Errors of Observation

Abstract

Although physics is an exact science, the pointer readings of the physicist’s instruments do not give the exact values of the quantities measured. All measurements in physics and in science generally are inaccurate in some degree, so that what is sometimes called the “accurate” value or the “actual” value of a physical quantity, such as a length, a time interval or a temperature, cannot be found. However, it seems reasonable to assume that the “accurate” value exists, and we shall be concerned to estimate limits between which this value lies. The closer these limits the more accurate the measurement. In short, as the “accurate” value is denied us, we shall endeavour to show how the “most accurate” value indicated by a set of measurements can be found, and how its accuracy can be estimated.

“And so we see that the poetry fades out of the problem, and by the time the serious application of exact science begins we are left with only pointer readings.”

Eddington