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Reality, Life, and Quantum Mechanics

Complexity: 
Hard

In recent years the idea that life can be reduced to chemistry and physics has become very prominent in the life sciences. According to this idea, all living organisms, including human beings, are simply aggregates of molecules interacting in accordance with chemical and physical laws. This conception of life has found particular emphasis in the fields of biochemistry and molecular biology, where the study of DNA, RNA, and the processes of protein synthesis have lent credence to the picture of the living cell as a molecular machine.

What are the molecules that combine together to make this machine, and what is really known of the laws governing their interaction? For the answers to these questions we must turn to physics, and in particular to the quantum theory, which provides the basis for the present understanding of atoms and molecules. However, we find ironically that modern physics presents a description of molecules that seriously undermines the mechanical picture developed by the molecular biologists. While the biologists have attempted to reduce life to the interaction of inanimate entities, the physicists have developed a conception of inanimate entities that necessitates the presence of life—the life of a conscious observer. We will briefly describe this development and indicate some of its implications for our understanding of the nature of reality, and in particular the nature of life.

To begin, let us consider how modern physics uses quantum mechanics to describe atoms and molecules. In popular books these are often depicted as three-dimensional shapes; but this is misleading. In fact, quantum mechanics provides no natural description of three-dimensional objects in space. In quantum mechanics all natural phenomena are described by means of a mathematical construct called the wave function. The wave function can be represented as a three-dimensional arrangement only for a very simple system. For example, we can represent the hydrogen atom three-dimensionally if we regard the nucleus as a fixed point and only the electron as an active entity. However, the wave function for the helium atom (with two electrons) requires six dimensions, and that for the carbon atom (with six electrons) requires eighteen dimensions. In general, the wave function for an entity composed of n particles requires 3n dimensions. So, if we tried to quantum- mechanically represent the complex molecules found in living organisms, we would require wave functions involving many thousands of geometric dimensions.

Actually, it is a mistake to think of the wave function as a model of objective reality. Rather, we should understand it to be only a store of information about the results of observations that could be made by a particular observer. In quantum mechanics there is a system of computational procedures called “observables,” which one can apply to the wave function to predict the expected results of corresponding observations. The wave functions and observables can be reformulated mathematically in many different ways, the only requirement being that for each observation all the reformulations yield the same predicted value. Thus modern physics deals only with observations, whereas nineteenth century physics dealt with arrangements of matter in space.

In this connection Werner Heisenberg pointed out, “The conception of the objective reality of the elementary particles has thus evaporated ... into the transparent clarity of a mathematics that represents no longer the behavior of the elementary particles but rather our knowledge of this behavior.” (Italics added.) It has not been possible to regard this “knowledge” as a representation of actual entities, in which symbolic expressions correspond in a one-to- one relationship to what actually exists.

One feature of this “knowledge” is that it inevitably possesses some ambiguity. The famous Heisenberg uncertainty principle states that the degree of uncertainty in either the position or the momentum of an electron must be at least as great as a specific small quantity. Thus we cannot conceive of the electron as a definite object with a definite position and momentum; we are limited to speaking simply of observations of “position of an electron” or “momentum of an electron,” and we cannot think of the electron separately from the observer and his measuring apparatus.

Ambiguities and Paradoxes

According to the quantum theory, natural processes can amplify atomic ambiguity without limit. To illustrate such amplification, Erwin Schrodinger conceived his famous “cat paradox,” which we will describe here in a slightly modified form. Suppose someone attaches a bomb to a railroad track and then connects the bomb to a Geiger counter so that the decay of a radioactive atom will cause it to explode. We then have a scenario in which, say, the 5 P.M. express train will derail if the atom decays within a certain period, and it will not derail if it doesn’t. Suppose we can describe the entire scene, including the train and its passengers, by quantum mechanics (this is a big assumption). The quantum theory would then predict that at 5:01 the wave function describes a train that is both derailed and not derailed! (See Fig. 1.) The quantum mechanical ambiguity in the state of the atom has become enormously amplified, and the “knowledge” represented by the wave function has become ambiguous on a large scale.

The situation of the 5 P.M. express is a source of difficulty if we try to interpret the quantum theory as a description of objective reality. The wave function at 5:01 describes the passengers on the train as simultaneously experiencing the derailment of the train and its normal functioning. Since no one ever actually has such an experience, there must be some deficiency in the theory.

In practice physicists try to remedy this deficiency by redefining the wave function whenever it develops a degree of ambiguity that entails impossible experiences for an observer. It has not been possible to justify this redefinition in terms of either physical forces or any other natural principle of causation. Rather, the wave function is said to be redefined by absolute chance. In our train example, we would have to choose a new wave function that either unambiguously represents a derailed train, or unambiguously represents a normal train. We would have to make this choice before any observer might perceive an impossible ambiguity, but we could attribute the choice to no natural cause other than pure chance.

Much controversy has arisen over this process of redefinition, and we will not attempt to do justice to this issue here. We can conclude, however, that the only sensible way to interpret the quantum theory is as a system of knowledge about observations. It has not been possible to interpret the theory as a description of actual entities existing in space. Furthermore, we can conclude that the knowledge conveyed by the theory is inherently uncertain and sometimes in need of revisions that cannot be determined by any known principles.

Strictly speaking, then, we cannot describe the world on the basis of quantum theory without positing a region that contains the observer and that cannot be described by the theory. Some physicists have proposed that the boundary of this region should be drawn at the point where atomic ambiguities first become amplified to the macroscopic level. Others, such as John von Neumann, have tried to reduce this region to zero, and thus they have been forced to posit a nonphysical observer whom von Neumann called the “abstract ego.” In either case, difficulties and paradoxes arise, and the theory does not give an adequate account of the observer.

In addition, we cannot expect the quantum theory to give an adequate description of the gross behavior of living beings, even if we disregard their role as possible observers of events. The problem of ambiguity in the quantum theory suggests that it may be seriously incomplete, even as a description of the behavior of inanimate matter. What, then, to speak of the quantum theory’s description of the measurable behavior of living organisms? Even without undertaking the formidable calculations required to generate such a description, we can anticipate that it, too, will be inadequate.

Needed: a New Theory of Physics

From the above discussion, we can see the need for a new theory of physics—one resolving both the problem of ambiguity and that of the observer’s role. One prominent physicist, Eugene Wigner, has suggested that such a theory should directly take life into account. He has proposed that many of the principles, entities, and laws involved with life are presently unknown because they do not play a highly significant role in the nonliving phenomena on which the present theory is based.

In making this proposal, Wigner has also pointed out another deficiency of the quantum theory, one that must be shared by all purely mathematical descriptions of natural phenomena. This deficiency is the failure of the theory to give any account of consciousness. As Wigner points out, our knowledge of our consciousness is primary, and our knowledge of all other things is the content of our consciousness. Thus consciousness exists, even though the arrays of numbers appearing in mathematical theories say nothing about it. A theory that truly accounts for life must deal with consciousness, and this means that the theory cannot be exclusively quantitative in nature.

Let us briefly describe how the Bhagavad-gita gives an outline for such a theory. Although the conceptions presented in the Bhagavad-gita are not at all compatible with the mechanistic worldview presently favored in the life sciences, they take on new relevance when we consider the dilemmas faced by modern physics.

Insights into the Enigmas

The Bhagavad-gita (18.61)describes the living organism as follows:

ishvarah sarva-bhutanam
hrid-deshe ’rjuna tishthati
bhramayan sarva-bhutani
yantrarudhani mayaya

This verse describes the organism as a machine (yantra) made of material energy, and to this degree the verse agrees with the mechanistic views of the biologists. However, it further says that the conscious self rides in this machine as a passenger, and that the machine is being directed by the Supreme Lord in His aspect as material controller (ishvarah), also known as paramatma. Elsewhere the Bhagavad-gita describes the paramatma as all-pervading and as the source of all material senses and qualities (Bg. 13.14-15). The paramatma directs the material apparatus through laws (summarily described as the modes of material nature) that are ultimately psychological in character.

In a very general way, the paramatma corresponds to the natural laws of the physicists, which are regarded as invariant in time and space and as the ultimate causal principles underlying all material phenomena. However, the paramatma possesses all-pervading consciousness, as well as unlimited qualities, and is thus not susceptible to complete description in mathematical terms.

The psychological modes by which the paramatma directs nature may be susceptible to quantitative description to some extent. These modes of nature correspond to the higher laws and entities Wigner felt would be necessary in any adequate theory of life. In the limiting case involving only inanimate matter, these higher laws should approximate the natural laws physicists have deduced from their observations of matter. However, in cases involving living beings, we may expect to find many phenomena that obey higher psychological laws but that defy explanation within the existing theories of physics.

By adjusting the actions of the material energy in accordance with both the modes of nature and the desires of the individual conscious living entities, the paramatma acts as the intermediary between these beings and the observable phenomena of nature. Thus the Bhagavad-gita provides a framework for understanding the nature of the observer and the nature of the observer’s interaction with matter. We can see that this is quite relevant to modern physics if we recall that the quantum theory is essentially a description of observations, and that the theory’s account of the observer and the process of observation is beset with serious difficulties.

At present we may find it extremely difficult to bridge the gap between the Bhagavad-gita’s description of the paramatma and the known laws of physics. Yet it is important to realize that modern scientific knowledge by no means rules out the possibility that both nature and the living beings have attributes lying far beyond the scope of our present theories. By remaining open to conceptions of life much broader than the limited mechanistic view, scientists will lose nothing. Rather, they may gain a deeper insight into both the perplexing enigmas of modern physics and the profound view of life presented in the Bhagavad-gita.