Hacker News: adonovan

New comment by adonovan in "How JPL keeps the 13-year-old Curiosity rover doing science"

adonovan — Sat, 13 Jun 2026 13:07:49 +0000

Understood. My point is that the job requirements are almost mutually exclusive: must be physically and mentally fit enough for arduous travel and harsh work, yet basically suicidal.

New comment by adonovan in "How JPL keeps the 13-year-old Curiosity rover doing science"

adonovan — Fri, 12 Jun 2026 11:37:07 +0000

Like enjoying earthly pleasures? The terminally ill do not make good astronauts.

New comment by adonovan in "How JPL keeps the 13-year-old Curiosity rover doing science"

adonovan — Thu, 11 Jun 2026 03:38:15 +0000

I'd be surprised if there's a single person alive who would volunteer for a suicide mission to a miserable cold dark planet and could travel there for nine months in a tin can through a harsh radiation/muscle atrophy/psychological environment and arrive in any condition to conduct useful scientific work.

New comment by adonovan in "Have a Coherent AI Policy"

adonovan — Fri, 15 May 2026 02:18:25 +0000

It seems quite common for the infrastructure teams to put up a dashboard just to keep a sense of what is going on, but it is then misinterpreted as a “leaderboard” and encourages the most prolific users to find creative ways to squander more to stay the “winner”. Management is slightly disappointed by the waste but also happy that staff are engaging with their future replacements.

New comment by adonovan in "Ask HN: We just had an actual UUID v4 collision..."

adonovan — Sat, 09 May 2026 03:57:31 +0000

For a while we’ve been fixing telemetry-reported crash bugs in the project I maintain, and now hardware bugs are showing up with some frequency. I was amazed how common they are. Sometimes data values (e.g. SP register) are corrupted, but other times even infallible operations (e.g loads of rodata constants) crash, indicating that the instruction itself was corrupted. So, yeah, I believe you’ll eventually see UUID collisions, but not because the underlying cryptanalysis was wrong.

New comment by adonovan in "Heat pump sales rise across Europe"

adonovan — Mon, 04 May 2026 20:43:32 +0000

Does the ground source heat up (or cool down) over time, making it less effective? The deep ground is very well insulated, which is why after a century of operation the London Underground is 10 degrees warmer. I wonder whether GSHP users need to balance their load by (say) consuming more heating than they actually need in winter so that summer cooling remains effective.

New comment by adonovan in "NASA Force"

adonovan — Fri, 17 Apr 2026 21:47:13 +0000

This administration does love "force".

New comment by adonovan in "Too much discussion of the XOR swap trick"

adonovan — Thu, 16 Apr 2026 12:16:01 +0000

Another situation to avoid the XOR trick, even when registers are tight, is when swapping pointers in a garbage-collected language, since the intermediate bit patterns are invalid pointers: if a GC mark phase occurs at that moment, you might lose some objects, or spuriously mark others as live.

New comment by adonovan in "The buns in McDonald's Japan's burger photos are all slightly askew"

adonovan — Thu, 16 Apr 2026 12:08:56 +0000

Quite. A burger that wears its hat at a jaunty angle for a rakish look.

New comment by adonovan in "Microsoft: Copilot is for entertainment purposes only"

adonovan — Wed, 01 Apr 2026 00:40:15 +0000

I once wrote a contract document in PostScript that changed the wording based on the date. Two parties could cryptographically sign an agreement in the document, which would change when printed on a later date.

One of the reasons we don’t use PostScript so much any more.

New comment by adonovan in "Siclair Microvision (1977)"

adonovan — Sun, 29 Mar 2026 15:25:43 +0000

It's not an illegal monopoly to be the sole entity capable of a technique. The problems come from manipulating the market to prevent competition.

New comment by adonovan in "Antimatter has been transported for the first time"

adonovan — Wed, 25 Mar 2026 21:54:37 +0000

The subject of this story is a single proton that you would definitely feel if it hit you: https://www.fourmilab.ch/documents/OhMyGodParticle/

New comment by adonovan in "How the Turner twins are mythbusting modern technical apparel"

adonovan — Thu, 19 Mar 2026 22:35:32 +0000

Also weird phrasing: "a staggering 1.8 degrees" begs the reader to think of it as a large number (which in fact it is, as you point out) yet their intent seems to be, ironically and paradoxically, to diminish it.

New comment by adonovan in "//go:fix inline and the source-level inliner"

adonovan — Tue, 17 Mar 2026 13:50:42 +0000

Thanks, that's a bug. We should never inline a function that directly calls recover. I've filed https://go.dev/issue/78193.

New comment by adonovan in "Ask HN: How is AI-assisted coding going for you professionally?"

adonovan — Mon, 16 Mar 2026 13:44:09 +0000

> The “will lead astray” part is concerning. If you already have a clear idea in mind, you probably don’t need to have the debate with coworkers.

Yeah, I certainly wouldn't trust it to run any distance unattended, and I started this project with strong ideas about the parameters of the design, so I know what I want and what won't fly. But as you say, it can help tease out unexpected pros and cons of certain choices along the way.

> In summary: obviate experts, receive correct guidance, save time —- pick any two.

It's simpler than that: it can't do the first, nor reliably the second, but it has saved me time.

New comment by adonovan in "Ask HN: How is AI-assisted coding going for you professionally?"

adonovan — Mon, 16 Mar 2026 12:18:08 +0000

I’ve been an overt AI hater but have found very recently that, though I still hate a great many things about AI, it has become useful for coding.

In 10m Gemini correctly diagnosed and then fixed a bug in a fairly subtle body of code that I was expecting to have to spend a couple hours working on.

I spent much of the past week using Gemini to build a prototype of a clean new (green field) system involving RPCs, static analysis, and sandboxing. I give it very specific instructions, usually after rounds of critical design discussions, and it generates structurally correct code that passes essentially valid tests. Error handling is a notable weakness. I review the code by hand after each step and often make changes, and I expect to go over the over the whole thing very carefully at the end, but it has saved me many hours this week.

Perhaps more valuable than the code has been the critical design conversation, in which it mostly is fluent at the level of an experienced engineer and has been able explain, defend, and justify design choices quite coherently. This saved time I would otherwise have spent debating with coworkers. But it’s not always right and it is easily led astray (and will lead astray), so you need a clear idea in mind, a firm hand, and good judgment.

New comment by adonovan in "LLM Writing Tropes.md"

adonovan — Sun, 08 Mar 2026 16:12:39 +0000

One annoying trope I keep seeing in Gemini output is the punchy invented concept name in a tripartite list:

- “The Pledge”:…

- “The Turn”:…

- “The Prestige”:…

(For this particular example I used real terms from the stage magic world, at least according to Christopher Nolan’s film, as it captures the same meaningless-to-the-uninitiated quality.)

New comment by adonovan in "Self-Portrait by Ernst Mach (1886)"

adonovan — Sat, 07 Mar 2026 22:21:04 +0000

Likewise! I often marvel at the patience of readers of earlier times. Of course, they had more time and fewer distractions, and I suspect that there was a dynamic at work in which both the writer and reader derived a certain satisfaction from long meandering sentences, the writer proving their skill, and the reader proving (to themselves) their stamina.

Nowadays we tend to write in a plainer style demanding a smaller “parser stack”. Some style manuals have excellent examples of sentences of equal length but very different “stack depth” and thus ease of comprehension.

New comment by adonovan in "10% of Firefox crashes are caused by bitflips"

adonovan — Fri, 06 Mar 2026 23:08:16 +0000

Good question. We don't know the true figure, but we extrapolate the denominator from estimates of the total number of Go users and the fraction of Go users that run gopls.

New comment by adonovan in "10% of Firefox crashes are caused by bitflips"

adonovan — Fri, 06 Mar 2026 04:15:39 +0000

Good point: I-cache is memory too. (Indeed it is SRAM, so its bits might be even more fragile than DRAM!)