Book Reviews : Ruminations on the Nature of Reality and the Universe

A Brief History of Time: From the Big Bang to Black Holes by Stephen W. Hawking (Bantam: $18.95; 198 pages)

In ancient times, back when the Greeks were inventing the idea of knowledge, philosophy included what we now call science. It wasn’t until after the Renaissance that science became a subject in its own right, and after that, scientists soon left philosophers in the dust.

Scientific knowledge, based on hypotheses and experiments, increased at such a clip that it allowed little room for mere ruminations about deeper questions, which could not be resolved anyway. Physics pushed aside metaphysics.

But philosophy and physics seek to answer the same basic question: What is the nature of reality? In the 20th Century, physics has made extraordinary strides toward answering that question, and in the process, physicists have discovered that the stuff of reality is more bizarre than anyone dreamed of. Their findings have kicked common sense into a cocked hat.

Drawn Back to Philosophy

Oddly, in an effort to make sense of their new knowledge, many physicists in this century have been drawn back to philosophy. This movement started with the theory of relativity, which overturned Newton’s neat three-dimensional world, and got a big push from quantum mechanics, which showed once and for all that it was impossible to obtain complete and total knowledge of the universe and everything in it.

These findings of physics have had a profound effect on our notions of knowledge itself. Theoretical physics has become much more like philosophy than many physicists would like to admit.

Stephen W. Hawking is among the world’s foremost theoretical physicists. So it is not surprising that “A Brief History of Time,” which draws together all of his work, is as much about philosophy as it is about physics.

In this book for general readers, Hawking asks the tough, troubling, paradoxical questions that physics has posed about reality, and he skillfully weaves together an answer that is as close to accurate as we are likely to come.

Hawking’s personal story is incredible in itself. He is the Lucasian Professor of Mathematics at Cambridge University--a chair once held by Isaac Newton. But for the last 20 years he has suffered from Lou Gehrig’s disease, which has confined him to a wheelchair and left him without the ability to speak or to use more than three fingers.

His mind and spirit remain undimmed. He writes with a verve, passion and humor that belie his physical circumstances. In this short book, he traces the history of thought and knowledge about the cosmos and the structure of matter, underscores the problems of contemporary theories and proposes a solution and a world view.

All of this is within the grasp of interested laymen, though the book demands more than passing attention. Hawking writes with clarity and precision, and part of the book’s charm is the insight it gives into the mental processes of a great thinker.

“The basic ideas about the origin and fate of the universe can be stated without mathematics in a form that people without a scientific education can understand,” Hawking tells us at the outset. The book is a proof of that assertion, though theoretical physics always demands full attention.

One of the problems of contemporary physics is that it has two powerful tools--general relativity, which describes the large-scale structure of the universe, and quantum mechanics, which deals with matter on the atomic scale--and they are inconsistent with each other.

At the risk of oversimplifying a bit, general relativity allows for the universe to have had a beginning, while quantum mechanics does not. This leads Hawking to wonder, “Does the universe in fact have a beginning or an end? And if so, what are they like?”

His solution to this problem is to devise what he calls the quantum theory of gravity, which seeks to unite quantum mechanics and general relativity. There was certainly a Big Bang that started the universe, Hawking writes, but it is meaningless to ask what happened before. Like the surface of a sphere, the universe has no boundaries.

The concept of time began with the Big Bang, he says, and he concedes that this point was made long before him.

“The concept of time has no meaning before the beginning of the universe,” Hawking writes. “This was first pointed out by St. Augustine. When asked: What did God do before He created the universe? Augustine didn’t reply: He was preparing hell for people who asked such questions. Instead, he said that time was a property of the universe that God created, and that time did not exist before the beginning of the universe.”

Hawking mentions God repeatedly through the book, though he remains neutral on the question of God’s existence.

“So long as the universe had a beginning, we could suppose it had a creator,” he writes. “But if the universe is really completely self-contained, having no boundary or edge, it would have neither beginning nor end: it would simply be. What place, then, for a creator?”

But he goes on to say that even if physics could come up with a theory that explains everything, some questions would still remain: “Why does the universe go to all the bother of existing? Is the unified theory so compelling that it brings about its own existence? Or does it need a creator, and, if so, does He have any other effect on the universe? And who created Him? . . .

“If we find the answer to that, it would be the ultimate triumph of human reason--for then we would know the mind of God.”

The Greeks had it right. Physics and philosophy are the same.