The Clock Ambiguity and the Emergence of Physical Laws

          @misc{ scivideos_PIRSA:08100038,
            doi = {10.48660/08100038},
            url = {https://pirsa.org/08100038},
            author = {Albrecht, Andreas},
            keywords = {Cosmology},
            language = {en},
            title = {The Clock Ambiguity and the Emergence of Physical Laws},
            publisher = {Perimeter Institute for Theoretical Physics},
            year = {2008},
            month = {oct},
            note = {PIRSA:08100038 see, \url{https://scivideos.org/index.php/pirsa/08100038}}
          }
          

Abstract

The “clock ambiguity” is a general feature of standard formulations of quantum gravity, as well as a much wider class of theoretical frameworks. The clock ambiguity completely undermines any attempt at uniquely specifying laws of physics at the fundamental level. In this talk I explain in simple terms how the clock ambiguity arises. I then present a number of concrete results which suggest that a statistical approach to physical laws could allow sharp predictions to emerge despite the clock ambiguity. Along the way, I get to ask some interesting questions about what we expect of fundamental laws of physics, and give some surprising answers.