The mathematical formulae of physics express the mathematical relations realized in this activity.
The unexpected result has been the elimination of bits of matter as the self-identical supports for physical properties. At first, throughout the nineteenth century, the notion of matter was extended. The empty space was conceived as filled with ether. This ether was nothing else than the ordinary matter of the original common-sense notion. It had the properties of a jelly, with its continuity, its cohesion, its flexibility, and its inertia. The ordinary matter of common sense then merely represented certain exceptional entanglements in the ether — that is to say, knots in the ether. These entanglements, which are relatively infrequent throughout space, impose stresses and strains throughout the whole of the jelly-like ether. Also, the agitations of ordinary matter are transmitted through the ether as
