Max Tegmark on Theory of everything

“If we assume that reality exists independently of humans, then for a description to be complete, it must also be well-defined according to non-human entities—aliens or supercomputers, say—that lack any understanding of human concepts. Put differently, such a description must be expressible in a form that is devoid of any human baggage like “particle”, “observation” or other English words.”

“I will... argue that... our universe is not just described by mathematics—it is mathematics. ...this hypothesis... should... be useful in narrowing down what an ultimate theory of everything can look like. The foundation of my argument is the assumption that there exists an external physical reality independent of us humans. ...Our most successful theories, such as general relativity and quantum mechanics, describe only parts of this reality... In contrast, the holy grail of theoretical physics is a theory of everything—a complete description of reality.”

“We need to distinguish between two different ways of viewing the external physical reality: the outside view or bird perspective of a mathematician studying the mathematical structure and the inside view or frog perspective of an observer living in it. ...a mathematical structure is an abstract, immutable entity existing outside of space and time. If history were a movie, the structure would therefore correspond not to a single frame of it but to the entire videotape. ... If a future physics textbook contains the TOE, then its equations are the complete description of the mathematical structure that is the external physical reality. ...is rather than corresponds to...If our external physical reality is isomorphic to a mathematical structure, it therefore fits the definition of being a mathematical structure.”