Measurement of the One-Way Speed of Light
Using the Phipps protocol to establish the absolute phase (synchronism) of a remote clock, we conclude that a one-way measurement of the speed of light is possible. The analysis focuses on precisely-defined experimental operational procedures, and uses only technologically-feasible, automatic-recording instruments which operate independently of human observers. It is not based on the theory of relativity, but rather depends on one key experimentally-supported hypothesis: the frequency f of a clock moving with self-measured (proper) speed V in inertial frame S is f = f0 / Sqrt(1 + v2/c2), where f0 is the frequency of the clock when it is at rest in S, and c is the two-way speed of light. A preliminary survey of the frequency stability and synchronization procedures used in Very Long Base Line astronomical arrays and in the satellite-based Global Positioning System suggests that data already exist which demonstrate that the one-way speed of light deviates from the two-way speed by less than one part in 107, or about 30 m/sec.