If clocks are subject to physical laws (and they are) and clocks measure time (as they are said to) then time cannot be used in physics (circular reasoning) only deduced from physics.
“The issue which is being avoided by every physicist I have ever met is that, "clocks do not measure time"! Not if interaction between two entities requires that they exist "at the same time". Physicists set up a coordinate system as if time is a measurable variable, deflecting attention from the fact that it isn't. Time is a deduced variable, very convenient to the description of physical phenomena, but deduced none the less.” — DoctorDick
http://www.physicsforums.com/showthr...560#post196560
