Comment on 'The principle of relativity and the indeterminancy of special relativity'

This contribution adds to the points on the 'indeterminacy of special relativity' made by de Abreu and Guerra. We show that the Lorentz transformation can be composed by the physical observations made in a frame K of events in a frame K', namely (i) objects in K' are moving at a speed v relative to K, (ii) distances and time intervals measured by K' are at variance with those measured by K and (iii) the concept of simultaneity is different in K' compared to K. The order in which the composition is executed determines the nature of the middle aspect ( ii). This essential uncertainty of the theory can be resolved only by a universal synchronicity as discussed in [1] based on the unique frame in which the one-way speed of light is constant in all directions.