Skip to main content

Chaos: unpredictable but understandable

Etienne Ghys

Research Director at CNRS, Professor at the École normale supérieure in Lyon Permanent Secretary of the Academy of Science of France

It is unusual for a mathematical idea to spread through society. But this is the case with chaos theory, popularized by the butterfly effect, imagined by the American meteorologist Edward Lorenz, who in 1972 asked the famous question: “Does the flapping of a butterfly’s wings in Brazil trigger a tornado in Texas?” The idea in this picture is that a small cause can have big consequences. But can chaos theory be summed up in such a simplistic way? Can a scientific theory be satisfied with negative statements? Are mathematicians responsible for the inadequate transmission of this theory? This lecture will attempt to address these questions and, in particular, to describe the positive side of the theory. Because there is a positive side. Chaos sometimes creates a kind of order. Chaotic systems may be unpredictable, but they are far from incomprehensible.

Before the lectures, from 17:30, the University’s public science labs, Scienscope, offer activities.

2 November 2020 - 18:30

Venue : Auditoire Piaget, Uni Dufour 24 rue Général-Dufour, 1204 Genève

Info : Simultaneous translation to French and English
- Lecture live streamed on this page.

Free entrance, on registration

Due to the health situation:

  • Face mask is mandatory in university buildings and for the duration of the event.
  • Dispensers of hydroalcoholic solution are available at the entrance.
  • The cleanliness of the premises is ensured in accordance with the UNIGE protection plan.

Public talks

Disorder, chance and large numbers
Disorder, chance and large numbers

3 November 2020 - 18:30

Laure Saint-Raymond

Professor at the École normale supérieure in Lyon
Bôcher Memorial Prize in 2020

More information
A mathematical journey From the infinitely small to the infinitely large
A mathematical journey From the infinitely small to the infinitely large

4 November 2020 - 18:30

Martin Hairer

Professor of mathematics at Imperial College London
Fields Medal in 2014 (obtained for research conducted at UNIGE)

More information
The music of shapes
The music of shapes

5 November 2020 - 18:30

Alain Connes

Professor at the Collège de France,
at the Institut des hautes études scientifiques at the University of Paris-Saclay
and at Ohio State University, Columbus
Fields medal in 1982

More information
Mathematics : art or science?
Mathematics : art or science?

6 November 2020 - 18:30

Stanislav Smirnov

Professeur à l’Université de Genève
Médaille Fields en 2010

More information

Scientific journalist, physicist, mathematician
Director of Science Communication at the Fondation Geneva Science and Diplomacy Anticipator.

More information

Previous editions


Gravity, l'attraction universelle


La révolution génomique


Les secrets du soleil


Architecture moléculaire


La révolution quantique


Grandes épidémies: le retour ?


[r]évolution climatique ?