The distance of a star from the Sun, as measured in the rest frame of the Sun and star, is 5.3 ligh-years. Consider a spaceship that departs the solar system at a speed c bound for the star, when the two clocks: one at the Sun and the other at the spaceship, are synchronized at t = 0. Calculate the time of arrival of the spaceship in the rest frame of the Sun: (a) as measured by the Sun clock. (b) as measured by the spaceship clock. Note: This assignment is related with the realistic examples of the Lorentz' transformations and their consequences.