The 20th century was the most remarkable period in the history of human civilization. Packed within little more than one hundred years was the mapping of the universe from the interior of atoms to the ends of outer space. The nature of matter was defined. Science blossomed. Humans invented machines to do their labor and created a cyber world of automation to augment their thinking. These innovations created a complex, confusing, and diverse society in conflict with longstanding cultural values. Society has changed from one in which manpower is the critical economic element to one in which manpower is largely superfluous. Such is "The 20th Century Legacy". In this book Frank J. Welch, a retired scientist and longtime manager of technology, traces the development of technology and science over recent years and explains their effect on society and government. His "outside the box" view explains how the popular understanding of science and technology and their effects on society is incorrect and misleading. He notes that diversity inhibits cultural controls over destructive human behaviors.