ABSTRACT
It is astonishing to realize that we have never written an exactly correct equation on any physical system! And, furthermore, we never will! What engineers do is to create idealized models of physical systems, models to which we can apply the laws of physics in mathematical form, in order to predict ideal system performance . If we have created “good” models, actual system performance closely matches that of the ideal . This modeling approach has proved to be remarkably effective, permitting the development of all sorts of products from large modern aircraft to the tiny cell phone and millions of products in between . Still, always bear in mind that there are no perfect models .
