Thomas rotation and Mocanu paradox -- not at all paradoxical

Abstract

Non-commutativity of the Einstein velocity addition, in case of non-collinear velocities, seemingly gives rise to a conflict with reciprocity principle. However, Thomas rotation comes at a rescue and the paradox is avoided. It is shown that such a resolution of the so called Mocanu paradox is completely natural from the point of view of basic premises of special relativity.