Abstract: Are things in the real world governed by the mathematical equations of fundamental theories in physics? If we take seriously the practice of fitting facts into equations, the answer should be no. To give a mathematical description of a real phenomenon requires bridge principles. However, given the constraints of theory, even these employ highly idealized fictional objects and processes, more akin to artful theatrical distortions than to true descriptions of things in the world.

Keywords: bridge principles, idealized objects, fictional objects, mathematical equations in physics,