we know that those frame of references which are in uniform motion relative to an inertial frame of reference are called inertial frame. but the inertial frame we are using for comparing will also be in unfiorm motion relative to an another inertial frame of reference and that inertial will be related to another inertial frame.then how we will come to an end,mean is there any absolute inertial frame of reference which can be used for comparing?