1. Notation: our Lorentz metric is diag (+++−) 1. μ,v, λ,…=0,1,2,3 are space-time indices; α,β,λ,…=0, 1, 2, 3, 5 are sphere space indices.x 0=t, x 5=λ in the flat case (3). Units:c=1.
2. N. B. Conformalpoint transformations of space-time are included in this formalism as the special case of null spheres: λ=0. Although many workers consider only these, this is not correct and fruitful physically in our opinion (see ref. (3)).R. L. Ingraham: inLectures in Theoretical Physics, Vol.13 (Boulder, Colo., 1971). In particular, the present theory of inertial e.m. motion is excluded.
3. R. L. Ingraham: inLectures in Theoretical Physics, Vol.13 (Boulder, Colo., 1971).
4. Note that even for flat space-time angle space has constant curvature ≠0. We mean the extra uneven curvature caused by mass-energy.
5. R. L. Ingraham:Proc. Nat. Acad. Sci.,41, 165 (1955);Phys. Rev.,101, 1411 (1956).