Wormhole

you have to make a wormhole for the time travel if with out a wormhole you can't travel through Time shafely 

if you go to time in past or to future  then the earth goes far away from the point you are

 so if u want to travel in time without a wormhole so you have to creat with a space shuttle to make that huge energy required 

 so simple make a worm hole and certain time 

to make a worm hole you make a field with plasma like philadelphia experiment

but you gone through wave through(that everything is a wave when nobody see it) so don't touch any thing through travel 

so be carefull