Welcome to The Nonlinear Library, where we use Text-to-Speech software to convert the best writing from the Rationalist and EA communities into audio. This is: AXRP Episode 15 - Natural Abstractions with John Wentworth, published by DanielFilan on May 23, 2022 on The AI Alignment Forum.
Google Podcasts link
Why does anybody care about natural abstractions? Do they somehow relate to math, or value learning? How do E. coli bacteria find sources of sugar? All these questions and more will be answered in this interview with John Wentworth, where we talk about his research plan of understanding agency via natural abstractions.
Topics we discuss:
Agency in E. coli
Agency in financial markets
Inferring agency in real-world systems
Selection theorems
(Natural) abstractions
Information at a distance
Why the natural abstraction hypothesis matters
Unnatural abstractions in humans
Probability, determinism, and abstraction
Whence probabilities in deterministic universes?
Abstraction and maximum entropy distributions
Natural abstractions and impact
Learning human values
The shape of the research landscape
Following John’s work
Daniel Filan: Hello, everybody. Today I’ll be speaking with John Wentworth, an independent AI alignment researcher who focuses on formalizing abstraction. For links to what we’re discussing, you can check the description of this episode and you can read the transcripts at axrp.net. Well, welcome to AXRP, John.
John Wentworth: Thank you. Thank you to our live studio audience for showing up today.
Agency in E. coli
Daniel Filan: So I guess the first thing I’d like to ask is I see you as being interested in resolving confusions around agency, or things that we don’t understand about agency. So what don’t we understand about agency?
John Wentworth: Whew. All right. Well, let’s start chronologically from where I started. I started out, first, in two directions in parallel. One of them was in biology, like systems biology and, to some extent, synthetic biology, looking at E. coli. Biologists always describe E. coli as collecting information from their environment and using that to keep an internal model of what’s going on with the world, and then making decisions based on that in order to achieve good things.
John Wentworth: So they’re using these very agency-loaded intuitions to understand what’s going on with the E. coli, but the actual models they have are just these simple dynamical systems, occasionally with some feedback loops in there. They don’t have a way to take the low-level dynamics of the E. coli and back out these agency primitives that they’re talking about, like goals and world models and stuff.
Daniel Filan: Sorry, E. coli, it’s a single-celled organism, right?
John Wentworth: Yes.
Daniel Filan: Is the claim that the single cells are taking in information about their environment and like . Right?
John Wentworth: Yes. One simple example of this is chemotaxis. So you’ve got this E. coli. It’s swimming around in a little pool of water and you drop in a sugar cube. There’ll be a chemical gradient of sugar that drops off as you move away from the grain of sugar. The E. coli will attempt to swim up that gradient, which is actually an interesting problem because when you’re at a length scale that small, the E. coli’s measurements of the sugar gradient are extremely noisy. So it actually has to do pretty good tracking of that sugar gradient over time to keep track of whether it’s swimming up the gradient or down the gradient.
Daniel Filan: Is it using some momentum algorithm, or is it just accepting the high variance and hoping it’ll wash out over time?
John Wentworth: It is essentially a momentum algorithm.
Daniel Filan: Okay, which is basically, roughly, continuing to move in the direction it used to move, something like that.
John Wentworth: Yes. Basically it tracks the sugar concentration over time. If it’s trending upwards, it keeps swimming and if it’s trending downwards, it just stops and tumbles in place...