SPEED OF LIGHT IN VACUUM OF MOVING INERTIAL REFERENCE FRAME

“Speed of light in vacuum of a moving inertial reference frame (IRF)” is introduced as a new concept. It is defined as a value equal to the fourth component of the four-dimensional speed of IRF, moving relatively to a resting IRF. Application of this concept to light propagation in moving and resting light clocks leads to elimination from physics of time dilation effect for moving IRF owing to exact equality of a moving light clock time unit to a resting light clock time unit.