Special Theory of Relativity. Twin Paradox The case of the 21 year old twins. One twin travels to space for one year at a speed of 0.998 c, then he comes back to earth, he is surprised when he meets with his twin brother, why? How old is his twin brother? (age of traveler, age of the twin who stayed back on Earth) a. 21, 48 b. 22, 38 c. 22, 37 d. 22, 62 e. 22, 16