Hello, I have a doubt regarding the postulates of SR. The two postulates, according to Schutz, are: 1) No experiment can measure the absolute velocity of an observer; the results of any experiment performed by an observer do not depend on his speed relative to other observers who are not involved in the experiment. 2) The speed of light relative to any unaccelerated observer is c, regardless of the motion of the light's source relative to the observer. Couldn't we combine these two postulates into one? I'm thinking of something along the lines of: All the laws of physics are the same in every inertial frame of reference. With this, I'm thinking you reach both of the original postulates- this new postulate implies that Maxwell's equations must hold in every inertial frame, so c must be the same in every inertial frame (which takes care of original postulate 2). Also, from this you can conclude that for an observer who is in an inertial frame of reference, the same laws of physics will hold as for another inertial observer moving at a different speed. Therefore, the first observer's experimental results will not be affected by their speed relative to the other observer (this takes care of original postulate 1). What do you all think?