Well, Time travel is probably too hard for us to comprehend for now since it has to do with nerdy quantum physics and ultimate multiverse and timeline stuff and we dont know that much about it. I'd say time traveling in a single universe isn't possible, but maybe in another universe / dimension? maybe everytime we "time travel" we create an alternate universe where that one is affected, and ours is left unharmed, Once again, im too lazy to completely discuss this topic.
My skype is, Donovan Aldama if you wish to speak with me