Top News, Articles, and Interviews in Philosophy

The Metaphysics of Timeline Branching: Stuff

Philosophy News image
The grandfather problem is a classic time travel problem. Oversimplified a bit, the problem is as follows. If time travel is possible, then a person should be able to go back in time and kill their grandfather before they have any children. But if they do, then they would never exist and thus would not be able to go back in time and kill their grandfather. So, their grandfather would not be killed and thus they would exist and be able to go back in time and kill him. But if they kill him, then they would not exist. And so on. There have been attempts of varying quality to solve this problem and one is to advance the notion of timeline branching. The super simple version is that time is like a river and travelling back in time to change things results in the creation of a new branch of the river, flowing onward in a somewhat different direction. So, imagine that Sally goes back in time to kill her grandfather. She succeeds and thus creates a new timeline in which he dies. Presumably, she returns to her own timeline and finds that her original grandfather was never killed by her. She might keep trying and from her perspective she would kill him over and over, only to return to find that she never succeeds—but with each trip to the past, she creates another new timeline. For those who prefer their time travel murder free, any change a time traveler made would presumably create a new timeline—and this would include the smallest change. Time travelers would certainly end up creating new timelines in which they (or, more likely, someone like them) exist and would probably keep traveling in time—thus creating branches off the branches. While having so many branches would seem excessive, there are metaphysical concerns for even having one additional timeline branch. Each extra timeline branch would seem to require the creation of an entire new universe. But even if it created less than that, there would still be the same concern—albeit on a smaller scale. This concern is. . .

Continue reading . . .

News source: A Philosopher's Blog

blog comments powered by Disqus