In the early seventies it became apparent to me that certain topological features of physical theories were being ignored. That is, you never have 1.23 holes, you have an integer number of holes. The same is true for the topological property of self intersection. The number of self intersections is an integer. The Quantum theory also places emphasis on the rational numbers.
Quanta come in integer numbers.
Charge, after Millikan's experiments is recognized as a rational entity. How do you put these physical ideas together. The first job is to formulate what is a topological property. Using the Lie derivative with respect to a vector field V as the description of an evolutionary process permits the closed integrals of closed forms to be defined as deformation invariants. These closed integrals of closed forms are called deRham period integrals.