Trinity Baptist Church: Sunday School, Apr. 12, 2009

Apologetics

 

Week 9: Miracles and quantum mechanics.  Does modern science prove that miracles cannot occur?  Doesn't science adequately explain all natural phenomena?

The notes for this topic will be a bit sparser than for previous weeks because I will largely follow the outline of my essay Quantum Mechanics and Materialism.

Does modern science prove that miracles cannot occur?

No!  In fact, our current understanding of physics leads to the opposite conclusion.   Let’s examine some widely-believed historical ideas about science and physics and then ask whether these ideas are supported or undermined by quantum physics:

Idea #1: The laws of physics cannot be violated; hence miracles are impossible.

This objection was (and is) the central argument that traditional materialism made against the miracle claims of Christianity.  The world of classical (or Newtonian) physics could be described as a clockwork universe, in which each part of the universe interacted with the other parts according to deterministic, inviolable laws.

An excellent illustration of Newtonian physics is provided by the game of billiards (sounds much classier than “pool”).  We all recognize that billiard balls follow trajectories or paths prescribed by simple mechanical laws.  A ball moves in a straight line until it hits the wall or another ball.  The very basis for the success of good pool players is their ability to judge precisely the path of each ball given the force with which they hit it. Although even a good player might misjudge the path taken by a ball, there is in principle one and only one path that each ball will take (assuming a perfectly smooth table, no air resistance, etc..).  Newtonian physics views the entire universe, in a sense, as a game of billiards.  Each atom in the universe is like a tiny billiard ball interacting with other billiard balls.  Although the rules of this interaction are more complicated than those of billiard balls, we could in theory predict the entire history of the universe if we knew the initial positions and velocities of each particle at the very beginning.  In other words, classical (Newtonian) mechanics is deterministic: if we know the initial state of some system (like a billiard table), we can predict with 100% accuracy its state at some future time.  The only uncertainty comes from our inability to exactly know its initial state.

It is clear why a classical view of the universe could be used to support the non-existence of miracles.  If I place a billiard ball on a flat table, it will never spontaneously start rolling (by Newton’s first law: an object at rest tends to stay at rest).  I could wait a million years and it will never start rolling.  Such a process would be absolutely impossible according to the laws of classical physics.  If so, then we can similarly argue that water does not turn into wine.  Such a process is absolutely impossible according to the laws of classical physics.  Thus, it doesn’t matter what evidence we have that says such an event occurred: it is rendered impossible a priori .  Readers will, of course, see the major flaw in this logic (what if there can be causes with origins outside the natural?), but let us for a moment accept this argument as plausible.  The real problem is not that it is specious, but that it is based on a classical mechanical view of the universe which died an ignoble death almost ninety years ago.

Unlike classical mechanics, quantum mechanics is non-deterministic (assuming that we include the measurement process in our definition of quantum mechanics).  In other words, quantum mechanics states that we cannot prescribe with certainty the outcome of any observation, even if we know the precise state of the system in question.  Rather, the possible outcomes of a measurement are probabilistic in nature.  This nondeterminism may at first appear unsurprising, since classical mechanics also allows for probabilistic behavior due to our lack of knowledge.  However, the shocking claim of quantum mechanics is that randomness is not due to our lack of knowledge but is inherent.  The Heisenberg Uncertainty Principle is the most commonly known concept that illustrates this point.  The Uncertainty Principle states that we can never simultaneously know both the position and momentum of any particle with infinite precision.  It is not that we do not have sufficiently advanced technology to measure the particle with infinite precision.  It is that it is impossible to do so, no matter how advanced our technology.  If we know the position of a particle with infinite precision, then our measurement of its momentum will yield a completely random result, and vice versa. 

What does this discussion have to do with miracles?  Put simply, quantum mechanics says that physical laws, even the laws of mechanics, are inherently probabilistic (this is slightly imprecise language, since nondeterminism actually only emerges at measurement, not during free evolution, but to a layman, this picture is sufficiently valid).  For instance, the Feynman path integral formulation of quantum mechanics states that unlike classical particles, which take only a single path, quantum particles take all paths simultaneously.  “Normal paths” or ones that we associate with classical mechanics, have a high probability of occurring, whereas “bizarre paths” occur with very low probability.  Nonetheless, all paths are taken with some finite (though possibly small) probability.   To use our billiards illustration, a quantum mechanical billiard ball would not only travel in a straight line, it would also take a path in which it curves to the left, or to the right, or leaps off the table, or teleports into the living room, all at the same time.  The probability of each nonclassical path would be extremely small, but would not be zero.  Therefore, it would be rigorously invalid to say that any particular path, no matter how unlikely, was impossible.  We now see the connection to miracles.  Classical physics allowed materialists to claim that certain events were simply impossible “according to the laws of physics”.  Quantum mechanics rules out such an appeal.  All we can say now is that some event is highly improbable “according to the laws of physics”.  But there is a world of difference between impossible and improbable.  If something is truly impossible, I can ignore it.  If something is merely improbable, I need to at least consider it.

Idea #2: Even if God exists, he cannot intervene in the natural world without “clumsily” violating the laws of physics that he himself created.

This objection was partially answered in the last point. Essentially, all the laws of physics give us are probabilities.  One very tough question for which physicists as yet have no real answer is what determines actuality.  In other words, if quantum mechanics states that the two outcomes of a measurement are both equally likely, and we perform the measurement, what (or whom) determines which of the two outcomes we actually observe?  This problem, sometimes known as the problem of “wavefunction collapse”, is a major difficulty for physicists and is the crucial question addressed by all modern interpretations of quantum mechanics.  The bottom line is that physicists currently have no answer to this problem.  The results of measurements “simply are”.  They have no natural cause.  That is true whether the measurement outcome was very likely or highly unlikely.

It is interesting to reflect on the Bible’s consistent message about God’s sovereignty and immanence.  God is both sovereign (meaning that he rules over and controls every event in history) and immanent (meaning that he acts in and is present to the universe); see Psalm 33 and  Psalm 139 for a good illustration of both concepts.  Numerous times, the Bible states that God is responsible for the outcome of every event, even the casting of lots (!) which is a random event like flipping a coin or rolling a die.  Within a classical, Newtonian framework, it is difficult to see how this is the case, since it seems that “physical laws” are the proximate cause of events.  However, quantum mechanics (if it is true) provides Christians with a glorious and beautiful understanding of God’s sovereignty.  Far from being a clockwork universe powered by deterministic natural laws, ours is a fluid universe in which every interaction between subatomic particles is subject to God’s intervention and sovereignty.  It is true that God operates primarily through “physical laws”, but even these physical laws seem to allow, to point to, and to bow before the sovereignty of God.

The other side of this idea is that the necessity of faith is also underscored.  In a Newtonian universe, it is at least possible to clearly and rigorously define a miracle as the “violation of natural laws”.  However, in a quantum universe, there is no event that would clearly be a miracle using such a definition.  Were a materialist to witness an elephant teleport from one side of a house to the other, he could still claim that he had seen nothing more than a highly improbable, but nonetheless possible, manifestation of the laws of quantum mechanics.

Idea #3: The universe does not contain entities which are unknowable or inaccessible to science and reason.

Again, quantum mechanics demolishes this idea.  The Heisenberg Uncertainty principle is a good, popular rejoinder to this objection since it explicitly states that some realities like the simultaneous position and momentum of a particle are unknowable.  More generally, in quantum mechanics, the fundamental object is the wavefunction which is essentially inaccessible to measurement.  We can probe various aspects and properties of a particle’s wavefunction, but we have no access to the wavefunction itself.  Thus according to quantum mechanics, fundamental reality is fundamentally hidden from the observer.

Idea #4: Consciousness and subjective experience are collective properties of matter.  There is no such thing as mind-body duality nor is there any independent, objective reality to our consciousness.

Many people believe that quantum mechanics necessitates the definition of a separate entity of ‘mind” or “consciousness” as distinct from matter.  Although there is debate among physicists about this assertion, there are certain undeniable facts.

1.  Quantum mechanics as it is currently formulated rests on two types of governing processes, which Erwin Schodinger referred to as Process 1 and Process 2.

2.  Process 1 can be called “unitary evolution” and proceeds whenever a system is isolated from its environment, so that it experiences no external interactions.

3.  Process 2 can be called “measurement” and corresponds to traditional types of measurement with measuring devices like a photodetector or a human eye.  It also corresponds to more general interactions with some external environment.

4.  Whenever we measure something, we see that Process 2 has occurred.

The question is, if physical systems undergo only Process 1 when left “on their own”, then why does measurement cause them to undergo Process 2?  After all, aren’t all measuring devices merely physical devices?  Isn’t the human eye just another physical system?  If so, how can a physical system (subject only to Process 1) cause another physical system (subject only to Process 1) undergo Process 2?  In other words, there are two types of processes in the universe, one of which seems to apply to all physical systems and the other one of which seems to apply to “something else”.  Well, what is that “something else”?  It can’t be another “physical system” or it would also undergo Process 1.  Furthermore, at its root we run against this “something else” in quantum mechanics fundamentally when we talk about our own subjective experiences of measurement.  Consequently, it is not a stretch by any means to postulate that this “something else” which causes Process 2 is our own consciousness.

This point is debatable, since it is possible (but difficult) to deny that consciousness plays any special role in quantum mechanics.  It suffices to say that of the three major interpretive school of quantum mechanics (neorealism, Copenhagen, and many-worlds), the Copenhagen interpretation lends itself very explicitly to classical mind-body dualism.  Neorealism is much less popular and I’m not sure what it says about consciousness.  Most physicists that I know of are not neorealists.  The only other alternative to Copenhagen is many-worlds theory.  While many-worlds theory does indeed allow you to (somewhat) escape the requirement that consciousness play a special role in the universe, it comes at a great cost for a materialist, because it assumes that not only does quantum mechanics say that any event can possibly occur, but that every event does actually occur in parallel universes.  So it renders an attitude of skepticism with respect to miracles highly dubious, since there is a universe (an infinite number of universes, actually) in which any supposed miracle actually did occur.  Furthermore, I’m not convinced that many-worlds actually does effectively avoid the problems of assigning a special role to consciousness.

Obviously, this discussion is a bit technical and mystifying.  See my essay Quantum Mechanics and Materialism for a slightly more in depth discussion.  The bottom line is that quantum mechanics seems to imply a special role for consciousness or “mind” that is notably absent from a classical conception of the universe. 

Conclusions

In my opinion, quantum mechanics seems to clearly strike at the heart of many assumptions of the classical materialist worldview.  It might also be said that quantum mechanics strikes at the heart of the entire Enlightenment project, which believed that human reason was sufficient to discover and comprehend all truth.  Certainly, the quantum mechanical world that we have discovered is radically unlike what we “expect” the universe to look like as human beings.  Furthermore, quantum mechanics is so complicated and bizarre that we may begin to question whether our intelligence really is sufficient to understand the nature of reality.  What makes us think so?  Certainly, the intelligence of many of us is not even sufficient to grasp quantum mechanics.  What about the next theory?  Or the next after that?

The biblical worldview has two answers to this problem that people have struggled with since the Enlightenment.  The first is that God is greater than our comprehension.  Long before quantum mechanics, long before classical mechanics, God declared to his people Israel that he was a God beyond our comprehension, that His thoughts were not our thoughts, nor His ways our ways (see Isaiah 55:8-9).  As materialists, we might be shocked to find that the universe is unlike what we imagined, but as Christians we should not be.  God is infinitely above and beyond us.  He did not ask us when He created the universe nor should we expect to be able to understand all He does.  But the Christian response is not one of indignance, but of wonder.  If God is so much greater and wiser than we had imagined, we ought to trust and love him all the more.  The second answer of the Bible is that we need revelation.  We would like to believe that we can discover and understand the truths of the universe without God’s help or even without his existence.  This idea is simply false.  The scientific endeavor aims to discover truth without revelation, but really it is only discovering the truths of God’s general revelation.  Creation itself is a revelation of God’s glory and wisdom.  Without it, science would have nothing to study.  And had God not created the universe according to order and wisdom, science would fail utterly.  Even so, when we come to the truths of modern physics and realize that reality is far more foreign and glorious than we imagine, perhaps it is time to realize our limitations.  If I cannot understand the basics of quantum physics, what assurance do I have that I will be able to understand any truth about God or reality?  No, I need God himself to graciously speak. Perhaps he hasn’t. Perhaps he is a silent God who keeps his truth hidden from the world and leaves us to stumble in darkness.  But what if he has?  What if he has spoken to us, not to reveal to us the mysteries of quantum mechanics, but the mysteries of his holiness, love, grace and forgiveness?  Am I listening?