>>12653364ok. you and me both accelerate to 0.5c in separate space ships. i travel at 0.5c for 1 year in my reference frame until slowing down and coming back to earth, while you travel for 2 years in your reference frame until slowing down and coming back to earth.
we both experienced the same acceleration and deceleration. from my reference frame you spent more time at 0.5c but from your reference frame i spent more time at 0.5c. whose clock is behind?
