Section II: Space as the Fundamental Substance, and Aether, from "Is Space the Only Substance in the Universe|?"

II.                   SPACE AS THE ULTIMATE SUBSTANCE, AN “AETHEREAL” DISCOURSE

One Logical “Short Leap” Forward Changes Everything

The name applied to this proposal is the “Nothing but Space” model, but this will be open to future changes in terminology. The basic thesis or Fundamental Principle is that many of the unsolved mysteries of science could be unraveled by conceiving of space as not only a component of the universe, but as the fundamental substance of which the universe is made, as well as the medium of fields.  Matter, energy, and anything else that exists would consist of processes including waves and additions/deletions of quantized space, with discrete, constant, universal units. Most of what is proposed here as flows logically, directly or indirectly, as hypotheses from that Fundamental Principle.  It is a single but critical step forward toward unity and simplicity of physical theory.

            This is actually not far from currently accepted theory, and therefore should not be rejected out of hand. It is a logical next step from currently accepted concepts that will be reviewed in this article, including that space has physical properties, that it is expanding, that particles have wave equivalents, that familiar mechanical waves require material media to transmit them, and that in the absence of an aether, we have nothing but space itself to serve as such a medium where matter cannot fill that role. Yet this short conceptual “quantum leap” has apparently rarely been previously taken by physicists, probably because it seems to defy both human intuition and physics orthodoxy.

            In recent years, a number of both professional and amateur scientists and philosophers have continued to express dissatisfaction with current theories, and to explore solutions to the mysteries of space and matter in which either space or spacetime is a fundamental substance and/or medium. Much of this work has been self-published or posted on the Internet without peer review. Goodman (1994), in a self-published book, presaged the Fundamental Principle by proposing that all forms of matter and energy are vibrations of space itself, propagating at the speed of light, or a flow of space. Schaffer (2009), a philosopher, called spacetime “the one substance.” He supported the view that regions of spacetime define material objects, and claimed that DesCartes had held a similar view. LaFreniére (2009) said that matter and energy are entirely made of waves, and attempted to characterize some of them graphically. He described the electron as a spherical standing wave.  Hobson (2013), a physicist, dared to assert that there are no particles, only waves.

            Lindner (2015), a physician and philosophy of physics scholar, assailed modern physics theory on philosophical grounds, as being mathematical but not relating to actual cosmic entities, and called for a theory of space. He proposed that gravity is due to space flowing into matter, but did not say why that occurs or what becomes of the space. Ryan, another philosopher, published a book, “The Substance of Spacetime” (2016), in which he characterized spacetime as the fundamental substance on which both matter and energy depend.  (See also “Space as a Substance; Substantivalism” below.) Information on other such past theorists with similar views is welcomed, so they can be appropriately cited and credited.  These innovative thinkers have not extrapolated the implications of space as the ultimate substance as extensively as has been attempted in the present paper, to all of physics and of physical reality.

            The ontology of the proposed model differs from traditional lay concepts. It suggests that rather than assuming things other than space exist and have properties, things may instead be entirely defined by their properties. This is reasonable, because in history, humans have first become aware of properties, then have decided or learned what to attribute them to. Thus, we sense that solid objects fall to earth, and that it takes energy to move them. We are taught to call those properties gravity and inertia, and to attribute them to a hypothetical substance called mass, and another concept called matter if the mass occupies space. However, mass may not necessarily have independent existence and then just happen for some reason to have properties of gravity and inertia. Manor (2015) distinguished that inertia, not mass, increases with velocity, suggesting that these properties are separable. We should focus on the properties we detect, and see whether scientific evidence suggests that they may be associated with something else. In this model, gravity and inertia are all associated with waves and other processes in space.

            “Other processes in space,” a term utilized throughout this article, is meant to include  vibrations and seemingly random motion of units of space. Also included are additions and deletions of units of space, both as general trends of expansion or contraction and as to-and-fro oscillations of individual or small groups of units.

            Energy and its various types are other hypothetical entities to which we attribute various properties that we experience. Heat and sound are examples of how properties can be attributed to phantom entities. Each seems like a real “something” to us, but actually consists of motion or waves within a medium. Sound is produced by vibrations, the energy of which is transmitted to mechanical waves transmitted by any medium of matter, gaseous, liquid, or "solid."           

            Heat can be described as being an entity that causes molecular motion, but can more simply be defined as being molecular motion. This eliminates the unnecessary theoretical conception of a separate and independent heat entity. The energy of the molecular motion is interconvertible to radiant heat, which is the range of electromagnetic waves (mostly in the infrared spectrum) that can most easily be generated by moving molecules, and can conversely cause molecules to move.  

            Analogously to sound and heat actually being processes in mechanical media, matter and energy are proposed in the present model to be inter-convertible processes occurring within the medium of space. These either consist of or capable of generating waves in that medium.

Space as a Substance; Substantivalism

A common conception of space, dating to antiquity, is that it consists of nothingness. Leucippus, Democritus and Lucretius wrote that the world was constructed out of “atoms and the void,” and the void was a truly empty place. This concept persisted in Epicurean philosophy during the Greek and Roman periods. (Stanford Encyclopedia of Philosophy 2016).  However, not all classical philosophers thought that space was devoid of properties.   Plato, in his work Timaeus, described physical bodies (matter) as a part of space limited by geometric surfaces, themselves containing nothing but space (Jammer, 1954). 

            During later centuries, philosophers debated whether space was a substance of some kind. Philosophers who argued that space and time exist in their own right were called substantivalists, while relationalists were those who disagreed. Newton supported the substantivalist position, but his views were nuanced. He thought that absolute space was definitely not material, yet it was part of the physical, not mental, realm. Newton described space as what might be called a “pseudo-substance,” “more like a substance than a descriptive property, yet not quite a substance” (Huggett & Hoefer 2021).  Maudlin (1993) did a historical and philosophical review and found substantivalist arguments stronger. Schaffer (2009) claimed that most philosophers today  are substantivalists, and distinguished between dualistic substantivalism (material objects being one substance and regions of spacetime being another, which he admitted is the more natural and popular view), vs. monistic substantivalism which he supported (comprised of several schools of thought in which spacetime defines material objects). P. Jackson (2012) argued strongly against the persistent idea that space is nothing, proposing that if instead it is considered as a “diffuse dielectric medium” of intergalactic extent, it should be helpful in unifying relativity with “quantum systems.”  

            In support of its being a substance, space has a number of physical properties on its own. It conducts electromagnetic waves and gravitation, and their fields and quantum wave functions exist within space. Space also allows matter to exist within it and to travel through it. Its expansion implies that it is “something” that can be increased. Dimensions and geometry of course depend on space. Ruh (2022) derived a number of real properties of space including pressure and density.

            Space has permittivity and permeability. Permittivity measures the resistance offered by the material in the formation of an electric field, while permeability measures the ability of the material to allow the magnetic lines of force to pass through it (Byju’s 2021).                      

            One of the most definitive properties of space is an apparent limiting velocity for anything passing through it, which we refer to in equations as c, the speed of light. Characteristics like these strongly suggest that space is an integral and essential component of the universe. 

            What then exists beyond the extent of our universe? Since the 1950s, Everett and some other theoretical physicists have proposed a hypothetical multiverse consisting of multiple universes, a concept long found in ancient Greek philosophy and Eastern religions. Speculation is possible that an irregularity found in the cosmic microwave background radiation could be due to collision with another universe, however today’s experimental physics cannot receive any information from beyond the universe we know, so hypotheses about other universes cannot be experimentally tested or verified for now (Fernandez 2020).  They are utilized in science fiction (Koboldt 2021), but also seem an appropriate and serious ongoing topic for the philosophy of science. What the present model suggests, however, is that the universe is not surrounded by space, because space is what is inside and not outside the universe.

The Aether Hypothesis and Space

From Aristotle in the 4^th century B.C. until 1887, most scientists believed in a hypothetical "luminiferous aether" as a medium that filled space and conducted light, but the Michelson-Morley experiment that year showed it not to be a medium that could speed up or retard the speed of light, by means of its own motion relative to the observers on earth. Many scientists thereafter ceased to believe in an aether altogether (Ball 2004, Pilkington 2004).

            That seemed to leave just “empty space,” with no additional substance to take over the properties that had previously been assigned to the aether, including being the medium for transmission of light waves and gravity.  Yet for some reason, the reassignment of those properties to space itself as a substance apparently has rarely been seriously proposed. The dots have all been there but apparently were rarely connected fully. Descartes, though, may have presaged this concept, because he used the words aether and space synonymously (Pilkington 2004). 

            Einstein had evolving views about the existence of an aether. His special relativity theory made no reference to such a substance and he was widely credited with having destroyed the concept of it. However, 15 years after introducing special relativity and 5 years after introducing general relativity, he delivered a lecture at the University of Leiden that included these selected remarks (translated; highlighting added):

…The next position which it was possible to take up in face of this state of things appeared to be the following. The aether does not exist at all. The electromagnetic fields are not states of a medium, and are not bound down to any bearer, but they are independent realities which are not reducible to anything else, exactly like the atoms of ponderable matter…Certainly, from the standpoint of the special theory of relativity, the aether hypothesis appears at first to be an empty hypothesis… But on the other hand there is a weighty argument to be adduced in favour of the aether hypothesis. To deny the aether is ultimately to assume that empty space has no physical qualities whatever…Newton objectivizes space. Since he classes his absolute space together with real things, for him rotation relative to an absolute space is also something real. Newton might no less well have called his absolute space "aether”…More careful reflection teaches us however, that the special theory of relativity does not compel us to deny aether. We may assume the existence of an aether; only we must give up ascribing a definite state of motion to it…We shall see later that this point of view…is justified by the results of the general theory of relativity…Recapitulating, we may say that according to the general theory of relativity space is endowed with physical qualities; in this sense, therefore, there exists an ether… (Einstein, 1920).

            Thus, Einstein acknowledged that Newton could have accepted absolute space as the “aether” medium, and he seemed to imply that he could as well, and that the term aether could be applied to the ability of space to carry out its many properties.

            In the “Nothing but Space” model, no medium other than space is required for transmission of gravitational effects and electromagnetic waves. Space also can be considered to be made up of basic minimum units, unchanging in size, time, or location, as building blocks. The advantages of such a conception are discussed further below.

Units of Space

The fundamental units of space are probably related to Planck units. It turns out to be meaningless to consider anything smaller than a cubic Planck length, which equals approximately 1.616255*10⁻³⁵ meter, because physics breaks down for anything smaller than that due to quantum effects. Likewise, the shortest time interval that can be measured is a Planck second, the length of time for light to traverse a Planck length. The radius of a quark, considered as a “point particle” in QCD theory, is now estimated at 0.43 x 10⁻¹⁸ m, larger by an order of 10¹⁷ than a Planck length (Center for Perfection Studies 2014; Butterworth 2018).

            The smallest possible basic units of space, which could not be composed of anything smaller or simpler, would therefore likely be cubic Planck lengths. Units containing a larger volume of space might each be capable of carrying energy information in each, but so could collections of multiple, multi-functional, minimum-size units involved in a wave.  A new term, “volon,” is proposed for the fundamental volume unit of space, in the style of electron, proton, etc., to represent a unit of volume.  No association is intended with any past or present commercial or other unrelated use of the term, or to Rousseau’s term “volonté” to refer to the general will (e.g., https://www.masarishop.com/brands/the-volon.html).  

            In Figure 1, “volons” are represented as tiny cubes, but they could be tiny blobs without fixed shapes that fit together. There could even be tiny gaps between them if conceptualized according to Euclidean geometry (or the geometries of special and general relativity). As discussed immediately below, any geometrical system is a theoretical framework or grid to localize events in space, which may approximate reality but not necessarily conform perfectly to it.  If there were indeed geometric gaps between units of space, those could not themselves be referred to as “space.”

            Such quantum-scale units of space are reminiscent of the quantum-scale loops of spacetime in loop quantum gravity theory (Rovelli 2008). That theory similarly postulates quantized units of spacetime (though not simply of space). In the course of over a century that both general relativity and quantum theory have existed, this and many other efforts (including string theories) have been proposed to develop a theory of quantum gravity, but none have yet been considered complete or have been generally accepted (Wood 2019; Rovelli 2008).  This leaves an opening for the present model, which may involve simpler mathematics because only three dimensions need to be considered at a time, and complex metric tensors in curvilinear spacetime may be unnecessary.  .

Questioning the Reality of Dimensionless Points, “Singularities,” and Infinity

Euclidean geometry, about 2,400 years old and historically the second most studied reference after the Bible, has concepts that are abstract and theoretical rather than real, for example definitions that imply the existence of points without dimensions, lines with only one dimension and that can extend straight indefinitely regardless of the curvature of space, and surfaces with no thickness (Norton 2022).  There is no evidence that any of these exist in reality. The geometries of special relativity with 4-dimensional spacetime, and of general relativity with curbed spacetime, contradict Euclid and are similarly hypothetical.

            Points would have to occupy at least “volon” size, lines and flat surfaces would have to have at least “volon” thickness and to occupy three-dimensional space, which violates the Euclidean definitions. Lines could not be truly straight, because they would be curved by space deletions and additions. Waves and quantum uncertainty also require distributions in space and cannot exist in dimensionless points. These contradictions do not negate the usefulness of Euclidean geometry for mathematical problem-solving, but are important when considering the reality of such concepts as “singularities” and “point particles” in physics and cosmology theories. LaFrenière (2009) preferred to refer to points as granules, “because a point cannot exist.”

             A “singularity” would be infinitely small with no volume, so there is no way it would contain, generate, or destroy anything.  Since physics would break down in such entities (Walchover 2018), it seems unwise to include them in major physics theories like the “Big Bang” or black holes. Nothing infinitely large or small in space or time has ever been identified, even though the concept of approaching it as a limit is useful in calculus, so the concept of any actual infinity should be excluded from physics theories.

The Dimensions of it All                                                      

No comprehensive modern theory of the universe seems to be able to make do with only our familiar three dimensions. Special and general relativity require four. Current string theories depend on the existence of ten or eleven (Melbeus & Ohlsson 2012). This new model includes the capacity for space to be deleted from or added to an existing manifold. If "volons" of three-dimensional space suddenly appear and disappear, the question naturally arises, where does this space go to or come from? A convenient way to imagine this is that there are three additional dimensions, to and from which space transfers.

            In the present proposed model, these extra dimensions would always be present, but we could not see them, because light (including the entire spectrum of electromagnetic radiation) as we know it is limited to transmission in only three of them. Hypothetically, there might be a different equivalent of light in the alternate dimensions.