Quantum Physics and Theology: An Unexpected Kinship
By John Polkinghorne (Part 1)
I’m going to review the book, “Quantum Physics and Theology: An Unexpected Kinship” by John Polkinghorne. Polkinghorne was professor of mathematical physics at the University of Cambridge from 1968 to 1979, when he resigned his chair to study for the priesthood, becoming an ordained Anglican priest in 1982. He served as the president of Queens’ College, Cambridge from 1988 until 1996. I reviewed, “Testing Scripture: A Scientist Explores the Bible” by Polkinghorne for Imonk, which you can find here. He worked on theories about elementary particles, played a role in the discovery of the quark, and researched the analytic and high-energy properties of Feynman integrals and the foundations of S-Matrix Theory. I share Polkinghorne’s viewpoint on the congruence of science and Christianity, which he calls critical realism. Polkinghorne and I believe that science and religion address aspects of the same reality. I frequently quote the aphorism, “All Truth is God’s Truth”, which sums it up quite nicely for me. As John says in the preface:
…to present this book, which is an essay with a single controlling theme, namely that, contrary to an all-too-common misjudgment, it is not the case that theology and science are chalk and cheese, a matter of airy opinion compared with solid fact. Nor does the essential difference between them lie in a contrast between belief on the basis to submission to an unquestionable authority and belief based on grounds of rational motivation. Quite the contrary, for there are significant degrees of cousinly relationship between the ways in which science and theology conduct their truth-seeking enquiries into the nature of reality…
Plus, I thought we could dip our toes into, and dabble in some quantum physics (of which I am stricly a layman, so feel free to correct any mistakes I make). The structure of the book is John illustrating some point made first by an example drawn from physics, and then by an analogous example drawn from theology.
Chapter 1 is entitled, “The Search for Truth”. Polkinghorne asserts that the pursuit of truthful knowledge is a widely accepted goal in the scientific community. Scientists believe that they gain an understanding of the physical world that will prove to be reliable and persuasively insightful. He realizes that the idea that nuclear matter is composed of quarks and gluons is unlikely to be the very last word in fundamental physics—maybe the speculations of the string theorists will prove to be correct, and the quarks, currently treated as basic constituents, will themselves turn out eventually to be manifestations of the properties of very small loops vibrating in an extended multidimensional spacetime. But for now, quark theory is a reliable picture of the behavior of matter encountered on a certain scale of detailed structure. Polkinghorne calls this picture or account verisimultudinous, which he defines as “truth, never grasped totally and exhaustively, but that can be approximated to in an intellectually satisfying manner even if it does not qualify to be described in an absolute senses as ‘complete'”.
He asserts theologians entertain similar aspirations. He says:
While the infinite reality of God will always elude being confined within the finite limits of human reason, theologians believe that the divine nature has been revealed to us in manners accessible to human understanding, so that these self-manifestations of deity provide a reliable guide to the Creator’s relationship with creatures and to God’s intentions for ultimate human fulfilment.
Nevertheless, Polkinghorne outlines four distinctive features of religious experience that express the contrast between science and theology.
- First the development of theological understanding is a more complex process than is the case for scientific understanding. Science achieves cumulative success, accessible in the present without a continual need to return to the past. But theology has the role of tradition as the indispensable resource for access to a reservoir of attained understanding which has continuing significance. Theologians need to be in continuing active dialogue with the generations that precede it, lest the specific insights that they attained should be lost.
- Second, the initiative for placing the physical world under scrutiny lies with the scientists. In the case of divine reality, God can take the initiative in conveying truth, and at least in some cases, if God doesn’t take the initiative then the truth is never gained.
- Third, science can succeed in eliciting virtually universal acceptance for its well-winnowed conclusions—the phenomena of “settled science” that, while being modified by new data, is not likely to be completely overturned. The theological scene, in contrast, is significantly fragmented.
- The fourth point of difference between theology and science relates to the consequences flowing from the embrace of belief. My belief in elementary particles does not affect my life in any significant way outside the laboratory. In contrast, my belief that Jesus Christ is the incarnate Son of God has, or should have, consequences for all aspects of my life.
John’s first example drawn from physics is the dual nature of light. Is the fundamental nature of radiation and matter described better by a wave or a particle? Or do we need both? (Much of my discussion of quantum theory will be drawn from “Introducing Quantum Theory: A Graphic Guide”.
Isaac Newton and Dutch physicist Christiaan Huygens argued about the nature of light back in the 1600’s. Newton said light was best described by waves while Huygens said particles were a better description. Think of a pulse transmitted along a string—this is the simplest type of wave.
The double slit experiment was first reported by Thomas Young in 1801. His demonstration of interference by alternate bright and dark lines was taken to be clear evidence for the wave nature of light. See for yourself in Young’s original sketch reproduced here:
By the time of Maxwell’s Electromagnetic Theory of 1865, the 19th Century physicists were satisfied that light consisted of waves.
But as the 20th Century dawned, a young Albert Einstein re-introduced the idea of corpuscles to explain the photoelectric effect (the observation that many metals emit electrons when light shines upon them). In 1909 he demonstrated that two distinct terms appeared in Planck’s equations describing black-body radiation [a mathematical relationship formulated in 1900 by German physicist Max Planck to explain the spectral-energy distribution of radiation emitted by a blackbody (a hypothetical body that completely absorbs all radiant energy falling upon it, reaches some equilibrium temperature, and then reemits that energy as quickly as it absorbs it]. Those two distinct terms indicated a duality in the nature of light. In 1924, Louis de Broglie demonstrated the astounding idea that particles could exhibit wave properties.
In just a few years, all of de Broglie’s ideas were confirmed by experiment. During the twelve month period from June 1925 to June 1926, three distinct and independent developments of a complete quantum theory were published—and shown to be equivalent.
Modern Quantum Theory was born.
So Polkinghorne sets out five points of “cousinly relationship” or analogy between the two seminal developments: the exploration of quantum insight, and the exploration of Christological insight. The first is (1) Moments of enforced radical revision. The crisis in physics that led to quantum theory began with the great perplexity at the dual nature of light, as I tried to outline above.
Polkinghorne notes that in the New Testament, the writers knew that when they referred to Jesus they were speaking about someone who lived a human life in Palestine within living memory. Yet they also found that when they spoke about their experiences of the risen Christ, they were driven to use divine-sounding language about him. For example, Jesus is repeatedly given the title “Lord”, despite the fact that monotheistic Jews associated this title with the one true God of Israel, using it as a substitute for the unutterable divine name in the reading of scripture. How could this possibly make sense? After all Jesus was crucified and Jews saw this form of execution as a sign of divine rejection (Deut. 21:23).
(2) A period of unresolved confusion. From 1900 to 1925, physicists had to live with the paradox of wave/particle duality unresolved. Niels Bohr and others tried various techniques for making the best of a baffling situation, but these expedients were no more than patches clapped on to the broken edifice of Newtonian physics. In the New Testament, the tension between human and divine language used about Jesus is simply there, without any systematic theological attempts being made to resolve the matter. The authenticity and power of what God had done in Christ was, to early Christians, so overwhelming sufficient to sustain them they didn’t need an overarching theoretical account. Yet, Polkinghorne says, the intellectual instability taken by the New Testament writers couldn’t be ignored indefinitely.
(3) New Synthesis and Understanding. In the case of physics, new insight came with startling suddenness through the discoveries of Werner Heisenberg and Erwin Schrodinger in 1925-1926. John says:
Paul Dirac emphasized that the formal basis of quantum theory lay in what he called the superposition principle. This asserts that there are quantum states that are formed by adding together in a mathematically well-defined way, physical possibilities that Newtonian physics and commonsense would hold to be absolutely incapable of mixing with each other. For example, an electron can be in a state that is a mixture of “here” and “there”, a combination that reflects the fuzzy unpicturability of the quantum world and which also leads to a probabilistic interpretation, since a 50-50 mixture of these possibilities is found to imply that, if a number of measurements of positions are actually on electrons in this state, half the time the electron will be found “here” and half the time “there”. This counterintuitive principle just had to be accepted as an article of quantum faith.
The quest for a deeper understanding of the fundamental phenomena recorded in the New Testament, eventually led the Church to a trinitarian understanding of the nature of God through the Church Councils from Nicaea, 325, to Chalcedon, 451. John quotes Richard Feynman:
Because atomic behavior is so unlike ordinary experience, it is very difficult to get used to, and it appears peculiar and mysterious to everyone… we shall tackle immediately the basic element of the mysterious behavior in its most strange form. We choose to examine a phenomenon which is impossible, absolutely impossible, to explain in any classical way, and which has in it the heart of quantum mechanics. In reality, it contains the only mystery. We cannot make the mystery go away by “explaining” how it works. We will just tell you how it works.
The Fathers of the Church, who at the Councils had formulated fundamental Christian insights, would, I believe, have been quite content to echo Feynman’s words, “We will just tell you how it works”.
(4) Continued wrestling with unsolved problems. Even in science, total success is often elusive. Quantum theory has proved to be extremely impressive in agreement with experimental results. However, how does it come about that a particular result is obtained on a particular occasion of measurement, so that the electron is found to be “here” this time rather than “there”? It is embarrassing for a physicist to admit that currently there is no wholly satisfactory or universally accepted answer to that entirely reasonable question.
Theology also has to be content with a partial degree of understanding. Trinitarian terminology, for example in its attempt to discriminate the divine Persons in terms of a distinction between begetting and procession, can sometime seem to be involved in trying to speak what is ineffable. The definitions of Chalcedon; in Christ there are two natures—“without confusion, without change, without division, without separation” are more of a statement of boundaries of the enclosure within which orthodox Christian thinking is contained, but it does not formulate the precise form that thinking has to take. In fact, further Christological arguments, both within and without the Chalcedon bounds has continued down the centuries since 451.
(5) Deeper implication. A persuasive argument for a theory lies in offering further successful explanations concerning phenomena not explicitly originally considered. An example would be the EPR effect or quantum entanglement; entangled particles remain connected so that actions performed on one affect the other, even when separated by great distances, which is supposedly contradicted by Einstein’s limit of anything moving faster than the speed of light, but has been experimentally verified.
Incarnational theology has offered some analogous degree of new insight. Polkinghorne cites Jurgen Moltmann and the concept of divine participation in creaturely suffering through the cross of Christ. Moltmann emphasizes that the Christian God is the crucified God, the One who is not just a compassionate spectator of the suffering of His creatures, but a fellow-sharer in the travail of creation. The concept of a suffering God affords theology some help as it wrestles with its most difficult problem, the evil and suffering present in this world.
Polkinghorne hopes this book will encourage those of a scientific cast of mind to take theological discussion more seriously, and it will offer theologians the worked example common to science of the “bottom-up thinking” in moving from experience to understanding. It’s a daring, bold move, even if some might find it trite; I find it exiting and I like it.