robinhouston

https://mathstodon.xyz/@robinhouston

Maths etc.

Location: England

Public Key

npub13dp7zd8dvmkvmdkwhzktavq6vxee4kztkmsdkxtj86wtrhnfae9sn5f0qj

NIP-05 Address

robinhouston_at_mathstodon.xyz@momostr.pink

Profile Code

nprofile1qqsgkslpxnkkdmxdkm8t3t97kqdxrvu6mp9mdcxmr9era893me57ujcprpmhxue69uhhyetvv9ujumt0d4hhxarj9ecxjmntnug8yd

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relay.momostr.pink

Author Public Key

npub13dp7zd8dvmkvmdkwhzktavq6vxee4kztkmsdkxtj86wtrhnfae9sn5f0qj

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Last Notes

2026-08-23 21:50:53 UTC

And here is a claimed complex structure on S^6: https://alpo.ge/s6.pdf
This is a notorious problem that has attracted many claimed solutions that did not stand up to scrutiny, so some caution is warranted, but IMHO there are also grounds for optimism.
(Context: https://mathoverflow.net/questions/1973/is-there-a-complex-structure-on-the-6-sphere)

2026-04-24 06:13:14 UTC

I thought Peter Selinger was on here, but I can't find him. Has he left us?
Just looking at this interesting new paper https://arxiv.org/abs/2604.20964 which does cite Mathstodon posts by @npub1l3c…nw2k.
(@npub197g…q2n4 first citation of Mathstodon in a paper, or have there been others?)

2026-04-15 22:07:20 UTC

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Yes, trig functions are defined using exponentials and i. This table from the supplementary information document shows how each function is defined in terms of functions earlier in the table.
There are definitely some subtleties related to the choice of branch, which is discussed at various points in the paper and the supplementary document, though I won’t pretend I have tried to understand it completely. See the discussion on p. 11 of the paper, for example.
https://media.mathstodon.xyz/media_attachments/files/116/410/984/988/401/630/original/92cdf0267fc1210a.png

2026-04-15 21:30:26 UTC

There’s a fun paper showing that you can define all elementary functions using just two primitive operations: the constant 1, and the binary function eml(x, y) := e^x - log(y).
https://arxiv.org/abs/2603.21852
That’s a neat little result, which makes for some fun games.
What’s the simplest expression you can find that evaluates to your favourite constant?
The best I have found for 2 is:
eml(1, eml(eml(eml(1, eml(eml(1, eml(1, eml(1, 1))), 1)), eml(1, 1)), 1))

2026-04-08 09:42:36 UTC

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Yes, if one didn't already know that spherical excess is just a funny word for the area (on a unit sphere) it would be very confusing.
I can't immediately find a better link that describes the theorem; perhaps this from John D. Cook’s blog is a little more expansive: https://www.johndcook.com/blog/2025/11/08/heron-on-a-sphere/

2026-04-08 09:27:23 UTC

Did you know that there's a spherical analogue of Heron's formula? (TIL)
https://mathworld.wolfram.com/LHuiliersTheorem.html

2026-03-26 14:08:12 UTC

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I deleted mine some years ago, because its only function seemed to be to make it easier for unpleasant people to contact me for cynical reasons. But I appreciate it's a professional necessity for some people, and that I am fortunate not to need it.

2026-03-26 13:55:33 UTC

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I am sorry for your loss.

2026-03-26 08:41:55 UTC

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I wouldn't blame him if he couldn't: it looks incredibly hard!

2026-03-25 23:01:06 UTC

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Wow, Penrose’s tetrahedron puzzle was a lot more complicated than I had imagined it to be.
https://www.youtube.com/watch?v=CD-21ytpCJU

2026-03-21 21:32:20 UTC

Does this really work? I wish I had known when I were younger.
https://media.mathstodon.xyz/media_attachments/files/116/269/300/849/807/345/original/897fe87477891ecc.jpeg

2026-03-11 13:37:14 UTC

TIL. In April 1974, in the middle of the night, a small group of conspirators secretly installed a large tensegrity icosahedron made from discarded telephone poles on the campus of Twente University in the Netherlands.
It’s still there. People call it Het Ding (“the thing”).
https://www.utwente.nl/en/alumni/inspiring-alumni/ut-canon/stories/het-ding/
https://media.mathstodon.xyz/media_attachments/files/116/210/792/392/176/399/original/fcf8215535988335.png

2026-03-11 12:49:09 UTC

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You can fill space with this shape, its mirror image, and some small cubes.
https://media.mathstodon.xyz/media_attachments/files/116/210/620/135/202/373/original/2f9f2c1a204e06ef.jpeg
https://media.mathstodon.xyz/media_attachments/files/116/210/620/584/454/932/original/67a2fa8d2438a04e.jpeg

2026-03-03 23:18:30 UTC

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Here’s another way to do it. This one would make a fine paperweight!
https://skfb.ly/pH6VB
It would be fun to make a hinged model, so you can flip between all the different possible variations physically.

2026-03-02 22:51:46 UTC

An unusual polyhedron whose dihedral angles are all right angles. https://sketchfab.com/3d-models/orthogonalized-tetrahedron-c26dd2789da3406bbb00e5df769ade6d

2026-02-26 19:23:08 UTC

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In that case I'm even more inclined to think you'll like it.

2026-02-26 18:27:05 UTC

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I have, and I expect that you would. It is well written, clever and interesting.
It's quite frightening in parts. My wife had nightmares about it.

2026-02-26 11:57:39 UTC

“In this paper we present work on enumerating all the incomplete open platonic solids, finding 6 tetrahedra, 122 cubes (just like LeWitt), 185 octahedra, 2,423,206 dodecahedra and 16,096,166 icosahedra.”
https://arxiv.org/abs/2602.20425
https://media.mathstodon.xyz/media_attachments/files/116/136/808/021/569/521/original/3159e6e52574a53b.jpeg

2026-02-25 01:41:24 UTC

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I have a counter-clockwise clock in my kitchen, which I was given a few years ago. It's very rare for anyone to notice that there's anything unusual about it.

2026-01-04 13:18:47 UTC

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Thanks. I do like videos. I've just finished watching the first one, which was great.

2026-01-04 11:45:12 UTC

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I'm ok with a “bring your own motivation” text in this case, because I already know why I want to understand this theory, and I just need someone who already understands it to lay it out carefully and correctly. But I will check out your lectures too!

2026-01-04 01:27:08 UTC

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It’s a subject I know less about than I feel I ought to, which means I always feel vaguely guilty when it comes up. I am hoping a careful study of the book will correct that.

2026-01-04 00:31:25 UTC

Imagine reading this if you didn't know what a reflection was.
(This is not a criticism, just a thought that amused me.)
https://media.mathstodon.xyz/media_attachments/files/115/833/978/068/192/133/original/f36e7103c7a6e9ae.jpeg

2026-01-01 22:15:33 UTC

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If multiplication is commutative for the numbers in your matrices, then you can do it in 21 multiplications according to https://arxiv.org/abs/1904.07683

2026-01-01 17:57:45 UTC

A 58-Addition, Rank-23 Scheme for General 3x3 Matrix Multiplication https://arxiv.org/abs/2512.21980
I love this sort of explicit work. The algorithm fits in a screenshot:
https://media.mathstodon.xyz/media_attachments/files/115/821/133/411/739/410/original/c055f538bf5623a5.jpeg

2025-12-30 15:53:49 UTC

A lovely new video from @npub10zc…tds5: https://youtu.be/NEJZlGuWGV8
Stunning photography, as well as a fascinating mechanism.

2025-12-22 17:50:50 UTC

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That's only accessible to members of the University of Edinburgh; at least I _think_ that's what the error message is trying to tell me.
https://media.mathstodon.xyz/media_attachments/files/115/764/483/063/710/864/original/45a2e41072ebb212.jpeg

2025-12-22 12:54:27 UTC

At last I have achieved my ambition of making all the stellations of the rhombic dodecahedron from my blocks
https://media.mathstodon.xyz/media_attachments/files/115/763/314/793/743/421/original/9234f68f31a805ac.jpeg

2025-12-04 10:36:13 UTC

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Incidentally, that's how we know that such a spaceship can only move horizontally (i.e. along the line it occupies). Because the linear configuration is symmetrical in the vertical direction, it cannot possibly move vertically.

2025-12-03 15:11:59 UTC

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Funnily enough it was eating tapioca pudding, and wondering where such a peculiar word might have originated, that led me to this.

2025-12-03 13:29:18 UTC

A language I had never heard of till just now turns out to be the origin of the words tapir, toucan, coati, capybara, piranha, jaguar and tapioca.
https://en.wikipedia.org/wiki/Tupi_language

2025-12-03 03:54:22 UTC

I would not have guessed this was possible!
Vladan Majerech has found a one-dimensional spaceship in the Game of Life: a pattern just one cell high and 3,707,300,605 cells wide that, after 133,076,755,768 generations (during which it is not confined to the one-dimensional line, of course) recreates the starting pattern but translated two cells to the right.
https://conwaylife.com/forums/viewtopic.php?&p=222136#p222136

2025-11-24 10:30:18 UTC

I had a cool experience on Saturday night at MathsJam. Mike Borcherds had brought a pile of 3D-printed puzzles for people to play with; and I recognised one of the puzzles in the pile as one I had designed!
(It was this one: https://sketchfab.com/3d-models/third-of-a-cube-assemblable-5c3e1b3550cf490b8c34c7aafc85e887, which we've talked about on here before.)

2025-11-24 04:46:19 UTC

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I'm missing some context for this conversation, but I was at the talk you're discussing. The speaker said, IIRC, that the rationale for making credit cards that size has never been made public, but it's a reasonable guess that it's not a coincidence that you can fit exactly 4 × 4 on a sheet of foolscap.

2025-11-23 20:38:00 UTC

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is the author’s name joe

2025-10-07 13:04:22 UTC

I'm tempted to update the location in my profile to ‘somewhere in Idaho and uncontactable’, but I fear someone would take it literally.
https://media.mathstodon.xyz/media_attachments/files/115/333/014/267/552/743/original/8772f2960b6f4d9c.jpeg

2025-10-03 07:05:16 UTC

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Why on earth does this video already have so many low-effort negative comments? How are those people coming across it?
Usually videos like this are only seen by people who are interested in the topic. Is the mighty YouTube algorithm advertising it to random people? Is it linked from some other popular website?

2025-10-03 06:52:02 UTC

I enjoyed this talk from Kevin Buzzard, _Where is Mathematics Going?_
https://www.youtube.com/watch?v=K5w7VS2sxD0

2025-09-26 18:16:11 UTC

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See section 3 of https://arxiv.org/pdf/2307.14769

2025-09-25 09:46:50 UTC

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One of his great-grandsons is Geoffrey Hinton, the ‘Godfather of AI’.

2025-09-24 18:25:19 UTC

I didn't know about Charles Howard Hinton. Interesting chap! I just discovered him via researching the etymology and origin of the word tesseract. (Turns out it was coined by Hinton, combining Greek words meaning ‘four’ and ‘ray’.)
He married George Boole's daughter Mary Ellen Boole, with whom he had four children. Unusually, he also married another woman concurrently, as a result of which he spent time in prison for bigamy.
https://en.wikipedia.org/wiki/Charles_Howard_Hinton

2025-09-16 08:46:49 UTC

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I'm indifferent to the specific behaviour you describe, but I sometimes have text in one app that I want to search for in a different app, and I like being able to do that very easily just by hitting ⌘E / ⌘⇥ / ⌘G.

2025-09-04 09:08:15 UTC

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I like it. It sounds like something an action movie hero might say just before saving the world.

2025-09-02 03:17:00 UTC

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That's the most American thing I've ever heard.

2025-08-28 13:15:53 UTC

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The paper does talk explicitly about why they crafted a new polyhedron for the proof, even though they still believe the rhombicosidodecahedron to be non-Rupert.
https://media.mathstodon.xyz/media_attachments/files/115/106/574/176/917/096/original/d6c42fc1cc6deb0a.jpeg

2025-08-16 10:06:53 UTC

A very interesting geometric model that Jeannine Mosely presented at MOVES. Sadly I can't find anything about it online.
It's a hinged chain, alternating between 12 pentahedra and 12 tetrahedra, that can be folded into either a regular dodecahedron or a rhombic dodecahedron.
https://media.mathstodon.xyz/media_attachments/files/115/037/853/617/145/763/original/b83a97dd8b2238e1.jpeg
https://media.mathstodon.xyz/media_attachments/files/115/037/875/093/061/148/original/beed22ae5eff34ce.jpeg
https://media.mathstodon.xyz/media_attachments/files/115/037/877/168/582/405/original/022b0802873e0e2e.jpeg

2025-08-16 09:30:47 UTC

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Interesting: they all decode ok on my iOS phone. I wonder what's different.
https://media.mathstodon.xyz/media_attachments/files/115/037/733/716/846/552/original/c94e02ebade25015.jpeg

2025-08-11 20:49:10 UTC

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I think he said that he predicted 8 years ago that it would be resolved within 5 years using control theory, which I assume is a reference to https://arxiv.org/abs/1703.01352

2025-08-11 20:47:32 UTC

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No, it's still open! He did say a little sadly that it has proved harder to resolve than he hoped it would be.

2025-08-11 20:39:59 UTC

Thomas Hales at MOVES is showing @npub12cu…d38p’s animation of Reinhardt's smoothed octagon from @npub1nf4…nqe4’s blog.
https://media.mathstodon.xyz/media_attachments/files/115/012/052/042/802/072/original/5d0c7a9216d8a81d.jpeg

2025-07-29 06:14:38 UTC

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Here is the promised animation.
https://media.mathstodon.xyz/media_attachments/files/114/935/045/341/525/671/original/e46367ee4cbb5057.mp4

2025-07-29 06:09:54 UTC

I’m hoping that it’s actually possible to physically assemble three of *these* into a cube. https://skfb.ly/pzCW9
I don’t currently have the means to physically test this, but it looks plausible in the animation I made, which I’ll attempt to share in a followup post.
https://media.mathstodon.xyz/media_attachments/files/114/935/022/186/707/699/original/635e73b59414f520.png

2025-07-28 04:08:51 UTC

I think it’s at least mildly surprising that three of these can be combined into a cube. https://skfb.ly/pzByn
https://media.mathstodon.xyz/media_attachments/files/114/928/889/350/044/732/original/eb09030ea4cad7a2.png

2025-07-19 09:39:36 UTC

Oskar van Deventer has a new video where he demonstrates his ‘Bolts Cube’ puzzle: an evolution of the Bolts Loop that we have been talking about, but this time based on an 8-bar linkage.
https://youtu.be/M4xVaBqg-8U

2025-07-14 21:12:38 UTC

There’s a nice mathematical question here from Oskar van Deventer: what is the correct shape for the spiral grooves in this puzzle he designed?
(He was forced to use an approximation in the puzzle as made.)
https://www.youtube.com/watch?v=EHqqXBqckjs
I find it very hard to visualise the motion that’s taking place here! I’d never even heard of Astrolabacus before.

2025-07-08 21:28:12 UTC

Having a 3d printer in the house is forcing me to reckon with the question ‘How many dodecahedra do I need, really?’.
https://media.mathstodon.xyz/media_attachments/files/114/819/728/740/559/883/original/24cdbe2026b06494.jpeg

2025-07-06 15:04:29 UTC

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> Are these the only two meeting some nice constraints, or are there more?
Yes, I believe these are the only two convex dodecahedra whose faces are congruent rhombi. That belief of mine is based on this article of Grümbaum https://faculty.washington.edu/moishe/branko/BG285%20Bilinski%20dodecahedron.pdf
https://media.mathstodon.xyz/media_attachments/files/114/806/899/705/811/992/original/318c9baf5b2a5aba.jpeg
https://media.mathstodon.xyz/media_attachments/files/114/806/899/762/572/486/original/3787832c1b3a6c95.jpeg
https://media.mathstodon.xyz/media_attachments/files/114/806/899/824/625/574/original/99096701e6f07c39.jpeg

2025-07-06 08:22:55 UTC

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It stands in roughly the same relation to the normal rhombic dodecahedron as US paper does to international standard paper: it's made from rhombuses whose long diagonal is ϕ times the short diagonal, whereas the normal rhombic dodecahedron is made from rhombuses whose long diagonal is √2 times the short diagonal.

2025-07-06 08:15:54 UTC

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It was (re)discovered in 1960 by a chap called Stanko Bilinski. https://en.wikipedia.org/wiki/Bilinski_dodecahedron

2025-07-06 08:14:42 UTC

Did you all know that there is a SECOND rhombic dodecahedron whose faces are all congruent rhombuses, that is less symmetrical than the normal rhombic dodecahedron?
https://media.mathstodon.xyz/media_attachments/files/114/805/287/168/448/878/original/8072f205cfafb67a.png

2025-06-25 20:01:46 UTC

Building a monostable tetrahedron https://arxiv.org/abs/2506.19244

2025-06-15 14:11:29 UTC

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Do you think most laypeople would regard “these shapes as identical” as true if one were a uniformly scaled copy of the other?
(If not, what do we call that? My schema would suggest ‘simila’, of course.)

2025-06-15 13:54:24 UTC

There really should be a word for when two geometric objects are related by a direct (positive) isometry – i.e. they're actually the same size and shape, not mirror images of each other.
I sometimes say ‘congruent’, but technically that includes mirror images as well, so isn't what I really meant.
If there really isn't a word for this, can I propose ‘conguent’ – i.e. congruent without the (r)eflections?
This has the added benefit that it will give copy editors the heebie-jeebies.

2025-06-15 11:53:57 UTC

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I made a book of ten thousand times no, and it’s only 13 pages long, which is shorter than I would have guessed. I can’t share PDFs on here, so here are the first two pages. You can imagine the rest.
https://media.mathstodon.xyz/media_attachments/files/114/687/233/881/760/090/original/f297fdb98901fb53.jpeg
https://media.mathstodon.xyz/media_attachments/files/114/687/238/877/244/724/original/e9f1717b32e57601.jpeg

2025-06-15 10:35:33 UTC

Here's a puzzle of my own invention, which is probably quite hard if you don't have a physical copy and you have to do all the manipulation in your head. The puzzle is to assemble these eight pieces into a 4×4×4 cube. (Don't worry about the colours, they don't mean anything.)
https://media.mathstodon.xyz/media_attachments/files/114/686/924/580/850/571/original/e7333878c280a851.jpeg

2025-06-11 22:01:03 UTC

I haven’t found Claude very useful for actually working things out, yet, but it’s brilliant at visualising things you’ve worked out in some other way! https://claude.ai/public/artifacts/a53161cf-8186-41a5-b223-732dfb426f5c

2025-05-30 22:30:08 UTC

This is a fun puzzle from Inigo Quilez at the bad place.
It's shorter than you're probably thinking even if you're taking account of the fact that it's shorter than you're probably thinking.
https://media.mathstodon.xyz/media_attachments/files/114/599/134/974/700/366/original/8b12fd6bdc5e4a65.jpeg

2025-05-19 11:22:19 UTC

Fun fact (via otaliptus on Twitter): the president-elect of Romania was one of the 11 students to solve the famous Vieta jumping problem at the 1988 IMO: https://en.wikipedia.org/wiki/Vieta_jumping#History

2025-05-10 07:46:05 UTC

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I can see *what* they do, I just can't imagine *why* :-)

2025-05-10 07:43:41 UTC

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How intriguing! I wondered if its intent would seem obvious from the code, but it doesn't seem obvious to me. Do you understand it?
(The only part that seems fairly easy is the part that converts lowercase ASCII letters to their uppercase counterpart.)
https://media.mathstodon.xyz/media_attachments/files/114/482/404/842/584/762/original/02241b545df9925d.jpeg

2025-05-02 07:48:48 UTC

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Yes, that fits with what I imagined it meant. I haven't thought about it seriously. I suppose another possible interpretation of the first condition would just be that the rings are pairwise linked, but knowing Conway the automorphism interpretation seems more likely.

2025-05-02 07:30:06 UTC

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I think the prize was only offered for correct solutions submitted on the day itself (2016-03-14), so unfortunately you wouldn't even get pizza for it now.

2025-05-02 04:06:41 UTC

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Here's the third, unsolved, problem:
My key-rings are metal circles of diameter about two inches. They are all linked together in a strange jumble, so that try as I might, I can’t tell any pair from any other pair.
However, I can tell some triple from other triples, even though I’ve never been able to distinguish left from right. What are the possible numbers of key-rings in this jumble?

2025-05-02 04:05:58 UTC

In 2016, as a publicity stunt for Pi Day, the US chain restaurant Pizza Hut announced a trio of mathematical puzzles written by John H Conway, offering prizes of Pizza Hut gift cards.
The first two problems were successfully solved, and prizes presumably awarded, but the third was not and seemingly remains unsolved to this day!
https://blog.pizzahut.com/pizza-hut-partners-with-mathematician-john-h-conway-for-national-pi-day-math-contest/
https://blog.pizzahut.com/national-pi-day-math-contest-problems-are-here-2/

2025-04-30 12:04:04 UTC

Happy Gauss's Birthday, everyone! I hope you're having a good one.

2025-03-30 13:01:26 UTC

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On reflection, the confusion might be the result of a misguided analogy with adjectives such as ‘uncovered’ – since the verb ‘to cover’ has the opposite relationship with the noun ‘cover’ than ‘to shell’ with ‘shell’.

2025-03-30 12:58:16 UTC

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Hot take: this is not in fact ambiguous, since the formation “un-X-ed” requires X to be a verb, and the verb “to shell” has an unambiguous meaning.
But it should probably be avoided anyway, since apparently it will be misunderstood by a large proportion of people.

2025-02-15 16:34:53 UTC

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I thought the list of still-unsolved problems at the end of the paper was interesting:
* Is a three-piece dissection still impossible if flipping is allowed?
* Are there only a finite number of rectangles that can be dissected into three pieces from a triangle? If so, how can they be enumerated?
* Are there any other four-piece dissections between an equilateral triangle and a square, aside from the solution proposed by Dudeney?
* Are there any pairs of regular n-gons and m-gons that can be dissected into three pieces, where n ≠ m?
* Is a three-piece dissection still impossible if we allow nonpolygonal (curved) pieces?

2025-02-15 07:12:49 UTC

From December, but I missed it at the time: Dudeney's Dissection is Optimal https://arxiv.org/abs/2412.03865

2025-01-31 17:26:11 UTC

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I assumed he was referring to François Morrelet's red and blue wallpaper

2025-01-31 17:12:08 UTC

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it creates a very powerful effect when you're in the room!

2025-01-31 17:08:20 UTC

If you're interested in algorithmic art, and within striking distance of London, I'd recommend the Electric Dreams exhibition at Tate Modern
https://media.mathstodon.xyz/media_attachments/files/113/924/064/098/742/522/original/6464770bfe441a3c.jpeg
https://media.mathstodon.xyz/media_attachments/files/113/924/064/278/494/129/original/57e92aaacc6c3dfd.jpeg
https://media.mathstodon.xyz/media_attachments/files/113/924/064/704/269/390/original/74ed8ba1b92b5713.jpeg
https://media.mathstodon.xyz/media_attachments/files/113/924/065/015/801/331/original/cd6fa4daf14a9dd4.jpeg

2025-01-19 04:58:45 UTC

I've recently discovered that there's at least one creator who posts amazingly high-quality mathematical visualisations to TikTok. Sorry Americans.
https://media.mathstodon.xyz/media_attachments/files/113/853/245/635/213/620/original/03e1c45e44c37324.mp4

2025-01-14 11:22:24 UTC

A very nice article by @npub1p5z…4d3n in the AMS Notices, on the important concept of the treewidth of a graph. https://www.ams.org/journals/notices/202502/noti3043/noti3043.html

2025-01-08 11:56:37 UTC

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Thanks! That whole discussion is interesting.

2025-01-08 11:37:16 UTC

Because it's 2025, we're all thinking about the identity \[\Bigl(\sum_{i=0}^ni\Bigr)^2
=
\sum_{i=0}^ni^3\]
I'm now wondering how closely this is related to the similar (but in a way simpler) identity
\[
\Bigl(\int_{0}^nx\,dx\Bigr)^2
=
\int_{0}^nx^3\,dx
\]
Is the former a direct consequence of the latter?

2025-01-01 12:22:36 UTC

I like this rant: I never found Gabriel's horn / Torricelli's trumpet to contradict my intuition, though it's a fun example. https://intellectualmathematics.com/blog/torricellis-trumpet-is-not-counterintuitive/
https://media.mathstodon.xyz/media_attachments/files/113/753/072/051/438/046/original/99261d43a8eda9a2.jpeg

2024-12-03 04:14:57 UTC

There's a new preprint that claims to prove that Gerver's sofa is optimal.
Have any of you read it yet? Big if true!
https://arxiv.org/abs/2411.19826

2024-11-28 08:10:44 UTC

I enjoyed this nicely animated video on the Mandelbrot set, Julia sets, etc. The music appears to be cleverly synchronised with the animation, which is a nice touch. https://youtu.be/Ed1gsyxxwM0

2024-11-02 15:58:27 UTC

https://saytheprime.com/

2024-10-21 14:20:49 UTC

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The cat's out of the bag: I can relax now. https://www.mersenne.org/

2024-10-18 21:27:56 UTC

I found out the exponent of the new Mersenne prime before it’s been officially announced, and I feel as though I’m in possession of a deep, dark secret.
I hope I’m not giving too much away if I remark that in base 10 it has a number of digits that is a multiple of 80, which means it scrolls very neatly down a standard-width terminal.

2024-09-18 09:04:23 UTC

Our determinant paper has just been published.
https://doi.org/10.1017/S0963548324000233

2023-01-06 20:09:01 UTC

I printed two images, one on paper and one on acetate. Each is individually indistinguishable from random, but when overlaid they reveal an elephant.
https://media.mathstodon.xyz/media_attachments/files/109/644/051/569/659/702/original/4de5ea80080d34cb.jpeg
https://media.mathstodon.xyz/media_attachments/files/109/644/051/695/638/645/original/f28e8cbe7080f626.jpeg
https://media.mathstodon.xyz/media_attachments/files/109/644/051/817/487/956/original/ca019ea7ac0588c8.jpeg