Howard P. Robertson

"That the existence of these motions is a desideratum, if not... a necessity, for a geometry applicable to physical space, has been forcefully argued on a priori grounds by von Helmholtz, Whitehead, Ru…"

"The field equation may... be given a geometrical foundation, at least to a first approximation, by replacing it with the requirement that the mean curvature of the space vanish at any point at which n…"

"In considerations involving the nature of the world as a whole the irregularities caused by the aggregation of matter into stars and stellar systems may be ignored; and if we further assume that the t…"

"Let a thin, flat metal plate be heated... so that the temperature T is not uniform... clamp or otherwise constrain the plate to keep it from buckling... remain flat... Make simple geometric measuremen…"

"In what respect... does the general theory of relativity differ...? The answer is: in its universality; the force of gravitation in the geometrical structure acts equally on all matter. There is here …"

"H. P. Robertson, Hermann Weyl, On a problem in the theory of groups arising in the foundations of infinitesimal geometry Bulletin of the American Mathematical Society, 35 pp. 686-690."

"An "empty world," i.e., a homogeneous manifold at all points at which equations are satisfied, has, according to the theory, a constant Riemann curvature, and any deviation from this fundamental solut…"

"What is the true geometry of the plate? ...Anyone examining the situation will prefer Poincaré's common-sense solution... to attribute it Euclidean geometry, and to consider the measured deviations...…"