Hacker News: rxm

New comment by rxm in "Making a vintage LLM from scratch"

rxm — Fri, 12 Jun 2026 00:48:32 +0000

Nice project. I’m curious to see how it writes after instruct.

New comment by rxm in "Large Concept Models: Language modeling in a sentence representation space"

rxm — Wed, 01 Jan 2025 20:22:23 +0000

What used to be feature engineering a decade or more ago now seems to have shifted to developing distributed representations. LLMs use word tokens (for words or the entities in images). But there are many more. The 3D Fields (or whatever they have evolved to) developed by Fei-Fei Li's group represent visual information in a way better suited for geometrical tasks. Wav2Vec, the convolutional features for YOLO and friends, and these sentence representations are other examples. I would love to read a review of this circle of ideas.

New comment by rxm in "What's Wrong with these Equations? (1989) [pdf]"

rxm — Sat, 05 Feb 2022 12:39:04 +0000

I also prefer to number just the important equations. One of the advantages of numbering all equations is that the reader can binary search an equation by number. I try to mitigate that loss by providing page numbers or section numbers.

Providing “contrast” is something I appreciate as a reader. It is much easier to provide in person, on a whiteboard. Maybe we need papers to have references to YouTube derivations :)

New comment by rxm in "Why are American houses so flimsy and poorly built?"

rxm — Tue, 05 Oct 2021 10:10:53 +0000

One of my pet theories is that flimsy homes reflect an economics signaling problem: it is hard to prove to a buyer the value of quality. Whereas size is easier. As a suburban home owner, I would have preferred the quality-square footage point to lean a bit more towards quality.

New comment by rxm in "Movies every physics lover should watch (2020)"

rxm — Thu, 13 May 2021 13:53:32 +0000

I also like Contact, which I think of as Sagan’s struggle with reconciling religion and science for himself. Also, I nlike what the article mentions, I recall the book being based on the script.

New comment by rxm in "Rollerball Pens of 2021"

rxm — Sat, 23 Jan 2021 16:49:00 +0000

I got through graduate school and over a decade of research with my inexpensive but very smooth Uni-ball cylinders (or classic roller) micro, 0.5mm pens. They were light, with a minimal and elegant design, inexpensive, and wrote great. Then, about a decade ago, something happened to them. I now go between a Jetstream (a ballpoint) and the Uni-ball Eye (which feels identical to the Vision to me).

New comment by rxm in "Computer codes that transformed science"

rxm — Thu, 21 Jan 2021 02:16:53 +0000

I would have included symbolic algebra systems to the list. Many famous calculations in physics and mathematics may not have been attempted without them. Macsyma and Reduce paved the way for Mathematica and Maple. There are still many symbolic algebra algorithms waiting to be implemented. The love and care many open source symbolic systems are receiving is a reflection of their need and importance to science and technology.

New comment by rxm in "Simulating Fluid Dynamics with Cellular Automata (1986) [pdf]"

rxm — Thu, 14 Jan 2021 02:07:13 +0000

Amazing things can happen when cellular automata have symmetries. Conserve number and momentum and you're a few steps from the HPP gas [0]. Make the momentum flow a bit more isotropic, and you are on your way to the FHP gas [1]. The history I remember is that Hasslacher and Wolfram had overlapped at the IAS early 1980s. On the summer of 1985 Hasslacher visited Frisch in Nice. It was there that they guessed that the hexagonal lattice might brake the strange conservation laws of HPP. After that it was a few days until they had a set of rules for the lattice gas fluid in 2d. From France Hasslacher called Shimomura at Los Alamos and asked him if could implement them. In a few days Shimomura has a crowd staring at his screen watching a simulation of a fluid flow past an obstacle shedding vortices in real simulation time. We can do that today with our smartphones, but at the time it must have been a first.

[0]: Hardy, Pomeau, & Pazzis (1973) JMP: 10.1063/1.1666248

[1]: Frisch, Hasslacher, & Pomeau (1986) PRL: 10.1103/PhysRevLett.56.1505

New comment by rxm in "URL shorteners set ad tracking cookies"

rxm — Tue, 05 Jan 2021 02:29:25 +0000

Some URL shorteners provide a copy of their mappings to the Internet Archive as a promise that if they stop functioning for any reason the archive will continue to provide the mapping (and make the mapping file available).

[0]: https://archive.org/details/301works-faq

New comment by rxm in "The Amazon AWS Premium"

rxm — Sat, 14 Dec 2019 20:49:41 +0000

Until the early 2010s we ran our own tiny data center (six to eight racks in two separate locations). When we re-evaluated whether to have the racks hosted somewhere else, it worked out way cheaper to run the machines ourselves. But when we included the costs of the sporadic stuff, cloud providers became cheaper.

The sporadic stuff adds up. This is the "other stuff" one needs to do to keep the machines running. It includes the time it took someone to swap a failing drive, or the loss of productivity when the system went down (because of faulty air conditioning maintenance procedure), or the costs of procuring hardware, or dealing with the network provider, and so on. This stuff adds up. We ran a tight ship. Every minute someone spent dealing with the racks of computers was a minute they did not spend creating a product for our customers.

The only thing we had some difficulty with was intermediate reliability storage, at the level of non-raided spinning disks. But that was then, when the offerings where thinner.

New comment by rxm in "Copyright Lawsuits Could Come to Regular Internet Users Under a New Law"

rxm — Thu, 01 Aug 2019 11:02:26 +0000

> any Internet user who uploads a copyrighted work could find themselves subject to a largely unappealable $5,000 penalty

Shared a viral amateur video? I understood that this law would allow a troll firm to contact the video creator and offer to sue you and all those that did so.

New comment by rxm in "Math versus Dirty Data"

rxm — Thu, 25 Jul 2019 12:21:09 +0000

In most organizations I have interacted with getting data with known sampling is always a problem. “The temperature sensor sends a measurement every 5 minutes.” Except, I learned after a lot of debugging, when the air-conditioner gets maintained and the readings become a fixed value.

It’s not the organizations fault. Discovering and maintaining a known sampling for the data is part of the process. I consider it a win when I can get a team to accept that the data process will need to be debugged just like code.

New comment by rxm in "The Books of College Libraries Are Turning into Wallpaper"

rxm — Mon, 27 May 2019 12:12:40 +0000

There are many aspects of a library of technical books that I miss online: the curation process, the higher bit rate once you are holding the book, and the lack of distractions in the library.

What I fear may go away is the long form books offer. When exploring a new topic, articles are often too dense. In books, authors can establish the background, help create a shared vocabulary, and motivate what is often so condensed in a research article.

New comment by rxm in "Awesome jq"

rxm — Sat, 10 Nov 2018 23:04:22 +0000

What awk and send are to files of lines, jq is to json. I find it indispensable on the command line. Jq is a functional language. It took me a bit to get used to it, but now it is one of the first tools I install in a new machine. The linked article is a curated list of jq related resources. After the manual, I found the cookbook helpful.

New comment by rxm in "The Kruskal Count Card Trick"

rxm — Mon, 07 May 2018 15:21:40 +0000

One of the conversations was about reading. Let the kids read anything: comic books, fun novels, fantasy picture books. He re-assured me that they would eventually expand into other things. Martin was right.

New comment by rxm in "The Kruskal Count Card Trick"

rxm — Fri, 04 May 2018 17:29:06 +0000

When I was a graduate student, in the late 80s, I was waiting for a flight to Los Alamos in Albuquerque. There was only one other person in the lounge, obviously also going to Los Alamos. I started chatting and he introduced himself as Martin Kruskal. Idiot me had no idea whom I was speaking to. I said “The only Kruskal I know invented this amazing card trick having to do with dynamical systems.” He stared at me, obviously pleased. “Not many people know my brother and I are into magic.” He did not want to take credit for the trick and attributed it to his brother. He would come often to Los Alamos and I miss chatting with him (got lots of advice on bringing up girls).

New comment by rxm in "Ask HN: What is so great about Bloomberg Terminal?"

rxm — Sun, 26 Feb 2017 22:51:28 +0000

Thanks for the example. What you just did is one of the hardest things to communicate about data. A casual user would never notice this. I find "data curation" doesn't always get the importance it deserves.

New comment by rxm in "Ask HN: Does anyone still use TextMate?"

rxm — Fri, 18 Nov 2016 01:33:21 +0000

I still use textmate. I started with vi, which I still use for small edits, switched to sam, back to vi when I stopped having X on my Mac, and then to textmate. I have tried sublime and atom. I am sure they can be configured to work as I would like, but out of the box the distance seemed too far.

My desire to configure is strongest when I start writing reports (in LaTeX or markdown). I long for a distraction free mode with easy spell checking.

The math of coffee brewing

rxm — Thu, 17 Nov 2016 11:28:37 +0000

Article URL: http://phys.org/news/2016-11-mathematics-coffee-ideal-brew.html

Comments URL: https://news.ycombinator.com/item?id=12976452

Points: 2

# Comments: 0

New comment by rxm in "[dead]"

rxm — Wed, 09 Nov 2016 05:58:58 +0000

Does anyone know when this post was written?