Hacker News: evanb

New comment by evanb in "ArXiv's Next Chapter"

evanb — Wed, 01 Jul 2026 11:05:21 +0000

I’m RSS-subscribed to a few sections relevant to my research.

New comment by evanb in "Alan Greenspan has died"

evanb — Tue, 23 Jun 2026 11:12:13 +0000

The gilded age’s wealthy were also the winners of winner-take-all technologies such as the railroad and oil.

New comment by evanb in "Introducing Boron Buckyballs: Theory that B80 cages can’t be made is disproved"

evanb — Sun, 07 Jun 2026 13:31:19 +0000

Given the energy scales involved, it's more likely that the issue lies with the approximations DFT makes to quantum mechanics, rather than the approximations quantum mechanics makes to quantum field theory.

New comment by evanb in "Ask HN: What was your "oh shit" moment with GenAI?"

evanb — Sun, 07 Jun 2026 00:17:39 +0000

I'm a professor of physics; my research area is computational quantum field theory. I was beginning a new approach for a certain kind of model. I know the model has not been simulated before (a collaborator has just constructed it for the first time using in-field knowledge developed in the last year).

I've been steadily more impressed, but the real startling moment was earlier this week, I could show that in a particular operation I had a bug (some identity wasn't satisfied) but I couldn't understand why. In one try Claude Code grokked my code, explained the problem to me (there were some dimension-dependent minus signs that needed to be computed), and fixed it.

New comment by evanb in "Apartment Birds Heard Recently"

evanb — Fri, 29 May 2026 13:24:31 +0000

The description is at https://theodore.net/projects/AvianVisitors/

Apartment Birds Heard Recently

evanb — Fri, 29 May 2026 13:24:31 +0000

Article URL: https://bird.onethreenine.net/

Comments URL: https://news.ycombinator.com/item?id=48322816

Points: 2

# Comments: 1

New comment by evanb in "Quarkdown – Markdown with Superpowers"

evanb — Mon, 27 Apr 2026 17:18:38 +0000

By the Standard Model of Physics Software you can edit Quarkdown in Atom to get Quarkup and change your Neutron Mail to Proton Mail, but it only works if you type with your left hand and create an Electron app and an anti-Neutrinos AI blogpost.

New comment by evanb in "Introduction to spherical harmonics for graphics programmers"

evanb — Thu, 16 Apr 2026 11:50:16 +0000

In case the author is reading this, if you're going to introduce the complex-valued harmonics you should be careful to put the complex conjugate in the inner product

     = ∫ f(ω)^* g(ω) dω

which does match the corresponding linear-algebra inner product if the vectors are over the complex numbers

    p . q = Σ_i p^*_i q_i

which guarantees that p.p ≥ 0 even for complex p (and does not change the only-real case).

New comment by evanb in "Tofolli gates are all you need"

evanb — Sun, 12 Apr 2026 19:34:01 +0000

Hmm. As a physicist my intuition is that information-preserving transformations are unitary (unitary transformations are 1-to-1). If a compression algorithm is going to yield a bit string (the zip file, for example) shorter than the original it can't be 1-to-1. So it must yield the zip file and some other stuff to make up for the space saved by the compression.

New comment by evanb in "Tofolli gates are all you need"

evanb — Sun, 12 Apr 2026 13:36:43 +0000

You could package all your data into a zip using this language but you would also have a worthless stretch of memory seemingly filled with noise / things you’re not interested in.

New comment by evanb in "John Coltrane illustrates the mathematics of jazz"

evanb — Tue, 07 Apr 2026 22:43:47 +0000

I don't remember much about music theory but I know enough about symmetry to know that there's a mistake in the diagram at 9 o'clock.

New comment by evanb in "Isseven"

evanb — Sun, 05 Apr 2026 04:01:49 +0000

Bug report: I tried 6.999999̅ and got false. So there's some nonstandard model of the reals being leveraged here.

New comment by evanb in "Prompt Injecting Contributing.md"

evanb — Thu, 19 Mar 2026 22:19:04 +0000

Of course that's true, but (in the context of the GP) code's bespoke artisanal nature is not the one most people value.

New comment by evanb in "Prompt Injecting Contributing.md"

evanb — Thu, 19 Mar 2026 19:29:41 +0000

I have always anthropomorphized my computer as me to some extent. "I sent an email." "I browsed the web." Did I? Or did my computer do those things at my behest?

New comment by evanb in "Why Mathematica does not simplify sinh(arccosh(x))"

evanb — Sun, 15 Mar 2026 12:44:08 +0000

As a term-rewriting system the rule x-x=0 presumably won’t be in Simplify, it’ll be inside - (or Plus, actually). Instead I’d expect there to be strategies. Pick a strategy using a heuristic, push evaluation as far as it’ll go, pick a strategy, etc. But a lot of the work will be normal evaluation, not Simplify-specific.

New comment by evanb in "Rethinking Syntax: Binding by Adjacency"

evanb — Mon, 09 Mar 2026 19:14:30 +0000

Mathematica has Infix [0], which expresses the adjacency with a ~ (because Mathematica reserves pure blankspace for multiplication). But it works fine to do eg. `"hello"~StringJoin~" world"`; I was always surprised we could only have the predefined operators in many other languages and we couldn't define our own.

This seems like a great attempt. I would be worried about how much parsing and backtracking might be required to infer the infix precedence in a totally general system (like garden-path sentences[1]) or actually ambiguous parse trees (which is cured by adopting some rule like right precedence and parens, but what rule you pick makes some 'natural language' constructions work over others).

[0] https://reference.wolfram.com/language/ref/Infix.html

[1] https://en.wikipedia.org/wiki/Garden-path_sentence

New comment by evanb in "Woxi: Wolfram Mathematica Reimplementation in Rust"

evanb — Sat, 28 Feb 2026 23:04:44 +0000

Mathematica has symbolic and infinite-precision addition, so you can't automatically take advantage of obvious compiled code.

New comment by evanb in "Woxi: Wolfram Mathematica Reimplementation in Rust"

evanb — Sat, 28 Feb 2026 23:03:02 +0000

> The initial focus is to implement a subset of the Wolfram Language so that it can be used for CLI scripting and notebooks.

If you have Mathematica installed you can write CLI scripts and notebooks.

New comment by evanb in "The Pentagon Feuding with an AI Company Is a Bad Sign"

evanb — Thu, 26 Feb 2026 17:58:44 +0000

They did consider it, got a contract that affirmed that the military would be bound by the same pre-existing terms of service as every other user, and want to resist the military's pressure to renegotiate.

Surely that might be naive but the entire issue is that they want to stick to the original contract, which is of course the purpose of a contract in the first place.

New comment by evanb in "Pentagon sets Friday deadline for Anthropic to abandon ethics rules for AI"

evanb — Wed, 25 Feb 2026 11:09:56 +0000

IANAL but it seems 3rd-amendment-adjacent.