Run on turbowarp: https://turbowarp.org/665881909 After several minutes see the characteristic scrolls and spirals. This simulates the bz chemical reaction oscillating chaotically. The patterns never exactly repeat (chaos) yet a beautiful order emerges. Each square is a chemical state that depends upon the state of neighboring squares. There's spatial interaction of positive and negative feedback. The only randomness is in the intitial conditions, the rules of change are deterministic. The result is deterministic chaos and beautiful patterns.You'll see expanding circles and, often after some time, spirals and scrolls may emerge, but not every time.
For the full range of colors, set color dilution to 1. For more subtle coloring, set to 2 or higher. This high res version runs on turbowarp. My regular Scratch speed version, with lower resolution: https://scratch.mit.edu/projects/527156716/ It's called the "Belousov-Zhabotinsky" (BZ) reaction. Positive feedback in this system moves the state further in the direction it was already going. Negative feedback moves the state back to a state of zero once the threshold maximum state is reached (like recovering from a illness). I set the "color effect" to equal the state. The max state is 200. Minumum state is zero. We use lists and stamping. Part of our Beautiful Discovery box "DeCODING Spots and Stripes"
