On Tuesday, July 17, 2018 at 2:34:47 PM UTC+1, Martin Brown wrote:


It is clear that you can travel into the distant future if you could
travel fast enough so that your clock age was relativistically slowed
compared to the stay at home observer.


People can make a career out of playing around with timekeeping including reliving the same physical experience with each day. There was once a slogan when travelling on Concorde that you arrive before you left and a person could, in practicality, experience noon twice or more as their meridian turned midway to the circle of illumination each day. The speed of the aircraft at the latitudes for London and New York allowed for the experience but much harder to achieve at the latitudes of the Equator.

They could also travel from New Zealand to San Fran and arrive long before they left but all these things are a quirk of timekeeping on a round and rotating Earth where time and distance is encapsulated within the 24 hour and Lat/Long systems.

These are the only perspectives acceptable when it comes to clocks and traveling at speed and although entertaining for a while are really conceptual dead ends. To be fair it does bring up motion in time and why we do not cheat the normal passage of time even when we now can experience noon twice in one day by crossing the date line or travelling faster than the Earth is turning at certain latitudes.