Tired of going to Scott "Other" Aaronson's blog to find out what's currently known about the busy beaver game? I maintain a community website that has summaries for the known numbers in Busy Beaver research, the Busy Beaver Gauge.
I started this site last year because I was worried that Other Scott was excluding some research and not doing a great job of sharing links and history. For example, when it comes to Turing machines implementing the Goldbach conjecture, Other Scott gives O'Rear's 2016 result but not the other two confirmed improvements in the same year, nor the recent 2024 work by Leng.
Concretely, here's what I offer that Other Scott doesn't:
- A clear definition of which problems are useful to study
- Other languages besides Turing machines: binary lambda calculus and brainfuck
- A plan for how to expand the Gauge as a living book: more problems, more languages and machines
- The content itself is available on GitHub for contributions and reuse under CC-BY-NC-SA
- All tables are machine-computed when possible to reduce the risk of handwritten typos in (large) numbers
- Fearless interlinking with community wikis and exporting of knowledge rather than a complexity-zoo-style silo
- Acknowledgement that e.g. Firoozbakht is part of the mathematical community
I accept PRs, although most folks ping me on IRC (korvo
on Libera Chat, try #esolangs
) and I'm fairly decent at keeping up on the news once it escapes Discord. Also, you (yes, you!) can probably learn how to write programs that attempt to solve these problems, and I'll credit you if your attempt is short or novel.
Wolfram has a blog post about lambda calculus. As usual, there are no citations and the bibliography is for the wrong blog post and missing many important foundational papers. There are no new results in this blog post (and IMO barely anything interesting) and it's mostly accurate, so it's okay to share the pretty pictures with friends as long as the reader keeps in mind that the author is writing to glorify themselves and make drawings rather than to communicate the essential facts or conduct peer review. I will award partial credit for citing John Tromp's effort in defining these diagrams, although Wolfram ignores that Tromp and an entire community of online enthusiasts have been studying them for decades. But yeah, it's a Mathematica ad.
In which I am pedantic about computer science (but also where I'm putting most of my sneers too, including a punchline)
For example, Wolfram's wrong that every closed lambda term corresponds to a combinator; it's a reasonable assumption that turns out to not make sense upon closer inspection. It's okay, because I know that he was just quoting the same 1992 paper by Fokker that I cited when writing the esolangs page for closed lambda terms, which has the same incorrect claim verbatim as its first sentence. Also, credit to Wolfram for listing Fokker in the bibliography; this is one of the foundational papers that we'd expect to see. With that in mind, here's some differences between my article and his.
The name "Fokker" appears over a dozen times in my article and nowhere in Wolfram's article. Also, I love being citogenic and my article is the origin of the phrase "Fokker size". I think that this is a big miss on his part because he can't envision a future where somebody says something like "The Fokker metric space" or "enriched over Fokker size". I've already written "some closed lambda terms with small Fokker size" in the public domain and it's only a matter of time until Zipf's law wears it down to "some small Fokkers".
Also, while "Tromp" only appears once in my article, it appears next to somebody known only as "mtve" when they collaborated to produce what Wolfram calls a "size-7 lambda" known as Alpha. I love little results like these which aren't formally published and only exist on community wikis. Would have been pretty fascinating if Alpha were complete, wouldn't it Steve!? Would have merited a mention of progress in the community amongst small lambda terms, huh Steve!?
I also checked the BB Gauge for Binary Lambda Calculus (BLC), since it's one of the topics I already wrote up, and found that Wolfram's completely omitted Felgenhauer from the picture too, with that name in neither the text nor bibliography. Felgenhauer's made about as many constructions in BLC as Tromp; Felgenhauer 2014 constructs that Goodstein sequence, for example. Also, Wolfram didn't write that sequence, they sourced it from a living paper not in the bibliography, written by…Felgenhauer! So it's yet another case of Wolfram just handily choosing to omit a name from a decade-old result in the hopes that somebody will prefer his new presentation to the old one.
Finally, what's the point of all this? I think Wolfram writes these posts to advertise Mathematica (which is actually called Wolfram Mathematica and uses a programming language called Wolfram BuT DiD YoU KnOw) He also promotes his attempt at rewriting all of physics to have his logo upon it, and this blog post is a gateway to that project in the sense that Wolfram genuinely believes that staring at these chaotic geometries will reveal the equations of divine nature. Meanwhile I wrote my article in order to ~~win an IRC argument against~~ make a reasonable presentation of an interesting phenomenon in computer science directly to Felgenhauer & Tromp, and while they don't fully agree with me, we together can't disagree with what's presented in the article. That's peer review, right?