Relativity, Twin Paradox, Time Dilation, Lenghts Contraction, Lorentz Transformation.
In my article “MATHEMATICAL CALCULATIONS, APPLYING THE LORENTZ TRANSFORMATIONS” and in other precedents I wrote that, in the spaceship frame S_1, the astronaut twin can assume that he is the same age as his brother. The distances of the frame S contract with respect to the frame S_1 when the frame