A Plea for Absolute Motion

Abstract

NEWTON believed in the possibility of absolute motion (i.e. motion in space not necessarily relative to other material bodies), founding his argument on the fact that the rotation of a planet might be detected by experiment on the planet itself without reference to outside bodies. Newton's reasoning is unanswerable, but it only takes us part of the way. Though it proves that using the principle of gyrostatic action we can determine direction in space absolutely, it fails to distinguish one parallel line from another. We can only observe relative motion. This statement, which no one doubts, is generally taken to be synonymous with the assertion that nothing but relative motion will ever be known. So firmly is this generalisation rooted in the present generation of philosophers that I am afraid the expression of a contrary opinion will only result in placing its author on the “Index” of De Morgan's Budget of Paradoxes.