The status of the laws of physics is one of the great foundational questions of science. Many theoretical physicists working on fundamental problems tacitly assume that the laws are infinitely precise, immutable, universal and eternal mathematical relationships, occupying the ontological basement of reality. In cosmology, transcendent laws are often invoked to explain the origin of the universe from nothing as a lawlike physical process. There is, however, a contrarian concept, deriving from the field of computation, and exemplified by Rolf Landauer’s hypothesis that as idealized mathematical relationships cannot be implemented in the real universe they should not be invoked as fundamental laws; real computations always involve imprecision and uncertainty. Even on a cosmic scale the observable universe will have a finite computational capacity. John Wheeler famously championed the notion that the laws of physics are ultimately mutable and imprecise. These considerations of Landauer and Wheeler suggest a new source of unknowability in the universe deriving from limitations on computational power, and invite a reformulation of the halting problem of the theory of computation.
Paul Davies