[Munch's Master]

Time is a measurement as many people have said, so technically a time machine is the slider on the measuring scale. If time machines worked by slidy rulers it'd be cool.
I had a discussion on time travel tday with someone, very enjoyable. I still say that time is free-forming and free-flowing- the reason we don't know of an ytime travellers is because they do and don't exist at the same time- they have lived, are living and do not yet live all at once. Time reshapes itself to keep o in an even flow- if you go back in time and shoot Hitler as a child, you can't shoot him because he's already been shot by you so he's not alie to be shot, so you don't know who he ever was so you don't go back to kill him- basically time moudls itself around you. If you shoot Hitler as a child it makes no difference because he's already been shot, is being shot as we speak and is about to be shot.

It'd be easier to explain with some diagrams. But it's the same with the whole 'go back and kill your grandma' thing. It isn't a paradox because it physically can't happen- you go back in time and kill your grandma, and time merely erases you. It restructures itself and leaves you out. And you can't control how it is retructured, because it has already been restructured in your lifetime because the future you has already restructured it. So in effect you have the case of 'somebody has to alter the timeline because nby doing so, the timeline stays as it always has been. If you don't alter it, history is changed. For example say in fact you are the one who kills/killed JFK- you have to go back in time to shoot him because if you don't, he lives on and you have changed history. But again time flows aroundthe problem, in my theory.
I would say the timeline can only be damaged if you travel forward, because it's creating a change in time that hasn't yet happened- you know when the change to the timeline is coming so time again adapts, sending you down a different path anbd changing FUTURE, rather than HISTORY. as such time IS changed by being redirected, rather than restructured and repaired. Like taking a certain branching path on a complicated spider diagram. It's hard to explain fully without gestures and diagrams so I'll have to leave it at that.