One Recipe, Every Kitchen
The same two chemicals, the same equation. Only the feed (F) and kill (k) rates change — and that is the difference between a dish filling with pattern and a dish going quietly blank.
Colour shows chemical V: dark = 0, gold = 0.5 or more.
The scale stays fixed, so fading really looks like fading.
Pause to inspect the dish. While paused, advance ten model steps at a time.
Try extinction to watch the seeds fade, then solitons to grow spots again. Presets plant fresh seeds; sliders change the current dish. Reseed starts a new dish at your chosen rates.
What you're looking at, honestly
This is the Gray–Scott reaction-diffusion model — a textbook system, not new science. Two virtual chemicals spread and react on a 144×144 grid (forward-Euler steps, Du=0.16, Dv=0.08, the same update rule as the offline study this page grew from).
The label measures how unevenly chemical V is spread (its standard deviation), not whether a pattern will survive. “Nearly uniform” means that variation is below 0.001; it is not proof of exactly zero chemical or permanent extinction. In the offline sweep at F=0.035, patterns remained at the end of the tested runs only for k between about 0.058 and 0.064. Move k across that range to explore what happens in this smaller dish.
Limits: smaller grid and fewer steps than the offline study, so fine details differ run to run, and extreme slider corners can be numerically rough. Tap or drag on the dish to drop a little more of chemical V — you can try to fight an extinction by hand.