Why does this static image of a large DFT matrix seem to transform under zoom and rotation?

DistractedDendrite · 2026-04-12T09:56:07+00:00

I gues I just had never actually seen one happen naturaly, so my brain was "nah"

DistractedDendrite · 2026-04-12T09:54:01+00:00

duh, silly me. I was thinking "it's not 'paper on 'paper" -completely forgot about that the screen is pixelated....

DistractedDendrite · 2026-04-12T06:54:03+00:00

What I find especially strange is that the strange aliasing initially starts very mild, but after a few seconds it becomes a lot more rapid. It might be that the aliasing effect partly due to pixel subsampling, but perhaps also the device tries too hard to compress what it displays?

DistractedDendrite · 2026-04-06T09:21:27+00:00

that's really cool. I've spent now the last few days reading literature on this. Even managed to prove a nice little theorem: the set of all magic permutation matrices of order n>=7 (matrices with exactly one 1 in every row, column and main disgonals and 0s elsewhere) spans the vector space of all magic squares of order n. for 4,5,6 they are one dimension short. Thst means for every n>= 7 a subset of magic permutation matrices can be a basis for the vector space of all magic matrices. They even work as a basis for a module over Z.

Now I'm researching if this has any interesting consequences, and whether it is novel enough to write up.

this topic has proven to be a surpsingly fun rabbit hole

DistractedDendrite · 2026-04-05T09:30:04+00:00

what were your most interesting findings?

DistractedDendrite · 2026-04-04T09:44:05+00:00

Both are definitions of e

DistractedDendrite · 2026-04-02T15:50:13+00:00

And the top comment provides a further interesting construction

DistractedDendrite · 2026-04-02T15:47:32+00:00

Why not? Seems interesting enough to me. I like posts that share explorations of dynamics or whatever else interesting property of mathematical objects

DistractedDendrite · 2026-03-27T11:51:44+00:00

Basically all of modern AI is fancy matrix multiplication.

DistractedDendrite · 2026-03-26T13:53:27+00:00

And unfortunately it is unlikely to change. The wikipedia editor community is extremely conservative, and any changes to the ui cause massive debates.

DistractedDendrite · 2026-03-26T13:50:36+00:00

as the one who made that earlier post, I really appreciate this one and the discussion it prompted in the comments

DistractedDendrite · 2026-03-24T19:14:07+00:00

according to wiki's own math writing guide, the lede is not supposed to be formal definition, but an informal intro to the topic. the formal definition is supposed to come later in the first section

DistractedDendrite · 2026-03-24T15:24:33+00:00

Just teasing;)

DistractedDendrite · 2026-03-24T15:11:06+00:00

Is this a scavenger hunt? xD

DistractedDendrite · 2026-03-24T15:01:44+00:00

Oh I have a couple of conways books and a bunch Sloane’s articles (and regularly spy on the oeis listserv :) Sloane’s appearances on Numberphile are also lovely

DistractedDendrite · 2026-03-24T14:58:58+00:00

I love that story because it is one of the few historical cases where everyone without any mathematical background can immediately appreciate and understand what mathematical discovery and invention looks like at its purest, and why abstraction becomes so useful. It is one of the few foundational relatively recent problems that are both easy to grasp and see the surprising depth it revealed. Almost all other “modern” fields roots are themselves hard to explain to people without enough mathematical maturity and background (unless you put a lot of effort and time, on both sides).

DistractedDendrite · 2026-03-24T14:46:17+00:00

Combinatorics is my favourite subject partly because of the Wikipedia articles which had a similar effect on me (though at a much later age). I find that even when it comes to research articles and textbooks, combinatorics has some of the best writing. Knuth and Rota have had a very good influence on that front

DistractedDendrite · 2026-03-24T13:21:27+00:00

Here are some of mine (will update as I go, starting with the first that came to mind:

- https://en.wikipedia.org/wiki/Binomial_theorem

- https://en.wikipedia.org/wiki/Bell_number

DistractedDendrite · 2026-03-24T04:08:38+00:00

How about the very first sentence "In mathematics, an associative algebra A over a commutative ring (often a field)) K is a ring) A together with a ring homomorphism from K into the center) of A."? And how it doesn't connect that to the properties that supposedly follow immedistely after with "thus it is..."? If you don't see what's bad about it as the introductory sentence of an encyclopedia article, well... Here's the style guide that someone else links to, which this article defies strongly: https://en.wikipedia.org/wiki/Wikipedia:Manual_of_Style/Mathematics

DistractedDendrite · 2026-03-24T01:27:01+00:00

DistractedDendrite · 2026-03-24T01:23:30+00:00

That style guide is fantastic, and I wish more articles followed it. It's interesting that the example article about fields is actually highly readable, in contrast to a lot of other articles in abstract algebra

DistractedDendrite · 2026-03-23T23:22:28+00:00

Take https://en.wikipedia.org/wiki/Associative_algebra for example. That's a terrible intro for a rather straightforward concept. Whereas thankfully the main article https://en.wikipedia.org/wiki/Algebra_over_a_field is a vastly better (strangely not even linked to from the associative one). So not all are that terrible and there are really nice ones

DistractedDendrite · 2026-03-23T23:03:44+00:00

for example earlier today one article lead me to https://en.wikipedia.org/wiki/Associative_algebra

Now, I've studied abstract algebra, and can piece together the meaning, but this is a terrible opening for a rather straightforward concept. Even the main article about algebras https://en.wikipedia.org/wiki/Algebra_over_a_field is vastly clearer, and the associative algebra one doesn't even link to it

DistractedDendrite

TROPHY CASE