Logic of gauge

The logic of gauge theory is considered by tracing its development from general relativity to Yang-Mills theory, through Weyl’s two gauge theories. A handful of elements—which for want of better terms can be called \emph{geometrical justice}, \emph{matter wave}, \emph{second clock effect}, \emph{twice too many energy levels}—are enough to produce Weyl’s second theory; and from there, all that’s needed to reach the Yang-Mills formalism is a \emph{non-Abelian structure group} (say $\mathbb{S}\mathbb{U}\text{(}N\text{)}$).