February 22, 2026
Shade, shapes, and four crayon chaos
The Four-Color Theorem 1852–1976
Four colors, 50 years, infinite drama: math internet reignites the map-color wars
TLDR: A 50th‑anniversary retelling of the Four‑Color Theorem (every map needs only four colors) sparked fresh fights over whether computer‑assisted proofs “count” and who deserves credit. Between purists, pragmatists, and meme lords, the community turned a classic result into a debate on what proof means—plus endless four‑crayon jokes
Math internet is in full gossip mode as a 50th‑anniversary piece revisits the Four‑Color Theorem—the 1976 result that proved any map can be colored with just four colors so neighbors don’t match. The article strolls through the cast—De Morgan, the Guthrie brothers (one later a botanist!), Hamilton throwing shade with “quaternion of colours,” and miscredit magnet Möbius—and the comments section immediately turned into a color‑coded cage match.
The hottest fight? Whether the 1976 computer‑assisted proof by Appel & Haken counts as “real” math. Purists called it “brute‑force bingo,” while pragmatists fired back: if computers help catch every case, it’s still a proof. Others argued credit: “Give Francis Guthrie his flowers”—literally, since a plant is named after him—versus team De Morgan. Möbius fans sheepishly learned his five‑sons puzzle isn’t the same thing. Meanwhile, jokesters flooded in with memes: four‑crayon starter packs, “Color me skeptical,” and Succession‑style jokes about the dying king’s land.
Amid the chaos, educators cheered the storytelling, newbies loved the simple “four crayons beat infinity” explanation, and historians relished Hamilton’s petty one‑liner. The calm middle noted that later streamlined proofs are still computer‑aided, linking to overview pages. Verdict? The theorem stands, but the community is here for the drama, the dad jokes, and the eternal question: what even counts as proof
Key Points
- •The four-color problem, posed in 1852 by Francis Guthrie, was proven in 1976 by Kenneth Appel and Wolfgang Haken.
- •Augustus De Morgan publicized the problem and was a prominent mathematician, writer, and first president of the London Mathematical Society.
- •De Morgan’s 1852 letter to Hamilton documented the query that four colors suffice; the student was later identified as Frederick Guthrie.
- •Frederick Guthrie credited the problem to his brother Francis in an 1880 note; Francis became a professor in South Africa and a botany expert.
- •The problem was wrongly linked to August Möbius’s 1840 five-region partition; the earliest printed description appeared in The Athenaeum in 1854 signed “F. G.”.