Hacker News: imurray

New comment by imurray in "The Road Not Taken: A World Where IPv4 Evolved"

imurray — Thu, 12 Mar 2026 18:17:53 +0000

Reminds me of https://cr.yp.to/djbdns/ipv6mess.html

Which has been discussed previously: https://hn.algolia.com/?q=The+IPv6+mess

New comment by imurray in "The Road Not Taken: A World Where IPv4 Evolved"

imurray — Thu, 12 Mar 2026 18:13:42 +0000

I think that's meant to be covered by the "IPv4x when we can. NAT when we must" part, in particular "ISPs used carrier‑grade NAT as a compatibility shim rather than a lifeline: if you needed to reach an IPv4‑only service, CGNAT stepped in while IPv4x traffic flowed natively and without ceremony."

It seemed strange that the need for CGNAT wasn't mentioned until after the MIT story. The "Nothing broke" claim in that story seems unlikely; I was on a public IP at University at the end of the 90s and if I'd suddenly been put behind NAT, some things I did would have broken until the workarounds were worked out.

New comment by imurray in "The Falkirk Wheel"

imurray — Wed, 11 Feb 2026 15:07:01 +0000

Ooof, I'd never seen that. Thanks! From the wikipedia link:

> The May 1799 test at Oakengates carried a party of investors aboard the vessel, who nearly suffocated before they could be freed.

(!) ...and eventually they built a flight of nineteen locks instead, with a steam-powered pump to return water. The lift locks (and Falkirk Wheel) are a really impressive and elegant solution in comparison.

New comment by imurray in "The Falkirk Wheel"

imurray — Wed, 11 Feb 2026 10:31:41 +0000

The Falkirk Wheel is cool and a fun trip, along with the nearby Kelpies, which were much more striking in person than I'd anticipated.

The wheel is a one-of-a-kind, but there are other ways of avoiding having a ladder of flood locks, see: https://en.wikipedia.org/wiki/Boat_lift

I really liked this one in Peterborough, Ontario, Canada: https://en.wikipedia.org/wiki/Peterborough_Lift_Lock Built as a real working lift lock (originally 1904), rather than as a tourist attraction. Powered by a little bit of extra water in one of the buckets to tip the balance and drive the pistons.

New comment by imurray in "Show HN: Yourshoesmells.com – Find the most smelly boulder gym"

imurray — Tue, 04 Nov 2025 11:32:32 +0000

The site didn't load for me in Firefox, but I found these fantastic for preventing climbing shoe stink: https://bootbananas.com/product/original-shoe-deodorisers/ They absorb sweat, not just mask the smell.

New comment by imurray in "Anscombe's Quartet"

imurray — Tue, 09 Sep 2025 13:47:16 +0000

It's clearly hard, but there are tools for doing exploratory visualization of high-dim data. GGobi http://ggobi.org/ and all the ones that arrange points but try to get local neighborhoods correct (t-sne, umap, et al.).

New comment by imurray in "What Is Complexity in Chess?"

imurray — Mon, 01 Sep 2025 13:53:16 +0000

Some things that may be of interest. First relevant to the posted article:

A site that has used neural nets to classify go moves that good players would probably make that weaker players (of varying ranks) would probably not: https://neuralnetgoproblems.com/ (code available on github)

https://ai-sensei.com/challenge (behind login wall, and in future possibly a pay wall) is a similar idea, but the difficulty of evaluating the position is determined by how users of the site perform in practice.

And more generally, but relevant to your comment:

Players can play humans at an appropriate rank on OGS https://online-go.com/ (not as popular as the Eastern servers, but probably popular enough) -- or against calibrated rank "human-like" AI players by painfully setting up the right katago models themselves, or by paying for a subscription on ai-sensei.com

A go education site that's currently largely by and pitched at Westerners: https://gomagic.org/ for leveling up from the basics.

And a lot of books are now available easily and electronically in English (and some in German): https://gobooks.com/ --- I'd recommend "graded go problems for beginners", "tesuji", and "attack and defense".

Some good sites aren't (fully) available in English, like https://www.101weiqi.com/ -- but there are chrome and firefox extensions to translate just enough of it to make it usable.

[To help search engines: go is also known as weiqi and baduk]

New comment by imurray in "Blazing Matrix Products"

imurray — Fri, 27 Jun 2025 12:14:57 +0000

This post is for those interested high-performance matrix multiplication in BQN (an APL-like array language).

The main thing I got out of it was the footnotes, in particular: https://en.algorithmica.org/hpc/algorithms/matmul/ is a really nice post on fast matrix multiplication, and is a chapter of what looks like a nice online book.

New comment by imurray in "The bitter lesson is coming for tokenization"

imurray — Tue, 24 Jun 2025 17:31:29 +0000

A PhD thesis that explores some aspects of the limitation: https://era.ed.ac.uk/handle/1842/42931

Detecting and preventing unargmaxable outputs in bottlenecked neural networks, Andreas Grivas (2024)

New comment by imurray in "How to (actually) send DTMF on Android without being the default call app"

imurray — Fri, 06 Jun 2025 16:37:27 +0000

> generating DTMF tones yourself and injecting them into the audio stream?

When I was an undergrad I had an audio file for each digit and a winamp playlist for each of my frequently dialed numbers. I'd hold my (landline) phone against the computer speakers and double-click the playlist to dial. I'm sure I spent more time setting this up than it ever saved, but it was somehow pleasing that this ridiculously over-powered speed dialer worked.

New comment by imurray in "Browser extension (Firefox, Chrome, Opera, Edge) to redirect URLs based on regex"

imurray — Mon, 02 Jun 2025 15:14:07 +0000

I wrote firefox and chrome extensions that do exactly what you want:

Firefox: https://addons.mozilla.org/en-US/firefox/addon/redirectify/

Chrome: https://chrome.google.com/webstore/detail/redirectify/mhjmbf...

Source: https://github.com/imurray/redirectify

Sadly I never got around to making it configurable, so it's just a fixed table of rules for a handful of journal and pre-print sites.

New comment by imurray in "How can AI researchers save energy? By going backward"

imurray — Mon, 02 Jun 2025 12:20:21 +0000

Another machine learning paper ("ancient", 2015) where being able to exactly reverse a computation was useful: https://arxiv.org/abs/1502.03492

New comment by imurray in "How can AI researchers save energy? By going backward"

imurray — Mon, 02 Jun 2025 09:53:35 +0000

I'm sceptical about the energy motivation, but there are multiple reasons why making invertible deep learning architectures can be interesting or useful. Cf, a series of workshops from 2019-2021: https://invertibleworkshop.github.io/

Since then diffusion models have been popular. Generating from these can be seen as a special case of a continuous time normalizing flow, and so (in theory) is a reversible computation. Although the distilled/fast generation that's run in production is probably not that!

Simulating differential equations is not usually actually reversible in practice due to round-off errors. But when done carefully, simulations performed in a computer can actually be exactly bit-for-bit reversible: https://arxiv.org/abs/1704.07715

Correcting Myths in the Mapping of Cholera

imurray — Sat, 31 May 2025 11:32:04 +0000

Article URL: https://www.maps.com/snow-mistake-correcting-myths-in-the-mapping-of-cholera/

Comments URL: https://news.ycombinator.com/item?id=44143545

Points: 1

# Comments: 0

New comment by imurray in "Yes-rs: A fast, memory-safe rewrite of the classic Unix yes command"

imurray — Tue, 27 May 2025 12:17:21 +0000

No, it will be about the same. The algorithm is wrong (calling write repeatedly) and -O3 isn't sufficient to rewrite that.

New comment by imurray in "Does Earth have two high-tide bulges on opposite sides? (2014)"

imurray — Thu, 22 May 2025 19:00:16 +0000

I was asked why there are two tides a day in an interview for my undergraduate University place. I blundered through to the classic answer. This stackexchange discussion made me realize I was even more of an imposter than I thought :-).

Does Earth have two high-tide bulges on opposite sides? (2014)

imurray — Thu, 22 May 2025 18:58:25 +0000

Article URL: http://physics.stackexchange.com/questions/121830/does-earth-really-have-two-high-tide-bulges-on-opposite-sides

Comments URL: https://news.ycombinator.com/item?id=44065458

Points: 294

# Comments: 90

New comment by imurray in "Animated Factorization (2012)"

imurray — Thu, 22 May 2025 14:58:57 +0000

Heh. I submitted it in Oct 2012. I submitted a few things back then, none got traction and I stopped bothering :-).

New comment by imurray in "Viral ChatGPT trend is doing 'reverse location search' from photos"

imurray — Fri, 18 Apr 2025 10:13:16 +0000

A photo taken on my street (no exif) "only" gives the correct town in chatgpt and gemini, and then incorrectly guesses the precise neighbourhood/street when pushed. Gemini claimed to have done a reverse image search, but I'm not convinced it did. An actual Google reverse image search found similar photos, taken a bit further along the same street or in a different direction, labelled with the correct street (no LLM required).

New comment by imurray in "Show HN: HNSW index for vector embeddings in approx 500 LOC"

imurray — Tue, 08 Apr 2025 17:24:57 +0000

Looks neat. It would be useful to compare to other implementations: https://ann-benchmarks.com/ -- potentially not just speed, but implementation details that might change recall.