Fuck that, it's possible.
When NASA sent up the first moon mission they put an atomic clock at Capcom and another in the shuttle. The point? To see if the crazy ass speed they would attain would effect the passage of time.
Results: The clock in the shuttle was behind the clock at Capcom that hadn't moved. This formulated the theory about how if you travel at light speed people on Earth will age faster then you
the faster you go the larger the difference, keep going and it's only rational that time would eventually screech to a halt, but what happens then if you go even faster?
I call this the "Vtec just kicked in theory"
no seriously, this is something I've thought of for awhile, obviously the effects G force have on our bodies make this almost impossible, but in theory if time does in fact slow down proportionate to your relative speed them time travel IS possible