Even at the level of basic physical theory, the same issues arise.
The conservation of energy is a common feature in many physical theories.
The year 1900 saw a major physical theory entered into the books and nothing has been quite the same since.
World 3 includes physical theory as a particular case.
By either name it means that a physical theory has limits.
Without space and time, it is difficult to formulate a physical theory.
No really successful physical theory ever completely disappears from the scene.
In standard physical theories, no information can travel faster than the speed of light.
It was perhaps more a program than a full physical theory, the ideas that are developed not being worked out in a quantitative way.
The physical theory that suggested such fundamental numbers as made life possible in the first place could be changed.
