Time Travel: Threat or Menace?

By Max Woerner Chase

In this post:


I'm reconsidering the stuff I'll put in OMICE whenever I get to it; I've currently written nothing, I don't mind admitting. What brought this on is finally reading On the Notion of Cause, which is recommended by the fascinating blog Graphical Linear Algebra. In On the Notion of Cause, Bertrand Russell critiques a tendency in philosophy to evaluate the natural sciences in terms of their ability to derive statements about cause and effect. Russell argues that "cause" and "effect" aren't sensible concepts applied to reality at large. The fundamental nature of physical laws is one of relations, which can, in a sufficiently isolated system, provide a basis for indirect control of an output using an input. Because it's easier to reason about causal-like systems, we engineer things to behave in a causal fashion.

For an example of a partially isolated system, consider a bubble under some wallpaper. We expect that pushing down on the bubble in one place will cause the wallpaper to bubble elsewhere, but we usually can't predict where it will end up. It is... extremely difficult for me to figure out how to describe this stuff without phrasing things in terms of causality. In terms of predictive power, getting an accurate picture of what will happen in a situation requires close knowledge of the state of the local universe, and the more information you use in the prediction, the less generally applicable the prediction is. Given a hundred bubbles on the wall, you'd have a rough time coming up with a general answer to questions like "which way will the bubble go".

Okay, that was my attempt to apply Russell's arguments to a different situation, now what does this mean for OMICE? Well, I'd had some ideas along the lines of "reality behaves more like this than like that, so you should structure your stories more in the former way". I suspect the consequent is still true, but rather than appealing to reality, I'm going to have to appeal to how people think about the world, which, usually it's hard to tell the difference. Switching gears to thinking about time travel (the, like, original mission of the OMI), what does On the Notion of Cause mean for reasoning about time travel? Most obviously, if "cause" and "effect" aren't fundamental to nature, then what can be meant, if anything, by the notion of an "uncaused cause"?

I'm going to try to avoid saying "because" when trying to reason about this, because it makes my head hurt. When we think about time travel stories, they're normally people messing around in the past of their light cone. Imagining that we observe this from outside the timeline, we see an unusual path that relations take. The "obvious" behavior to expect from long-range correlation is some kind of interference pattern; boundary conditions constrain the configurations of matter within the boundary. Think of it perhaps like a shadow falling on phase space, I dunno. Yet another hurdle to thinking about this stuff is that closed timelike curves make it hard for me to reason about the symmetries related to conservation laws, probably because I don't actually know enough about Noether's theorem in the first place. Thinking about it at a very high level, a CTC introduces topological features that reduce the symmetry of the universe, so it must inherently violate conservation laws. That may have been complete bullshit; all available evidence points to, I am not qualified to make that determination in terms of truth value, so I guess in an On Bullshit sense, it definitely sort of is? This is why I want to get editors.

Anyway, there was some stuff I wanted to say about a thing I read elsewhere, about the CTC allowing for an overwhelming resonance that disallows the CTC or at least prevents normal matter from entering it, but I can't find it right now, and I absolutely do not trust myself to rederive the argument.

If we pretend that kind of thing doesn't happen, for narrative purposes, then we end up with a situation where several things are at least arguable:

Thinking about all of these things, I find myself wondering, in a poor man's poor man's Philip K. Dick kind of way, if the inside of the regime is habitable, what does it look like? With the arrow of time breaking down, do people sometimes remember the future? Is there just one self-creating temporal conspiracy or plague, or several competing? Who's the sap that I, as the author, set up as smart enough to make this possible, and dumb enough to make it happen?

Well, I'll have to think about it later, because it's midnight now, time to publish.