Why are we trying to invent time travel? I don’t see the point. It’s just too confusing, too paradoxy. I think that’s not a word, maybe paradoxical? It’s in the dictionary…
Moving on, let’s say a guy invents time travel. He goes back, and steps on a spider before coming back and writing a paper on it an winning the Nobel Prize. 1,473 years later, let’s say, Abraham Lincoln’s great great great grandfather is walking around, and is NOT distracted by a spider stopping him from seeing the most beautiful girl he’s ever seen. She is now his wife, not Abraham Lincoln’s great great great grandmother. Now, Abraham Lincoln doesn’t exist.
THAT’S how dangerous time travel can be. If I where to make a time machine, I would make a law that states, “this is for viewing time, and observing future and past ONLY.”
On other circumstances, let’s say aliens invented time travel. They receive the first ever transition, knowing that if they come, we might already have destroyed ourselves. They go back in time, go to Earth. And at some point it leads to war. They have the overall advantage since they can control time.
This brings me to another law I would enforce on a time portal, “Only for military purposes, may any acts upon time be made.”
Maybe they should just stop the production entirely, let it go. Why the trouble?