Reference: Postulate Mechanics (PM)
The dimension of Substantiality may be described through infinity of sub-dimensions; but the sub-dimensions that stand out are substance, space and time.
The most obvious substance is matter. The smallest particle of matter is called an atom. An atom has volume, which determines its space. An atom also has a duration, which determines its time. Therefore, substance (atom), space and time are intimately related to each other, though we may study them separately.
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The Substance (Atom)
Atom is a good place to start because it contains the whole spectrum of substance, which is matter, energy and thought.
The real matter is the most concentrated form of substance that constitutes the nucleus of the atom. It is extremely dense, small and rigid. We may call it ‘solid substance.’
Much less concentrated form of substance constitutes the rest of the atom. It is made of electrons that are quite fluid and not that rigid. Since they have motion, we may associate them with energy. We may call this electronic region to be made up of ‘liquid substance.’
The interatomic space is filled with least concentrated form of substance, which is referred to as radiation. It is made of quanta that is extremely fluid and has extreme motion. We definitely associate radiation with energy. We may call this interatomic region to be filled with ‘gaseous substance.’
The atomic model is the result of a large number of experiments. This model is consistent in itself as well as with all the experimental observations. We associate this model with thought. We may call it the ‘mental substance’ of atom.
Thus, in atom we find the whole spectrum of substance from matter to energy to thought.
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The Space
As far as we can see, the substance is infinite, and so is space. The space is considered to be filled with substance. We may say that space demarcates the extents of substance. Substance and space go hand in hand.
We consider the space of an object to be filled with matter. In general, we measure empty space as if it is going to be filled with matter. The subject of school geometry treats space in that manner. However, the theory of relativity treats empty space as if it is filled with energy. The space of an atom and its surroundings is filled with both matter and energy. The empty space that we imagine is actually filled with ‘mental substance’ or thought. That is the space in which our dreams exist.
Space is actually an extension of substance. Space cannot exist in the absence of substance.
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The Time
The stars, the sun, the moon, and the planets appear to be existing forever. Their permanent endurance seems to provide us with the background of infinite time. Against this background we see things, that have lesser duration or time, moving and changing.
As the thickness of the substance changes from matter to energy inside the atom, we observe increased motion. Increasing motion means that the substance is less fixed in space. In other words, it has lesser duration. Energy is much lesser duration or time than matter.
Thought or mental substance also has varying durations, or time. For example, fixed ideas and beliefs have very long durations; and general attention of a person has much less duration, or time.
Time shows how dynamic a substance is. Time cannot exist in the absence of substance.
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Substantiality
We encounter substantiality all over the place in the universe. Substance has extents (space) and duration (time). Space and time vary in their characteristics with the thickness of substance from matter to energy to thought.
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