From: JASA 19 (June 1967): 33-35.
Physicists at the beginning of this century were confronted by radically conflicting experimental behavior: Light exhibited clear wave-like behavior in interference and diffraction effects; yet in other experiments, such as the photo-electric effect, certain particle-like behavior was observed. To compound the difficulty it was soon discovered that micro-world particles such as electrons exhibited wave-like behavior by forming diffraction patterns upon scattering
*W. Jim Neidhardt is with the Physics Department, Newark College of Engineering, Newark, New Jersey.
How has this problem been resolved to date? Part of the difficulty may be due to applying our understanding of one realm of experience to another, different realm. We live in a "large" world of basketballs, drops of water, ocean waves, . . . As we cannot have direct contact with the "little" world of atoms, we choose to apply our "large" world concepts hoping they may fit. Is it not then reasonable to expect that if we ask questions that force part of Nature into an uncomfortable mold we may expect some puzzles in the answers we receive?
The existing knowledge of physics about the "little" world can be summarized as follows. Asking Nature particle questions gives particle answers and a complaint of wave ignorance. Or asking wave questions gives wave answers and a complaint of particle ignorance. Note that both wave and particle characteristics are observed depending upon the (experimental) question asked; attempts to explain particle behavior in terms of waves or vice-versa (that is, assuming either one behavior or the other is present) has not been successful.
The most successful solution of the wave-particle quality to date is that of Niels Bohr in what has come to be known as his complementarity principle. Bohr first pinpointed clearly the reason for the uncertainty principle:
The critical point is here that any attempt to analyze in the customary way of classical physics ("large" world physics), the "individualality" of atomic processes, as conditioned by the quantum of action (h), will be frustrated by the unavoidable interaction between the atomic objects concerned and the measuring instruments indispensable for that purposel . . . The action of the measuring on the object under investigation cannot be disregarded and will entail a mutual exclusion of the various kinds of information required for a complete mechanical description of the usual type. This apparent incompleteness of the mechanical analysis of atomic phenomena issues ultimately from the ignorance of the reaction of the object on the measuring instruments inherent in any measurement.2
Bohr then characterized the seemingly contradictory wave-particle nature of micro-world entities as complementary aspects of physical reality. Using light as an example, Bohr stated:
Indeed, the spacial continuity (wave property) of our picture of light propogation and the atornicity of the light (particle property) effects are complementary aspects in the sense that they account for equally important features of the light phenomena which can never be brought into direct contradiction with one another, since their closer analysis in mechanical terms (the concepts of the "large" world we can actually experience) demand mutually exclusive experimental arrangements. However great the contrasts exhibited by atomic pbenomena must be viewed complementary in the sense that they exhaust all definable knowledge about the objects concerned.3
There are a number of lessons that can be learned from the history of modem physics. The taking of concepts from one realm of experience to describe another different realm is a sometimes necessary step because of limits on the human frame of reference. It should be further realized that such forcing of the descriptions used in one experiential realm into another can lead to paradox. The great lesson of modern physics is that certain conflicting parts of reality cannot be brought together by forcing the evidence to fit one description or the other. Nor can part of the evidence be assumed false; all of it must be faced as valid. Only when these phenomena are considered as mutually exclusive aspects of the same thing does understanding occur. Indeed, the phenomena must be complementary in that together they exhaust all definable knowledge on the phenomena involved.
Biblical revelation of the nature of God and man and of God's actions in history have forced Christian Theologians to utilize similar complementary approaches to reality. Some examples follow.
Consider first the Biblical view of the nature of man as angel and yet brute. For in Psalm 8:4 we read: What is man that thou art mindful of him and the son of man that thou dost care for Him?
Yet thou has made him little less than God, and dost crown him with glory and honor.and yet in Gen. 2:7:
The Lord God formed man from the dust of the ground and breathed into his nostrils the breath of life and man became a living being.
These statements show that the Bible teaches that man has been created in the image of God. He can a) think, b) communicate, c) think beyond himself, d) relate to others, e) forgive others, etc. Yet man is also linked to the dust of the earth - be is related to the natural order as is an animal. Man is limited by hunger, pain, etc., he acts by and from instinct in many things thereby being only concerned with the physical gratification of self. The Biblical view of man is thus a complementary view; only by seeing man as both angel and brute does a realistic picture of human nature emerge. As the Christian philosopher, Blaise Pascal, has stated:
It is dangerous to make man see too clearly his equality with the brutes without showing him his greatness. It is also dangerous to make him see his greatness too clearly apart from his vileness. It is still more dangerous to leave him in ignorance of both. But it is very advantageous to show him both. Man must not think that he is on a level with the brutes or with the angels, nor must be be ignorant of both sides of his nature; but he must know both.4
The Biblical evidence that Jesus Christ was both truly human and truly divine in His earthly stay; the Biblical evidence that man is both free and yet under the providence of God as expressed by St. Paul in I Cor. 15: 10:
I ... yet not I, but the grace of God which was with me.
are further areas where the Christian Church uses the complementary description to do justice to the Biblical evidence. Ignoring Jesus's humanity or his deity has led to a church without the presence of God. When the Bible speaks of Christ as man, His divine nature is set aside; when Christ is shown to be God, his human nature is set aside. Yet only when both sides of His nature are accepted as true does the full impact of Christ's work on earth manifest itself to finite man. As one last example consider the compactness of this statement of the Christian view of the human predicament modeled after Bohr's complementarity principle. Indeed, the free will present in our Christian understanding of the human situation and the ample evidence of God's providence are complementary aspects in the sense that they account for equally important features of human behavior which can never be brought into direct contradiction with one another, since their closer analysis in finite human terms demand mutually exclusive experiential arrangements. These factors are fully complementary in the sense that they exhaust all definable knowledge about the situation concerned.
In summary, it has been shown that complementary
descriptions of reality are useful for both scientists
and theologians in resolving paradoxial behavior peculiar to their respective disciplines. The great hope of
extreme reductionalists that all aspects of contradictory
behavior be reduced to a single aspect is seen to be
shattered by the data of both science and Christianity.
Apparent irreconcilable behavior must be accepted at
face value in both science and theology perhaps directly pointing to deeper, hidden dimensions of reality
which our finite, limited human viewpoint cannot fully
comprehend. Both scientist and theologian work to
make clear the mystery present in their two respective
disciplines, yet the humbling virtue of honesty requires
that mystery be accepted rather than distorting the
truth observed in God's world. True theology as well as
true science comes from individuals who are in sympa
thy with the insight of Albert Einstein:
The most beautiful and profound emotion we can experience is the sensation of the mystical. It is the power of true science. He to whom this emotion is a stranger, who can no longer wonder and stand rapt in awe, is as good as dead.5
1. Niels Bohr, Atomic Physics and Human Knowledge, Science Editions, Inc., New York (1961), p. 19.
2. Ibid., p. 7.
3. Ibid., p. 5.
4. Blaise Pascal, Pensees and The Provincial Letters, Random House, New York (1941), p. 132.
5. Lincoln Barnett, The Universe and Dr. Einstein, Signet Science Library Books, New York ( 1964), p. 108.