Types of Time Travel to the Past
For my own reference (and that of anyone else who's interested), I'm listing the types of time travel to the past that I'm aware of. Any other thoughts or things I've missed, let me know. It Changes the Past This is the most straightforward. You go to the past, and every action has a cascading effect on the future. Butterfly effect and all. And it's why, as Hawking said, time travel to the past isn't possible -- because every action changes the future which changes the action of the person who went to the past, which changes the future, etc., an infinite feedback loop resulting in travel to the past never being accomplished. But, continuing in theory anyway.... It Can Change Minor Events, But Not Major Events Like water droplets flowing through a pipe, each drop of water may move wherever it wants. But, ultimately, the flow of water will end up in the same place due to the constraints of the pipe. Thus, in this view, some unknown force causes major events to ha