Wrong. It is many in the public who make the mistake of assumign that "theory" and "fact" are mutually exclusive concepts. Newtons theories of gravitation are fact; the theory of relativity is a fact, numerous aerodynamic theories are flying over your head every day.
Actually, they are wrong. Einstein showed it to be so. All scientific theories are mathematical models of phenomena. Most are just first-order approximations. The whole notions of tension, normal force and friction are methods of dealing with extraordinarily complex behavior.