Saving Time

agency is time travel

Since time is the direction of increased entropy, this feels like it has some deep connection to the notion of agents as things that reduce entropy (only locally, obviously) to achieve their preferences: https://www.lesswrong.com/posts/Q4hLMDrFd8fbteeZ8/measuring-optimization-power [LW · GW] (I'm not sure this is 100% on-point to what I mean, but it's the closest thing I could find.)

Since agents can only decrease entropy locally, not globally, I wonder if we could similarly say that they can "reverse the arrow of time" only in some local sense. (Omega can predict me, but I can't predict Omega. And even Omega can't predict everything, because something something second law of thermodynamics.)

An agent is a mechanism through which the future is able to affect the past

I love this!

My impression is that all this time business in decision making is more of an artifact of computing solutions to constraint problems (unlike in physics, where it's actually an important concept). There is a process of computation that works with things such as propositions about the world, which are sometimes events in the physical sense, and the process goes through these events in the world in some order, often against physical time. But it's more like construction of Kleene fixpoints or some more elaborate thing like tracing statements in a control flow graph or Abstracting Abstract Machines, a particular way of solving a constraint problem that describes the situation, than anything characterising the phenomenon of finding solutions in general. Or perhaps just going up in some domain in something like Scott semantics of a computation, for whatever reason, getting more detailed information about its behavior. "The order in domains" seems like the most relevant meaning for time in decision making, which isn't a whole lot like time.

(Edit May 2022: I now take this more seriously [LW(p) · GW(p)], with logical time and updatelessness motivating looking into reasoning in spaces similar to Scott domains. That is, perhaps agents should reason in a way compatible with a notion of logical time, not just be describable this way as computations.)

This post helped me understand the motivation for the Finite Factored Sets work, which I was confused about for a while. The framing of agency as time travel is a great intuition pump. 

The primary confusing thing about Newcomb's problem is that we want to think of our decision as coming “before” the filling of the boxes, in spite of the fact that it physically comes after.

I've been puzzling in my amateurish way over Newcomb's problem a bit. The way I think the causal flow goes is:

T0: Omega accurately simulates the agent at T1-T2, and fills the boxes accordingly.

T1: The agent deliberates about whether to one-box or two-box.

T2: The agent irrevocably commits to one-boxing or two-boxing.

The agent thinks there's a paradox, because it feels like they're making a choice at T1. In fact, they are not. To Omega, their behavior is as predictable as a one-line computer program. The "agent" does not choose to one-box or two-box. They are fated to one-box or two-box.

Understood this way, I don't think the problem violates causality.

An agent is a mechanism through which the future is able to affect the past. An agent models the future consequences of its actions, and chooses actions on the basis of those consequences. In that sense, the consequence causes the action, in spite of the fact that the action comes earlier in the standard physical sense.

TL:DR;

This model sounds wrong (if still useful) in a way you are probably already aware of.

The agent chooses to take an action based on its calculations and model of the consequences of said action. The agent can be wrong about future, and thus it is not the consequence (in the (real) future) which causes the action, but an error or the past version of the environment (specifically the agent's observations/records) which causes the action.

An attempt at a concrete example: imagine bots trading on the stock market. Do you expect those bots to always predict the future accurately? (Even without cosmic radiation or mundane technological failures, I expect someone to write a program that (eventually) compiles, but has a 'wrong line' or uses the wrong formula, etc. Not 'inverting the utility function bad' - unless there's a lot of traders, but maybe something analogous to' P(A or B) = P(A) + P(B) + P(A&B)'*.)

*It's supposed to be -, not +, P(A&B).

Firstly, we don't understand where this logical time might come from, or how to learn it

Okay, you can't write a sentence like that and expect me not to say that it's another manifestation of the problem of the criterion [LW · GW].

Yes, I realize this is not the problem you're interested in, but it's one I'm interested in, so this seems like a good opportunity to think about it anyway.

The issue seems to be that we don't have a good way to ground the order on world states (or, subjectively speaking if we want to be maximally cautious here, experience moments) since we only ever are experiencing one moment at a time and any evidence we have about previous (or future) moments is something encoded within the present moment, say as a thought. So we don't have a fully justifiable notion of what it means for one moment to come before or after another since any evidence I try to collect about it is at some level indistinguishable from the situation where I'm a Botlzmann brain that exists for only one moment and then vanishes.

Of course we can be pragmatic about it, since that's really the only option if we want to do stuff, and we certainly are, hence why we have theories of time or causality at all. So ultimately I guess I agree with you there's not much to say here about this first problem, since at some point it becomes an unresolvable question of metaphysics, and if we build a robust enough model of time then the metaphysical question is of no practical importance anyway for the level of abstraction at which we are operating.

Great post, lot of food for thought, thanks!

IIRC, in "Good and Real" Gary Drescher suggests to first consider a modified version of Newcomb's Problem, where both boxes are transparent. He then goes on to propose a solution in which agent precommits to one-box before being presented with the problem in a first place. This way, as I understand, causal diagram would first feature a node where agent chooses to precommit, and it both deterministically causes their later action to one-box, and Omega's action to put $1000000 in larger box. This initial node for choosing to precommit does look like an agent's abstract model of their and Omega's actions.

Alternatively, in this paper, "Unboxing the Concepts in Newcomb’s Paradox: Causation, Prediction, Decision in Causal Knowledge Patterns", Roland Poellinger suggests to augment ordinary causal networks with new type of undirected edge, he calls an "epistemic contour". In his setup, this edge connects agent's action to select either one or two boxes and Omega's prediction. This edge is not cut when performing do(A) operation on the causal graph, but the
information is passed backwards in time, thus formalizing the notion of "prediction".

I think newcomes problem can be resolved by throwing out the idea that a decision is being made at any point. We're mixing levels or engaging in a kind of category error where the there is a chain of three deterministic events that lead to an outcome rather than a decision point that can go either way. The nature of the person receiving the box is analyzed, that determines the contents of the box, and then subsequently one or two boxes are taken as a consequence of determined nature of the Box taker not a free choice or even the contents of the boxes. There is no decision.

The essential problem is that people try to conceptualize this problem both in terms of limited knowledge subjective decision making which generates the illusion of choice and erroneously try to reconcile that with an objectively deterministic universe, Heisenberg uncertainty notwithstanding.

An additional point of subjective confusion comes from the fact that knowledge of the nature of the problem affects the state of the box taker and may change whether one or two boxes are taken. That creates the subjective experience of a decision but objectively it's simply another factor contributing to the cause effect chain.

But the problem runs deeper than that. If we draw an arrow in the direction of the deterministic function, we will be drawing an arrow of time from the more refined version of the structure to the coarser version of that structure, which is in the opposite direction of all of our examples.

 As I currently understand this after thinking about it for a bit, we are talking about the coarseness of the model from the perspective of the model in the timeframe that it is in and not the time frame that we are in. It would make sense for our predictions of the model to become more coarse with each step forward in time if we are predicting it from a certain time into the future time-space. I don't know if this makes sense but I would be grateful for a clarification!

Time is also crucial for thinking about agency. My best short-phrase definition of agency is that agency is time travel. An agent is a mechanism through which the future is able to affect the past.

Yeahssss...except that there is no need to take that literally...agents build models of future states and act on them, even though they are approximate. If agents could act on the actual future, no one would be killed in an accident, or lose on the stock market.

The primary confusing thing about Newcomb’s problem is that we want to think of our decision as coming “before” the filling of the boxes, in spite of the fact that it physically comes after.

Newcomb's problem isn't a fact...it's not an empirical problem to be solved. You should not be inferring "how time works" from it.

This is hinting that maybe we want to understand some other “logical” time in addition to the time of physics

Ok...

Maybe the solution here is to think of there being many different types of “before” and “after,” “cause” and “effect,” etc. For example, we could say that X is before Y from an agent-first perspective, but Y is before X from a physics-first perspective

If an agent is complex enough to build multiple models , or simulations, they can run some virtual time forwards or backwards, or whatever....in a virtual sense, within the simulation. The important point is that a realistic agent loses information every time they go up another level of virtuality.

What is then stopping us from swapping the two copies of the coarser node?

Isn't it precisely that they're playing different roles in an abstracted model of reality? Though alternatively, you can just throw more logical nodes at the problem and create a common logical cause for both.

Also, would you say what you have in mind is built out of of augmenting a collection of causal graphs with logical nodes, or do you have something incompatible in mind?

Is logical time at all like cost semantics? also this -- cost semantics of a programming language are sort of like "number of beta reductions" from lambda calculus.