Does Time Exist at the Most Fundamental Level?

This video is part of the PROTEUS project that has received funding from the European Research Council (ERC) under the Horizon 2020 research and innovation programme (Grant agreement No. 758145)

Abstract

Our current theories of gravitation and quantum theory employ different concepts of time. Whereas time in general relativity is dynamical, time in quantum theory is an external parameter. The question thus arises what
happens with time if the two theories are combined into a theory of quantum gravity. What is the role of time there?

My talk consists of three parts. I first review how our physical concept of time evolved from Newton to Einstein. I then motivate to combining Einstein’s theory of relativity with quantum theory and discuss the concept of time in one particular approach. A general result will be the absence of time at a fundamental level. In the final part I show how time can be recovered as an approximation and how the arrow of time emerges from a fundamentally timeless world.

Ref.: C. Kiefer, Einstein Studies 13 (2017) 287-295; see also arXiv:0909.3767 [gr-qc] .

Bio

Claus Kiefer is Professor of theoretical physics at the University of Cologne. His research interests focus on quantum gravity and the foundations of quantum theory, black holes and general cosmological questions. In 2009, his essay, “Does Time Exist in Quantum Gravity?”, was awarded second prize by the Foundational Questions Institute, New York. In 2012, his essay, “Can Effects of Quantum Gravity Be Observed in the Cosmic Microwave Background?” (written together with Manuel Krämer), was awarded first prize by the Gravity Research Foundation, Wellesley Hills, USA.