The theory by Dewey B. Larson’s is built-up from two basic postulates or notions:
To understand it, intensive study of some books (obligatory "Nothing But Motion") with open mind is recommended.
FIRST FUNDAMENTAL POSTULATE
“The physical universe is composed entirely of one component, Motion, existing in
three dimensions, in discrete units, and with two reciprocal aspects, space and
time" (with Time in 3 dimensions like Space)
SECOND FUNDAMENTAL POSTULATE
“The physical universe conforms to the relations of ordinary commutative
mathematics, its primary magnitudes are absolute, and its geometry is Euclidean.”
In contrast to conventional physics, where the basic assumption is some
"material particle" (particles of the atom......) here the basic assumption ist MOTION.
Motion=Space/Time (both 3-dimensional) - analog 1-dimensional v=s/t
There is a steady "progression" (flow) of the Motion - we experience the linear ("distance") aspect of a
flowing time and the spatial expansion of the universe
Instead of zero speed we have 1 as reference.
1 = basic unit = speed of light
conventional speed expressed as: 1/n (with n=units of speed)
fasterThanLightSpeed: n (units of speed)
So there are two interwoven "sectors" of the universe:
the "material" sector with speed under the speed of light
the "cosmic" sector with speed greater than light
Time and Space are reciprocal aspects of MOTION
the "two sides of a coin" or "Yin-Yang"