Changing Concepts
of the Nature of Motion

Dewey B. Larson

When the theory of the universe of motion, the Reciprocal System of theory as we are calling it, was first being introduced to the scientific community in books and lectures, about twenty-five years ago, one of the principal obstacles with which we had to contend was the generally accepted concept of the nature of motion, in which motion is regarded as a continuous change in the position of some "thing" in a three-dimensional space that acts as a background or container. In the Reciprocal System of theory, motion is defined simply as a relation between space and time, which means that "things" do not participate in the simplest types of motion. For those who were not willing to entertain the possibility that their basic concept of the nature of motion might be wrong, this closed the door to any consideration of the new theory, in spite of the outstanding successes of that theory in dealing with the most recalcitrant and long-standing problems of physical science.

In the years that have followed, our activities aimed at promoting understanding of the theory have been directed primarily at those who are open-minded enough to recognize that the need for conceptual modifications cannot be ruled out. We have therefore been engaged mainly in extending the application of the theory and clarifying those points that have been questioned. However, now that a quarter of a century has elapsed, a new generation of scientists is coming in contact with these ideas, and the earlier questions about the basic concepts are resurfacing. A review of the fundamental situation therefore appears to be in order at this time.

This history of science clearly demonstrates that long-continued existence of a major scientific problem is rarely due to the lack of adequate methods of dealing with such problems, or to deficiencies in the abilities of the investigators. Almost without exception, when such a problem is finally solved it is found that the obstacle that has so long stood in the way of solution is an error in one of the fundamental concepts on which the previous thought has been based. Before any significant progress could be made it was necessary to change the conceptual base from which the problem had been viewed.

This is always a difficult undertaking. For example, the idea of inertia seems almost self-evident today, and even a schoolboy is able to grasp it. But, as Herbert Butterfield points out in his book The Origins of Modern Science, until the days of Galileo and Newton the problem that was finally solved by the formulation of this concept "defeated the greatest intellects for centuries." The then prevailing view of the nature of motion--the theory developed by Aristotle--"was hard for the human mind to escape from... because it was part of a system which was such a colossal intellectual feat in itself." Butterfield goes on to say:

This experience with Galileo's discovery illustrates the fact that we actually know very little about the basic structure of the universe. The concepts on which thinking about such subjects is based are not products of scientific investigation and research. They are the ideas that our early ancestors derived from observation of the world about them, and they have achieved their present unquestioning acceptance only because they have remained unchallenged for so long a time. When we subject them to a critical examination we find that they are not, in fact, derived directly from empirical observations. Instead, they are assumptions suggested by those observations.

For example, we know practically nothing about the nature and properties of time. We have a vague impression that it is some kind of a moving forward, and that is all that we have to work with. But time enters into every physical activity in one way or another, so in order to deal with those activities, we have to make assumptions about the properties of this almost totally unknown entity. Not one of these assumptions is free from doubts. Physical theory assumes that time is unidirectional, and one of our important physical principles, the Second Law of Thermodynamics, is based on this assumption, but the mathematics of motion are equally consistent with a reverse flow. The theory assumes, in nearly all applications, that the flow is uniform, but Relativity theory, which challenges this assumption in its field of application, is also generally accepted. The theory assumes that time is one dimensional, but the investigators working along the outer boundaries of science are continually advancing hypotheses that call for the existence of additional time dimensions.

Little more is actually known about the nature and properties of the other basic physical entities. The physicists cannot answer such questions as "What is matter?" or "What is an electric charge?" And the validity of the assumptions that are made about these entities is just as doubtful as that of the assumptions about time. No doubt many are valid statements of the physical facts. Perhaps most of them are. But it is totally unrealistic to take the stand that all of the assumptions that have been made about these poorly understood basic physical entities--at least 30 or 40 assumptions in all--are factual. And no one knows which ones are wrong. Furthermore, an error in one of these fundamental assumptions necessarily results in many errors in the structure of thought that rests on the fundamentals. Thus, there is no justification for rejecting a new theory simply because it conflicts with an existing idea or belief, or even if it conflicts with many aspects of previous thought. A conflict with the observed facts is, of course, fatal, but a conflict with previous theory, or assumption, is something that should be considered on its merits.

In Aristotle's concept of motion, it was assumed that continuous application of a force is necessary for production of a continuous motion. Galileo's conclusion from his experiments was that this assumption is wrong, and that motion continues on the same basis indefinitely unless a force is applied to change it. Direct verification of basic assumptions of this kind by means of observations is impossible, but we can develop the consequences of each of the rival assumptions and see which set of consequences agrees more closely with those observations. On this basis, Aristotle's concept was ultimately disproved and abandoned, after long and acrimonious controversy with those who refused to concede any possibility that their long-standing beliefs might be in need of revision.

The same kind of a situation now exists with respect to those aspects of motion that are redefined by the Reciprocal System of theory. Just as Galileo met an obstinate adherence to the dictum that "Continuous motion cannot exist without continuous application of force," so we are now told, just as positively, that "Motion cannot exist without something moving." Both of these confident pronouncements are pure assumptions. Neither has any support from observation. Indeed, both are specifically contradicted by modern astronomical observations. The motions of the planets, for instance, are incompatible with Aristotle's assumption. Similarly, the motions of the galaxies flatly contradict the assumption that underlies the twentieth-century motion concept.

The following assumptions enter into this concept:

The status of assumption 3 has always been somewhat dubious, in spite of its general acceptance, because there is no trace of the "something" in the mathematics of motion. It serves only to identify the motion under consideration. Where the motion can be identified in some other manner, the mathematics are equally applicable. The recent discovery of the recession of the galaxies has provided a definite refutation of the assumption. It is now generally conceded that the recession is not a movement of the galaxies themselves. The astronomers are agreed that they are being carried outward by what is called the "expansion of the universe."

This expression merely describes what is occurring; it does not explain anything. But whatever the nature of the "expansion" may be, it clearly must apply to all locations in space, not merely to those that are occupied by galaxies. Here, then, is a motion that is not a motion of any entity that could be called a "thing." Thus, the contention that there cannot be motion unless some "thing" is moving is refuted by actual observation. However, for the benefit of those to whom this kind of motion presents conceptual difficulties, we can legitimately say that it is motion of spatial locations. Each galaxy remains in a particular location, but the locations move outward.

Assumption 2 is likewise invalidated by the observed galactic recession. Galaxy X is receding from galaxy A, and at time t occupies a position on an extension of the line AX. But X is also receding from galaxy B, and at time t it also occupies a position on an extension of the line BX. When we take the other galaxies into account, it is evident that galaxy X does not occupy any specific position in the space of a universal "container." The invalidation of assumptions 2 and 3 makes assumption 1 untenable.

When we take the other galaxies into account, we find that galaxy X occupies all positions in what we ordinarily call "space" at a certain distance from the initial point of the motion. This is obviously incompatible with the concept of "space" as a container in which each physical object has a specific location, as asserted by assumption number 1. Indeed, it can be seen that the "space" and "time" of our ordinary experience are not physical entities at all; they are merely mental constructs that constitute a reference system which we use for relating the quantities of space and time that do have an actual physical existence, those that take part in the various motions of which the universe is composed.

Furthermore, this is an incomplete reference system. It is not capable of representing the positions of the receding galaxies in their true character. It can represent only the positions relative to some reference point. Nor is this its only deficiency. Our investigations have shown that there are a number of other types of motions that, like the scalar motion of the galaxies, it cannot represent correctly, and still others, such as motion in more than one dimension, that it cannot represent at all. What we are up against here is a range of variability of physical motion (relations between space and time) that far exceeds the capability of any system of reference that has thus far been devised.

However, when the space and time of our ordinary experience, extension space, as we may call it, is viewed in its true capacity as a reference system, it is easy to see that there is no obstacle in the way of representing a simple motion, one that is not motion of anything. As defined by the theory of the universe of motion, this simple motion is a relation between a quantity of space and a quantity of time, and is measured as speed. If we specify an initial point we can represent the amount of space corresponding to any given amount of time by a line in the reference system extending away from the initial point. Obviously, there is no need to identify this line with any "thing."

Thus, the conceptual basis of the explanation of the nature of motion embodied in the postulates of the Reciprocal System is just as rational and logical as that of the currently accepted theories. It is merely different. The question as to which of the two is correct is not a matter of which one we like better. It is an issue that can be settled by the same procedure that was used to resolve the analogous questions raised by Galileo; that is by developing the consequences of each hypothesis and comparing the results with the relevant observations and measurements. There can be no doubt of the verdict if all of the evidence is examined. As we have shown in our publications, the theory of the universe of motion produces the kind of a comprehensive and fully integrated general physical theory that has long been sought, but never before even approached.

In looking back on the history of the development of thought with respect to the nature of motion prior to the acceptance of the concept of inertia, a striking feature of the situation is the extent to which Aristotle and his disciples were forced to call upon the actions of "angels" and other hypothetical existences to take care of gaps in their explanations of physical phenomena. As Butterfield puts it, Aristotle's universe was one "in which unseen hands had to be in constant operation." The great achievement of Galileo and Newton was to put the science of mechanics on a sound physical, rather than metaphysical, basis.

Today, physics in general is the same kind of a position that mechanics occupied before Galileo. The physicists have built a structure of rather loosely related theories that have had some spectacular successes--another "colossal intellectual feat." But like Aristotle's system, "modern physics" has many gaps in its structure, and to fill those gaps, or at least to conceal them, the modern theorists have resorted to the same expedient that was employed by Aristotle. In their universe, too, as in his, "unseen hands" must be in continual operation.

Of course, present-day scientists do not speak of "angels" or "demons," but the mysterious "forces" of modern physics are exactly the same things under different names. They are pure inventions, designed to overcome specific difficulties in accepted theory, with no other functions to perform, and with no independent evidence of their existence (that is, no evidence other than that they agree with the observations that they were specifically designed to fit). Aside from the name, there is nothing to distinguish the "nuclear force" that holds the hypothetical nucleus of the atom together for the modern physicist from the "angels" that pushed the planets along in their paths for Aristotle. No reason is given for the existence of these strangely limited "forces," nor are we given any explanation of how they operate. "We do not ask how mass gets a grip on space-time and causes the curvature which our theory postulates," says Arthur Eddington.

The problems in mechanics could not be solved without paying the price--to many a very high price--of giving up some cherished ideas and beliefs of long standing. But, the rewards were enormous. Again quoting Butterfield:

The world of science now faces the same kind of an issue. If the scientific community recognizes that a number of the basic assumptions of present-day physics have been invalidated by modern discoveries such as the recession of the galaxies and the interconvertibility of matter and non-matter, then some of the ideas that are now hailed as the "greatest achievements of science" must be discarded in favor of new--and to some, disturbing--concepts. But once more, as in Galileo's day, the door will be opened to "a flood of further discoveries."

The theory of the universe of motion, in its present stage of development, accounts for all of the major physical phenomena, and a large and growing assortment of subsidiary phenomena as well, by pure deduction from a single set of basic premises, without the introduction of any supplementary assumptions. A particularly significant point is that this deductive development accounts for the existence of the basic physical entities--matter, radiation, electricity, etc.--as well as the properties of those entities.

In the quarter of a century since the first publication of the theory no one has attempted to refute the foregoing statement. Those who reject the theory invariably do so on the ground that the conclusions derived from the theoretical development conflict with some of the generally accepted ideas, which, of course, they do. Sooner or later, perhaps when the devastating effect that recent empirical discoveries have had on the basic assumptions of "modern physics," are more generally recognized, the scientific community will find it necessary to face this issue, rather than continuing to evade it. In the meantime, we will continue extending the application of the theory into additional areas and into more detail, each step in this process adding to the already overwhelming mass of evidence confirming the validity of the development as a whole.