yea, time travel has always been possible. i saw something about a while ago on pbs. but time trravel is only really interesting if you can go to the past!
in fact everybody has their own personal time or clock. the simple act or driving in a car or going up in an elevator changes your time from that of other peoples.
yeah, by an EXTREMELY minute & probably immeasurable amount..but..yeah...like, if two people, were born @ the SAME exact time, to the trillionths of a second, and you waited 10 years & gauged their age, to us, they'd both be 10, but, in terms of quantum physics & such, their age would differ because of their differing rates of movement through life