I've been thinking about time travel for many years and the way I see it is this.
In order to move either backwards or forwards in time everything must have already happened.
If you travel back in time you are from the future and are travelling into a past that has already happened,
if you travel forward in time you are from the past and you are travelling into a future that must have already happened.
This means everything past or present has already happened therefore it cannot be changed.
So time travel maybe possible but changing time is not..
This is my opinion can anyone see why it might be wrong??
The grandfather thing doesn't work