There’s one of you on earth, and one on mars. They start out (by assumption) the same, but will presumably increasingly diverge due to different input from the environment. What else is there to know? What does the word ‘same’ mean for you?
And what exactly does that mean if the ‘you’ on earth doesn’t get to experience the other one’s sensations first hand? Why should I care chat happens to him/me?
That’s between your world model and your values. If this happened to me, I’d care because the other instance of myself happens to have similar values to the instance making the judgement, and will therefore try to steer the future into states which we will both prefer.
Sebastian_Hagen2 comments on Timeless Identity