Cheers, thanks to Mariner for the freebie!
I'm just reading Brain Greene's ''the elegant universe''
time being the 4th dimension, if you travel in 3 dimensions your motion through time is diverted to movement ,
in this manner you sacrifice speed through time for speed through space, and in doing so age slower compared to a relative onlooker.
I only studied Physics to UK A Level, and then Master of Engineering, but I recall enough to make this book a really good read.,
I didn't know for instance that Photons from the Big Bang have been proven not to have aged ...
It makes perfect sense now to me reading this,