The ""new"" Scientific American is 40 years old, a transformation of a scholarly journal launched in 1845. Flanagan (with Gerard Piel and Donald Miller, Jr.) led the new team; now retired from 37 years as editor, Flanagan assumes a new role as author in this primer of contemporary science that is lot more amenable to lay readers than S.A. itself. Flanagan writes with an easy clarity, waxing enthusiastic about the major advances of the decades and underscoring technology's role in those advances. He tackles four main subjects: physics, astronomy, geology and biology. The section on physics deals not only with the glamor of what Flanagan calls ""Holy Grail"" physics--the quantum physicists' search for what happened in the first flash after the Big Bang--but also solid state physics, nuclear weapons, and the use of accelerators to construct ultimate theories of matter (strings, quarks, etc). Astronomy comes next, with a summary of what we know and how we know it. The importance of space telescopes, of infrared, x-ray, and gamma ray analyses is emphasized, and the inevitable question raised about whether the universe is open or closed. Geology sums up plate tectonics and ties in with astromony, insofar as Flanagan relates earth evolution to the planet's birth and position in the solar system. From the evolution of the planet to the evolution of life is a natural transition, developed next in the chapter on biology. Here, Flanagan points to the many paths--microbiology, biochemistry, x-ray crystallography, and genetics--that have led to current knowledge, and the challenges biologists face. As a dividend, Flanagan adds chapters on technology (from Bronze Age to Bessemer process to bits and pixels), and he concludes by properly putting in their place assorted cranks, and testifying to his own strongly held conviction of the madness of the Strategic Defense Initiative. In sum: a exemplary, not overly detailed or technical, exposition of post-WW II science.