Il y a la dilatation de l espace temps, quand on va assez vite l espace se restreint. "But here is where Einstein comes to the rescue. If we
could build a spaceship that could whisk us into space at speeds very close to light speed, then the
distances to the stars would shrink, and the amount of shrinking would increase the closer to light
speed we could travel. If we managed to travel at 99.99999999 percent of light speed, then we could
travel out of the Milky Way and all the way to the neighboring Andromeda galaxy, almost 3 million
light-years away, in a mere fifty years" Brian Cox