The more adventuresome of two twins, Roger, boarded a spaceship for the stars, which accelerated at 1g (1 ly/yy) for 5 years of his time, and then decelerated for 5 years. By this time Roger was home sick, so he repeated the accelerate - decelerate sequence for a trip back home. How old was his twin brother Fred upon Roger's return? Also, how far away from home did Roger get on his voyage?
