nLab theory of everything




physics, mathematical physics, philosophy of physics

Surveys, textbooks and lecture notes

theory (physics), model (physics)

experiment, measurement, computable physics



In physics, specifically in fundamental physics/high energy physics, the term theory of everything is used to refer to a (hypothetical) theory which coherently subsumes “all” of fundamental physics, in some sense.

Taken at face value this terminology has its evident problems, but its usage is to be understood in the context of the situation of the field of theoretical physics at the turn to the 21st century, where it has the evident and justified restricted meaning of a theory which, somehow, coherently subsumes and possibly explains from more fundamental principles both the standard model of particle physics on the one hand, based on Yang-Mills theory, and the standard model of cosmology on the other hand, based on Einstein gravity.

One issue here is to do so at the level of quantum field theory proper, for more on this see at quantum gravity. Another is to possibly find a explanation for some of the random-looking structures in these standard models, for more on this see at grand unified field theory.

(Notice here that in their colloquial meaning the terms theory of everything and grand unified field theory largely overlap, but that as technical terms they are understood very differenty, indeed the term grand unified field theory is used almost exclusively for gauge group-unification, which is not even part of all proposals for a “theory of everything”).


Back in the days, David Hilbert would speak of “Weltgesetze”, see starting on page 396 in

  • Tilman Sauer, Ulrich Majer with Arne Schirrmacher, Heinz-Jürgen Schmidt (eds.), David Hilbert’s “Lectures on the foundations of physics”, 1915-1927 : relativity, quantum theory and epistemology, Springer 2009

Last revised on September 26, 2021 at 13:36:05. See the history of this page for a list of all contributions to it.