Time travel's been one of man's wildest fantasies for centuries.Time travel is the concept of moving between different points in time in a manner analogous to moving between different points in space, generally using a theoretical invention known as a "time machine".


There are two direction of time: Backward and Forward

,so time travel is categorized into two types:

1.Forward Time travel

2.Backward Time travel



Forward Time travel


From Einstein relativity,in different point of space the speed of time is different [due to the different in gravatitional field].so if we go to those point where the time is slow ,then every activity of our body also slows down.In earth time is going normally ,so every activity on there is faster than in your place.After your clock[mechanical or electronic] ticks 1 year,at the same time earth clock will tick more than that.That means you have travelled to future.By finding or creating the place where clock ticks slowly ,we can go to the time machine or create time machine.






In artificial satellite the same clock ticks in different place at different rate.So in positioning satellite(GPS,GLONASS,etc) ticking in different rate wont give you your exact location.So the time on all satellite must be exact,to solve this they callibrate each clock for each each location.so u can get your exact location.