As of: 2026-10-30 13:42 CET.
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# Rybin on OpenAI's proof that the plane is not 5-colourable: 'totally unbelievable alien math?'

Dmitry Rybin (@DmitryRybin1), X, 2026-10-07.
Source: https://x.com/DmitryRybin1/status/2107852898617229724

## Why it matters

High-reach (~261k views) first reaction to OpenAI's claimed lower bound 6 for the chromatic number of the plane, pointing to its transfer to 'weakly measurable' colourings.

## Summary

Dmitry Rybin says he tried to read OpenAI's manuscript "The Euclidean plane is not five-colorable" (family 158 of the 6 Oct 2026
release) and found it "alien math": the model shows that any K-colouring can be replaced by a "weakly measurable" one, a step he says
seems to come out of nowhere. First post of a two-post thread.

## Archived text

> I was trying to read the OpenAI proof that chromatic number of a plane is >= 6. But it is totally unbelievable alien math?
>
> Somehow the model found that any K-coloring <=> "weakly measurable" K-coloring, which seems out of nowhere
>
> 1/2

Archived 2026-10-29 via fxtwitter (unofficial).
Counts: 260,647 views, 929 likes, 34 reposts, 41 replies (at fetch time)

## Cited in

- 2026-10-06: [Chromatic number of the plane is 6 or 7, OpenAI claims (Lean)](https://postcutoff.com/e/2026-10-06-openai-plane-not-five-colourable-hadwiger-nelson-claim/)