G Carroll Strait. The World and I. Volume 16, Issue 1, January 2001.
The Bohr-Einstein extended debate about the interpretation of atomic and subatomic physics was a pivotal event whose outcome has shifted the foundations of Western culture toward Eastern and New Age religions.
When Albert Einstein said “God does not play dice” and Niels Bohr replied “Einstein, stop telling God what to do,” neither was speaking of a God of purpose, values, love, or authority. And they certainly were not speaking of a God involved with the unfolding of human, biological, or even geological history. Nonetheless, in this interchange, one man stood closer to the God of such traits and the other closer to a radically different kind of god.
Both were Nobel Prize-winning physicists: Einstein won the 1921 prize for his 1905 paper explaining the photoelectric effect, a phenomenon in which some materials exposed to ultraviolet light eject electrons in ways unexplainable by classical physics. Bohr, eight years younger than Einstein, won the 1922 prize for his work in 1911-13. In that period, he developed the first effective working model of the hydrogen atom, with its dense nucleus surrounded by a single electron.
Although Einstein and Bohr at times may have referred to God, both would have been considered essentially a-religious by Einstein’s hereditary Judaism and Bohr’s hereditary Lutheranism. The reference to God not playing dice occurred in the context of debate about the foundations of physics. Einstein was defending a position of realism, that there must be an underlying world in which cause-and effect relations hold, even if we cannot perceive it with our instruments.
Bohr, rebutting whatever objection Einstein raised, was promoting the view that we have no grounds or legitimacy to assume anything about a possible world beyond our instrumental reports. Rather, we must reconcile ourselves to the fact that we ourselves cannot imagine, and our instruments cannot show us, a unitary picture of the atomic and subatomic worlds. Depending on our choice of instruments we may perceive light as either a particle or a wave, but never both at once. Furthermore, even if we choose to look for a particle we cannot with ultimate precision measure both its position and momentum. We are then left with our mathematics as a predictive guide and source of probabilistic descriptions.
Following Bohr’s lead, quantum physicists have broadened and deepened the mathematics of quantum theory so profoundly that it has become the most widely successful theory of physics ever. Most quantum physicists pay little daily attention to the perplexing philosophical issues raised by Bohr’s “Copenhagen interpretation” of the theory that so bothered Einstein. Beyond the walls of physics labs and classrooms, however, the Copenhagen interpretation has exerted tremendous influence on popular culture. Before examining that influence, let’s delve a bit deeper into the specifics of the Bohr-Einstein debate.
The quantum arena in which Bohr and Einstein debated was at the then-far extremes of scientific investigation-at the level of atoms, which are so tiny that a baseball would need to be enlarged to roughly the size of Earth if its constituent atoms were to be made as big as baseballs. If the atoms composing Einstein and Bohr were enlarged to baseball size, each scientist would be big enough to throw an “Earthball.” But how could those “planet pitchers” probe the baseball-sized atoms? How could they touch or even look at atoms? Whatever instruments they might use to probe the atoms’ Lilliputian world, how could they understand their instrument reports?
In their Nobel Prize-winning researches, both Einstein and Bohr offered profound new insights into the atomic world as it was reported to human senses by the day’s advanced instruments and experimental techniques. Both relied on the radical new notion that energy at the atomic and subatomic levels is intrinsically quantized, meaning that it comes in discrete units. Scientists needed this quantum hypothesis to make sense of the experimental data.
In the course of trying to understand what was happening inside the atom, Einstein and Bohr found themselves on opposite sides of a debate about the nature of reality itself. The debate began in earnest in 1927 and continued intermittently until Einstein’s death in 1955. During that time, the mainstream of physics was won over to Bohr’s Copenhagen interpretation, and Einstein was left as the odd man out, defending an apparently outmoded worldview.
In defense of realism
What does the debate mean for religion and science? The profound importance is that in the debate Einstein was the conservative realist, wanting to hold on to a subatomic ground of the universe that is there regardless of whether any human being is looking at that ground. The world we experience is just independently there. We can in principle, if not yet in fact, probe it in a cause-and-effect, deterministic manner.
Such a realistically grounded world is presumed today by multitudes of Western-trained people around the globe, including most of the nonmystical members of the Western, monotheistic religions. In defending a realistic basement foundation of the universe, therefore, Einstein may unwittingly have been one of the great twentieth-century defenders of Western monotheism. Although his special and general theories of relativity eliminated the notion of simultaneity at a distance, merged space with time, and made energy and matter interconvertible, Einstein still assumed that his relativity theories described a continuously existing, causally connected world.
A different world
Bohr’s Copenhagen interpretation, or complementarity model, presents a different reality” from the one defended by Einstein. Taking complementarity seriously, Bohr suggests—no, he demands—that the message from the atomic and subatomic worlds is that we cannot say unambiguously what quantum reality is: neither conceptually, nor mathematically, nor in any other way. Only for the moments in which our scientific instruments interact with the quantum world can we describe the aspect of that world our instruments touch. And we have to choose what our instruments will look for: either a wave or a particle but never both at once. Furthermore, if we choose to look at a particle, we must reconcile ourselves to there being an intrinsic quantum of uncertainty in the precision with which we can simultaneously measure both its momentum and position.
Just as Einstein had earlier relinquished the absolute categories of space and time, Bohr now relinquished Einstein’s cherfished causality, replacing it, if at all, with a probabilistic causality. (Recall Einstein’s comment about God not playing dice.) Furthermore, Bohr relinquished the traditional distinction between the observing subject and the independently existing object, replacing it with the essential unity of subject and object at the quantum level.
Quantum experiments clearly tell us what Einstein refused to accept even to his death: that any notion of deep, continuously existing, independent reality undergirding the world we experience is an illusion, a faulty a priori conceptual category. While Bohr tended to skirt around absolute pronouncements, one of his chief collaborators in developing the Copenhagen interpretation, Werner Heisenberg, was not so circumspect. Heisenberg said, “If we want to describe what happens in an atomic event, we have to realize that the word happens can only apply to the observation, not to the state of affairs between observations.”
In terms of today’s instruments and conceptual models, electrons perform as particles in flowing as electric current through a lightbulb filament, but they act as a wave when they are used for taking pictures in an electron microscope. In human sight, light behaves like a wave when it travels from the printed page through the pupil of the eye and onto the retina. Yet when that same light triggers a rod or cone in the retina to send a signal toward the optic nerve, it behaves as a particle.
If scientists get extremely precise and try to nail down exactly what an electron or a light beam is, they find they cannot resolve the paradox.
In debating the nature of the quantum world, Bohr and Einstein scaled heights attempted by few others. Their debate at the Solvay conference of theoretical physicists in Brussels in 1927 was described in a letter by one of their colleagues, the Dutch physicist Paul Ehrenfeld.
It was delightful for me to be present during the conversations between Bohr and Einstein. Like a game of chess, Einstein all the time with new examples. In a certain sense a kind of Perpetuum Mobile of the second kind to break the uncertainty relation. Bohr from out of philosophical smoke clouds constantly searching for the tools to crush one example after the other. Einstein like a jack-in-the-box: jumping out fresh every morning. Oh, that was priceless. But I am almost without reservation pro Bohr and contra Einstein. His attitude to Bohr is now exactly like the attitude of the defenders of absolute simultaneity towards him.
Here was Einstein, the champion of the old guard, attacking the champion of the quantum iconoclasts, whose ideas were already winning over the mainstream of physics. Ironically, Bohr was only advancing the conceptual radicalism initiated earlier by Einstein. By 1927, working closely with a group of brilliant collaborators centered on his Institute for Theoretical Physics in Copenhagen, Bohr had moved beyond Einstein’s realistic worldview.
Complementarity was his new guide. For Bohr, complementarity was the tool by which humans gain deeper understanding when presented with two antithetical concepts or properties describing the same entity.
- If our instruments tell us that we can “see” an electron as either a wave or a particle depending on how we look at it, then let us not see contradiction but rather complementarity arising at the limits of our perception.
- If we cannot with quantum precision measure both the momentum and position of an electron, let us not see threat to a necessarily causal world but rather follow this lead into a deeper appreciation of the nature of things.
- If we cannot at the quantum level distinguish between the observing subject and the observed object, then let us not mourn the loss of the external world. Rather let us celebrate the gain of deeper truth in knowing the complementarity between the two perspectives: seeing the observing subject and the observed object as separate and seeing no clear boundaries by which to define observing subject and observed object.
As physics became securely grounded in his theory, Bohr went on to apply his complementarity philosophy to such diverse fields as psychology and biology. Yet Einstein refused to surrender.
Over the years, the pattern remained substantially the one set at the 1927 Solvay Conference. Einstein, the historical grand master, offered evermore ingenious thought tests of the quantum theory, setting the stage for Bohr, the quantum master, to further strengthen quantum theory’s claim to validity as it overcame the grand master’s tests.
Perhaps the most celebrated and enduring of the tests Einstein proposed was an experiment described in a paper written jointly with Boris Podolsky and Robert Rosen. (For posterity, the name has become the EPR experiment.) The paper presented an experiment that followed quantum theory precisely, yet the theory itself predicts a “non-sensical” outcome of the experiment: a “spooky” instant interaction between two originally linked particles even if they were widely separate. Since instant interaction would require communication at speeds faster than the speed of light, argued EPR, and Einstein’s special theory of relativity specifically rules out such signaling, quantum theory itself must be flawed.
After analyzing all possible angles to the EPR paper, Bohr certified that both the experiment and the outcome predicted in the paper were fully consistent with quantum theory. Not to worry, he asserted. From the quantum view, the two particles, once linked or entangled, can be considered part of one quantum system. Their distinction as two apparently separate particles arises only because we have elected to measure out two independent particles. Instant signaling is natural within a single quantum system. It is only our corrupted categories that cause us to recoil from the apparent paradox of instant signaling.
EPR presented a great test for experimental physicists. When technology and expertise finally permitted the test to be made in 1983 by a French team led by physicist Alain Aspect, the results confirmed the validity of the EPR prediction. In the quantum world, particles could indeed carry on some kind of mysterious, instantaneous communication. Quantum theory was vindicated again, and the real world defended by Einstein was deviant from the experimental data.
The positive EPR experiment holds profound implications not only for physics but for the interactions of science and religion. Such implications become more apparent when we note the rise of diffuse New Age spirituality movements in the latter decades of the twentieth century. These movements are often deliberately not associated with any of the established religions. Surprisingly to the uninitiated, quantum theory, the positive EPR experiment, and a wealth of related derivative writings have been incorporated into diverse manifestations of New Age spirituality.
In this way, quantum theory and its progeny support people in pursuing their own spirituality apart from any established religion, especially apart from the monotheistic trio of Judaism, Christianity, and Islam.
The meeting of East and West If quantum theory had remained an esoteric field of study by physicists, it would offer little challenge to Western monotheism. Instead, quantum theory has “escaped” from the physics world into the world of popular culture, where it has emerged as a potent element affecting the mix of religious/philosophical systems now circulating at the global level.
While professional physicists as well as professionals in both the Eastern and Western religions may take issue with popular interpretations of quantum theory, a significant public has chosen to disregard objections from the professionals. Two early books aiming to move insights of quantum theory into the popular culture were The Tao of Physics by Fritjof Capra, published in 1975, and The Dancing Wu Li Masters: An Overview of the New Physics (1979), by Gary Zukav.
Zukav’s book, a best-seller, is an insightful telling of the origins of quantum theory. The first chapter, “Einstein Doesn’t Like It,” draws out clearly the radical disjunct imposed on classical physics (as culminated through Einstein) by the emergent quantum theory, especially the Copenhagen interpretation. Yet Zukav carries the story further. He identifies the Copenhagen interpretation as an opening for relieving one of Western intellectuals’ sources of angst, the unrequited dominance of the rational over the irrational: “The Copenhagen Interpretation began a monumental reunion which was all but unnoticed at the time. The rational part of our psyche, typified by science, began to merge again with that other part of us which we had ignored since the 1700s, our irrational side.”
He goes further, claiming that the emergence of the Copenhagen interpretation is a sort of Waterloo event for overarching rational thought: “The extraordinary importance of the Copenhagen Interpretation lies in the fact that for the first time, scientists attempting to formulate a consistent physics were forced by their own findings to acknowledge that a complete understanding of reality lies beyond the capabilities of rational thought.”
Like Zukav, Capra endeavors to explain modern physics to the nonphysicist, but he is much more explicit in drawing parallels between modern physics and Eastern religions. Thus he explains at the beginning of his book, “The following chapters . . are intended to suggest that Eastern thought, and more generally, mystical thought provide a consistent and relevant philosophical background to the theories of contemporary science; a conception of the world in which man’s scientific discoveries can be in perfect harmony with his spiritual beliefs and religious beliefs.”
Disregarding the professionals
Regardless of what the professionals may say, Zukav and Capra have touched a deep, responsive chord in a spiritually thirsty people. That chord sounds when the authors identify modern physics (including both quantum theory and relativity theory) as pointing toward worldviews and mystical states of union associated primarily with the Eastern religions. Zukav wrote, “According to mystics from around the world, each moment of enlightenment (grace/insight/samadhi/satori) reveals that everything—all the separate parts of the universe—are manifestations of the same whole. There is only one reality, and it is whole and one.”
Similarly, Capra stated, “The further we penetrate into the submicroscopic world, the more we shall realize how the modern physicist, like the Eastern mystic, has come to see the world as a system of inseparable, interacting and ever moving parts with man being an integral part of the system.”
The quantum issues debated by Bohr and Einstein paved the way for a great flowering of speculation about the interconnectedness of all things. While the Copenhagen interpretation marked the first generation of quantum theory and speculation, the EPR experiment opened the way to a second generation. Together these two generations support speculations like those of Zukav and Capra. They have also cohered around the concept of a holographic universe, as first formulated by physicist David Bohm and neuroscientist Karl Pribram.
As the spiritual books and groups claiming a place for quantum theory and modern physics within their worldview proliferate, the nonmystical mainstreams of the Western monotheisms are increasingly affected. The wave of interest has surely not crested. How to Know God, “poet-prophet of alternative medicine” Deepak Chopra’s newest book, is closely integrated with ideas from quantum theory.
Chopra on miracle workers: “As we know from our quantum model, any object can be reduced to packets of energy … The medicine man turns a mental image into physical reality-in fact, this is what all miracle workers do. At the quantum level they ‘see’ a new result, and in that vision the new result emerges.”
Chopra on miracles: “Nothing is more fascinating than to watch science blurring its edges into spirit. There are no easier words for the transition zone [between God and the material world] than ‘quantum’ and no easier words for God than virtual.’ To track down a miracle one must go into these domains. Miracles indicate that reality doesn’t begin and end at the material level.”
Quantum spirituality
Sampling briefly from the quantum cornucopia showering upon society far beyond the world of science, we see a spiritually vital message being propagated through the print media quite independent of support from any particular religious denomination. The message ties in not only with Eastern religions but with New Age spirituality of many sorts, much of alternative medicine, and even more traditional mystical and spiritualist groups.
Out of this amalgam, several Eastern religion-derived themes have been integrated with quantum theory, yielding a kind of quantum spirituality not easily wedded to the nonmystical mainstreams of Western monotheism. The contrast is sharpened by comparing several key features of Christianity with similar features of quantum spirituality.
Some 70-plus years after the momentous 1927 Solvay conference, Bohr’s quantum baby has burrowed into the deepest realms of human thought on spiritual matters, and the tunnel leads east. In the meantime, a small remnant of physicists, sharing Einstein’s philosophical commitment to an externally independent reality, continue to search for ways to resurrect the externally real world. Should Einstein’s heirs succeed, they would lend unintended supported to Western monotheism. Until, if ever, they do, the signs point clearly toward further expansion of quantum spirituality at the expense of the Western monotheisms.