THE NEOLITHIC TRANSITION IN EUROPE. Human behavior is much more complicated than the behavior of atoms, liquids, or planets. Nevertheless, physicists and mathematicians have attempted to apply their equations in the social sphere; recent examples recounted in Physics News Update include such topics as the arms race (Update 403), economics (Update 395), bird flocking (Update 395), and the making of group decisions (Update 385). Now two Spanish physicists have applied diffusion/reaction equations--- governing, say, the diffusion of one fluid through another with due allowance for chemical reactions along the way---to the diffusion of agricultural technology into Europe in the early centuries of the Neolithic epoch roughly 10,000 years ago. Such an effort had been tried before, but the model predictions poorly matched the observed anthropological, linguistic, and genetic data. According to Joaquim Fort of the University of Girona (jfort@watt.udg.es, 011-34-972-418-490), a much better match can be achieved by using equations with additional "time-delay" terms of the type used successfully to model the spread of forest fires and epidemics. In the case of human migration a time delay factor would reflect the fact that generally the offspring of migrating farmers must grow to adulthood before they themselves "diffuse" outwards. Fort believes that mathematical modeling will become even more important to anthropology and history, but only in concert with high-quality data from fieldwork. (Fort and Mendez, Physical Review LettersScientific American, Oct 1990; see figure at Physics News Graphics.)