Relativity, Twin Paradox, Time Dilation, Lenghts Contraction, Lorentz Transformation.
time t = t_1 = (1/γ)*(d/v). This is the example that should make us reflect. If the spaceship with the tail leaves with zero speed and arrives at zero speed (and if we are concerned only with the arrival of the end of the tail), the astronaut twin arrives on the planet at time t = (1/γ)*(d/v), t =