This is Essay CXVII of Mr. Stolyarov’s series, “A Rational Cosmology,” which seeks to present objective, absolute, rationally grounded views of terms such as universe, matter, volume, space, time, motion, sound, light, forces, fields, and even the higher-order concepts of life, consciousness, and volition. See the index of all the essays in “A Rational Cosmology” here.
This essay shall endeavor to show that in a universe with more than one entity and the presence of some observer, it is possible to define motion in absolute terms by holding a reference point mentally fixed.
In his remarks on the ideas in A Rational Cosmology, Mr. Fainberg writes the following about motion:
“Space has been defined in A Rational Cosmology as a relationship between two or more distinct entities. Space itself is not an entity and therefore cannot be the point of reference. This definition has an important corollary: contrary to Aristotle, there is no such a thing as absolute rest. In the hypothetical universe comprised of only one object, it would be impossible to determine if this object is moving or not. In the universe comprised of two objects, it would be impossible to determine which one of them is moving. The same principle applies to any number of objects. Every entity is resting or moving only relatively to another entity. Therefore, velocities of moving objects are relative to the object of reference, which can be voluntarily chosen.”
There is some truth in what Mr. Fainberg says here, and I would like to explain my understanding of it in the context of my views of space and of motion.
In a hypothetical one-object universe with no intelligent observer of that object, there is indeed no distinction between rest and motion and no way to determine whether that object moved or not — provided, of course, that the object has no component parts that move relative to each other.
However, if we, as observers, try to model the behavior of that object, we can do so via a three-dimensional Cartesian Coordinate System. We can designate some point on the object at time t as (0, 0, 0) on our coordinate system and hold that point mentally fixed. If the object departs from that point at some other time t+1, we can measure the object’s motion relative to (0, 0, 0) during one unit of time.
Of course, we as observers would not exist in a one-object universe by definition — since an observer would be a second entity introduced into the universe. It is true, then, that in order to determine whether any entity moves, some second entity is required (such as an intelligent observer, a measuring tool, or even an imagined point of reference which an intelligent observer needs to think of).
In a two-entity universe, however, it may well be possible to determine whether an object is at rest or in motion. One entity simply needs to be the observer himself; the observer notes the other entity’s position at time t and calls it (0, 0, 0). He remembers where (0, 0, 0) is and would be able to identify it even if no entity was there any longer. He can then compare the other entity’s subsequent positions with its position at time t and thus determine whether or not it moved.
This determination, of course, depends on the selection of an arbitrary fixed reference point — but any such point is as good as any other for finding that absolute motion occurs. For example, the observer himself might be moving away from (0, 0, 0) while he observes the other entity doing the same. In this two-object universe, it might be possible to say that both entities moved and how much they moved — because motion is calculated relative to a fixed and imagined reference point.
Since in our universe there exist more than two entities and we as observers also exist, it is possible to furnish an absolute definition of motion applicable to the world in which we live.
Read other parts of “A Rational Cosmology” by clicking here.