April 12, 2026
Size drama, donut edition
Is Math Big or Small?
Pocket toy or rideable theme park? The math world can’t agree
TLDR: A playful essay asks whether math should be pictured tiny in your hand or huge enough to walk through, using Thurston’s 1970s “train tracks” mural as the case study. The comments split: some say math is all sizes at once, others say scale doesn’t matter until the end—cue donut jokes.
A math talk asked a deceptively simple question: how big is math? Think donut-shaped big (a “torus”) you can wander inside, or palm‑sized small you can hold. The article tours a 1970s Berkeley mural by legend Bill Thurston, where messy curves became “train tracks” and the name itself invited everyone to ride the math like a tiny locomotive. Vibes: whimsical, artsy, a little rebellious.
Then the comments rolled in and turned it into a scale war. One voice went full cosmic: “smaller than the smallest and bigger than the biggest” — the kind of line that launched instant screenshot memes. A veteran illustrator fired back with a hot take: scale isn’t even first — sometimes there’s no scale at all; he just zooms as needed, like pinch‑to‑zoom for ideas. And then a minimalist hero dropped a single word — “Yes.” — which the thread crowned as peak answer, because apparently the size of math is… both.
Fans cheered the Thurston lore and the rebellious mural, while jokesters kept asking, “So… how big is your donut?” Theme park math vs pocket math became the meme of the day. The real takeaway? Naming and pictures set the mood of ideas, and the community is delightfully split between riding the train and tossing the tracks entirely.
Key Points
- •The article explores how the chosen scale influences mathematical illustrations and understanding.
- •A 1971 UC Berkeley paint-in led to a Thurston–Sullivan mural depicting a curve in a thrice punctured plane.
- •Thurston observed laminations—parallel strands that split or merge—emerging from iterative deformation.
- •He encoded laminations as “train tracks” by collapsing parallel strands via ties, a term he coined with a train doodle.
- •These ideas relate to Thurston’s later theory of pseudo-Anosov maps and inspired further illustrations, such as Conan Wu’s work.