Now we remind, how the erroneousness of RT kinematic concepts can be proved most easily. For the "yes-no"-type results only one of different evidences of two observers could be true. Therefore, at least one of moving observers would be wrong in mutually exclusive judgements. However, the situation can always be made symmetrical with respect to the third resting observer. Then his evidences will coincide with the classical (checked for ) result, and in this case the evidences of both first and second observers should transfer to this result. However, since both the first and second observer moves relative to the third one, all three their evidences will be different. Owing to situation symmetry, both the first and second observer occurs to be wrong in his judgements, and only the third, resting observer describes the true (classical) result. Exactly in this manner the inconsistency of the concept of time (the time is irreversible!) was proved in the modified paradox of the twins [48,51], as well as the inconsistency of the "relativity of simultaneity" concept . (Note that the space-time diagram  does not change the physics of even conventional paradox of the twins: all additional aging of Earth's inhabitant arises suddenly (!), when the motion of an astronaut changes at the far point and is only geometrically expressed as the change of lines of simultaneity).
We begin the detailed analysis of relativity theory with a modified "twins paradox".