ABSTRACT
The twentieth century witnessed the ascendancy of the telephone, automobile and radio; then television and computers, as well as growing control over most epidemic scourges. We also began to understand theoretical physics, a new cosmology, and the molecular basis of life. We first left the Earth's surface in powered machines built for the purpose, and progress in research hastened the translation of new knowledge into more and more innovative technology. The century staged, also, the most devastating wars in history and nearly globalized terrorism; we are still counting all their dead.
