'Through the wormhole, the scientist can see himself as he was one minute ago. But what if our scientist uses the wormhole to shoot his earlier self? He's now dead. So who fired the shot?' - Stephen Hawking.
My hypothesis
If we alter the time, we are essentially branching the time from where it is changed. Eg. Shooting through a wormhole to his own self. That is if a person shoots his past counter part then he never existed in future, then who shot him?
This can be explained as follows- when the person shot himself he branched the time from that instance. Let us assume that A is the person in present, and B is the same person in past. When A shot B he changed the future of B but past of A remains intact. Thus he branched the time, the instant he changes anything to past.
This can also explain different dimension. As we are changing time(T) ,we all know that frequency is 1/T so we are also changing frequency. So according to super string theory that world will start vibrating to a different frequency and thus a new dimension is created.
This also explains why no one ever remember any time travel from future. This is so because in our world time travel haven't been possible yet. And if some one encounters any future traveller he moved to an another dimension but his original counter part has never met any such traveller.
Thus time helps itself from violating time space continuum.
