At last year’s ISUS convention, a number of individuals expressed difficulty in comprehending the difference between clock space and coordinate space and the difference between clock time and coordinate time. This note will review these concepts to aid the understanding of these individuals.
Larson states : “We begin with one-dimensional space s and one-dimensional time t…. Dividing space by time we obtain velocity s/t….” Space and time do not exist separately; they exist only as aspects of motion. Motion in the most general sense is thus a relation of space to time, and in the Reciprocal System space and time have no properties other than what they have as aspects of motion. In defining motion, we can start with units of space and time, as Larson did in the quotation, or with units of motion and define space and time as the two aspects of that motion; the definitions are equivalent.
The basic space-time unit is thus one-dimensional and is a progression. We reject the Relativity doctrine that space and time are joined in four-dimensional continuum and that space and time magnitudes are purely relative. From the postulates of the Reciprocal System we compute the absolute natural unit of space to be 4.558816×10-6 cm and the absolute natural unit of time to be 1.520655×10-16 sec. Their ration is 2.997930×1010 cm/sec, the speed of light. The progression originates everywhere and is thus omnipresent. Larson stats : “Unit velocity is a… true physical datum with a finite magnitude.” Thus we begin with clock space-time, rather than with coordinate space or coordinate time (or a combination of coordinate space with clock time). Conventional physicists (and individuals new to the Reciprocal System) keep trying to start with some type of 3-D or higher metric; we reject this approach entirely.
Coordinate space and coordinate time result from clock space and clock time. Larson explicitly states : “There is a general framework of the universe, an extension space, generated by translational motion….” ; likewise, there is an “extension” time, generated by translational motion, the progression. This motion is scalarly outward in all directions and thus the overall distribution of the 1-dimensional progressing units is 3-dimensional. In The Unmysterious Uniuerse , I wrote “…with respect to any particular progressing unit, coordinate space and coordinate time include all other progressing units…. The progression of a single unit of space is one-dimensional, but the progression of all space units is distributed in three-dimensions.” Stationary coordinate space (or stationary coordinate time) can arise only in the context of a gravitationally-bound material system (or cosmic system), in which the atoms of matter (or c-matter) have neutralized the space progression (or time progression).
When Larson states  that “undisplaced space-time is the physical equivalent of nothing” he means that a unit of space-time is not a photon, a sub-atom, an atom, or an electric or magnetic charge. These other entities are interchangeable, either directly or indirectly, but a unit of space-time is not. It cannot be changed into something else, and it cannot be used as an energy source. But this does not mean that space-time is “nothing”; it is unit motion, not zero motion, and is every bit as much an existent as anything physical. Larson says  “In terms of [a] building analogy, [space and time] correspond to the bricks of which the building [i.e., the universe] is to be constructed.”