re: #312 HappyWarrior

Okay here’s my premise. Some very idealistic scientists develop time travel. They all agree KILL HITLER and they succeed. Hitler is gone but their machine as they attempt to return to the present begins to falter because the only reason they invented time travel was to kill Hitter who is no longer in their timeline. Or they face an angry Austrian mob for killing that Hitler kid.

The only way time travel possibly works is if every instance involves traveling to an alternate Universe where the record needle of time just happens to be set to an earlier “now” point in the groove. So from that alternative Universe “past” you should only be able to create and go “forward” to alternative presents and futures, with no way to return to your original starting point in your original Universe. Even if you could it would be like you never left and didn’t change anything, because all the actions you took would be playing out in alternate timelines.

Beyond the practical and logical aspects this is also the only ethical way for time travel to ever work, because your actions wouldn’t invariably cause millions of people to be erased from existence altogether.