An oscillating chemical reaction moves outward in waves, producing a ripplelike effect in this still image from what is a continually unfolding process..
Color changes in this Belousav-Zhabotinsky chemical reaction (named for its discoverers) are a result of the reaction's effect on a marker dye. The phenomenon may be displayed as a series of still images from moments during the process or as a movie.
Laboratory of Anatol Zhabotinsky, Brandeis University. Image by Felice Frankel, MIT.