Book excerpt: Science at the Frontier takes you on a journey through the minds of some of the nation's leading young scientists as they explore the most exciting areas of discovery today. Based on the second Frontiers of Science symposium sponsored by the National Academy of Sciences, this book describes recent accomplishments and new directions in ten basic fields, represented by outstanding scientists convening to discuss their research. It captures the excitement and personal quality of these exchanges, sometimes pointing to surprising connections spanning the boundaries of traditional disciplines, while providing a context for the reader that explains the basic scientific framework for the fields under discussion. The volume explores: New modifications to scientific theory as geologists probe deep inside the earth and astrophysicists reach to the limits of the observable universe for answers to some of nature's most fundamental and vexing questions. The influence of research in smog formation on the public debate about how to effectively control air pollution. The increasing use of computer modeling in science, from describing the evolution of cellular automata to revealing the workings of the human brain via neural networks. The rise of dynamical systems (the study of chaotic behavior in nature) to a full-fledged science. The search to understand the regulation of gene activity and the many biological problems-such as the onset of cancer-to which it applies. Recent progress in the quest to transform what we know about photosynthesis into functional, efficient systems to tap the sun's energy. Current developments in magnetic resonance imaging and its promise for new breakthroughs in medical diagnosis. Throughout this work the reader is witness to scientific discovery and debate centered on such common concerns as the dramatic and transforming effect of computers on scientists' thinking and research; the development of more cross-disciplinary perspectives; and the very nature of the scientific enterprise itself-what it is to be part of it, and its significance for society. Science at the Frontier is must reading for informed lay readers, scientists interested in fields other than their own, and science students considering a future specialization.