I did some searching on tesla a long time ago and found out that all his papers work notes etc are being held under close watch, or should i say hidden from the public.

Also that thanks to that we had an increase in technology on electricity and stuff you can do with it.

However there was also a large potential for destruction, so ofcourse it got confiscated, but also note that tesla did have his moments and ideas about building a tesla gun of sorts that would simply blow away an entire state.
And all he would need would be relatively simple to make and cost efficient.

So my guess is that most of that type of research is being used an implemented, knowing that our public technology is behind about 50 years and that was something wich was said 50 years ago, so you can imagine the leaps we took since then.

But then we get to time travel and i must say the john titor i simply haven`t investigated it throuroughly to form a fact, however i watched an anime called: steins gate.

It deals with time travel and branching timelines.
It is a very good concept and it even involves the CERN, but it is pretty well done and if you watch it you go like, hey this might actually be plausible.

so check it out and see if it indeed spark some interrest and ideas.