Reaction–diffusion System - Wikipedia - polar coordinates  ## Metadata - Author: **polar coordinates** - Full Title: Reaction–diffusion System - Wikipedia - Category: #articles - URL: https://en.wikipedia.org/wiki/Reaction%E2%80%93diffusion_system ## Highlights - Reaction–diffusion systems are mathematical models which correspond to several physical phenomena. The most common is the change in space and time of the concentration of one or more chemical substances: local chemical reactions in which the substances are transformed into each other, and diffusion which causes the substances to spread out over a surface in space