Famous figures
Portraits of famous mathematicians, historical and contemporary

Salon 2016: maths transform our society | Tangente
The unmissable Salon Culture et Jeux Mathématiques will run from Thursday 26 to Sunday 29 May on Place Saint-Sulpice. Save these dates for the (free) mathematics event of the year!

Pierre Boulez, mathematics and glory | Tangente
"Music is a hidden practice of arithmetic, the mind unaware that it is counting," said Leibniz. Pierre Boulez, who died on 5 January, conductor, composer and teacher of music and musical composition all at once, revealed to the whole world the hidden face of "his" music, in which mathematics runs through like a watermark.

Three brilliant mathematicians would have turned 100
1916 evokes the Battle of Verdun. That same year, Halmos, Shannon and Apéry were born. Though very different, they would share an unconventional personality and an original contribution.

Richard Dedekind: Numbers and concepts
Richard Dedekind died on February 12, 1916. This gives Tangente an opportunity to profile a German mathematician fascinated by numbers, whose legacy continues to shape mathematics today. The concepts he introduced lie at the heart of modern algebra.

Mega primes: A new GIMPS record | Tangente
A quest that may seem far-fetched or pointless to some, but is of the utmost importance for our secret codes, is that of "mega primes" — in other words, prime numbers with more than a million digits.

Math teacher: a dangerous job for the government | Tangente
A middle school math teacher was arrested at New York's John F. Kennedy International Airport while boarding a plane in possession of a ruler, a protractor, a compass, a slide rule and a calculator.

Babylonians calculated Jupiter's course | Tangente
Fourteen centuries before the Europeans, the Babylonians already knew enough geometry to calculate Jupiter's course!

The proportional compass
Two thin, hinged plates for calculating proportions.

The king of geometry: Thales' theorem
In France, Thales' theorem concerns parallel lines and proportionality. Its proof, combining algebra and plane geometry, is remarkably elegant. It also leads naturally to two landmark results in triangle geometry: Menelaus' and Ceva's theorems.

From the Fields Medal to the Abel Prize: researchers in the spotlight
Since the beginning of the 20th century, a host of awards have been established to honor the finest researchers. What do they bring to mathematics? Do they spur research? And how well do our fellow countrymen fare?

Tales of Thales
Thales fascinates! Many historians of science and mathematics have taken an interest in this legendary figure.

The subverted geometry of Julien Prévieux | Tangente
The exhibition by Julien Prévieux, winner of the 2014 Marcel Duchamp Prize, "Des corps schématiques", running until 1 February 2016 at the Centre Pompidou (Paris), is not, strictly speaking, mathematical art, but since its theme is the recording of movement, some of the artist's geometric obsessions inevitably appear.

Thales and his theorem: historical uncertainty explained | Tangente
Who has never heard of Thales's theorem? Yet this extremely famous geometric statement is also one of the theorems whose history is least certain. Let's try to separate history from legend...

Commemorative maths prizes: honoring legacy | Tangente
Prizes help cultivate an appreciation for mathematics and recognize original teaching approaches. A prize has also just been created in tribute to a Chadian mathematician who was politically "eliminated".

Euler's correspondence with his contemporaries | Tangente
Leonhard Euler maintained an extensive network of correspondents across Enlightenment Europe. His exchanges with Christian Goldbach, of particular interest for number theory, have just been published.

Tao solves Erdős's discrepancy conjecture | Tangente
Terence Tao is one of the great "problem posers" of his time, since a photograph that went around the world shows him, at ten years old, already at work with the famous Hungarian mathematician.

Sophie Germain stamp: first look at the design | Tangente
A woman at the IHP!

Conjecture, conjecture... something will always come of it
Conjectures are especially famous when they have simple statements and resist mathematicians’ efforts for a long time. They give mathematics an air of mystery and bring great renown to those who solve them, but above all to those who first formulated them, such as Fermat and Goldbach.

The engine of mathematics
Mathematical progress owes much to conjectures, large and small, that challenge mathematicians. This was true long before Landon Clay and others offered million-dollar prizes: conjectures are the engine of mathematics.

John von Neumann: means and excess
The Banach–Tarski paradox claims that, in theory, the pieces of a single loaf can be turned into two loaves. It fell to the protean genius John von Neumann to explain the underlying reason for this mathematical miracle. The notion of amenability that he introduced then spread widely.
