It is perfectly relevant , actually , because time passes quicker for you outside of the gravitational field than it does for me , inside of it as in , you are far enough away for it to be negligible . I am on planet A , with lots of gravity . You are somewhere else . We both have watches that start at 0 and start ticking . When you and I meet up , your watch will have ticked more . Period . That ' s it . My explanation of why this happens is not flawed it is your flawed understanding of the premise I constructed and the symmetry of time dilation . The reason it ' s important to mention that we synchronize clocks is because if we don ' t , there is no way to compare how time has passed . It ' s not vague , it ' s how the thought experiment works . Hell , take any 4 vector and you see that time slows down as velocity increases , always . There are experiments that prove this astr . gsu . eduhbaseRelativairtim . html yet you keep arguing . I don ' t understand what you ' re trying to prove , here . Time dilation exists , always , no matter what , and it doesn ' t matter if you observe the other clock going slower because you both define simultaneous events differently .