Book excerpt: "This encyclopedia covers a period of enormous scientific discovery. Scientists developed previously unimagined theories, disciplines, and applications: relativity and quantum physics; cultural anthropology; psychoanalysis and behavioral theory; and insulin and antibiotics. Science became the moving force in the world, with effects on all aspects of life and thought. Although most encyclopedias about science treat it in isolation, Science in the Early Twentieth Century details the great scientific advances of this key period and places them firmly within their social context."--BOOK JACKET.