Mark Dominus @mjd@mathstodon.xyz

YOU MATHEMATICIANS THINK YOU SO SMART, THAN EXPLAIN THIS!!1!

New math post on my blog: A maybe-interesting number trick? https://blog.plover.com/math/GF32.html

New math post on my blog: How are finite fields constructed? https://blog.plover.com/math/se/finite-fields.html

New math post on my blog: What does it mean to expand a function “in powers of x-1”? https://blog.plover.com/math/se/taylor-series.html

New math post on my blog: What does it mean to expand a function “in powers of x-1”? https://blog.plover.com/math/se/taylor-series.html

New math post on my blog: Ron Graham has died https://blog.plover.com/math/graham.html

WHAT YOU MEAN “DIMENSIONAL HOMOGENEITY”??!?

New math post on my blog: Weird constants in math problems https://blog.plover.com/math/odd-constants.html

New math post on my blog: Infinite zeroes with one on the end https://blog.plover.com/math/omega-plus-one.html

I really hate this tired claim: “This is confusing because \(0.\bar 01\) seems to indicate a decimal with "infinite zeros and then a one at the end." Which, of course, is absurd.” Sure, it's not a real number, but there's nothing intrinsically wrong with an infinite sequence of zeroes followed by a one.
https://math.stackexchange.com/questions/3691414/doesnt-0-overline9-1-lead-to-consequences-like-a-0-overline01-a-and-2-1#comment7585973_3691414

If you want to go the jargon route, you can distill it down to once sentence, something like “Take an irreducible polynomial X of degree k over the finite field GF(p) and compute the quotient ring GF(p)[x] /‹X›, what's so hard about that?”
But of course such an answer is useless to almost anyone who doesn't already know it.

Someone on Math SE asked how to calculate the multiplication table of a finite field, and I wrote up a brief but sufficient explanation at a fairly low jargon level. Might be good for undergrads or advanced high school students. https://math.stackexchange.com/a/3660966/25554

Sir Thomas Urquhart was a 17th-century Scottish eccentric who tried to systematize a new language for trigonometry; the law of sines was abbreviated as “eproso”, which (if you know the system) encapsulates its meaning.

https://blog.plover.com/book/Urquhart-2.html

Notes on dealing better with half-baked mathematics questions : https://blog.plover.com/misc/half-baked.html

Easy but fun problem I found in an ancient Math SE post: What is the smallest integer greater than 1 such that ½ of it is a perfect square and ⅕ of it is a perfect fifth power?

It's easy to obtain Pennsylvania mail-in ballots : https://www.votespa.com/Pages/default.aspx

https://unknought.tumblr.com/post/190938771995/normal-mathematician-look-at-this-theorem-i
> *normal mathematician*: Look at this theorem I proved!
> *category theorist*: By thinking deeply about your result I was able to prove a far-reaching generalization of it.
> *normal mathematician*: Cool! What are some other examples of it?
> *category theorist*: …
Ouch.

\(2\cdot3\cdot5\cdot11\cdot 17\)