Physicist and philosopher
Conference : What does the polysemy of time reveal to us?
Étienne Klein is a French physicist and philosopher of science. A graduate of École Centrale Paris, he holds a DEA (Master of Advanced Studies) in theoretical physics, as well as a Ph.D. in philosophy of science and an accreditation to supervise research (HDR). He is currently head of the Laboratoire des Recherches sur les Sciences de la Matière (LARSIM), a research laboratory belonging to the CEA and located in Saclay near Paris. He taught quantum physics and particle physics at Centrale Paris for several years and currently teaches philosophy of science. He is a specialist in the question of time in physics and has written a number of essays on the subject. He presents a radio chronicle La Conversation scientifique every Saturday, on the French public station France Culture. Étienne Klein is the author of many books. He practises mountain-climbing and other endurance sports.
We reflect on time but we never really know what it is we are thinking about: is it a substance? a fluid? an illusion? or a social construct? There are many common sayings that suggest it's a physical being, while others imply the opposite, for example that it's just a figment of our imagination, or an aspect of natural processes. So, fundamentally, what is time really like? Is it how our language suggests? How we think we perceive or experience it? How it is represented by physicists? How it is thought of by philosophers?