Sophie Schmieg

Random childhood anecdote, posted as individual toot in order to not derail some random joke post about kids these days not being into non-Euclidean geometry:

I have three siblings, spaced two years apart each. All four of us went to the same high school. My youngest sister's math teacher wanted to do a cute little segment about triangles always having inner angles sum up to 180 degrees. It was supposed to take the form of a trial. My sister was assigned the role of prosecutor charging a triangle accused of having an inner angle sum different from 180 degrees. Obviously, taking her role very seriously, she consulted the Schmieg dinner table, and a plan was hatched, involving a grapefruit and a marker. The trial came, and just as the defense had produced what they thought was irrefutable proof that their client was innocent, my sister took out the grapefruit, drew a triangle connecting one pole to the equator using three right angles, and said "So how do you explain this?!?" Leading to the teacher/judge having to explain non-Euclidean geometry to a bunch of 10 year olds.

And to make this anecdote even better, in a different class the same day she had a substitute teacher who didn't know my sister, but seeing the triangled up grapefruit, approached her and asked her "Are you a Schmieg?". Our family name has racked up quite some reputation…

Sep 28, 2025 at 5:36pmWeb
Show threadSophie SchmiegSep 28, 2025
Nota Bene: since this story took place in Germany, the math teacher in question was quite well paid and had a university level mathematics education to fall back to, which, from having taught that course myself later, should include a full class on geometry, teaching not just the Euclidean, but the Hilbert axiomatisation. He also taught the math extracurricular, so he was very much up to the challenge 🙂.
The triangle on the stand was still acquitted on account of being planar itself, so the story had a happy ending, and no triangles had to go to geometry jail.
Show threadSophie SchmiegSep 29

It is just now that I realized that you could make the excellent cross-cultural pun that the triangle was pleading the fifth.

Triangle: I'm pleading the fifth, your honor!
Judge: your right to remain silent?
Triangle: no, your honor, I'm pleading that given a line and a point not on that line there is exactly one line through that point parallel to the given line!

Show threadScott FrancisSep 29
@sophieschmieg there's dad jokes, and then there's nerd dad jokes [EDIT: and then there's math nerd dad jokes] ... it's like a spectrum or a continuum, really
Show threadMeredithSep 29
@sophieschmieg I need to give you an award of some sort. Top marks, I giggle-snorted
Show thread⁂ Fish Id WardrobeSep 29
@sophieschmieg assuming the line was of infinite length (or that two lines on top of each other are parallel)
Show threadSophie SchmiegSep 29
@fishidwardrobe that is not necessary, it is already implied by saying "line" given the other axioms.
Show threadJordanSep 28, 2025
@sophieschmieg Oh, that's clever, you can slice the grapefruit and it's still a triangle.
Show threadPurpleNessaSep 29, 2025
@sophieschmieg This story is one of the best I've ever read!
The trial, the teacher, the grapefruit! The substitute 🤣
Show threadIrenes (many)Sep 29, 2025
@sophieschmieg oh this is amazing
Show threadBill SeitzSep 29
@sophieschmieg hopefully the sphere would have helped him escape
Show threadMartin AuswögerSep 28, 2025
@sophieschmieg I have a maths problem with your text „I have three siblings, spaced two years apart each. All three of us…“ ☺️
Show threadMike PSep 28, 2025
@ausi @sophieschmieg Clearly time is grapefruit-shaped, too ;)
Show threadSophie SchmiegSep 28, 2025
@ausi argh, I forgot to count myself…
Show threadMartin AuswögerSep 28, 2025

@sophieschmieg sometimes we forget that we count as well, but we definitely do, happens to the best of us ☺️

My siblings and I also stood out at school, as you may have guessed 😅

Show threadDaanloSep 28, 2025
@sophieschmieg @ausi classic off by 1 error ;)
Show threadOrca 🌻 | 🎀 | 🪁 | 🏴🏳️‍⚧️Sep 28, 2025
@sophieschmieg @ausi off by one error ​​
Show threadD2Sep 28, 2025
@ausi @sophieschmieg that’s just a zero indexing bug.
Show threadJeff MartinSep 28, 2025
@sophieschmieg The world is messy. Simplifying assumptions keep us sane, if sometimes slightly incorrect.
Show threadcynicalsecurity Sep 28, 2025
@sophieschmieg what is it with future Mathematicians and non-Eucledean geometry? I found a book in the school library (which had been donated) called “Non-Euclidean geometry” by Rolf Nevanlinna, translated into Italian… started reading it during “library time”, borrowed it, started asking inopportune questions during Maths, ended up having to pull strings on a rotating Earth globe, then said “what if the angles never add up to 180?”, was sent for early breaktime 🙄
Show threadvarx/socialSep 28, 2025
@sophieschmieg I was definitely *that* kid in a number of classes. My mom has been approached 30 years later in the grocery store by one of my elementary school teachers—"Are you [varx]'s mom?" Which is a weird feeling. 😆
Show threadKo Simon toku ingoa Sep 28, 2025
@donkey; @davemosk; @lightweight; @richardhulse y'all'll probably enjoy this childhood anecdote from @sophieschmieg
Show threaddonkeySep 28, 2025
@SimonCHulse 🤣
Show thread2somethingSep 29, 2025
@sophieschmieg I love your sister.
Show threadFull Metal ArchaeopteryxSep 29, 2025

@sophieschmieg
My sibling was four years younger than me, and we looked enough alike that most of the faculty recognized them before even seeing our relatively (there's a pun there! Surely spotted after the fact) unique last name

Said sibling was as much of a disappointment as I (smart but does not apply themself) 😅

Show threadLe Néandertal se sent las, lasSep 29, 2025
@sophieschmieg so, assigning the role of prosecutor to your sister was the assurance of getting a high quality plea
Show threadThe Gneech! Awww YeahSep 29, 2025
@sophieschmieg ping @JoeSodium
Show threadJoe SodiumSep 29
@the_gneech @sophieschmieg 💖
Show threadhundrixSep 29
@tiphaine Yo je crois qu'on a retrouvé ta famille 🤣
Show threadhairylarrySep 29

@sophieschmieg

Been there. Done that.

Show threadThe Animal and the MachineSep 29
@sophieschmieg
I love this story. 💛
Show threadPeter LudemannSep 30
@sophieschmieg In 4th grade, teacher was showing us long division, using 22÷7 .. which came out 3.1428... Teacher scratches his head and mutters that π is 3.14159... At which point I pipe up and say that 22-over-7 is an _approximation_ of pi and the teacher says "d'oh". We actually got along fins and he was the person who noticed that I'm short-sighted because I was squinting at the blackboard.
Show threadVessOnSecuritySep 30

@sophieschmieg When I was a kid, my math teacher once called my parents to complain that I was asking questions she didn't know the answer of.

We were studying magnetic field flow through a surface and it involved a "normal" - a vector anchored to the surface and pointing away from it, at a right angle. I asked how do you do this on a Moebius surface, which has only one side and you can't draw a vector pointing away from one of the sides.

Many years later, I found the answer of my question in a Russian text book. It said that magnetic flow is simply not defined through one-sided surfaces. 🤣

Show threadMichael WeissSep 30
@sophieschmieg I gotta say, your family definitely came at this trial from the right angle.
Show threadJohn KaniarzOct 3

@sophieschmieg “I have three siblings, spaced two years apart each.”

I’ve heard of the rhythm method, but never at this timescale.

Show threadJobOct 15

@sophieschmieg I choose to believe that the teacher was a Machiavellian mastermind who knew what they were doing when they asked your sister, and that they were betting on the Schmieg family to deliver. It was a set-up from the beginning, to get the class emotionally invested in advanced mathematics by having their minds blown!

(that probably was not actually the case, but wouldn't the world be a better place if there were more maths teachers like that?)