The Anthropic Cosmological Principle, by John Barrow and Frank Tipler. New York: Oxford University Press. 706 pp. $29.95. ``Imagine a universe in which one or another of the fundamental dimensionless constants of physics is altered by a few percent one way or the other? Man could never come into being in such a universe. That is the central point of the anthropic principle.''
So writes John A. Wheeler of the University of Texas in the foreword to a controversial new book by John D. Barrow and Frank J. Tipler.
In an attempt to define this principle, the authors of ``The Anthropic Cosmological Principle'' review a wide range of scientific literature, old and new. They themselves are scientists; John Barrow is an astronomer with the University of Sussex, and Frank Tipler is a physicist from Tulane University. They warn the reader that their book ``will necessarily involve the use of some fairly sophisticated mathematics and require some familiarity with the concepts of modern physics.''
Nonetheless, these scientists are writing for an audience of ``theologians and philosophers,'' as well as scientists. It remains to be seen whether they will reach their intended audience. The motive is clear, the path strewn with obstacles.
The ``basic truths'' they assume are the ``big bang'' theory, evolution, and the theories of physics. From this basis, Barrow and Tipler attempt to quantify and explain several anthropic principles, or, in their words, principles that ``seek to link aspects of the global and local structure of the Universe to those conditions necessary for the existence of living observers.''
Putting their efforts in recent historical perspective suggests why this book has proved controversial. Following Newton and Darwin, many philosophers have felt that the universe was completely deterministic, and that given enough time and effort, all of the effects we observe could be predicted. Thus the ordinary working of physical laws would account for all the wondrous order that had been accepted as evidence of a creator.
In this century, the sciences -- physics, cosmology, biology -- have been rethought, reformed, and extended in many new directions. So the question is, has man's place in his own sciences changed since the stark mechanistic view of nature that held sway in the philosophy of the 19th century?
Barrow and Tipler invite their readers to consider man's place in the universe. A great deal of their text deals with teleological arguments -- arguments about the evidence of design in nature.
How the authors view their enterprise is conveyed in the following passage -- a passage that may act as a warning about the style of their prose!
``We shall see that the simpler teleological arguments (that is, arguments which invoke design in order to infer purpose) concerning biological systems were supplanted by Darwin's work, but the system of eutaxiological arguments (that is arguments which state that order must have a cause, but may not have a purpose, and that we may study it without knowing its purpose, for example a watch could be understood as a mechanical device without realizing it is used to tell time) regarding `coincidences' in the astronomical make-up of the Universe and in the fortuitous form of the laws of Nature were left unscathed by these developments and it is these arguments that have evolved into the modern Anthropic Principles. But careful thinkers would not jump now so readily to the conclusions of the early seekers after Design. The modern view of Nature stresses its unfinished and changing character. This is the real sense in which our world differs from a watch. An unfinished watch does not work and the discovery of time's role in Nature led to an abandonment of Design arguments based upon omnipresent harmony and perfection in favour of those that concentrated upon current co-present coincidences....''
Briefly, then, teleological or eutaxiological arguments are based on the appearance of a design in nature that is unique in the sense that a keystone of an arch is unique: Without it, everything would fall apart.
One of the many examples traced through this book is that of the uniqueness of water. Unless water possessed the special properties it does, the animal species could not exist.
``Water is actually one of the strangest substances known to science. This may seem a rather odd thing to say about a substance as familiar but it is surely true. Its specific heat, its surface tension, and most of its other physical properties have values anomalously higher or lower than those of any other known material. The fact that its solid phase is less dense than its liquid phase (ice floats) is virtually a unique property.'' The fact that ice floats is far from the only unique property of water. Do the properties of water follow from an anthropic principle that determines the physical laws in such a manner as to permit human existence?
Lawrence J. Henderson, a professor of biological chemistry at Harvard at the turn of the century, considered this idea. ``Henderson was led to reflect on teleology in the biochemical world through his work on the regulation of acidity and alkalinity in living organisms.... Henderson searched the chemical literature and uncovered a large number of substances whose peculiar properties were essential to life.'' Henderson presented an argument that the properties of matter are ``in a fundamentally teleological sense, a preparation for life.''
So must human existence follow from the fundamental laws of physics? In earlier days such an idea would be cited as evidence of a Designer. However, ``moderns'' assert ``that the development of life was at all times the result of natural selection acting on changes in the hereditary structure. Thus, ultimately there is no teleology acting in a living organism; the planning which a living creature undertakes to guide his future actions can ultimately be reduced to mechanism, to the interaction of the elements in accordance with ascertainable physical laws. Furthermore, concerning the existence of a Designer, Henderson remained an agnostic.''
From their definitions and historical review of both prior attempts to find anthropic principles and the current theories of physics, Barrow and Tipler draw some very interesting conclusions.
``Indeed, one of the seeming implications of science as it has developed over the past few centuries is that mankind is an insignificant accident lost in the immensity of the Cosmos. The evolution of the human species was an extremely fortuitous accident, one which is unlikely to have occurred elsewhere in the visible universe.'' Not much hope in those sentiments for the ultimate triumph of man, mankind, or intelligent life.
The conclusions of this book will come as cold comfort to most readers, who, unlike the authors, find it emotionally impossible, and perhaps dishonest, to ``take the behavioral point of view,'' but according to Barrow and Tipler, the future, if there is one, belongs to machines.
So ``life'' is leading up to robots? Only machines could survive the future as it is envisioned by these scientists, who agree that ``the ultimate future of the Universe involves great cold or great heat, and that human life -- the species Homo sapiens -- cannot survive in either environment.... But though our species is doomed, our civilization and indeed the values we care about may not be ... from the behavioral point of view intelligent machines can be regarded as people. These machines may be our ultimate heirs, our ultimate descendants, because under certain circumstances they could survive forever the extreme conditions near the Final State. Our civilization may be continued indefinitely by them, and the values of humankind may thus be transmitted to an arbitrarily distant futurity,'' the authors of ``The Anthropic Principle conclude.''
Given the context, would it be rude to ask what these scientists refer to when they write the words ``our civilization and indeed the values we care about''?
Their book has nonetheless jolted us into asking ourselves the same questions.
Barrow and Tipler have succeeded in bringing together the thoughts of a wide variety of scientists and philosophers, and in raising many interesting questions. Their attempt to formulate the vocabulary and structure of anthropic cosmological principles is scholarly. They are to be commended for displaying the equations, tables, graphs, quotations, and references essential to their subject. It is difficult to imagine a subject that requires as wide an intellectual range and depth. This makes the text heavy going. Nonetheless, their book will inspire discussion and debate, as we again think through the place of science, history, philosophy, and man in the universe.