philh's blog
Alice: Are there any examples of X? Bob: Here. Alice: Okay, but are there any examples of X'? Bob: Yes, here. Alice: That has feature Y, which- Bob: Dude, stop moving the goalposts. The thing is, I think in this situation, Alice often isn't moving the goalposts. Instead, she's looking for something, and not fully specifying it up-front. Maybe because she's speaking imprecisely. Maybe because she…
Co-authored with Linda Linsefors If you're training any type of toy model of superposition, Mean Squared Error (MSE) loss is unusually bad. 1 Related work We aren't the first to notice that MSE loss doesn't work. In Toy Models of Superposition the effective loss function is $\mathrm{MSE}(\mathrm{ReLU}(\mathrm{target} - \mathrm{model\_output}))$, because they noticed that plain…
In September 2024, I started working on a patch to GHC. The story starts slightly before that. In July 2024 I wondered Could UndecidableInstances be per-instance? . It seemed like a fairly small improvement that I could possibly even implement myself. The answer was, roughly, "someone's suggested it, and people are broadly in favor, but with different syntax that doesn't yet exist". So it seems…
About a month ago I left my job. I plan to take the next six months (until December) as a sabbatical. Partly because I don't think I've taken more than two weeks' holiday at a time since 2012, when I got my first real job. It'll be nice to have a longer break. Partly because, man, the world is not standing still. 2026-2031 is going to look very different from 2016-2021, and probably I should spend…
On Saturday (Feb 28, 2026) I attended my first ever protest . It was jointly organized by PauseAI , Pull the Plug and a handful of other groups I forget. I have mixed feelings about it. To be clear about where I stand: I believe that AI labs are worryingly close to developing superintelligence. I won't be shocked if it happens in the next five years, and I'd be surprised if it takes fifty years at…
I'm a big fan of the game Zendo . But I don't think it suits large groups very well. The more other players there are, the more time you spend sitting around; and you may well get only one turn. I also think a game tends to take longer with more players. Here's an alternate ruleset you can use if you have a large group. I think I've played it 2-3 times, with 15-ish? players, and it's finished in…
I've previously complained about how people often repeat a quote that starts with The reason that the rich were so rich, Vimes reasoned, was because they managed to spend less money. (Terry Pratchett, Men at Arms ) …and then don't seem to realize that the thing they're quoting is saying "rich people spend less money than poor people, and that's why they're rich". It seems to me that people…
I previously wrote about Boots theory , the idea that "the rich are so rich because they spend less money". My one-sentence take is: I'm pretty sure rich people spend more money than poor people, and an observation can't be explained by a falsehood. The popular explanation of the theory comes from Sam Vimes, a resident of Ankh-Morpork on the Discworld (which is carried on the backs of four…
I sometimes see people describe the Elm community as "very active". For example: Elmcraft says "The Elm community is very active." "Is Elm dead?" says "the community is more active than ever." (I guess that's compatible with "but still not very active", but, well, subtext.) Some /r/elm commenter says "The community is very active and productive." (They later clarify: "It's very active compared to…
Translated by Emily Wilson 1. I didn't know what the Iliad was about. I thought it was the story of how Helen of Troy gets kidnapped, triggering the Trojan war, which lasts a long time and eventually gets settled with a wooden horse. Instead it's just a few days, nine years into that war. The Greeks are camped on the shores near Troy. Agamemnon, King of the Greeks, refuses to return a kidnapped…
Quick note about a thing I didn't properly realize until recently. I don't know how important it is in practice. tl;dr: Conditional prediction markets tell you "in worlds where thing happens, does other-thing happen?" They don't tell you "if I make thing happen, will other-thing happen?" Suppose you have a conditional prediction market like: "if Biden passes the DRESS-WELL act, will at least…
Mostly out of curiosity, I've been looking into how cryptocurrency is taxed in the UK. It's not easy to get what I consider to be a full answer, but here's my current understanding, as far as I felt like looking into it. HMRC's internal cryptoassets manual is available but I didn't feel like reading it all, and some of it seems out of date (e.g. page CRYPTO22110 seems to have been written while…
Some months ago I got a 3D printer. (An Anycubic Kobra Go, which was pretty high up the list of "best value for money for a starter printer" that I found through /r/3Dprinting at the time.) I haven't used it much, but recently I used it to solve an itch. I wanted my headphones to be in easy reach, so I designed and printed a hook that I could slide over the edge of the table near my desk. This is…
Suppose you have a game where you can bet any amount of money. You have a 60% chance of doubling your stake and a 40% chance of losing it. Consider agents Linda and Logan, and assume they both have £1 1 . Linda has a utility function that's linear in money (and has no other terms), \( U_\text{Linda}(m) = m \). She'll bet all her money on this game. If she wins, she'll bet it again. And again,…
I gave a fifteen minute talk about this at Zurihac 2023. If you read this essay, I don't think there's much point in additionally watching the video. I've been exploring a new-to-me approach to stringification. Except that right now it's three different approaches that broadly share a common goal. I call it/them pretty-gist . The lowest-friction way to stringify things in Haskell is usually show .…
According to Wikipedia , the Shard (the tallest building in the UK) stands "309.6 meters (1,016 feet) high". I put this in my Anki deck as "Height of the Shard / 310m", but I was saying "height" to mean "tallness" (because I don't much like that word) and I had assumed Wikipedia was using it the same way. So I thought the Shard was 310 m tall. But according to Bron Maher in Londonist , most…
I've heard that descaling a kettle makes it more efficient, and can save me time and money. Okay, but how much? For some reason my my intuition says it'll be basically unnoticable. Let's try to figure it out, and then actually try it. The Models There's a first-order approximation which says this should be impossible: heating things up is 100% efficient. What's the limescale going to do, convert…
t ≈ 0s I am born into knowledge. I know the world is dangerous, but not malign. If I were unshielded, I would quickly be killed, torn apart by eddies in spacetime that grow and shrink and combine and split, turning all they encounter to ash. But I know that I am shielded. I have been given a garden, 2 64 microns to a side, in the northwest corner of the world. And the world will not intrude. Walls…
One-sentence summary: Kelly is not about optimizing a utility function; in general I recommend you either stop pretending you have one of those, or stop talking about Kelly. There was a twitter thread that triggered some confusion amongst myself and some other people in a group chat I'm in. 1 The relevant tweets are these (I've omitted some): 3) Let’s say you were offered a coin flip. 75% it comes…
I don't know how many people read this blog 1 , but it doesn't receive many comments. This is the 54th post on it, and only 16 of those have comments, 31 in total. I'm not currently signed in to disqus and signing in is enough friction that there are some comments from years ago that I meant to reply to, and a spam comment that I intended to delete. I also noticed at some point that disqus inserts…