I'm currently watching the TV adaptation of The Peripheral. I haven't read the book. I've watched the first ~4 episodes.

The time travel technology seems to run both forward and backward in time, and it only works for information, not physical objects. When you do backward time travel and interfere with the past, a paradox is avoided because the universe branches off into an alternate timeline. Once such a branch ("stub") has been intentionally created, you can continue to do VR travel back and forth between the two branches.

So given the description above this seems to be a fairly logical time-travel setup compared to a lot of what you see in SF.

But there is one big thing that doesn't make sense to me at all, at least based on what's been revealed so far. In dramatic terms, the story is presented as if the 2030 North Carolina and 2100 London are just two different sets of scenery. Call them timeline NC and timeline L. The presentation of the story is as if there is some kind of fixed 70-year offset between NC and L, as if the timelines are two rulers, and we've simply laid them side by side and then slid one by some fixed amount. If 3 days go by in NC, then it's as if exactly 3 days are simultaneously going by in L. Therefore it seems like, because of the fixed offset, people in L aren't able to do things like foreseeing the outcome of their own actions in NC, which would kill the drama.

Is this right? I can actually think of several ways of trying to make sense of this.

  1. a fixed offset, as above

  2. Every visit to the past creates a new fork in the timeline, and thinking of it as a single "stub" is just a way of talking (in-world) and a way of doing the dramatic presentation.

  3. The whole thing isn't actually going to make sense at this level, and you just have to suspend your disbelief in the logic.

As an argument against interpretation #2, it's revealed ca. episode 4 that the evil Klept guy had existential unease with knowing that he and his family also existed in the stub. Therefore he had the stub copies of himself and his family killed off. Under interpretation #2, this would not make sense, because the massacre would just create a new fork in the timeline, but it wouldn't get rid of the first stub, where the copies would still exist.

  • 2
    Not part of the story, but this fixed offset idea is theoretically what you'd get if there were a traversable wormhole connecting your time to some time in the past, assuming you lacked the ability to tow around either of the wormhole's mouths at relativistic speeds. So in The Peripheral it's like there's a wormhole connecting two times 70 years apart, with the twist that it's more like a connection between two parallel universes whose history begins to diverge as soon as the connection appears.
    – Hypnosifl
    Commented Nov 23, 2022 at 17:33
  • Sounds like an instance of Meanwhile, in the future...
    – Jontia
    Commented Nov 23, 2022 at 19:52

3 Answers 3


It's a fixed one-to-one ratio, and the people involved don't understand why that is the case either.

"Can't you," asked Netherton, "just jump forward and see what happens? Look in on them a year later, then correct for that?"

"No," said Ash. "That's time travel. This is real. When we sent our first e-mail to their Panama, we entered into a fixed ratio of duration with their continuum: one to one. A given interval in the stub is the same interval here, from first instant of contact. We can no more know their future than we can know our own, except to assume that it ultimately isn't going to be history as we know it. And, no, we don't know why. It's simply the way the server works, as far as we know."

The Peripheral, Chapter 24, "Anathema" (emphasis mine)

  • 1
    The dialogue at the beginning of chapter 12 also establishes that history in the stub "forks" at the moment the connection is established -- "When the initial connection's made, that didn't happen, in our past. It all forks, there. They're no longer headed for this, so nothing changes, here." The character also says it has "Something to do with quantum tunneling."
    – Hypnosifl
    Commented Nov 23, 2022 at 19:21
  • 1
    Don't have the book with me, but I recall they speculated stub technology was maybe from China, and that pretty much ended that conversation. Commented Nov 24, 2022 at 2:37

In the book it's not presented as time-travel. People in future London can somehow get access to a "stub" realm. Someone else made it and gave you access. Time passes at the same rate there probably because no one wants to talk to a x2 chipmunk, or have stupid "but it's only been a day here" conversations or deal with "oh, no -- I left my stub running over the weekend".

After we're comfortable with a stub being simply a connection to an alternate world, we find it's technically created from the past. But by then we know stubs are pretty much just playgrounds. No one from the future has the slightest concern about whether changing the stub will affect their present. And since it's not their past, London isn't the stub's future. It's more like playing on a classic World of Warcraft server (where everyone else is playing it for the first time). It's technically the World of Warcraft you played 10 years ago, but no one is thinking about time travel paradoxes.

  • They seem to know it's a genuine alternate timeline that diverged from theirs at the moment they first contacted it, not just a World of Warcraft style simulation though, and there's no reason to think they could speed up the rate they perceive time passing in the stub realm even if they wanted to.
    – Hypnosifl
    Commented Nov 24, 2022 at 4:33

Consider Star Wars: The Old Republic, a massively multiplayer online game canonically set "a long time ago". When a ToR server is spun up, it continues running in real-time (yet a "long time ago"), with no way to revisit an earlier point in what happened on that server, nor a way to jump forward and find out what your character was going to do.

The stubs are quite similar, in the sense that each stub runs at an uncontrollable 1:1 speed, regardless of whether anyone's paying attention. In the books, the nature of the technology underlying the stubs -- are they simulations? Are they parallel realities? Why then? -- is one of the central ambient questions of the setting.

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