Hi, Does "calculus based physics" just mean the study of the phenomenon that displays calculus activity? I read a book recently by Heisenberg that confused me on this. He said our measurements of phenomenon are irreversible. Are scientists deriving mathematical activity from the world, or applying a mathematical structure to something in order to understand it? I don't quite understand what the later means. Heisenberg wrote that, at least at that time, scientists were disagreed on how to reconcile relativity and quantum physics when dealing with momentum and high energy. He said that the math could be tweaked though in order to find a resolution. Could someone explain what this means to me? Thanks!