies, some workers are overwhelmed with work while a whole section of the population is shut out of employment. Is this situation inevitable? Bertrand Russell dismantled certain dogmas of economic liberalism point by point and showed that other models of society are possible.
An epidemic of ODEs
In epidemiology, mathematical modeling has three aims: to understand, describe, and predict. Since the focus is on what happens in the "fairly distant" future, continuous-time models involving differential or partial differential equations are generally preferred.
Models for biology
Historically, differential equations emerged in response to geometrical questions and problems in physics, particularly the study of planetary motion, pendulums and, later, heat diffusion. Yet they have plenty of applications in biology too!
Convexity in finance | Tangente
Mathematics plays an important role in finance. In recent years, returns on capital have been drastically reduced for various economic and political reasons. In Europe today, negligible returns on capital are becoming the norm, yet inflation remains very real, at around 5%.
Optimizing consumption | Tangente
Making consumption choices is no easy matter. But for a rational consumer, the notion of convexity is extremely useful! Consumer theory provides a case in point here.
A geometric and historical concept
Etymologically, the word "geometry" means the measurement of the Earth. Geometry has therefore always dealt with "lengths" and "distances." Initially empirical, the concept was gradually refined, structured, and axiomatized from antiquity to the present day—a long journey through both time and space.
Measuring distances in the Age of Enlightenment
In the 18th century, many mathematical treatises dealt with practical geometry. They presented numerous problems involving the measurement of lines, areas and solids, together with their solutions. Various methods were reviewed for measuring the shortest path between two points.
The point farthest from France's borders
Where is the "true" center of France? The question sometimes crops up among fans of recreational mathematics and divides enthusiasts of geographical curiosities. Depending on the criterion used to define this center, it may lie in the Cher, the Indre or… the Finistère!
Berlekamp problem: a strategy game | Tangente
The idea of distance has applications in some unexpected fields. A playful example is the Berlekamp problem, in which Hamming distance makes an appearance—and proves particularly effective!
Donald in Mathmagic Land: finally in comic-book form | Tangente
Donald in Mathmagic Land (Hamilton Luske, 1959) is a 27-minute short film produced by Walt Disney Studios.
An example of a group in the social sciences
A simple, classic, real-world application of the mathematical concept of a group can be found in social anthropology. It was brought to light by the anthropologist and ethnologist Claude Lévi-Strauss, working with the mathematician André Weil.
Elegant problem-solving: eight puzzles | Tangente
The final installment in our three-part series on methods for solving problems with a minimum of technical machinery. The aim is to discover an imaginative, original approach that shifts the puzzle into familiar territory.
The Chinese remainder theorem
The periodic nature of planetary revolutions naturally gives rise to the notion of congruence. The earliest surviving written problem on this theme is known as the Chinese remainder theorem. Its universality has led to many fundamental applications in the theory of numbers and polynomials.
An incongruous little tour through the world of congruences
Cooks have long known that making the most of leftovers is an art. The same is true in mathematics, where congruence is a remarkably rich concept. This notion has applications ranging from everyday life to highly theoretical settings.
Are the French averse to assessment? | Tangente
An attempt to analyze young French people's poor performance in international assessments.
Littéramath: the mathematical literature site | Tangente
A project highlighting the links between mathematics and literature
Constant mean curvature surfaces
The study of surfaces still holds plenty of surprises! Anyone who enjoys making bubbles with soapy water will be familiar with minimal surfaces. Constant mean curvature surfaces, such as catenoids and unduloids, are less well known.
A major role in the Dreyfus affair
The Dreyfus affair ranks among the great fiascos of French legal history, tearing society apart in its day. Mathematicians played a major role in securing Captain Dreyfus's rehabilitation, notably by writing a report on an application of probability theory.
The rider's technique in show jumping
The properties of centers of mass can be cleverly exploited to improve how a rider and horse clear obstacles. Geometry, too, can serve the cause of sport!
Area and barycenter
Barycentric coordinates offer a fresh approach to Routh's theorem and its applications to several results in Euclidean geometry.