Math for everyone
Mathematical content accessible to everyone
Art, virtual tokens and blockchain | Tangente
The best-known blockchain is used to verify ownership of bitcoins in a way that is, in principle, tamper-proof.
Two and a half centuries of optimal transport
Moving a pile of sand, transferring colors from one image to another, minimizing a group’s travel time—all these problems can be tackled using optimal transport. Gaspard Monge pioneered a theory that computing has made remarkably effective.
Nivat's conjecture
Although easy to state, questions in discrete mathematics are generally hard to solve. Progress often comes when a problem is linked to another field. This is the case with Nivat's conjecture, which has resisted mathematicians for more than twenty years.
Teja Krašek in Escher's footsteps | Tangente
Born in Celje, Slovenia, Matjuska Teja Krašek (pronounced "Teyla Krashek") lives and works in Ljubljana. Her work draws on her fascination with symmetry, fractals and, more broadly, the beauty she sees in mathematics. She agreed to share her passion with us.
The 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?
The Zodiac's encrypted messages | Tangente
At the turn of the 1970s, a serial killer was at large in California. What set him apart was that he communicated with the police through seventeen letters, four of them encrypted. The first was deciphered in 1969; the second has only just been cracked. These cryptograms put a new spin on classic cryptographic methods.
Counting protesters | Tangente
One hundred thousand protesters, according to the organizers; twenty thousand, according to the police! The discrepancy between estimates of the number of people in a march is a perennial source of puzzlement—and mockery—for outside observers. Is there really no way to provide a reliable figure for the number of protesters?
Penrose and the sharing of knowledge | Tangente
Sir Roger Penrose is an outstanding popularizer, both in print and as a speaker.
Penrose and the Kleenex affair | Tangente
In the 1970s, Roger Penrose filed patent applications for several of his aperiodic tilings (!) and founded a company, Pentaflex, to manage the patent rights.
Nobel prizes in physics and mathematics | Tangente
The most famous winner of the Nobel Prize in Physics is probably Albert Einstein, honored in 1921 for his work on the photoelectric effect—not for his celebrated theory of relativity.
Penrose's impossible figures | Tangente
Penrose's name is associated with several "impossible objects."
Homo academicus in his labyrinth | Tangente
Exploring the literary corpus offers an opportunity to highlight some of the logical and paradoxical arguments that can be brought to bear. Let us take a closer look at Le Stratagème (The Stratagem), a story from Jorge Luis Borges's Le Livre de sable (The Book of Sand).
Le Tellier, maths guy and Prix Goncourt winner | Tangente
With Hervé Le Tellier, who has just received the prestigious Prix Goncourt for his novel L’Anomalie, where logic and magic jostle for space, literature meets mathematics.
2021 with a twist
As it does every year, Tangente's editorial team brings you a selection of ingenious calculations to celebrate the new year. The locked-down year of 2020 is gone; the year of games has begun. Welcome to 2021!
Diagonal Ramsey numbers
The events committee (BDF) at the École des champions wants to organise a party by inviting people selected at random from the new intake.
Dazzling Penrose tilings
Sir Roger Penrose is renowned for his remarkable and foundational work in geometry and cosmology, and for the applications of that work to black holes. It is puzzling, however, that he is famous to the general public for the tiling that bears his name, with its many remarkable properties.
Promoting reliable science communication | Tangente
Since 1968, the French Association for Scientific Information (AFIS) has published the quarterly magazine Science et Pseudo-Sciences. Its aims are to promote science and combat those who invoke its name as a cover for quackery.
Squares in art | Tangente
Several artists have taken an interest in the square in order to explore its geometry
Vaughan Jones, the knot magician
The mathematician Vaughan Jones, who died on September 6, 2020, profoundly influenced several areas of mathematics, including topology and functional analysis, as well as physics, particularly quantum theory. His name remains associated with powerful invariants in knot theory.
Three unsolved problems in geometry | Tangente
Geometry abounds in problems that remain unsolved. Some date back to the Renaissance! In tribute to Richard Kenneth Guy (1916–2020), here are three, gleaned from his book Unsolved Problems in Geometry (with Hallard Croft and Kenneth John Falconer, Springer, 1991).