The author, Serge Haroche is a member of the Academy of Sciences and professor at the College de France (Chair of quantum physics). He received the 2009 CNRS Gold Medal. In this "audio book", he invites us simply enough towards the infinitely small, the quantum world through the study of light. We must, I think, however, already master some basic physics to fully understand it. To listen several times! Here is the summary: 1-The universal light 2-Light and quantum physics 3-The superposition of states 4-particles trapped 5-Schrödinger's Cat 6-The non-destructive detection of light 7-The coldest objects in the universe Basic and applied 8-Search