Abstract

Nearly a half century before Einstein developed his general theory of relativity, the Cambridge geometer William Kingdon Clifford announced that matter might be nothing more than small hills of space curvature and matter in motion no more than variations in that curvature. Clifford assumed the reality of a fourth dimension of space according to the new non-Euclidean geometries. In this respect, Clifford merely followed the common assumption that geometry modeled physical reality, so the new non-Euclidean geometries represented real possibilities that space could be curved rather than Euclidean flat. These ideas were further elaborated in Clifford's Common Sense of the Exact Sciences of 1885, partially written and edited by Karl Pearson six years after Clifford's unfortunate death from consumption.

The short abstract of 1870 in which Clifford explained his model of space, "On the Space-Theory of Matter," has long been recognized in studies on general relativity and its history, but Clifford's concepts of space and their relationship to physics have been limited to the role of "anticipation" of Einstein's theory. Within this context, Clifford's model has been branded a "speculation" that was "untenable" during his brief professional career. E. T. Bell has gone so far as to liken Clifford's "brief prophecy" to hitting "the side of a barn at forty yards with a charge of buckshot." Yet these opinions of Clifford's contributions are completely inaccurate within the context of Clifford's time period era as well as when more recent trends in physics are taken into account. Clifford's work should now be regarded as the first significant step toward a unification theory in physics, rather than a simple 'precursor' to general relativity.