Faith in the crucible of the new physics.
A few weeks ago an acquaintance of ours, a theologian, remarked in the course of a stimulating dinner conversation that he considered quantum mechanics the greatest contemporary threat to Christianity. In fact, he said, if some of the results of this theory were really true, his own personal faith would be shattered.
Anyone in the habit of wandering through bookstores may see a spate of books on the “new physics.” Some of them are best sellers and have won prestigious book awards. To name a few: The Tao of Physics, Taking the Quantum Leap, God and the New Physics, and Looking Glass Universe. And there is one by a fine Christian writer, Virginia Stem Owens, called And the Trees Clap Their Hands. A glance at these titles shows that three of them explicitly deal with religious themes. In fact, the whole spectrum is represented from atheism (or close to it) to Zen Buddhism to Christianity. Whatever new physics is, it has theological implications.
It should be understood, however, that there is precious little that is new about the new physics. Most of the ideas are more than a half-century old and are routinely taught to physics students at the college level. Even though the authors of the above books are bursting with excitement and urgency, the new physics has taken a long time to reach the attention of the layperson. That seems surprising, but as molecular biophysicist Harold Morowitz points out, “Really deep concepts seem to take about 50 years to sink into the collective consciousness of the thinking community. So it is that only now are most of us beginning to sense the full impact of certain ideas that have been brewing in physics since the first quarter of this century.”
Besides that, the ideas of quantum theory are—to the layperson—just plain weird. So the general public, if it has had any piecemeal notions of what has been going on, has tended to ignore it (which is the proper business of the general public). But with all the books on the market, and more on the way according to Publisher’s Weekly, it’s getting so that a proper dinner conversation cannot be conducted without some passing reference to quantum theory.
The Practical Results Of Quantum Theory
We should note from the start that physicists themselves don’t know what to make of quantum theory, which has always been plagued with controversy. Certain crucial paradoxes remain stubbornly unresolved, though most working physicists have had to become enured to their discomfort. Despite all the haggling and puzzlement, however, quantum theory is one of the most brilliantly successful scientific theories ever devised. It explains a host of hitherto baffling phenomena associated with chemical bonding, atomic structure, mechanical and thermal properties of solids, and collapsed stars, to name a few. But its success is more than theoretical. On a practical level, it lies behind the laser, the electron microscope, the semiconductor, the transistor, the superconductor, and nuclear power. So we are talking about medicine, bombs, computers, and a host of everyday gadgets that either facilitate or clutter up our lives.
But transistors and semiconductors, important as they may be, are not what was bothering our theologian friend at dinner. What concerns him are the results of quantum theory, which, as any serious Christian thinker cannot ignore, have shaken some very basic presuppositions about God’s world, and hence about God himself. We want to explore these difficulties, and, we hope, put them to right so we can all get on with the proper enjoyment of God’s bounty. Just one disclaimer: We beg the forbearance of those people who know their physics. As they well know, anyone who purports to communicate in a brief article an understanding of quantum theory, albeit a smattering, is stark raving mad and a menace to society. So we don’t purport. Our intention is to stimulate thinking about some intriguing scientific ideas and, perhaps, along the way, provide a glimmer of perspective.
Classical Theology And Classical Physics
In his book God Did It, But How?, Robert Fischer has two parallel lists of presuppositions that have been fundamental to the structure of classical physics on one hand, and biblical theology on the other. We shall use this basic outline, but will deviate and expand upon it as necessary. On the side of classical science are the following basic presuppositions:
First, the physical world is real. It exists independent of us. As Einstein said, “The belief in an external world independent of the perceiving subject is the basis of all the natural sciences.” The observer is distinct from the observed.
Second, the physical world is orderly, or rational. For every effect, there is a cause. Everything was and is predictable—if not in practice, at least in theory. To quote Einstein again, “God does not play dice” with the cosmos.
Third, the physical world is understandable, and what we don’t understand is due to our ignorance. Our language and logic are definitely adequate for this scientific approach to the world.
On the theological side we have the following:
First, the God of the Bible is real. Although people throughout the ages have attempted to prove or disprove the existence of God, the Bible assumes he exists and makes no attempt to prove it.
Second, the God of the Bible is orderly, or rational. His laws are consistent and noncontradictory. He does not play dice with the cosmos.
Third, the God of the Bible is understandable, at least in part. We can know him and have a relationship with him. If it were not so, it would be meaningless to interpret God’s Word or his actions in the world. Our capacity for language and reason is also adequate for this theological approach to the world.
These lists are not supposed to represent isolated items but whole paradigms of presuppositions—whole complexes or models of concepts that are generally accepted as true. These paradigms determine not only what a person sees, but perhaps more important, what he is looking for. They are the glasses through which he or she views and interprets the world.
In earlier centuries, then, classical physics and classical theology were were so intertwined that they were not discernible as separate entities. The sixteenth- and seventeenth-century pioneers of physics shared, for the most part, the devout convictions that God had written the book of nature and that it, like the Bible, could be understood. Indeed, it was the proper role of man to understand nature since nature was a way in which God revealed himself.
And then the unraveling began.
What Is Reality?
There remained, and still remains, a strong mental and emotional connection between theology and science. Many Christians passionately desire to hold the two together, for good reason. The God of the Bible is the God of nature. He created and sustains the physical world. There should be no contradiction between his revelation in nature and that in Scripture. And indeed, as we shall see, there need be no contradiction.
But very serious problems arise when we attempt to identify a particular paradigm of science with the way God reveals himself in nature. It was a mistake to identify absolutely classical science with biblical theology, but an understandable mistake. The classical scientific paradigm had been unchallenged for almost 500 years. It was not even possible to conceive of an alternative—until the new physics. Relativity rocked the scientific world at the turn of the century, but did nothing whatsoever to challenge the most basic assumptions upon which science had been founded. Experimental investigations in the subatomic world and the interpretations of quantum theory now have changed all this. The old notions of independent reality, order, and intelligibility have all been rendered either meaningless or incorrect. Our theologian friend has felt the reverberations resulting from the destruction of the world view of classical science. And he feels that if you challenge any item in the scientific list, then you have automatically challenged the corresponding item on the theological list.
Billiard Balls And Electrons
Again, the central issue is the nature of reality itself. Take a billiard ball and roll it from one side of the table to the other. In order for the ball to get from one side to the other, it has to move along a certain path. It must have passed over all the possible positions on this path and moved with a certain speed and direction (the combination of speed and direction is called velocity). We can actually calculate both the position and the velocity of the ball at any moment in its journey. This is part of what makes the ball real to us: it has to be somewhere and moving at the same time. With the aid of a physicist (one who holds the usual, now accepted, view of quantum theory) and the appropriate experimental paraphernalia, let’s use an electron instead of a billard ball.
The first thing our physicist tells us is that we will not be able to see the electron in its flight. We will be able to see where it starts and where it hits, but we will not be able to predict exactly where it will hit beforehand as we could the billiard ball.
We suppose that the experimental machinery is not refined enough to permit this.
Not just that, the physicist replies, we cannot do it in theory. We can only predict where it will most likely hit. We have to use probability, he adds.
We are tempted to make a slightly sarcastic remark about the exactness of science, but then recall all the successes of the approach. So we shut up and ask what happens next.
You have a choice, he says. Would you like to know the position of the electron or would you like to know its velocity? You have to let me know ahead of time.
We are immediately suspicious. So, we say, why not both?
No way, he says. You can have one or the other but not both at the same time.
Why not? we wonder. Is it because our equipment is so crude compared to a delicate thing like an electron that if we try to measure one we automatically mess up the other?
Oh yes, there’s that, the physicist remarks offhandedly, but that’s not the real point. The fact is that if we choose to measure the velocity, for example, the electron does not have a location.
What you mean is that it has a location but we just can’t measure it, we solicitously correct (scientists really ought to learn how to use language).
No, he replies, fixing us with an amused look, it really does not exist.
Now we are in an incredulous huff. You mean to tell me that if we choose to measure the electron’s velocity that it gets from here to there without going in between? Or that if we choose to measure where the electron is located at any particular moment it doesn’t have any speed or direction—and it still gets over there?
Imperturbed, our physicist responds: You might say that. Of course, your problem is that you have some antiquated notions of “here” and “there”—so far as the subatomic world is concerned.
Now we’re indignant. What kind of philosophical claptrap is this? Do you actually teach this stuff to young people?
Our physicist is a veteran of many a skirmish with amateurs. He calmly replies: To be sure. It’s called Heisenberg’s Uncertainty Principle. The more certain we are of one aspect, the more uncertain the other becomes. There is some leeway. If we don’t insist on an accurate measurement of the velocity, then we get a tendency for the location to exist, and vice versa. Heisenberg envisioned a kind of intermediate reality in this situation, something somewhere between the massive reality of a billiard ball and the intellectual reality of ideas or images. It is like trying to nail down a warped board. Every time you nail down the reality of one end, the other pops up into unreality. But we could just nail each end part way. Then each would exist in this limbo of intermediate reality.
Let us leave our physicist and go it on our own.
Think of the way a television set works. An electron gun in the back of the set shoots electrons at the fluorescent screen in the front. If these electrons were like bullets or billiard balls we could follow each bullet from the gun to the screen. We could predict precisely where each would hit. But not so with “real” electrons. An electron leaves the gun and turns up on the screen. But in between it exists as an infinite number of ghostly cohorts or alter egos. None of these ghostly cohorts is real like a bullet, none has a path, but each has a certain potential for reality. The screen interacts with this ephemeral host and promotes exactly one into absolute reality. The mechanism of this interaction is a mystery. Indeed, the whole business has no cause. Certainly the gun and the screen have something to do with it, but they do not completely determine it, as would be the case with bullets or billiard balls. What we have is millions and millions of random events operating outside the laws of cause and effect, piling uncertainties upon uncertainties, and all accumulating in a sharp, clear picture on the screen. (Unless your set is like ours—we have no problem believing this ghost stuff.)
Light: Particle Or Wave?
All of this brings up the subject of the wave-particle nature of light. Since the 1820s physicists have known from various experiments that light behaves like waves. But about 1900 and shortly thereafter, Max Planck and Albert Einstein showed that light comes in bundles, or quanta, of energy called photons. Much of our present technology is based on one or the other of these aspects. Other subatomic particles, such as electrons, also share these dual characteristics. Whether you get a wave or a particle depends on your experimental design.
This dual nature of subatomic particles reflects what is known as Bohr’s Complementarity Principle. The two mutually exclusive, equally valid, and yet contrary views of particles are said to be complementary to each other. Describing a photon, for example, as a particle explains something about it that describing it as a wave does not. And vice versa: describing a photon as a wave explains something about the photon that describing it as a particle does not. The two descriptions—particle and wave—complement each other.
So far, so good. But the principle also implies that there is no reality until perception takes place, and that what is perceived depends on the choice of the perceiver.
The eminent physicist John Wheeler has constructed a thought experiment that helps clarify these admittedly cryptic remarks. Imagine, he says, light rays headed toward earth from a distant quasar. Right smack in the path of these rays is a galaxy that is 100 million light years from earth. The gravitational field surrounding this galaxy has a profound effect on our rays, and we observers on earth have a decision to make. We can observe the incoming light with equipment designed to show either its particle nature or its wave nature. We have to decide between them. If we choose the particle detector, we will see each photon swerving to the left or to the right as it travels through the galaxy’s gravitational field. But if we had chosen the wave detector, we would have seen the photon flowing around both sides of the galaxy and emerging as two distinct streams, much as a stream of water divides and flows around a rock. Our apparatus forced the photons to display one or the other of its complementary aspects. And the choice was ours. That seems amazing in itself, but here is the real stinger. What actually happened 100 million years ago? If we can choose in the present to have the photon appear on only one side as a particle or on both sides as a wave, have we retroactively created or recreated history? The photon got here, but how? As a particle or as a wave? This was not decided until the present. And we did the deciding.
This business of deciding and observing is another main tenet of quantum theory. It says that our very act of observation brings a subatomic phenomenon out of potential limbo into actual existence. In other words, we create physical reality. We are not talking about our subjective experience of a phenomenon; we actually create the “outside” world under objective experimental circumstances. Let’s clarify what we mean by the world. We do not mean the world of chairs, books, or trees. We mean the subatomic world that underlies these things. The world “up here” does not behave in such a strange manner. Nobody is saying that we create trees by looking at them. But if we go beneath the bark, into the cells and the molecules, if we go as far as we can down inside the atom, then we enter the world we are talking about—the world we create by observing.
If you are thinking that there must be a catch, that certainly we do not live in such an Alice-in-Wonderland world, then you stand in eminent company—eminent but small—you and Albert Einstein, and not very many other people. Einstein helped lay the foundations of quantum theory, but to his dying day he never believed that it told the whole story. There had to be something underneath it all, some set of controlling, hidden variables that would tie everything together into a nice cause-and-effect bundle. Einstein was always arguing for a predictable and understandable world. But the proponents of quantum theory, led by Niels Bohr, successfully countered Einstein’s arguments, and quantum theory continued its brilliant career undeterred.
Niels Bohr’s success over Einstein—a kind of scientific showdown—is an interesting story in itself (see accompanying article beginning on p. 24).
What The New Physics Means
So here is where quantum theory and its experimental verification have brought us. The world is not independent of us. At the subatomic level, reality is created from a myriad of ghostly possibilities by our own act of observation. Events apparently happen without cause. Unpredictability and uncertainty appear intrinsic to the universe at the deepest levels. Our language and logic seem inadequate to describe how something could appear in one place as a particle or in two places at the same time as a wave—all of which we are able to determine at some point in the future. Or how two things separated by an incalculable distance could instantly affect one another. In short, the paradigm of classical science mentioned at the outset of this article has been completely destroyed so far as the subatomic world is concerned. And common sense has not fared much better.
But what does it mean to us? Carl Henry states the orthodox view in God, Revelation and Authority: “Christianity affirms that this world is a rational universe, that it is God’s world; know-ability of the universe is grounded in God’s creation of man as a rational creature whose forms of thought correspond to the laws of logic subsisting in the mind of God, as well as to the rational character of the world as God’s creation.” Quantum theory, it would seem, contradicts Carl Henry and the rest of us.
By now it should be clear that we are in deep theological waters. The situation is reminiscent of that of thirteenth-century Christendom. Then the philosophy of Aristotle swept over the Western world. Churchmen believed that Christianity was being challenged by the greatest intellectual threat in its history. Remember the remark of our dinner companion, the theologian, that quantum theory—if true—could shatter his faith. The comparison is not a superficial one. The same basic issues were involved in the thirteenth century as now. We are talking about faith, reason, and reality. Today the argument takes the form of propositional versus nonpropositional theology. The new physics has added a fresh wrinkle in this time-honored debate, however. Whatever differences Christianity and science have had in the past, each has implicitly believed in the fundamental intelligibility of the physical universe. Now it appears that science is abandoning that field, leaving Christianity standing alone.
But not quite. Already certain physicists are seeking new images and concepts that tie things together as Einstein so passionately desired. But these new ideas are a far cry from his. Einstein’s common-sense approach is gone forever, but his vision lives on. These ideas involve notions of deeper, more intricate orders than have been hitherto conceived. The particle-wave duality may not be two separate complementary aspects of a subatomic entity but projections from a single unified phenomenon residing in a higher dimensional region. Everything at this point is pure speculation, of course. But that is how things get going. The centuries-old classical paradigm of science has been replaced by the quantum paradigm. Already, after only 60 years, there are tell-tale signs that the quantum paradigm will also be replaced.
Effects On Theology
But, says our theologian friend, what about the present claims of quantum theory? We have the claims of quantum theory on one hand and those of orthodox theology on the other. If God’s creation is irrational and unknowable, mightn’t it be true that there is no common ground based on reason between man and God? If God’s creation is unpredictable and capricious, might not the same hold true for God himself?
The answer is a flat out “no” on all counts. And all we need to support that claim is a medium-sized shelf of obtuse and learned books. So we will resort to telling a story, a true one.
Remember those ghostly particles we were talking about? This is not the first time that ghosts have stalked the annals of science. The redoubtable Irish bishop George Berkeley (1685–1753) attacked the foundations of the new math of his time: calculus. Newton had developed calculus in order to launch almost single-handedly the “new physics” of the seventeenth century. One of the central notions of calculus was the “infinitesimal.” Infinitesimals were thought of as infinitely small but non-zero quantities—things that shrink away to nothing but are still there. Berkeley gleefully pointed out the logical inconsistency of such dubious entities. “And what are these same evanescent increments? They are neither finite quantities, nor quantities infinitely small, nor yet nothing. May we not call them ghosts of departed quantities …?”
Anyone who is familiar with calculus can appreciate how apt this description is. And Berkeley had the mathematicians and physicists cornered—a strange reversal in the science-religion debate. How could something be and not be? No one could refute him. Berkeley’s point was that if religious skeptics can swallow this ghost business then they should have no trouble accepting religious mysteries and points of faith. But the scientists had faith that somehow what they were doing was right, and they proceeded to revolutionize the world—in the name of reason.
Two hundred years passed before the logical inconsistencies in calculus were resolved by reconstructing its foundations using a completely different approach, and infinitesimals were discarded as outdated fictions. Then in 1960, another 100 years after their demise, infinitesimals were resurrected. Their apparent logical inconsistencies were resolved by the creation of new mathematical entities called “hyper-real numbers.” These new numbers could be called “higher dimensional” numbers, figuratively speaking, in that they not only resolve all the old problems but include as a subset all the numbers with which we are familiar. Such a development had to wait on a better understanding of the nature of mathematical systems and the construction in the 1950s of a branch of mathematical logic called “model theory.” It turned out that Berkeley was right, and so were the mathematicians and physicists.
The problem is one of imagery and language. The physicists and mathematicians visualized the infinitesimal as something like a snowball that melts away to nothing and yet is still there. This metaphorical transference led them to a head-on collision course with the law of noncontradiction, the most basic principle of logic. But the modern concept of the infinitesmal is not at all illogical. It just took 300 years to shake off the snowball metaphor. The resulting image, if it can be called that at all, is far more abstract and cannot be likened to anything in our everyday experience. Yet even today, physicists find it useful to think of infinitesmals as something like snowballs, and their mathematician friends love to ridicule them for it. But it is all in good fun since everybody knows the true situation.
The moral to the story is clear. If we try to carry the language and imagery that have grown out of our everyday visible world to the subatomic world, we are in trouble. We peer down into the subatomic world and see little dots on photosensitive plates. Our use of language compels us to think of electrons as tiny little billiard balls. But they are not. They do not act like billiard balls at all. If we apply the logic of billiard ball concepts, we can expect paradoxical results in the subatomic world. But reason itself is not under attack. What we need are new ideas and new images.
Appreciating Creation As It Is
And what we need in the meantime are some good dinner conversation slogans. Just file these away and wait for your chance to trot them out. What you are supposed to do is lean forward, knit your brows, and reel these off in one breath: Complementary doesn’t mean contradictory, unbelievable doesn’t mean irrational, unknown doesn’t mean unknowable, and to say that language is inaccurate doesn’t mean that it is altogether inadequate. (Sorry that last one doesn’t have quite the ring as the others. You might have to practice it out loud a few times to get the right effect.) All those explicit and implicit double negatives ought to make a big impression. But if you are pressed on the matter, counter with an offer to pick up the check.
We did not explain away all the problems that quantum theory raises. Our theologian friend knew all along that we wouldn’t. He is a great deal smarter than we have perhaps led you to believe, and his faith is not about to come apart. But what we hoped to have shown is that quantum theory does not weaken the position of orthodox theology. Indeed, far from shattering our faith, quantum theory can inject a dose of good old-fashioned awe into our normally complacent view of God’s creation. The world is much, much stranger and more mysterious than our grandfathers thought. We might do well to realize anew how majestic God is.
