the earth spins at 464 metres a second.. so even a split second's difference can put you into the next suburb! and the process better take less than a millionth of a nanosecond otherwise there will be a trail of blood and organs for a couple of metres as your body gets transmitted and the parts that arrived a nanosecond earlier are moving with the earth as opposed to the parts arriving a nanosecond later at the original xyz/time co'ords
now factor in slight changes in the earth's shape not forgetting that a metre or two metres at this level is important, changes in the solarsystem, changes in our ability to measure time over several years, slight changes in earth's spinning speed because ALTHOUGH EVERY THING IS IN CONSTANT MOTION it's NOT IN CONTINUOUSLY MATHEMATICALLY PREDICTABLE MOTION.
and there you have it.. pretty fucking hard to do if not weighing on impossible, and when you have the ability to do it will time travel even be a priority or will killing the machines?
