White, Willard Alan.  "Whitehead, Special Relativity, and Simultaneity."  Process Studies 13, no.4 (Winter 1983): 275-85.

Abstract

I argue here that Whitehead's concept of simultaneity evolved from a Newtonian or quasi-Newtonian conception in his pre-metaphysical work to one very close to Einstein's in "Process and Reality".  [Abstract from The Philosopher's Index]