Time Travel has ALWAYS been possible

Why?

Because whether it was invented in the past, present or future in this galaxy or another (for the first time) it is also here now and always has been since before humans came here to earth.

Saying anyone is actually inventing it for the first time here on earth is completely ridiculous. If that person is trying to make public time travel they likely will disappear if they are on the right track because time travel is more secret (because it has to be) than nuclear weapons.

In fact, nuclear weapons are only under control because of time travel and it has always been this way since nuclear weapons first were invented during world war II. So, if you dream about having been nuked you likely have been (just on a time line that has already been corrected).

If you were born before 9-11-01 all of us basically died that day so if you remember it (from the first timeline) then that makes sense. I try not to think about it much myself as I prefer life here on the 2nd timeline (with or without Trump).

So, basically Time travel exists in the past, present and future of likely all galaxies at this point and all civilizations in all galaxies are affected by those changes all the time (whether they realize it or not).