A quantum computer is needed to calculate the relative displacement of space when traveling in time.
If you think we don’t/won’t have one, think again.
Think again? ... Um, isn’t there already a four cubit one, IIRC? I do not doubt humankind will figure out how to use quantum calculation. i firmly believe we will have live cell organ replicators (3D printers using living cells of various types). There Are already organs and structures being ‘printed’ using that technology. I also do not doubt that there are aspects of temporal/spatial reality which we have yet to even imagine we could exploit/explore for traversing spacetime with near zero passage of time. Photons already do it ... and they are nothing but a pinch of space, a grain of time, and energy. Can you tell me why there is inertia, even in deep space?