[This post first appeared on 24 September, 2007]
In my past segments, I have presented the argument that something non-computational and non-deterministic is taking place in human consciousness. In so doing, I have introduced the comparison of human beings to machines, particularly computers. On the surface the comparison is preposterous. Ask anybody! No serious person takes the comparison as a realistic possibility. Most people seem to know intuitively that people are capable of more than machines. So why not drop the whole subject and talk about something more interesting? Because we are interested in where reason will lead us in the search for God and because there are thoughtful and intelligent people who do believe that the universe is a giant computer.
For example, John Tierney, a science writer for the New York Times, states, “it is almost a mathematical certainty that we are living in someone else’s computer simulation” (“Our Lives Controlled From Some Guy’s Couch” by John Tierney, New York Times, August 14, 2007). In other words, the universe is a giant computer. He has based this conclusion on the work of Nick Bostrom, a philosopher at Oxford University. Professor Bostrom, for the record, states, “My gut feeling, and it’s nothing more than that, is that there’s a 20 percent chance we’re living in a computer simulation.”
But Mr. Tierney also raises the interesting question of how we should behave if, indeed, we are the products of a giant computer simulation. He presents the alternatives of living the traditional moral life or the ‘interesting’ life, the moral life presumably being dull. Perhaps, he muses, “You should try to be as interesting as possible, on the theory that the designer is more likely to keep you around for the next simulation.” Presumably, that might include all sorts of nefarious dealings to enhance one’s interest quotient. (It is intriguing to note that this choice between the ethical life and the interesting life is exactly the choice presented by Soren Kierkegaard in Either/Or more than 160 years ago.) From my point of view, the salient connection is that one’s view of the universe has moral repercussions and there are at least some people who think that the universe is a computer simulation. But perhaps Bostrom and Tierney have not pushed that thought through to the question about determinism.
So the question remains, if the universe is non-deterministic, where does that come from? Roger Penrose is a mathematician and a physicist and he thinks that ultimately one has to come to terms with the basic physics. Perhaps, a biologist would direct us to a biological answer. One is always most comfortable with the tools one knows best. But physics does occupy a unique position to address the question. We can make the case that quantum physics controls the action of atomic particles which make up atoms which form biological molecules which are the building blocks of all biological entities. The counter argument is that molecules – especially biological molecules – are much too large to be affected by quantum actions. Certainly the chemical composition is not affected by quantum actions.
Perhaps not directly, but remember that there are some very subtle processes taking place in the living cell. I shall use as my example an important biological molecule called tubulin, which Penrose introduces late in his book as one answer to the search for a science of consciousness. Tubulin consists of two separate units called alpha tubulin and beta tubulin, each composed of about 450 amino acids. Amino acid molecules are the building blocks of biological proteins. This tubulin dimer appears in two configurations that differ in the separation angle between the alpha and beta parts. In one configuration the angle of separation is about 30 degrees more than in the other configuration. These two different configurations of tubulin are controlled by the position of a few electrons that resides midway between the two parts. Tubulin plays a significant part in the structure and life of the cell. The significant problem of protein folding is a generalization of the tubulin example. The placement of a few electrons can affect the particular way that a protein folds. Improperly folded proteins have been implicated in several disease processes, most notably the prion diseases of creutzfeltd-jakob disease in humans and ‘mad cow’ disease in animals. DNA folding and RNA folding can affect the genes that are expressed within the cell. Folding of biological molecules is a huge area of research and folding can be controlled by the position of a few electrons, and that is within the power of quantum action.
Therefore, Penrose traces the source of non-deterministic action to quantum physics. But he does not think that quantum action on a few electrons is sufficient to give rise to consciousness. Penrose goes straight to the critical dilemma at the heart of quantum theory: the measurement problem. The measurement problem arose because quantum theory did not address in detail the issue of when the wave nature prevailed and when the particle nature prevailed. The theory says that the wave nature prevails until a measurement occurs or could in principle occur. When a measurement is made, the wave function is said to ‘collapse’ and the particle directs its energy to a specific location and with a specific momentum. When the wave function collapses, one of the possible locations is chosen at random by the universe according to standard theory. However, that randomness is modified by the set of possibilities given by the physical arrangement of the environment. At one point in his book, Penrose wonders if it really is random, but that is what the standard theory presumes. Once again, this is all behind the quantum veil and subject to informed speculation. When the expected result of an experiment needs to be calculated, a set of pseudo-random numbers can be used to simulate the assumed randomness. As Penrose makes clear in his discussion on non-computability, neither randomness nor pseudo randomness is any help toward solving the problem of consciousness.
In order for us to understand exactly where within the bounds of quantum theory this non-determinism is happening, we need some of Penrose’s terminology. There are two key processes that quantum physicists use to calculate the outcome of any quantum experiment. The first process Penrose calls ‘unitary evolution’ designated by the letter U. This is the process controlled by the wave function. This process is a completely deterministic rule for how the quantum state evolves with respect to time and position. Its value can be thought of as a kind of complex probability precursor, but it is not properly a probability function. This part of the process can be and often is calculated on the computer.
Penrose calls the second process ‘state vector reduction’ or ‘collapse of the wavefunction’ and is designated R. This process converts the complex probability precursor value of U into an actual probability distribution and, amazingly, chooses one of the possible outcomes. Converting the complex probability precursor into an actual probability function is completely deterministic. It is the ‘choice’ that Penrose points to as the source of quantum non-determinism. This part of the process cannot be calculated on a computer for a single quantum action, because the computer has no way to choose the outcome in the same way that the universe does. When an experiment is done to verify the U and R process, the individual outcomes appear random and not according to any recognizable pattern. If the experiment is done many times, the pattern that emerges conforms to the probability function derived by applying the deterministic part of the R process to the deterministic U process. The process of verifying an experiment, which is repeated many times, can be verified on the computer by substituting random or pseudo random choices for the non-deterministic choices of the R process. It is this substituting of random choices that gives the whole process a feel of statistical modeling.
A single quantum action, for example the transfer of a single photon of light, consists of a two-part process: U followed by R. The R process contains a non-deterministic choice of the actual time and location of the transfer from the various possibilities allowed by the physical arrangement. These two processes may be chained together so that one energy transfer follows another: U, R, U, R, etc. In addition, most events are composed of many, many transfers. For example, an ordinary electric light will produce an unimaginably huge number of photons each second (more than 1 followed by 17 zeroes.) To further complicate the analysis, the U process is often linked with other U processes and the outcomes of the associated R processes are dependent on each other. This has been called ‘quantum entanglement.’ It may be that the quantum entanglement between a controlled experiment and the uncontrolled environment is what gives the appearance of randomness.
Roger Penrose does not avoid controversy and he readily admits that he takes a more realistic view of the U and R processes than many physicists do. Since both U and R take place behind the quantum veil, this is an open question:
“To such as myself (and Einstein and Schrödinger too – so I am in good company), it makes no sense to use the term ‘reality’ just for objects that we can perceive, such as (certain types of) measuring devices, denying that the term can apply at some deeper underlying level. Undoubtedly, the world is strange and unfamiliar at the quantum level, but it is not ‘unreal’. How, indeed, can real objects be constructed from unreal constituents? Moreover, the mathematical laws that govern the quantum world are remarkably precise – as precise as the more familiar equations that control the behavior of macroscopic objects – despite the fuzzy images that are conjured up by such descriptions as ‘quantum fluctuations’ and ‘uncertainty principle’.” (Penrose, Shadows of the Mind, p. 313.)
But R is still subject to the measurement problem, since we don’t really know when it might occur. Penrose then proposes a new procedure called ‘objective reduction’, or OR, for the type of action that is needed to solve the measurement problem. Objective reduction takes place according to a set of criteria involving the amount of energy or mass that is being separated by the wave function. Once the amount of energy or mass becomes great enough or the separation becomes great enough, objective reduction takes place. The amount of mass / energy / separation is small enough that we never see quantum action in everyday life. The universe is still required to choose among the various possibilities for the transfer of mass /energy, but Penrose calls that decision non-deterministic rather than random. Penrose uses the phrase ‘nature chooses’, but I prefer to say the universe chooses because ultimately, if the process is objective, then it is happening throughout the universe and not only where consciousness is present.
But what kind of choice is the universe making? There are three possibilities as I see it. The choice could be calculated, like a calculated pseudo-random number, but the algorithm remains hidden from us. This is the possibility that Penrose has debunked by the Godel-Turing argument. The choice could be truly random, meaning that the possible outcomes are spread evenly over some interval and that there is no algorithmic connection between the random values chosen. The model for this type of choice is the throw of a dice as in “God is not playing at dice.” It is this possibility that perhaps led Albert Camus to write about the “benign indifference of the universe” in The Stranger. Note that the lack of an algorithmic connection between random values means that the choices are essentially free choices, unconstrained by prior or subsequent choices. But neither Penrose nor I think that truly random choices can lead to the coherence and power of consciousness. The third possibility is that there is some reasoning or intelligence behind the choice, but that reasoning is hidden from us behind the quantum veil. It would have to be this third possibility that biological entities use for intelligent decision-making, but only if there is some way for biological systems to prolong the period of quantum action.
Now we are at the point where we can plausibly say that the universe is making a choice for every transfer of energy that takes place in the universe. From the Godel-like arguments given previously, we have plausibly eliminated a method of choosing based on calculation. Penrose and many others think that biological components have the ability to tap into that choice-making power behind the quantum veil in order to arrive at a theory of consciousness. Can we now plausibly conclude that the choice-making power is consciousness, intelligent, and whole? The next segment will describe one possible way that biological systems can tap into the decision making power of the universe.