BOOK REVIEW / Briefer histories on a universal theme: Black holes and baby universes - Stephen Hawking: Bantam, pounds 16.99

STEPHEN HAWKING has done it again. In A Brief History of Time he succeeded in interesting the widest of audiences in the most abstract of theoretical astrophysics. Now he has once more broken out of the scientific ghetto to claim the intellectual and cultural high ground for science.

His new book, Black Holes and Baby Universes, consists of a series of essays and lectures: some of them are about himself and the motor neuron disease which has ravaged his life, confining him to a wheelchair and depriving him of speech; most of them discuss the theories and ideas which his extraordinary brain has generated. Black Holes and Baby Universes is more approachable than A Brief History - though whether this will lift its sales beyond the dizzy heights of the earlier book remains to be seen.

A Brief History had two things going for it. Paradoxically, the very difficulty of the ideas which it attempted to convey contributed to its attraction. In addition, the book had an essential unity: it was an extended essay with a beginning, a middle and an end (in notable contrast to the universe in which we live, according to the thesis of the book itself). As a collection of shorter essays, Black Holes lacks this single thread, and there are some repetitions between essays.

A Brief History also captivated its readers because it broke with conventional writing about science, which tends to the dreary cataloguing of facts, into a traditional literary form: it tells a story. Nor was it just any narrative, but the oldest story in human culture, the one about origins and endings. From the earliest written literature, through the ancient Sumerian epics of Gilgamesh and Enkidu, down to the dawning of our own Judaeo-Hellenic culture, humanity has been fascinated by the story of how our world began, of how it will end, and of what our place is in the scheme of things. A Brief History retold that story in the idiom of our age, the language of science.

But the scientific narrative is different from all that has gone before it. It does not speak to us in metaphor and parable (although that is often how scientists present their work for audiences), but asserts that it offers direct knowledge of how the world really is. In Black Holes and Baby Universes, Hawking makes the claim that through the mental discipline of modern science we can become 'masters of the universe', just as he concluded the earlier book by asserting that one day we can know 'the mind of God'.

Such claims have an undeniable poignancy, coming as they do from an intellect confined within such a wreck of a human body. And yet, the compass of modern science is extravagant. Consider the parable of Newton and the apple. Newton did not 'discover' the theory of gravity by observing the fall of an apple: his astonishing leap of the imagination was to see that the force governing the fall of fruit in the orchard is the same force which holds the moon and the planets in their courses. Who else but a genius could have seen such a connection? Yet, in contrast to the esoteric visions of the mystics, Newton's profound understanding of the interrelation of things is democratic: it is available to the rest of us.

Newtonian gravity, as modified by Einstein's general theory of relativity, holds good to the outermost limits of the observable universe. An apple might traverse perhaps three metres in its fall to the ground; the radius of the observable universe is approximately three hundred million billion billion metres. By experiments here on earth we can reach out and know what is happening on the other side of the cosmos. It is a startling paradox that, by pursuing a reductionist enterprise, science ends up as the ultimate in holistic philosophies, for it displays the fundamental

unities which underlie the chaotic mass of events and objects in our universe.

Black Holes and Baby Universes takes us still further, almost literally over the limit. Stephen Hawking tells how he managed a further unity, by combining the two greatest achievements of physics in the 20th century - quantum mechanics and general relativity - which had previously been considered incompatible. The insight has allowed him to look over the edge, back to the moment of creation itself and into the previously inaccessible territory of a black hole's interior. He describes other creations, as when a black hole can give rise to a baby universe, 'a small self-contained universe (which) branches off from our own region'.

Our own universe, we learn, has had not one, but infinitely many histories, some of them more probable than others. This indeterminacy of the past stems ultimately from the uncertainty principle of quantum mechanics and, Hawking hopes, might free us from the neo-Calvinism of Newton's clockwork universe, in which everything is inexorably pre-ordained.

As a professional physicist, Hawking largely confines himself to physics. But the impact of science on humanity's sense of its place in the scheme of things is much wider. As the moral philosopher Mary Midgley argued in her book Beast and Man, a decade ago, we cannot hope to construct a system of morality by a process of pure reason, totally separating values from facts. Instead, she remarked, moral values have to start from some contingent facts - not only that we exist, but also the biological fact that we are primates, rather than reptiles or molluscs.

It follows that there can be no moral absolutes: the highest of human moral values would be anathema to, say, an intelligent octopus. Our biology and our morality are inextricable. As a crude illustration, Mrs Thatcher's infamous apercu - that there is no such thing as society, only individuals and their families - is wrong for many reasons, not least because it is biologically false. Aristotle may have been the first to observe that man is a social animal, but it took evolutionary biology to prove the philosopher correct.

Hawking is right to assert that scientific understanding matters, and not just to underpin our technological civilisation. For science naturally engenders a sense of wonder - ultimately almost a religious wonder that the world is at all. Hawking's essay on the origin of the universe concludes: 'What is it that breathes fire into the equations and makes a universe for them to govern? Although science may solve the problem of how the universe began, it cannot answer the question: Why does the universe bother to exist?'

Black Holes and Baby Universes has already been subjected to an extraordinary attack by Bryan Appleyard, in the daily Independent. Underlying his case against Hawking was an objection to the cultural and intellectual status claimed for science. For those on the literary-artistic side of the great divide between the 'two cultures' identified by C P Snow in 1959, Appleyard's article was a wild cry of la patrie en danger.

Yet there is nothing to fear when scientists like Hawking tell their stories. Science, properly understood, is as life-enhancing and culturally enriching as art. When Galileo produced irrefutable observations that the earth was not the centre of the universe, so the story goes, contemporary sceptics refused to look through his telescope; Appleyard's seems to be a similarly closed medieval mind. Turn to Stephen Hawking if you would look outward, to the very ends of the universe.

see also 'Weighing the Universe': Steve Connor on the Great Unsolved Mysteries of Science, page 70