I still don't get why people think time is dimensional. Even if it was, things that MOVE through time, well, move. Moving means you no longer are where you were. So if you went 200 years back you'd notice you missed Earth by 200 years. BTW, you'd need to travel quite a distance after the time-travel, the Sol system is moving pretty fast. To solve the movement-problem you have to assume things extrude through time, which means their mass increases. If you went back and changed the past, why should the present care? If both past and present can coexist in an n-dimensional space, why should one bother with the state of the other? Would the past just re-extrude while removing any matter left by the former timeline? Would this re-extrusion ever catch up with the present or would it lag behind? I think until we resolved ALL of those conflicts we should assume the non-dimensionality or non-existence of time.