In physics and cosmology, digital physics (also referred to as digital ontology or digital philosophy) is a collection of theoretical perspectives based on the premise that the universe is describable by information. According to this theory, the universe can be conceived of as either the output of a deterministic or probabilistic computer program, a vast, digital computation device, or mathematically isomorphic to such a device.

The operations of computers must be compatible with the principles of information theory, statistical thermodynamics, and quantum mechanics. In 1957, a link among these fields was proposed by Edwin Jaynes.[2] He elaborated an interpretation of probability theory as generalized Aristotelian logic, a view linking fundamental physics with digital computers, because these are designed to implement the operations of classical logic and, equivalently, of Boolean algebra.[3]

The hypothesis that the universe is a digital computer was proposed by Konrad Zuse in his book Rechnender Raum (translated into English as Calculating Space). The term digital physics was[citation needed] employed by Edward Fredkin, who later came to prefer the term digital philosophy.[4] Others who have modeled the universe as a giant computer include Stephen Wolfram,[5] Juergen Schmidhuber,[1] and Nobel laureate Gerard 't Hooft.[6][not in citation given] These authors hold that the probabilistic nature of quantum physics is not necessarily incompatible with the notion of computability. Quantum versions of digital physics have recently been proposed by Seth Lloyd[7] and Paola Zizzi.[8]

Related ideas include Carl Friedrich von Weizsäcker's binary theory of ur-alternatives, pancomputationalism, computational universe theory, John Archibald Wheeler's "It from bit", and Max Tegmark's ultimate ensemble.

Digital physics suggests that there exists, at least in principle, a program for a universal computer that computes the evolution of the universe. The computer could be, for example, a huge cellular automaton (Zuse 1967[1][9])...