The 2018-2019 academic year was my last at the Collège de France. It allowed me to close the parenthesis opened in 2007-2008 on the annual Technological Innovation Liliane Bettencourt Chair with the lecture "Why and how the world is going digital". For this first introduction to computer science at the Collège de France, I had chosen a lecture for the general public, before moving on to more technical subjects in subsequent years. Closing the parenthesis meant returning eleven years later to a lecture aimed at a broad but curious and attentive audience, that of the Collège de France, to take stock of the state of computer science and outline the likely main lines of its evolution.
The computing landscape has changed a great deal since 2007: "digital" has revolutionized the world, drawing on computer science and all the technologies it nurtures. But the general public remains largely unaware of the true nature of computing and the causes of its major developments. It is little and poorly described in the media, which tend to focus all together on a single subject at a time, for example 3D printing, then automatic learning using deep neural networks, an artificial intelligence to which miracles or fears are indifferently attributed that have little to do with the reality, which is indeed impressive. Many other subjects, just as important but less conducive to fantasy, are all too rarely discussed. In fact, the popularization of computer science remains far less developed than that of physics or astronomy.