Twenty-Seven Characters

While similarly post-apocalyptic and “numbers-driven,” this post is not actually about a new NetFlix series. Rather, the main character of the story is HaluEval, a new “standard benchmark” for measuring whether a large language model is hallucinating — producing fluent, plausible-sounding text where it ought to be reporting a fact. The benchmark contains around 35,000 … Read more

FEMA Holds the Screwdrivers

When I introduced the junk drawer a few posts back, the example was a physical one. Most kitchens have a drawer that holds the screwdriver, the rubber bands, the takeout menus, the AAA batteries, and the one weird key nobody can identify. The drawer is not a failure of organization. It is the part of … Read more

There are no stupid questions… just answers that don’t travel.

There are no stupid questions… Dear NSQ, I grew up in Pittsburgh and learned to drive there. Last month I took a left turn from Tate Street onto West Market Street the way I always have — when the light turned green, I went, before the oncoming traffic could reach the intersection. The driver across … Read more

Your AI Makes Bean Soup? Sure, But Mine Makes 7 Bean Soup!

A Vice President at a large technology company sits down at the end of the quarter to evaluate her engineering team. She has twelve direct reports. They have spent the quarter using AI tools heavily, as the company’s leadership has insisted they do. She must now write performance reviews. She has to say, in writing, … Read more

The Baker’s Dozen: Redistricting, Race, and Messy Problems

Friday’s post argued that what the Court did in Louisiana v. Callais is best described as breaking a structural link — a load-bearing connection that was holding up many actions at once, not just the Louisiana map. That post was about what. This post is about why now. Why this case, why this term, why … Read more

Dispatches from the Underground: May 4, 2026

Wednesday morning I posted “You Can Get There From Here, Or: The Theorem in the Tagline,” a piece I had been meaning to write for fourteen years. It is a short essay about why McKelvey-Schofield — the result that majority preference cycles can wander anywhere in the policy space once procedural constraints fall away — … Read more

You Can Still Get There From Here (Or, How SCOTUS Changed the Map)

Justice Kagan opens her Callais dissent with a hypothetical. She knows it’s stylized, and she says so. Imagine a state shaped like a rectangle, with one of its six congressional districts a near-perfect circle in the middle. The circle is ninety percent Black. The other five districts, surrounding it, are ninety percent white. Voting is … Read more

Could We Tell?

The previous post used the phrase “local data” something like thirty times. The phrase did most of the heavy lifting in the argument: local data does not determine global structure, the more holes the underlying object has the more slack between local and global, and so on. I want to start this post by interrogating … Read more

You Can Get There From Here (or, the Theorem in the Tagline)

This blog has been operating under the subtitle “Three Implies Chaos” since 2012. Long-time readers know the phrase pulls multiple duty: Li and Yorke’s period-three theorem from chaotic dynamics, Arrow’s theorem on preference aggregation, the Gibbard-Satterthwaite theorem on strategic manipulation, and the McKelvey-Schofield chaos theorem on multidimensional voting. Each of these results says, in its … Read more

The Measurement Problem Has a Donut Hole

In 1867, the French mathematician Pierre Ossian Bonnet asked a question that sounds like it should have an obvious answer. If you know the metric of a compact surface at every point — the intrinsic distances and angles, the things you could measure if you were a tiny ant walking on the surface — and … Read more