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.
The relative merits of each method, relevant chiefly to the limits of the medium, figure in the Image and Meaning conferences and workshops.