** -v * t_1 = -d** (for any distance

**and for**

*d***) is a contradiction, because it means that the Earth**

*t_1 < t***with uniform rectilinear motion at speed**

*DOES NOT MOVE***.**

*-v*Come to think of it, the Earth

at time** t_1 = d / (v * gamma) **reaches the second spaceship

**, the motion of the Earth in the frame of the spaceship is therefore represented by**

*(x_1 = -d)***.**

*x_1 = - gamma * v * t_1*The distance of the spaceship in the frame of the Earth is ** x = v * t**, and in the frame of the spaceship the Earth is at distance

*d = gamma * v * t_1.**(d = v * t)*

In the frame of the Earth the elapsed time is

** t = gamma * t_1**, the preceding contradiction therefore means that, even if the Earth is moving with respect to the spaceship, all the clocks of the Earth's frame

**with respect to the clock of the astronaut twin.**

*DO NOT SLOW DOWN**THE CONTRADICTION NOW HAS A MEANING.*