Tolerances and Their Effect on Physical Measurements

Abstract

The tolerances that may be admitted in manufacturing processes have always been an important matter in works practice, but they have tended in the past not to be considered as a subject for deep study, but rather as a nuisance which would not arise in a perfect world. Recent developments in theoretical physics have very much altered this view, and have shown that the subject of errors and tolerances is not only interesting in itself, but is important in the foundations of physics.

A series of examples is given showing some interesting points in considering tolerances. It starts with the large numbers concerned in accident rates, and then takes a simple manufacturing process. Next, examples from acoustics and optics are considered, and then the “Uncertainty Principle” of the quantum theory, which lies at the basis of all physical measurement. Finally, it is shown that even pure mathematics is essentially based on the idea of tolerances.