*Reference: **A Logical Approach to Theoretical Physics*

Einstein replaced the classical concept of stationary aether of uniform density by *a mathematical object that is neither stationary nor in motion, and which has no substance.* If correct results are obtained from the mathematics of relativity, then Einstein’s mathematical object is likely equivalent to a fast moving substance of variable density.

The general notion of substance is anything that can be felt or detected because it has “innate force”. The substance may, therefore, be expressed as matter, the flowing electronic fluid, or the rapidly traveling light. Even the far reaching gravitational force may be classified as substance.

**Einstein replaced the classical concept of stationary aether of uniform density by a mathematical object of no substance. **

*NOTE: The 19th century concept of “stationary aether” was discredited, and correctly so. There is no stationary and uniform aether. But there is aether in the original sense of substance. Currently physics narrowly identifies the word “substance” with matter. Light is not matter, but, more correctly, light is a substance.*

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## The Original Aether

The word *aether*
denoted the ‘upper atmosphere’ and by extension the ‘substance that permeated
the cosmos,’ from which the stars and planets were made. The word *substance* denoted the ‘essence’ of
something substantial; and the word *cosmos*
denoted ‘order’ pointing to the orderliness of creation. Aether, in this sense,
is the substance of this universe. Aether then expresses itself as light and also
as the stars that shine so brightly.

The original aether may be described by the following spectrum of substance:

- Black Hole material
- Nuclear matter
- Electronic particles
- Gamma radiation
- X-ray radiation
- Ultraviolet radiation
- Visible radiation
- Infrared radiation
- Terahertz radiation
- Microwave radiation
- Radio waves
- Gravity
- Space
- Void
- Emptiness

The material objects are described in terms of their mass. The electromagnetic substance is described in terms of its frequency. Matter at the upper end is made up of very high frequencies. Space at the lower end denotes very low frequency. As frequency approaches zero we approach the void.

**The physical substance thins out continually from Black hole to
Emptiness.**

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## Substance and Geometry

Accompanying the idea of substance is the mathematical abstraction of geometry. Space represents the boundaries of matter. Void represents the boundaries of all substance.

The centers of mass of material bodies are represented by geometrical points. The centers “touch” each other through their intervening force, represented by geometrical distances.

The geometric distances are filled with forces and substances of variable density. The variable density is represented by interplay of durations, or motion.

The fourth dimension is not time but “duration” of substance, which may be represented objectively by mass density (or force density).

Each point in a space-duration reference frame has three spatial dimensions and a dimension of duration represented by density, frequency or inverse of velocity. This tells us that distances shall be much shorter if all densities are uniform and equal to the density of matter.

**The space-duration reference frame is a more objective representation of the mathematically subjective space-time reference frame of Einstein. **

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