Science in Christian Perspective


Randomness in Quantum Mechanics and Its Implications for Evolutionary Theory
Department of Physiology
University of California Berkeley, California 94720


From: JASA 26 (September 1974): 96-98

Randomness is intrinsically contained in quantum mechanics because the theory can predict only the probability of occurrence of events. But no one knows how this randomness in nature is generated. Mendel's laws and mutations are examples of such random events. At least four possibilities exist: 1) The world is truly random. 2) There is a yet-undiscovered underlying deterministic theory. 3) Some divine being occasionally modifies the randomness. 4) Some divine being determines the random numbers. This talk was one of about fifty given before the California State Board of Education on Nov. 9, 1972 concerning the teaching of evolution in public schools. As a postscript I give a Biblical outline of how God acts in the world. In God's eyes, the world is not random at all.

Quantum Mechanics

In the 1920's Schroedinger, Heiscnberg, Dirac and other physicists developed quantum mechanics, which forms the basis of all modern physical theories. Together with the electromagnetic, gravitational, strong, and weak forces, quantum mechanics is believed by most scientists to provide a complete description of physical and hence chemical, biological, geological, psychological and all other natural phenomena. Newton's classical laws of motion, for instance, which predict the paths of spacecraft so well, are merely macroscopic approximations of the quantum laws.

In quantum mechanics the behavior of a "particle" (e.g., an electron in a hydrogen atom) is described by a "wave function" which is a function of the spatial coordinates and time. The probability that the particle is near the specific point (x, y, z) at time t is given by the square of this wave function. The theory does not specify exactly where the particle is, only the probability that it is in a certain region. For macroscopic systems this uncertainty in positon is usually negligible.
If we were to make measurements on precisely identical hydrogen atoms, the electron would he found in various different positions at random, with a greater probability nearer the proton. Other atoms, molecules, and complex biological systems have similar wave functions, though the complexity of calculating them usually exceeds the capabilities of present computers.

As a second example I would like to discuss my thesis experiment, one of hundreds which have been adequately explained by quantum mechanics. We studied K-mesons produced by a particle accelerator. These radioactive particles weigh half as much as a proton and have a half life of only 12 billionths of a second, that is, half of them at random disintegrate after this time and half are left. Every one was, however, exactly identical, as far as we know, when it was made. Furthermore, 5% of the time-at random K-meson will disintegrate into three pi mesons, and the rest of the time into other particles. The directions and velocities of the pi mesons also follow a random distribution; we measured this distribution.

For comparing our data to theory we generated pseudo-data on a computer using random numbers whenever a random process occurred. The computer included the magnets, spark chambers, and other particle detectors, just like the real apparatus. The simulated data and the real data were identical within the 0.3% statistical error. The quantum prediction thus agreed with our results.


Now I did not tell you how we generated random numbers on a computer. Because digital computers are completely deterministic in performing calculations, our "random number" program was absolutely deterministic. We were most careful, though, that the "random numbers" were effectively random in a statistical sense. But, as far as the physics was concerned, there was no way to tell the difference between our real data and our deterministic computer-generated "data".

Quantum mechanics says that there is a basic unknowableness about the world. The K-meson will either decay or not decay after a certain time, but the

Is the world really random or does it only appear that way to our limited knowledge?

scientist cannot predict which. Quantum mechanics forms the foundation for all modern scientific theories. Quantum statistical mechanics describes the motion of large numbers of particles; air pressure is the average of the random impacts of gas molecules. Solid state physics describes solids by quantum mechanics; the hiss of a radio tuned between stations is caused by the random fluctuations in electron flow in the transistors. Weather calculations, presently inaccurate beyond a few days, are believed to he limited by random fluctuations in the atmosphere over times of months or years. Chemical reactions, including those in our bodies, are the chance interactions of molecules. Our eyes, able to detect single quanta (particles) of light, are limited to statistical fluctuations in the arrival of those quanta. The transmission from one neuron to another in our brains is influenced by randomness in the release of the transmitter chemical-our thoughts are not deterministic. Mutations and Mendel's laws of geneticssupposedly the driving forces of the evolutionary theory -are random. History and thus evolution are fundamentally impossible to predict through science because history depends on genetically-random individuals (e.g., Hitler) and "accidents" (e.g., where the bullet lodges during an assassination attempt). It is slightly possible that home sapiens will not exist on this planet five years from now.

Possible Interpretations

Is the world really random or does it only appear that way to our limited knowledge? At least four possibilities exist, all of which are equally consistent with present scientific data.
1. The world is truly random. There is no underlying meaning or purpose. Human beings are the result of random genetic combinations, mutations, and natural selection. Whether we live or whether we die or whether we murder another human being can all be possible outcomes of the quantum equations.
2. Quantum mechanics is only an approximation to an underlying deterministic theory, just as a deterministic random number program on a computer can generate effectively-random numbers. Perhaps scientists will some day discover such underlying processes. But again there is no basis for meaning or purpose.
3. Some divine being allows the world to run more or less randomly but modifies the random numbers at chosen occasions.
4. The "random numbers" are determined by a divine being for his own purposes. Processes appear random when scientists observe them, but present events and the origin of life are directed by this divine being.

As a scientist I feel that textbooks which declare that present-day events and the origin of life are the result of mindless and meaningless chance are expressing an assumption, not a scientific fact. Science teachers and texts should stress not only the limitations and uncertainties of present data and theories, but also the basic quantum-mechanical unknowableness and its implications for unpredictability in evolution and history. Humility in the face of this unknowableness is certainly in order.


For the Christian the evolution-creation controversy is only part of much larger considerations. The atheist sees only mechanistic, random physical processes in the world. But in the Bible almost every page is full of God's activity. God is active now; he did not stop after finishing creation.

1. Ancient Israel. God established his covenant with Abraham and worked in history for Israel's sake. Some theologians believe that God has restored Israel today in fulfillment of prophecy.
2. The fate of nations. Wise Solomon said, "The king's heart is a stream of water in the hand of the Lord; he turns it wherever he will." (Prov. 21:1, RSV)
3. The coming of Christ. Numerous prophecies foretold the coming of Jesus Christ. The virgin birth, miacles, and the resurrection were not natural events. Jesus predicted at his trial that he would come again on clouds of glory (Mt. 26:64).
4. The preaching of the Gospel throughout the
world. Jesus prophesied, "And this gospel of the kingdom will be preached throughout the whole world, as a testimony to all nations . . .". (Mt. 24:14) God is now bringing this about. In the early Christian church, the Lord added to their number day by day those who were being saved." (Acts 2:47b)
5. The Holy Spirit living in Christians. Jesus said to his disciples, "If you love me, you will keep my commandments. And I will pray the Father, and he will give you another Counselor, to be with you for
ever, even the Spirit of truth, whom the world cannot receive, because it neither sees him nor knows him; you know him, for he dwells with you and will he in you." (John 14:15-17)
6. God's care for each Christian. Jesus said at aonther time to his disciples, "Arc not two sparrows sold for a penny? And not one of them will fall to the ground without your Father's will. But even the hairs of your head are all numbered. Fear not, therefore; you are of more value than many sparrows." (Mt. 10: 29-31)
7. The power of prayer. Jesus again said, "If you abide in me, and my words abide in you, ask whatever you will, and it shall be done for you." (John 15:7)
8. God's direction of the future. Read the book of Revelation.
9. The reality of the Devil. Paul says, "For we are not contending against flesh and blood, but against the principalities, against the powers, against the world rulers of this present darkness, against the spiritual hosts of wickedness in the heavenly places." (Eph. 6:12)

Personally I believe that the fourth interpretation is correct, namely, God determines the random numbers. An interesting verse is, "The lot is cast into the lap, but the decision is wholly from the Lord." (Prov. 16:33). A modern paraphrase might be, "What appears random to man is wholly determined by God." Much of God's activity in the world today can be described within the known laws of science, in that God foresees (calculates?) the future and accordingly has chosen the initial conditions of the universe and the random numbers so that His will is fulfilled. But I also believe that God freely acts to perform miracles, such as the virgin birth and the resurrection.