The last century was defined by physics. From the minds of the world's leading physicists there flowed a river of ideas that would transport man kind to the very pinnacle of wonder and to the very depths of despair. This was a century that began with the certainties of absolute knowledge and ended with the knowledge of absolute uncertainty. It was a century in which physicists developed theories that would deny us the possibility that we can ever properly comprehend the nature of physical reality. It was also a century in which they built weapons with the capacity utterly to destroy this reality.