minchi

Let's say it is possible to go back in time, but it shouldn't be possible to change anything. If you do, according to the butterfly effect or grandfather paradox, you might be indirectly wiping out your existence. In essence, it's not the "traveling" that's not possible, it's the "change" you leave behind that's not possible. This way, the most one can do in the past is "observe", which is no better than watching a video or looking at old photographs (unless it's so far back that's there's no video or photograph, then I guess time traveling may be beneficial to archeologists and historians?). I believe the main reason one wants to go back in time is to change something, which is impossible, so, what is the point of time traveling?

Unless...you travel back to a parallel world...then you can do anything you want, like the Xiao Lou novel, but sadly nothing will take effect in your "original world"~

minchi

Yes, history always remains. It's a possibility that whatever you do in the past results in the same future because the "change" you made was actually what happened before you traveled. However, let's say someone tries to change a known future (ie. kill one's grandfather), the change can never be made, because a supreme force will stop the action from ever succeeding....
There's another possibility that changes that does not affect one's eventual birth is //possible//. It may then cause a corruption in the time and altered the future as one knows it (but still satisfy the conditions for one to build a time machine and travel back, although the conditions will be unbelievably strange..)...

Anyways, most of the theories support that the future can not be changed. Thus, time traveling with the intention of changing something, can be deemed futile.

minchi

Lol, I guess I was off topic from the start.

There are a lot of theories that provide a solution to time paradox, yours is one of them. What I said before, supreme force that prevents change, is another one.
I think we both agree that it's impossible to change the result though?

What I think I'm trying to say is, time traveling seems too dangerous (//possible//risk of time corruption) and reckless to be worth the trouble.