A little while ago I posted a review suggesting some problems with the latest installment in the science fiction anthology series, Black Mirror (Netflix). “Bandersnatch” is perhaps a bit shallow in some of the choices it makes (or rather, the choices it offers us to make), but one “plus” of the new episode (Netflix seems to prefer to call it an independent film) is its exposition of philosophy related to alternate timelines and time travel. In fact, we see the protagonist, Stefan Butler, engaging in various “do-overs” : going back in time and trying again. But is he really doing this or is it some sort of delusion or a drug induced hallucination?

Certainly we’re led to believe that Stefan’s psychologist thinks that he’s on the border of psychosis. Before Stefan’s mentor, Colin Ritman, offers up some of his thoughts about time and life, he offers Stefan what appears to be L.S.D or another hallucinogen. So we aren’t really sure whether what Stefan experiences just after this, such as seeing Colin jump off his high rise aparment’s balcony (to his death) is part of a hallucination. Since Stefan seems to awake from dozing off in his father’s car just as Colin is smooshed, we are led to believe that in this instance, he was experiencing a dream, and not “real” time travel or switching to an alternate time line. However, in the scenes immediately following this, Colin is notably absent, a condition that is clearly stressing out both his wife and boss (though his wife, who was present in the scene with Stefan, does not seem to have any knowledge of Colin falling to his death).

In this way, perhaps time travel in “Bandersnatch” serves the same allegorical purpose as Billy Pilgrim becoming “unstuck” in time in Kurt Vonnegut’s Slaughterhouse Five. That is, the reader becomes fairly sure that Billy probably isn’t really traveling time but rather experiencing some sort of flashback caused by post-traumatic stress disorder. Sometimes we aren’t really sure of this, such as when he seems to be experiencing an abduction by aliens called Tralfamadorians who teach him about the nature of time. Perhaps Colin Ritman serves as Stefan’s “Tralfamadorian”? As Billy learns about time in SH5, so does Stefan learn about time in “Bandersnatch.”

From a physics perspective, can time travel occur in the way show in “Bandersnatch?” That’s hard to say. But assuming its presenting what is supposed to be “real” time travel (as opposed to a dream, hallucination or other kind of delusion), I would have to say “no.” This is primarily because what “Bandersnatch” is mostly describing is a version of the “Many Worlds” (or “Many Histories”) hypothesis. That is, for every possibility (or every “choice”) there is a different Universe (or equivalently, we can think of it as “time line”) for each possible choice. We just happen to exist in a Universe that had you read my blog post (and thanks for that, by the way). As much as I hate to admit it, there are many Universes in which nobody ever reads my blog (perish the thought!). However, one key point of this hypotheses is that observers in one Universe can not see into the other or switch between them spontaneously. Though this seems like an ad hoc demand, it is essential if this theory is to lead to an effective interpretation of quantum mechanics. Since Many-Worlds was originally adopted as a potential interpretation of quantum mechanics and its probabilistic nature, the demand of no mixing of timelines has been kept. So if we want to keep a theory that allows for differing timelines for macroscopic possibilities *and* quantum probabilities, we have to keep these restrictions.

I hope you’ve learned a little about time and time travel! If you want to know more, feel free to take a look at my book, The Physics and Astronomy of Science Fiction, available from McFarland Publishing, and available for purchase in print or electronic form from Amazon.com or Barnesandnoble.com