In Meet the Robinsons, a boy travels through time to meet his future son and wife, self, parents, etc. In the process of all this, he is able to travel to the time before he was found at an orphanage door, knock on the door and help the keeper find himself. Earlier in the movie he was able to find himself in the future based off a decision he had not yet made before he traveled.
In a nutshell, a boy’s future self’s son had to come to motivate the boy to do something to secure the future where he is so he can go back in his past and do something that happened years before. Just not sensible.
And what’s worse is that his future son comes from the future to bring him to the future. No matter how you can travel through time, you cannot do that. Another time travel movie stated it well, “you can’t bring something from the future because it doesn’t yet exist.”
Anyway, I promised we’d look at traveling back in time. So follows the argument against it.
Just like with future time travel, backward time travel is impossible, but this time for four reasons:
People wouldn’t yet exist to exist in the past
This is pretty self-explanatory. All humans have a line of descendants. You couldn’t go back and meet Adam or Eve because you have not descended from them yet. You couldn’t be there because you have yet to exist. That is why some shows just stick to sending people ahead of time; it doesn’t have that problem.
You couldn’t meet anyone or disturb anything
As it turns out, time has a pretty undeniable rule: the future cannot impact the past. So, if you were to send yourself back in time, you have a problem because, if you change anything, talk to anyone, even occupy airspace, you would be changing the future. And since the future cannot change or impact the past, then time travel backward would be impossible.
God is the only One who can control time
As before, claiming people can take control of time, is blasphemy to God and something that humans cannot do. Period.