Discussion Group Report

Stephen Hawking, in his book A Brief History of Time, addresses the question in the title of this article. He asks, "...are we perhaps just chasing a mirage?" There seem to be three possibilities: " 1) There really is a complete unified theory, which we will some day discover if we are smart enough. 2) There is no ultimate theory of the universe, just an infinite sequence of theories that describe the universe more and more accurately. 3) There is no theory of the universe; events cannot be predicted beyond a certain extent but occur in a random and arbitrary manner."

Some would argue for the third possibility on the grounds that, if there were a complete set of laws, that would infringe God's freedom to change his mind and intervene in the world. St Augustine said the idea of a God that might want to change his mind is a fallacy of imagining God as a being existing in time: time is a property only of the universe that God created.

With the advent of quantum mechanics in the world, we have come to recognize that events cannot be predicted with complete accuracy. But that there is always a degree of uncertainty. One could ascribe this randomness to the intervention of God, but it would be a very strange kind of intervention, for there is no evidence that it is directed toward any purpose. Indeed, if it were, it would by definition not be random. "We have," Hawking states, "effectively removed the third possibility above by redefining the goal of science: our aim is to formulate a set of laws that enables us to predict events only up to the limit set by the uncertainty principle.

"The second possibility, that there is an infinite sequence of more and more refined theories, is in agreement with all our experience so far. On many occasions we have increased the sensitivity of our measurements or made a new class of observations, only to discover new phenomena that were not predicted by the existing theory, and to account for these we have had to develop a more advanced theory...We might indeed expect to find several new layers of structure more basic than the quarks and electrons that we now regard as "elementary" particles.

"However it seems that gravity may provide a limit to this sequence of 'boxes within boxes'...Thus it does seem that the sequence of more and more refined theories should have some limit as we go to higher and higher energies, so that there should be some ultimate theory of the universe...I think that there is a good chance that the study of the early universe and the requirements of mathematical consistency will lead us to a complete unified theory within the lifetime of some of us who are around today, always presuming we don't blow ourselves up first."

This book is Hawking's first for the non-specialist. Carl Sagan describes it as holding "rewards of many kinds for the lay audience...In this book," he says, "are lucid revelations in the frontiers of physics, astronomy. cosmology, and courage.

"This is also a book about God...or perhaps about the absence of God. The word God fills these pages. Hawking embarks on a quest to answer Einstein's famous question about whether God had any choice in creating the universe. Hawking is attempting, as he explicitly states, to understand the mind of God. And this makes all the more unexpected the conclusion of the effort, at least so far: a universe with no edge in space, no beginning or end of time, and nothing for a creator to do."