Preface

The source of all our knowledge about nature is the personal experience we gain by manipulating the things which we encounter in it. By exchanging this our personal experience with others, we attain to a common experience. Consequently, any theorizing we may do about nature should be consistent with our common experience. It was therefore with great unease that the scientific community came to realize at the turn of the last century that the theory it had developed to describe what was inside things contradicted our common experience with those very things themselves. If the entities which we presupposed populated the inside of things were to explain our common experience with those things, they would have to be thoroughly unlike any ordinary thing we had ever encountered. Thus, to take just one example, an electron does not possess a location despite the fact that all other particles we encounter in our experience do. Instead, the theory assigns to it only a probability of being found in a given location when a measurement inquiring after its position is actually performed. Prior to such a measurement, the electron is taken to be simultaneously in all possible locations in which it could possibly be found; in essence, the electron rests, not in any given state of specified position, but rather in a superposition of all such states. Bruce Rosenblum and Fred Kuttner of the University of California have recently described all the strange features of the constituents of things in their book Quantum Enigma: Physics Encounters Consciousness.

Naturally, this difference between the theory describing the constituents of things and the universal expectation that they would be just like the things they are supposed to constitute, engendered a wide-ranging debate within the community, a debate which sought to understand how some part of our experience could be so fundamentally unlike the rest of it. Throughout that debate, all participants agreed implicitly that atomic things were part of our common experience every bit as much as stones and fluids were, but they disagreed about whether their tendency to behave in a manner counter to our common sense was merely a temporary feature of a developing theory or whether it was a fundamental feature of it. Due principally to the unquestionable success that the new theory was having in explaining all of our experience with those phenomena which were related to the inside of things, the debate subsided; there are hardly any scientists today who entertain any doubt at all about the fact that quantum theory is the appropriate representation of how things look inside.

There is however a lingering debate going on about whether the strange way in which atomic entities seem to behave should really matter to us. Most people think not; constituents of things are what they are and, as long as the theory describing them works, we should not obsess too much about their failure to conform to our common sense. The Copenhagen settlement underlying this attitude is as follows. Constituents of things are objects of experience, except that they are so small compared to all other objects of experience, that we have no direct sensory access to them. Consequently, they must be approached with an observing apparatus. Since the apparatuses used to observe them are unavoidably much larger than atomic entities, these entities are bound to be uncontrollably disturbed by the act of observation and, therefore, what we can learn about them will be correspondingly limited. It is not that they necessarily lack the familiar properties of the things which we can directly approach; it is rather that we are not able to precisely ascertain just what values those properties might have. Naturally, when the size of the observed gets to be similar with the size of the apparatus observing it, these limitations ought to be lifted. And, in fact, quantum theory which describes the constituents of things, and classical theory which describes the things which are constituted of them, do approach each other when the size difference can be ignored.

But there is a dissenting view which is enabled by the very terms of the Copenhagen settlement itself. According to that settlement, while we cannot directly encounter the constituents of things, looking at atomic entities with an observing apparatus is as legitimate a way to experience them as it would have been encountering them with our senses. The dissenting view rejects this alternative way to experience. It asserts that we cannot become familiar with the constituents of things by any other means than direct encounter with them because using intermediary apparatuses to observe them always leaves us on the horns of a dilemma: are we seeing a real constituent through the apparatus or are we explaining the functioning of the observing apparatus by means of that constituent. On this view, therefore, we lack any experiential foundation for asserting that they are in fact objects of our experience. Of course, we may always simply suppose the constituents of things to be real, but then we are hardly justified in taking concrete steps to observe such a hypothetical entity as if it were a real thing.

Consequently, the notion that things in our common experience are thus possessed of two different manners of behaviour—one which is consistent with our common sense and one which is not—rests on a questionable foundation. In fact, to say that atomic entities are objects of experience is a mischaracterization: they are not objects of experience which, because of their small size, are not directly accessible to us; rather, they are not accessible to us at all because they are not objects of experience. On this dissenting view, quantum mechanics is not a description of how the objects inside things behave because they are not given to us to describe; rather, it is a conceptual structure axiomatically constructed by man in order to explain those phenomena which, like chemical, caloric, and optical phenomena, he naturally attributes to the inside of ordinary things. Modern science is not descriptive but axiomatic.

The axiomatic construct which modern science uses to explain these phenomena employs certain entities—such as molecules, atoms, electrons, protons, and so on—to imagine what is inside the things engaged in them. But what and how those entities are is not simply given to us from experience; what they are should rather be dictated by what the explanatory process requires of them. They are not objects of experience but objects of explanation. Identifying the ontological difference between these two objects requires that we focus attention on the manner in which the latter are what they are. This essay was written to address this issue. It explores the ontological character which quantum theory requires for its explanatory objects and contrasts it with the ontology of the objects we encounter in our daily activities.

The difference between them reflects the fact that the latter is given to us while the former is not. An object of explanation is not something we can simply find lying around like some piece of rock; if we wish to observe it, therefore, we must first give to ourselves by manufacturing it. Since we are not some God-like creature able to create things by fiat, and because the raison d'être of an object of explanation is to explain, this manufacturing process must somehow or other refer back to the explanation which was originally provided by the object we wish to manufacture. The simplest conception would be to incorporate into our observational set-up a re-creation of the experiential set-up which was previously explained by the object we are trying to manufacture. If, for instance, J.J. Thomson successfully explained what happens when we apply an electric potential between two pieces of metal located inside a vacuumed glass bottle by saying that electrons, emitted from the cathode travel towards the anode, then we are naturally inclined to also say that an electron gun, which after all is nothing but a replica of this neon-light-like set-up, is a generator of electrons; we can therefore use an electron gun to manufacture electrons.

This need for giving an object of explanation to ourselves by manufacturing it, is determinative of its ontology just as much as the reality we assign to an object of experience is determined by it being something given to us to encounter. The essay explores how this need determines the specific manner in which an object of explanation is what it is. This exploratory effort was helped by locating ourselves at the time when fundamental science questions were first asked rather than at the much later time when the answers were already well settled in. For at such later time, the incentive in the literature is to clarify and support the accepted answers with arguments and experimental evidence, while at the beginning other alternative answers were still possible. Consequently, we described the development of quantum mechanics not as the customary triumphal march of discovery recounted in standard historical texts, but rather as the thorny way of accommodation to the epistemological position that the scientific community had imposed upon itself when it decided that atomic entities were real but unapproachable.

Our analytic journey through modern science will lead us to an understanding which illuminates the reasons why quantum mechanics had to become the extremely successful but exceedingly strange theory that it is. The intrinsically probabilistic character of an atomic entity, for instance, as well as the attendant superposition of its states, is then a consequence of the theory having to consistently account for both the manufacturing and the observational set-ups which together constitute the act of observing a constituent of things.

No question is ever settled until it is settled right.