It was around 1920 that the hypothesis that particles of matter are also waves was proven. This dual "particle-wave" nature is a foundation of quantum physics and one of the most paradoxical concepts.

To observe these wave-like properties of atoms or molecules, we must significantly slow down their motion and therefore cool them. This is the dedication of Jean Dalibard: to cool the gas of atoms very close to absolute zero, around –270 degrees Celsius. To achieve this, he uses lasers that hinder the motion of the atoms in order to slow them down.

This experimental feat led to significant progress in fundamental physics and could serve as an approach method for the future quantum computer. In an exceptionally educational way, integrating his research into the thread of the history of physics, Jean Dalibard reveals to us some of the most astonishing properties of the infinitesimally small.