Looking at Nature as a Computer

Although not always identified as such, information has been a fundamental quantity in Physics since the advent of Statistical Mechanics, which recognized “counting states” as the fundamental operation needed to analyze thermodynamic systems. Quantum Mechanics (QM) was invented to fix the infinities that arose classically in trying to count the states of Black Body radiation. In QM, both amount and rate of change of information in a finite physical system are finite. As Quantum Statistical Mechanics developed, classical finite-state models naturally played a fundamental role, since only the finite-state character of the microscopic substratum normally enters into the macroscopic counting. Given more than a century of finite-state underpinnings, one might have expected that by now all of physics would be based on informational and computational concepts. That this isn't so may simply reflect the stubborn legacy of the continuum, and the recency and macroscopic character of computer science. In this paper, I discuss the origins of informational concepts in physics, and reexamine computationally some fundamental dynamical quantities.