Number 159 (Story #2), January 6, 1994 by Phillip F. Schewe and Ben Stein SELF-ORGANIZED CRITICALITY IN FRAGMENTING is what happens when you shatter a frozen potato. Danish scientists have fractured several objects such as gypsum, soap, paraffin, and potatoes, and inventoried all the fragments with masses larger than a milligram (Lene Oddershede et al, Phys. Rev. Lett. 8 Nov 1993). The probability of finding a fragment of a certain mass was found to scale inversely with a power of the mass. The particular power measured (the scaling exponent) depends on the object's shape---ball, cube, plate, bar, etc.---but not on the material itself. The researchers take this as evidence for self organized criticality. This is the name for a type of behavior in which the evolution of a system over a wide range of size scales is correlated. Some scientists suspect that self organized criticality is at work in such systems as sandpiles, forest fires, and even earthquakes. (Dallas Morning News, 20 Dec 1993.)