Collective Electrodynamics: Quantum Foundations of Electromagnetism
by Carver A. Mead
Cambridge, Massachusetts/London, England: MIT Press, 2000
(135 pages; $30.00, hardcover)
reviewed by David Haddon
The last seven decades ofthe twentieth century will be characterized in history as the dark ages of theoretical physics.” With these opening words of his MIT monograph Collective Electrodynamics, California Institute of Technology professor Carver Mead throws down the gauntlet to loyalists of the Copenhagen School of quantum physics of Niels Bohr and Werner Heisenberg. Mead, as one of the late twentieth century’s leading experimental physicists, bids to revitalize theoretical physics for the twenty-first century while incidentally purging it of the “formalism” and “irrationalism” of the Copenhagen School.
Sir Joseph John Thomson cracked open the door to the subatomic world when he discovered the electron in 1897, but this realm lacked a distinct name until after Max Planck reported in 1900 that, at the atomic level, matter heated until it glowed radiated energy in steps instead of continuously along a smooth curve as expected. He called the smallest step the quantum of energy, and because this constant proved to be so significant, the term quantum came to be applied to subatomic or quantum physics.
But it was not until the 1910s that the young Danish physicist Niels Bohr brilliantly used Planck’s quantum of energy in working out the “ladder” of energy levels of the one negatively charged electron that balances the positively charged proton of the hydrogen atom. He found that whole-number multiples of the quantum of energy matched the different energy levels of the electron in the hydrogen atom. When an electron fell to a lower energy level, the atom radiated a whole number of energy quanta as light, and when an atom absorbed a certain number of light quanta, an electron would jump to a higher level.
This stepped transfer of energy, along with the paradoxical results of experiments in which light and electrons sometimes did and sometimes did not form wave interference patterns, made it appear that light itself, as well as the electrons, sometimes acted like waves and sometimes like particles.1 In 1925 a young German associate of Bohr, Werner Heisenberg, worked out a statistical equation that predicted the wavelengths of the radiation from the atoms of different elements as they are observed in the light from the sun and stars. Using the quantum of energy, Heisenberg developed another equation that represented the limitation of precision (uncertainty) in simultaneously determining the momentum and the location of an electron.
Had Bohr and Heisenberg rested on these and their many other laurels, their legacy would not be so sharply challenged by scientists such as Mead today. But Bohr and the likeminded scientists associated with his lab in Copenhagen declared that the search for an understanding of the nature of matter had come to its limit with the observations suggesting that both light and matter (e.g., electrons) sometimes acted like waves and sometimes like particles. Bohr said that these two contradictory views of light and matter were complementary rather than mutually exclusive. He speculated that, at the atomic level, matter doesn’t have a definite existence as either a wave or a particle, but has only an Aristotelian potential existence. Heisenberg promoted his uncertainty equation into the Uncertainty Principle and denied not only the possibility of knowing the path of an electron between observations of it, but even that it had a definite path to know. In Physics and Philosophy: The Revolution in Modern Science,2 he frankly admitted that the logical law of noncontradiction had to be set aside in his statistical account of atomic entities.
The Triumph of the Copenhagen School
Albert Einstein challenged Heisenberg and Bohr’s interpretation as failing to provide a description of what happens to the atoms and electrons, but Bohr twice defeated Einstein in the eyes of the leading physicists of the era in public debate. Since then, Bohr’s Copenhagen School has dominated atomic physics. But with the dawn of the twenty-first century, Mead has renewed Einstein’s challenge, citing extensive experimental evidence of the exclusively wave nature of matter. Mead’s simple but revolutionary idea is that matter is not made of particles at all; it is entirely made of waves. This means that, contra Bohr, quantum physical reality is not an unintelligible contradiction but has a perfectly logical structure. As Einstein put it, “The Lord is subtle, but he is not malicious.”
Mead contends that Bohr’s contradictory, statistical approach to quantum physics arose from (1) his failure to break completely with a Newtonian model of the atom as a nucleus surrounded by point-particles like planets circling the sun, and (2) the crudity of the experimental apparatus available in the 1920s. Bohr clung to point-particles by introducing the contradictory duality of the Principle of Complementarity: The parts of the atom had to be viewed as both particles and waves and, hence, as neither one nor the other. Nevertheless, Bohr and Heisenberg’s statistical approach was effective enough to make many important predictions, and these successes helped make the Copenhagen interpretation of quantum physics plausible despite its abandonment of basic logic.
Even granting that cloud chambers, an apparatus used to observe the track of charged particles, are a relatively crude device, Mead may be unduly charitable in citing the experimental apparatus of the day as mitigating Bohr and Heisenberg’s quantum misinterpretations. Even cloud-chamber evidence suggests that an electron has a definite and continuous path in spacetime. Indeed, the direction of the curved path of the electron in an electric field depends on the strength and polarity of the field and can be predicted. In the face of this kind of evidence, Heisenberg nevertheless declared that his Uncertainty Principle meant that an electron doesn’t have a continuous path. In Physics and Beyond: Encounters and Conversations,3 Heisenberg writes of cloud-chamber observations that “perhaps what we really observed was something much less [than the path of an electron]. Perhaps we merely saw a series of discrete and ill-defined spots through which the electron had passed.” This seems to be a classic example of imposing a preconceived hypothesis on the recalcitrant observations.
Buoyed by their successes in predicting the spectra of radiation from hydrogen and other atoms, then, the Copenhagen scientists came to believe that their “mathematical formalism” defined both the ultimate nature of matter and the limits of knowledge about it (its epistemology). Bohr’s skills as a debater in his two encounters with the skeptical Einstein in 1927 and 1933 further strengthened the claim that microscopic realities could only be described by mathematical probabilities. The 1932 award of the Nobel Prize in physics to Heisenberg for the “creation of quantum mechanics” added yet more momentum. Thus, the Copenhagen School succeeded in imposing its new orthodoxy as the final form of atomic physics.
In Physics and Philosophy, Heisenberg describes his initial revulsion against accepting the contradictory wave-particle duality. After one late-night discussion with Bohr that “ended almost in despair,” he tells of how “I repeated to myself again and again the question: Can nature possibly be as absurd as it seemed to us in these atomic experiments?” (p. 42). But instead of questioning the contradictory wave-particle duality or at least suspending judgment on it, Heisenberg questioned—and finally abandoned—the rationality of nature. By contrast, early modern scientists had confidently affirmed the rationality of nature because they believed nature to be the work of a rational Creator. But later scientists, lacking the compass of revelation, quickly lost their way in the dark woods of the microcosm.
Bohr and Heisenberg both had a philosophical turn of mind and were not content with their dominant position as pioneers in quantum physics, the new frontier of science. They imposed a new paradigm on science itself. For over 300 years, mathematics had been fruitfully used to quantify, elucidate, and refute models that represented the underlying physical reality. But the Copenhagen School’s insistence on the wave-particle duality (complementarity) and on the discontinuity of the path of an electron (uncertainty) rendered a physical model of what their statistical equations described impossible. Instead of recognizing the situation to be anomalous and temporary, they codified it as the final, definitive state of physics. Since their equations did make useful predictions about quantum phenomena, the Copenhagen School and many other scientists succumbed to the temptation of total mathematical abstraction from physical reality.
The physical model became superfluous. All that remained were the equations, which somehow yielded useful predictions but provided no clue to the nature of the underlying physical realities. Karl Popper cogently challenged this “instrumentalism,” as he called it,4 but Copenhagen’s instrumentalist definition of science now may be even more firmly entrenched than Copenhagen’s quantum physics itself. Although the Einstein-Bohr debates became snarled with side issues, the central issue was whether or not science was obliged to describe the physical realities underlying the equations: Einstein insisted that it must; Bohr claimed that it was no longer possible.
Waves of Matter
Thus, Bohr led a rush to judgment by the Copenhagen physicists that fixed theoretical physics in a kind of mathematical-statistical limbo for the rest of the century. For Carver Mead, the result was a physics bereft of an intelligible concept of fundamental physical reality. But on the basis of the insights gained from his own experimental work with quantum phenomena, such as electron tunneling and superconducting loops, Mead has cut the Gordianknot of quantum complementarity. He claims that atoms, with their neutrons, protons, and electrons, are not particles at all but pure waves of matter. Mead cites as the gross evidence of the exclusively wave nature of both light and matter the discovery between 1933 and 1996 of ten examples of pure wave phenomena, including the ubiquitous laser of CD players, the self-propagating electrical currents of superconductors, and the Bose-Einstein condensate of atoms.
In the laser, for example, the peaks and valleys of the light waves are all perfectly aligned (in phase or coherent), emphasizing their wave nature. Similarly, in superconductors, the electrons of the current all take on the same phase so that they move in unison. And the Bose-Einstein condensate is a state of matter in which all the atoms act as one because all of the individual wave-atoms are likewise in phase or coherent. Thus, when the matter waves of electrons or of atoms are in phase, they display the same perfect alignment or coherence as the light waves of a laser.
The wave nature of electrons explains their stepped or quantum transfers of energy (that so puzzled Planck and others at the beginning of the twentieth century), because this is normal behavior for transfer of energy by standing waves. And the famous paradoxes of the absence or presence of interference patterns of light quanta and of electrons confronted with one or two holes in their paths are also explicable in terms of Mead’s view of these energy transfers as instantaneous energy interactions between radiating and absorbing atoms.
If, as the examples of pure wave action suggest, light, electrical current, and matter are all fundamentally wave phenomena associated with the electrical charges of atoms, they can all be described by the equations of electromagnetism. Indeed, Mead’s goal in Collective Electrodynamics is not to debunk Copenhagen, but to unify quantum mechanics and electromagnetism without using either Copenhagen’s statistical equation for quantum mechanics or Maxwell’s equations for electromagnetism.
In Part 1 of his monograph, Mead considers the current in a superconductor, which reveals collective electron behavior, that is, the way in-phase electron waves link up. Such pure wave action is absent in ordinary conductors because they are dominated by the interference of many electron waves of different frequencies and phases. Thus, the basic division of matter is not the Copenhagen division between large objects in classical physics and little objects in quantum physics, but that between out-of-phase or interfering waves of matter (classical) and in-phase or coherent waves (quantum). And Heisenberg’s uncertainty equation is valid, but mainly as a measure of the uncertainty of location inherent in the natural tendency of waves to spread out if not confined.
So, in the light of the advances in experimental physics over the last 70 years, Mead seeks at last to definitively vindicate Einstein’s insistence contra Bohr that “He doesn’t roll dice” (understood not as a theological statement but as an affirmation of the “rigorous causality” that Heisenberg explicitly denied). Mead’s work also vindicates theologian-philosopher R. C. Sproul, who, in his 1994 book, Not a Chance,5 criticized scientists who failed to conform to the basic presupposition of rationality, the law of noncontradiction. Boldly affirming on logical grounds that “a quantum leap is an illusion” (p. 47), Sproul predicted that scientists would eventually find a reasonable explanation for the behavior of electrons.
Mead fulfills Sproul’s prediction in Part 5 of his monograph by mathematically tracing “the continuous trajectory of the state of two radiatively coupled atoms through . . . a ‘quantum jump’” (p. 109). That is, contrary to the claims of some Copenhagen physicists that electrons do impossible things such as move instantly from one place to another without traversing the intervening space, electrons act as stepped but continuous wave functions and behave themselves with perfect intelligibility. And Mead shows all this without resorting to a statistical treatment. Thus, in place of Copenhagen’s discontinuous, indeterminate, and unintelligible physics, Mead offers a continuous, determinate, and rational discipline.
In his epilogue, Mead acknowledges his predecessors: “Following the tradition of Einstein and Schrödinger, the pioneers in this new endeavor, Jaynes, Cramer, Zeh and others, have given us a great foundation . . . [and] have put us in a position to finally settle the Einstein-Bohr debate—with a resounding victory for Einstein” (p. 127). Their work and their critiques of the Copenhagen School’s ideas helped Mead grasp the continuous nature of quantum jumps. But Mead’s main positive contribution is to show how to unify quantum mechanics and electromagnetism by the most appropriate of the basic equations of electromagnetism.
Although Mead’s equations are continuous and determinate, they need not be interpreted as affirming a determinism that rules out free will. Karl Popper’s devastating critique of inductivism and positivism holds that scientific theories can never be “proven,” “verified,” or “established,” but must always remain tentative. Hence, they are never strong enough to support the kind of determinism Laplace tried to impose on the basis of Newtonian physics. Popper specifically rejects a physical determinism of thought and action.6 Nevertheless, he also rejects with asperity the indeterminist physics of Heisenberg7 that makes quantum physical reality unknowable.
Bohr’s famous dictum that “A great truth is a truth of which the contrary is also a truth” betrays the irrational turn of mind that tarnished his brilliance as a scientist.8 Indeed, in their haste to appropriate the paradoxes of quantum physics for philosophical speculation and in their retreat from reality into an instrumental definition of science, Bohr and Heisenberg undermined the rationality of science itself. The unfortunate cultural consequences of Copenhagen’s irrationalism include the use of quantum physics as a basis for post-modernism in philosophy, and cultural studies as a basis for apologetics for oriental religions, such as Fritjoff Capra’s The Tao of Physics.9
Conversely, the return to reason of a hard science such as physics militates against the attacks on rationality by oriental religionists, New Agers, postmodernists, and cultural constructionists. This reemergence of a rational physics tends to support the biblical revelation of the Creator as rational (the Word or Logos of God), but we must remember that basing theology on empirical science is always a mistake.
Despite its mathematical rigor, professional apologists, philosophers, and Christian faculty in the sciences may want a copy of this breakthrough book heralding the end of Zen physics for its brief but incisive verbal critique of the Copenhagen interpretation of quantum physics. Mead, of course, could be wrong on many points of his argument unifying quantum physics and electromagnetism. He may even be wrong in his claim that matter is a purely wave phenomenon. (Mead’s is not the only alternative to Copenhagen that preserves the rationality of quantum reality.) But Copenhagen can’t possibly be right in its claim that quantum reality is irrational—or science as a rational discipline ends right there.
Since physics seems to be headed for a major self-correction, Christians in science and theology should inform themselves and their communities of this salutary revolt against irrationalism in physics by secular scientists. Those theologians heavily invested in arguments for free will based on twentieth-century quantum mechanics are likely to be disappointed by this news, but the demise of Newtonian physics at the beginning of the twentieth century was fair warning against basing theology on the shifting sands of empirical science. Nevertheless, this news of the reopening of a science to reason shows that God’s common grace is not absent from the world of science.
1. For a resolution of the apparent wave-particle behavior of light quanta and certain electrons, see physicist John Gribben’s engaging Schrödinger’s Kittens and the Search for Reality (New York: Little Brown and Co., 1995).
2. New York: Harper Torchbooks, 1962, p. 181.
3. New York: Harper Torchbooks, 1971, p. 78.
4. In Conjectures and Refutations: The Growth of Scientific Knowledge (New York: Basic Books, Inc., 2d ed.), Popper wrote that Bohr’s “so called principle of complementarity . . . amounted to a ‘renunciation’ of the attempt to interpret atomic theory as a description of anything. . . . Thus the instrumentalist philosophy was used here ad hoc in order to provide an escape for the theory from certain contradictions by which it was threatened.” Popper continues: “The instrumentalist view asserts that theories are nothing but instruments, while the Galilean view was that they are not only instruments but also—and mainly—descriptions of the world” (pp. 100–101, italics in the original). For Popper, the issue was nothing less than the survival of our scientific and philosophical heritage from the Greeks of “the tradition of critical discussion—not for its own sake, but in the interests of the search for truth” (p. 101).
5. Grand Rapids, Michigan: Baker, 1994.
6. Conjectures and Refutations, pp. 61, 293ff.
7. The Logic of Scientific Discovery (New York: Harper Torchbooks, 1968), pp. 248–250.
8. In writing about Bohr’s radical view of philosophical language as ambiguous, Paul Dirac cites Bohr’s own illustration: “‘There is a God’ [is] a statement of great wisdom and truth, and the converse ‘There is no God’ [is] also a statement of great wisdom and truth” (Niels Bohr: His Life and Work as Seen by His Friends and Colleagues, [Amsterdam: North Holland Publishing Co., 1968], p. 309).
9. Kopel, Dave, “Uncertain Uncertainty: Postmodernism Unravels,” National Review Online, April 4, 2002, 8:30 a.m. Kopel traces some roots of postmodernism to the Copenhagen School but has noproblem with Copenhagen’s Zen connection. Indeed, some eminent mathematicians and physicists such as John von Neumann and David Bohm have believed Copenhagen’s most extreme claim, that the consciousness of the observer affects quantum processes. But even many Copenhagen loyalists have abandoned this claim, and John Gribben, again in Schrödinger’s Kitten, op. cit., shows how the details of the instrumentation of the experiments and not the presence of a conscious observer affected the processes.
David Haddon is an author from Redding, California, who has written for InterVarsity Press and Baker Book House and whose articles have appeared in Christianity Today, National Review, and Learning. He holds a BS in engineering from the University of California at Berkeley and an MA in politics and literature from the University of Dallas. A shorter version of this review first appeared in the Spring 2002 issue of SCP Newsletter, Berkeley, California, an Evangelical apologetics publication.
David Haddon is an author from Redding, California, who has written for InterVarsity Press and Baker Book House and whose articles have appeared in Christianity Today, National Review, and Learning. He holds a B.S. in engineering from the University of California at Berkeley and an M.A. in politics and literature from the University of Dallas.
Not a subscriber? Subscribe to Touchstone today for full online access. Over 30 years of content!
Get a one-year full-access subscription to the Touchstone online archives for only $19.95. That's only $1.66 per month!
Get six issues (one year) of Touchstone PLUS full online access for only $29.95. That's only $2.50 per month!
Your subscription goes a long way to ensure that Touchstone is able to continue its mission of publishing quality Christian articles and commentary.
*Transactions will be processed on the secure server of The Fellowship of St. James website, the publisher of Touchstone.
from the touchstone online archives