Ok, i know this makes me look like a crackpot, but suppose for an instant there is an aether or absolute space or whatever! Let me be on a rod that travels tranversely with respect to aether and let me be exactly on the middle point of this rod. I have a GPS device with me and send it upwards for some distance. It transmits two light signals back to the ends of the rod and I synchronize my clocks at both ends to read the same time accordingly. Light travels same distances at same speed so i am certain that my clocks are synchronized! Now, very slowly I turn my rod so it travels longitudinally with respect to aether. Shouldn't my clocks remain synchronized and reading the same time? If so then I measure different light speeds for the inbound and outbound legs of a two-way trip of a beam of light! Reichenbach and Grunbaum have stated that ε=1/2 factor Einstein uses to synchronize two spatially remote clocks is an arbitrary plantation. Is it true? Why the one-way speed of light will never be measured?