Named after a man who found order in something that looked like noise.
Michel Hénon was an astronomer. In 1976 he wrote down two lines of arithmetic that produce a figure of infinite detail from a single starting point — and proved it was not random at all.
There is a genre of project that sells you a "deterministic generative system" and then keeps the generator on its own server. You are told the art is reproducible; you are given no way to reproduce it. What you actually receive is a row in someone's database and a promise about a program you have never seen.
The promise is usually true. That is not the point. A claim of verifiability that cannot be exercised is not verifiability — it is branding with a mathematical accent.
HENON is the same idea built the other way around. The generator is a few hundred lines and it is served to your browser in plain JavaScript. Every figure on this site is drawn on your machine. Every number is computed on your machine. If this domain stops resolving tomorrow, everything it ever told you can still be recomputed from an address and two lines of arithmetic.
It will not sell you a vault, because you already have one and so does everybody else. It will not mint a token to represent a vault, because the token would be a second thing that could disagree with the first.
It will not draw its creatures ahead of time. There is no folder of artwork behind this collection — every animal you see was composed from primitives by your own browser, out of traits the address chose. A project that ships pre-made pictures and calls itself generative is doing something else.
It will not quote a rarity off a thin sample. Below five hundred readings the census returns a refusal instead of a percentage, because a rarity computed from a handful of addresses is decoration wearing the clothes of a measurement. And it counts appearances in blocks rather than unique wallets, which it says on the page rather than in a footnote.
Michel Hénon (1931–2013) worked at the Nice Observatory on the motion of stars in galaxies. Looking for the simplest thing that could behave like a chaotic system, he stripped the problem down to two equations and a pocket calculator's worth of arithmetic.
What came out folds forever without repeating, and its fractal dimension is about 1.26 — more than a line, less than a surface. Fifty years later the same two lines still produce it, on hardware he could not have imagined, to the last decimal place. That durability is the whole reason this project is named after him.
The classic parameters, drawn by the same engine that draws every vault. Its measured dimension here is 1.266 — see verify.
Type is Silkscreen and IBM Plex Mono. Every figure is drawn on a small pixel grid and scaled up with smoothing off, so a pixel stays a pixel. No image files are used for artwork anywhere on this site — only the logo is a file.