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Mercury, November/December 1997 Table of Contents

Michael Heller
Pontifical Academy of Theology

The mind of God; the face of God; the God particle. Theological hand-waving has become cosmologists' favorite sport, and neither theology nor science benefits.

Cosmology gives us a global perspective of the universe, or at least what people at a given epoch consider to be a global perspective. The price that cosmology pays for this breadth is that, more than other sciences, it must base its theories on unverified, and perhaps unverifiable, assumptions. This peculiarity opens the door to philosophical and theological abuse.

As a natural science, the field is neutral with respect to philosophical or theological doctrines. Unfortunately, this does not prevent the abuse. It is usually the so-called God-of-the-gaps theology that snares too hasty a thinker. The trap consists not only in constructing "proofs" of God's existence from weak points of our knowledge, but also in rejecting God on the grounds that there are no gaps in our science in which he could safely dwell. Scientists, philosophers, and theologians have all been guilty.

Is there some principle, some kind of methodological rigor, that would defend cosmology from dangers of this kind? My proposal is that the intrinsic "problem situation" in science, rather than metaphysical prejudices, should guide responsible research in science, especially in those regions that are remote from experiment.

Never Say Never

In the once widely read book, God and the Astronomers, Robert Jastrow tells the story of the most remarkable discovery of modern cosmology: The universe had a beginning. He says that for science alone it is "impossible -- not just now, but ever -- to find out what force or forces brought the world into being at the moment." At the end, Jastrow dots his 'i':

It is not a matter of another year, another decade of work, another measurement, or another theory; at this moment it seems as though science will never be able to raise the curtain on the mystery of creation. For the scientist who has lived by his faith in the power of reason, the story ends like a bad dream. He has scaled the mountains of ignorance; he is about to conquer the highest peak; as he pulls himself over the final rock, he is greeted by a band of theologians who have been sitting there for centuries.

Very old, very very old. Last year, the Hubble Space Telescope and Keck Observatory caught this glimpse of a gravitationally lensed galaxy (upper right), the most distant known (z=4.92). Hubble's images of the early universe and its measurements of cosmic expansion are among the driving forces in cosmology today. Such discoveries set the "problem situation" -- the prevailing questions that scientists of our day seek to answer. When scientists venture away from this collective effort, they are capable of radical advances -- but also, more typically, of falling into traps laid by their philosophical prejudices. Image courtesy of Marijn Franx, University of Groningen, the Netherlands; Garth Illingworth, University of California, Santa Cruz; and NASA.

In spite of his professed skepticism, he says he is forced to take seriously the theological ramifications of the Big Bang:

When an astronomer writes about God, his colleagues assume he is either over the hill or going bonkers. In my case it should be understood from the start that I am an agnostic in religious matters. However, I am fascinated by some strange developments going on in astronomy -- partly because of their religious implications and partly because of the peculiar reactions of my colleagues.

Jastrow's book first appeared in 1978, and within half a decade cosmologists began to explore the questions Jastrow thought forbidden. Inflationary cosmology is precisely a theory of the forces that brought the world into being [see "The Cosmic Burp," March/April 1987, p. 34].

Another best seller tells this story, Stephen Hawking's Brief History of Time. The Big Bang theory, so admired by Jastrow, is a purely classical -- that is, non-quantum -- theory. But now we know that in the extreme densities of matter at the Big Bang, quantum effects must enter into play. So far, nobody has created a satisfactory quantum cosmology. Hawking's book tells about his search for such a theory.

When one tries to combine quantum mechanics with the general theory of relativity, new possibilities arise. The superdense universe could have come into existence via the quantum "tunneling" process, whereby particles can leap seemingly impossible barriers -- presumably including that between non-existence and existence. This process turns out to be atemporal. In the extreme conditions of the Big Bang, there is no time in any meaningful sense of this term. Time acquires spatial properties; it gradually becomes distinct as quantum correlations grow into a fully determined temporal order of things.

Know No Bounds

Because of these quantum effects, there is no singularity at the Big Bang, no sharp limit where the density is infinite. Space-time forms a finite, four-dimensional surface with no boundaries or singularities. This continuum is similar to that of a sphere, on which one can travel without ever finding an edge -- a feature Hawking calls "self-containedness," meaning that the universe is nowhere open for any intervention coming from outside. This, he says, "has profound implications for the role of God as Creator."

In Hawking's opinion, the proper time for God to act would be the beginning of the universe, when, by setting the rate of expansion and other initial conditions, he could determine the general structure and evolution of the cosmos. But if there are no boundaries and no singularities, there is no beginning at which God could act. Hawking writes: "Einstein once asked the question: 'How much choice did God have in constructing the universe?' If the no-boundary proposal is correct, he had no freedom at all to choose the initial conditions."

Of course, even if the universe is self-contained, God would still be free to choose the laws that govern it. But this freedom could also be illusory. If there is only one logically possible set of physical laws, God has no choice. Hawking writes:

There may well be only one, or a small number, of complete unified theories, such as the heterotic string theory, that are self-consistent and allow the existence of structures as complicated as human beings who can investigate the laws of the universe and ask about the nature of God.

Despite the there-may-well-be reasoning, the philosophical vistas opened by this model are worthy of contemplation. Hawking is aware that any physical theory, even the fully self-consistent and unified theory, "is just a set of rules and equations." The most important problem remains:

What is it that breathes fire into the equations and makes a universe for them to describe?... 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?

The final sentence of the book is: "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 Whatever God

What Hawking did not openly say was said by Carl Sagan in his introduction to Hawking's book:

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 in time, and nothing for Creator to do.

Yet even if the universe is self-contained, and even if only one set of physical laws is logically possible, one hardly could stop asking: Where do these laws come from? What is their nature? This is not a gap in our scientific theories; all of science is marked with the problem. Any attempt to comment on it leads us into difficult questions concerning the relationship between physical laws and the mathematical structures that express these laws [see "After the End of Science," p. 22]. These questions preoccupied Einstein and many other great scientists.

The examples of Jastrow and Hawking are typical. The first example comes from the period when people were coming to terms with the firework beginning of the universe. The second illustrates the present tendency to look for ultimate explanations in the (so far unknown) fundamental laws of physics. A few decades ago, religious interpretations of the Big Bang cosmology were an easy temptation, although the steady-state cosmology of that time could be considered a heroic struggle to defend the self-explanatory character of the universe. In our day, this attitude prevails to fill in all gaps in science with the most audacious hypotheses, which too often have philosophical motivation as their only rational basis.

Jastrow's comments are a generic case of God-of-the-gaps theology. In the Big Bang, the history of the universe (as contemplated backward in time) breaks down, creating an enormous gap in our knowledge. We do not know where the Big Bang comes from, we ignore its cause, we know nothing about the previous state of the world, we have no idea whether the world even existed before that critical event. Our ignorance is immense. It seems that only the hypothesis of God could help.

It is a hypothesis that will almost certainly turn out to be superfluous. God-of-the-gaps theology represents a lack of imagination, for what is now a boundary of science can soon be its well-explored region. This is both a theological and a scientific error. From the theological point of view, it reduces God to the rank of a dubious methodological principle; from the scientific point of view, it violates a rule never to go beyond natural phenomena.

It is only a difference in degree that separates Jastrow-like arguments from the physico-theology of the 17th century, when, from the harmony of planetary motions, people inferred the existence of the omnipotent clock-maker; or from the marvelous machinery of gnat's eye, they deduced the existence of the divine designer.

No Gaps, No God

The God-of-the-gaps theology is perhaps less transparent in my second example; nevertheless, it is there. Sagan clearly suggests that God should be rejected. For people accepting this, God is necessarily the God of the gaps: There are (or will be) no gaps, therefore the hypothesis of God is superfluous. One could put it shortly: no gaps, no God.

This is clearly very bad theology. Is it equally bad science? It depends. If it inspires the search for solutions to hitherto unsolved problems, it can promote scientific progress. But if its only goal is to populate science with strange hypotheses in order not to leave any gaps for metaphysical ingredients, the road to correct solutions could be easily blocked by misleading ideas.

Hawking's works are lasting contributions to science and he is too serious a researcher to allow himself to be guided by dubious ideologies. I suspect that the philosophical comments in his book are reflections after the fact, rather than principles guiding his scientific research. There is no doubt, however, that some researchers introduce metaphysical ideologies into their scientific work.

Twentieth-century science writings abound in such confusion. For instance, when quantum physicists discovered the uncertainty principle, many defenders of traditional philosophy claimed that humanity's free will was finally vindicated. Later on, other writers -- working from interpretations of quantum mechanics which emphasized conscious observers -- developed the ideology that in the beginning of the universe, when there were no other conscious observers besides God, his observing of the universe was necessary for laws to operate.

Nowadays the so-called strong anthropic principle creates a vast field of possibilities for similarly minded authors [see "The Anthropic Principle and the Early Universe," May/June 1981, p. 66]. From the fact that extremely fine-tuned initial conditions are indispensable for a universe such as ours, these authors build various versions of the old proof of God's existence from finality. They flesh out incomplete physical theories with the hypothesis of God or some other metaphysical doctrine.

There are equally many scientific theories that have been claimed not to leave any place for God. Many thinkers have used the theory of evolution as a weapon against religious interpretations of the world. In the eyes of such thinkers, the idea of God should be rejected since it is no longer needed to explain the adaptations of living things. This kind of argument is always based on the tacit presupposition that a given scientific theory is truly self-explanatory -- that no further assumption is needed to justify it.

In fact, such a claim can hardly be substantiated, since every scientific theory works on the assumption that the laws of nature are somehow given and enable the theory to operate. The theory of evolution assumes that the laws of probability permit natural selection. More sophisticated thinkers try to make science self-explanatory by invoking the methodological principle that science depends on experimental evidence. This is the source of various forms of the positivist anti-religious attitude. Yet this attitude is itself based on the assumption that methodological principles can serve as an ontology. A good methodology can easily turn out to be a bad ontology.

The Problem Situation

I do not say that metaphysics and theology are insignificant or meaningless; I am only arguing that they should not interfere with science. The best way of doing science is to stop thinking directly about any metaphysical preconditions or implications. In lieu of metaphysics, what should lead our research? In many sciences, experiments are the guide. But what about sciences so remote from laboratory experimentation as cosmology?

My answer is that this field should be guided by the same principle as any other branch of science. In doing research, we always face a certain "problem situation," as philosopher of science Karl Popper called it. A good scientific work poses new and often unexpected problems that are to be solved. Experimental data (if they are available) or experimental possibilities (if they are open) also define the state of the art. But when there are no well-defined problems and no broader effort to contribute to, experimental results are sterile and can only casually lead to valuable conclusions. In science, context is crucial.

There are local problem situations -- the ones that affect only a particular area of research -- and global problem situations -- which have important repercussions in an entire branch of science. An example of a global problem situation is the one that evolved in physics a century ago. Seemingly, it concerned only a very technical problem about the electrodynamics of moving bodies, but people such as Henri Poincaré, Hendrik Lorentz, and Einstein realized its importance for the very foundations of physics. Their work resulted in the special theory of relativity.

When speaking of such achievements, we should distinguish between the context of discovery and the context of justification. In the context of discovery -- the way scientists arrive at new ideas -- philosophy certainly can play an important role. For instance, Einstein was strongly influenced by philosophical views of Ernest Mach; without reading Mach's writings, he might never have started thinking about relativity.

But in the context of justification -- when the theory is ready to fight for its place in science -- no overt philosophical or theological premises should be taken into account. The only things that matter are empirical verification, mathematical elegance, and consonance with other physical theories. Einstein eventually abandoned Mach's philosophy, and his theory proved to be independent of any philosophical presuppositions.

Even if metaphysical ideas are fruitful in the context of discovery, scientists are most successful when they do not work with the aim of defending or destroying a given philosophical or theological doctrine. Historically, when this has happened, subjective goals have overpowered impartial objectivity. Metaphysics is most helpful when implicitly arrived at and only afterwards critically examined.

As far as the origin of the universe and of physical laws is concerned, the problem situation is formed largely by two major programs in theoretical physics: the quantization of gravity and the unification of physical interactions. Recently, observational astronomy has been another driving force in cosmology. Observers of early galaxy formation and large-scale structure have outpaced the theorists.

Gaps in our knowledge can be twofold. There are gaps through a deficit, when we know nothing about something we would like to know about. In such a case, we are looking for a knowledge that could fill the gap. The initial singularity in non-quantum cosmology is an example. The histories of particles and observers break down at the edge of space-time, beyond which a great hole in our knowledge extends.

There are also gaps through an excess, when we do not know something because the true hole in our knowledge is filled with empty hypotheses and misleading models. In such a case, the gap becomes a trap, and one does not realize when one has started hunting one's own shadow.

MICHAEL HELLER is a philosophy professor at the Pontifical Academy of Theology in Kraków, Poland. He is also affiliated with the Vatican Observatory. His email address is mheller@alumn.wsd.tarnow.pl. For a primer on the Big Bang, see The Universe in the Classroom, First Quarter 1997.