What is time? What is change? The Ontology of Dynamical Systems

Conférence de Johannes Jaeger (CRI / Complexity Science Hub Vienna) dans le cadre du cycle de conférences "Sciences in Context", organisé par le CRI et l'IEA de Paris

Sciences in Context est un nouveau cycle de conférences publiques, organisé par Muriel Mambrini et Pascal Kolbe, en collaboration avec l'Institut d'études avancées de Paris, visant à amener les concepts et les perspectives des SHS à la communauté du CRI.
Chaque conférence aura lieu le dernier mardi du mois avec des chercheurs du CRI et de l'IEA de Paris.
Les sujets de la conférence seront discutés lors d'une séance publique du Practical Philosophy Club le vendredi avant chaque conférence, afin de favoriser les échanges avec le conférencier invité.

Programme complet du cycle de conférences

Résumé

Ever since Zeno's paradox of the arrow, the nature of time and change has been a deep, puzzling mystery. How can Zeno's arrow move at any one instant? How can it traverse an infinity of instants before hitting its target? The idea of instantaneous velocities, introduced by Leibniz and Newton, seem to have solved Zeno's problem. However, major questions about the nature of time remain, and we are still struggling to find a rigorous and general definition of the concept of change. I will use the mathematical tools of dynamical and general systems theory (presented in an accessible and non-technical way) to introduce a general notion of change (or flow). It implies that any coherent concept of change must be extended in time. It must have a duration. In mathematical terms, change requires some sort of mapping or morphism forward over an interval of time. I will discuss how a time-extended concept of change leads to the sort of consistent causal dynamics we observe in the world. Change as a time-extended mapping with duration suggests the radical notion that instantaneous moments, or instants, do not exist. The abstract idea of instants is convenient for solving many practical and mathematical problems. However, it does not represent the true time-extended nature of the ever-flowing present moment.

Johannes Jaeger was educated in Switzerland, New York, and Cambridge. He is the former head of an interdisciplinary research laboratory at the Centre for Genomic Regulation (CRG) in Barcelona (from 2008 - 2015). In 2014/15, he was a fellow at the Institute for Advanced Study in Berlin. He was the director of the Konrad Lorenz Institute for Evolution and Cognition Research (KLI) in Klosterneuburg near Vienna from 2015 to 2017, and a visiting scientist at the Center for Systems Biology Dresden in 2017/18. He has a gues professorship at the University of Vienna, is associated with the Complexity Science Hub (CSH) Vienna, and is currently a fellow at CRI.