Twin paradoxClassical Mechanics Level 2
Dick is \( 20 \) years old when he takes off on a space voyage at a speed of \( 0.80\) \( c \) (\( c \) is the speed of light) to a star \( 20 \) light-years away. His wife Jane, also \( 20 \) years old, decides to wait for him to come back after successfully completing his mission. Finally, after \( 30 \) years of voyage in his reference frame, Dick comes back. How old is Jane upon his return?