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<front>
<journal-meta>
<journal-id journal-id-type="publisher-id">Front. Phys.</journal-id>
<journal-title-group>
<journal-title>Frontiers in Physics</journal-title>
<abbrev-journal-title abbrev-type="pubmed">Front. Phys.</abbrev-journal-title>
</journal-title-group>
<issn pub-type="epub">2296-424X</issn>
<publisher>
<publisher-name>Frontiers Media S.A.</publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id pub-id-type="publisher-id">1737947</article-id>
<article-id pub-id-type="doi">10.3389/fphy.2026.1737947</article-id>
<article-version article-version-type="Version of Record" vocab="NISO-RP-8-2008"/>
<article-categories>
<subj-group subj-group-type="heading">
<subject>Hypothesis and Theory</subject>
</subj-group>
</article-categories>
<title-group>
<article-title>Concept of quantum wave gravitation in the Euclidean model of space and time</article-title>
<alt-title alt-title-type="left-running-head">Machotka</alt-title>
<alt-title alt-title-type="right-running-head">
<ext-link ext-link-type="uri" xlink:href="https://doi.org/10.3389/fphy.2026.1737947">10.3389/fphy.2026.1737947</ext-link>
</alt-title>
</title-group>
<contrib-group>
<contrib contrib-type="author" corresp="yes">
<name>
<surname>Machotka</surname>
<given-names>Radovan</given-names>
</name>
<xref ref-type="aff" rid="aff1"/>
<xref ref-type="corresp" rid="c001">&#x2a;</xref>
<uri xlink:href="https://loop.frontiersin.org/people/2907661"/>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="Writing &#x2013; original draft" vocab-term-identifier="https://credit.niso.org/contributor-roles/writing-original-draft/">Writing &#x2013; original draft</role>
<role vocab="credit" vocab-identifier="https://credit.niso.org/" vocab-term="Writing &#x2013; review &#x26; editing" vocab-term-identifier="https://credit.niso.org/contributor-roles/Writing - review &#x26; editing/">Writing &#x2013; review and editing</role>
</contrib>
</contrib-group>
<aff id="aff1">
<institution>Brno University of Technology, Faculty of Civil Engineering, Institute of Geodesy</institution>, <city>Brno</city>, <country country="CZ">Czechia</country>
</aff>
<author-notes>
<corresp id="c001">
<label>&#x2a;</label>Correspondence: Radovan Machotka, <email xlink:href="mailto:machotka.r@vutbr.cz">machotka.r@vutbr.cz</email>
</corresp>
</author-notes>
<pub-date publication-format="electronic" date-type="pub" iso-8601-date="2026-02-19">
<day>19</day>
<month>02</month>
<year>2026</year>
</pub-date>
<pub-date publication-format="electronic" date-type="collection">
<year>2026</year>
</pub-date>
<volume>14</volume>
<elocation-id>1737947</elocation-id>
<history>
<date date-type="received">
<day>02</day>
<month>11</month>
<year>2025</year>
</date>
<date date-type="rev-recd">
<day>14</day>
<month>01</month>
<year>2026</year>
</date>
<date date-type="accepted">
<day>19</day>
<month>01</month>
<year>2026</year>
</date>
</history>
<permissions>
<copyright-statement>Copyright &#xa9; 2026 Machotka.</copyright-statement>
<copyright-year>2026</copyright-year>
<copyright-holder>Machotka</copyright-holder>
<license>
<ali:license_ref start_date="2026-02-19">https://creativecommons.org/licenses/by/4.0/</ali:license_ref>
<license-p>This is an open-access article distributed under the terms of the <ext-link ext-link-type="uri" xlink:href="https://creativecommons.org/licenses/by/4.0/">Creative Commons Attribution License (CC BY)</ext-link>. The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.</license-p>
</license>
</permissions>
<abstract>
<p>The Euclidean Model of Space and Time (EMST) was created as an alternative to the Special Theory of Relativity (STR) and the associated concept of spacetime. This model subsequently proved successful in describing elementary particles of matter and their wave properties in accordance with de Broglie&#x2019;s hypothesis. The model is based on a four-dimensional Euclidean space with one compactified dimension, thus differing fundamentally from Minkowski&#x2019;s (pseudo-Euclidean) space of STR. The fundamental contribution of the EMST lies in the integration of relativity and the wave properties of matter into a single theoretical framework. A logical step in the further development of the EMST as a unified physical concept is the formulation of a theory of gravitation. The article contains the foundations, justifications, and basic mathematical derivations of a scalar theory of gravitation, based exclusively on the wave nature of matter. It demonstrates the primary cause of gravitational action of one particle of matter on another, reveals the common origin of inertial and gravitational forces, and derives the Schwarzschild metric. It also shows small deviations from Newton&#x2019;s and Einstein&#x2019;s gravitation.</p>
</abstract>
<kwd-group>
<kwd>de Broglie waves</kwd>
<kwd>energy conservation</kwd>
<kwd>Euclidean metric</kwd>
<kwd>redshift</kwd>
<kwd>relativity</kwd>
<kwd>time dilation</kwd>
<kwd>variable speed of light</kwd>
<kwd>wave nature of matter</kwd>
</kwd-group>
<funding-group>
<funding-statement>The author(s) declared that financial support was received for this work and/or its publication. The author would like to thank Brno University of Technology for supporting this research under project No. FAST-S-25-8850.</funding-statement>
</funding-group>
<counts>
<fig-count count="6"/>
<table-count count="0"/>
<equation-count count="55"/>
<ref-count count="27"/>
<page-count count="00"/>
</counts>
<custom-meta-group>
<custom-meta>
<meta-name>section-at-acceptance</meta-name>
<meta-value>Cosmology</meta-value>
</custom-meta>
</custom-meta-group>
</article-meta>
</front>
<body>
<sec sec-type="intro" id="s1">
<label>1</label>
<title>Introduction</title>
<p>Gravitation, as the most universal physical force, is currently explained by the General Theory of Relativity (GTR), i.e., as a consequence of the curvature of space-time by matter [<xref ref-type="bibr" rid="B1">1</xref>]. The GTR is based on the Special Theory of Relativity (STR) [<xref ref-type="bibr" rid="B2">2</xref>] and shares its basic concept. However, conceptual problems within the STR, (e.g., [<xref ref-type="bibr" rid="B3">3</xref>&#x2013;<xref ref-type="bibr" rid="B6">6</xref>]) lead to its repeated questioning and attempts to find an alternative theory. One of these is the concept known as the Euclidean Model of Space and Time (EMST). The EMST, although created on different foundations than STR, leads to the same mathematical formulas and the same physical predictions. It is therefore potentially capable of replacing STR throughout its entire scope of validity [<xref ref-type="bibr" rid="B7">7</xref>]. At the same time, it is aimed to be compatible with the wave nature of matter and de Broglie&#x2019;s theorem of phase harmony [<xref ref-type="bibr" rid="B8">8</xref>]. It thus offers a connection between the so far incompatible understanding of relativity and the wave properties of matter. The EMST offers a unified explanation of relativistic and quantum phenomena at a fundamental level, which calls for increased attention to be paid to this different concept of space and time. The concept is still largely hypothetical, but the author has found no physical experiments that contradict it.</p>
<p>A logical and necessary step in the further development of the EMST as a fundamental physical concept describing the nature of space, time, and matter is the formulation of a theory of gravitation. This is the subject of this article. The EMST-based concept of the scalar theory of gravitation described hereafter has the potential to replace the GTR. Its aim is to demonstrate the potential of the EMST to provide a uniform explanation of quantum and relativistic phenomena and thus create a unified picture of the physical world. This is only a theoretical concept of theory of gravitation; a rigorous mathematical presentation of this theory in the form of tensor field equations will follow as the next step.</p>
<p>The basic considerations underlying theory of gravitation in the EMST concept are:<list list-type="order">
<list-item>
<p>According to the EMST, elementary particles of matter (so-called particle-waves) move in four-dimensional space E<sub>4</sub>-B at a uniform speed <italic>v</italic>
<sub>
<italic>4D</italic>
</sub>. If we were to assume that <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> could be locally variable in space, the motion of particle-waves would not be uniform and straight, but uneven and curved. The particle-waves would behave as if they were affected by external &#x201c;invisible&#x201d; forces. Given the universal influence of the <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> on all particle-waves in the space E<sub>4</sub>-B, this would explain the effect of gravitation on all matter. The value of the <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> would also influence the flow of time.</p>
</list-item>
<list-item>
<p>It can be shown that in an accelerated system S&#x2032;, the <italic>v</italic>
<sub>
<italic>4D</italic>
</sub>
<italic>&#x2019;</italic> is locally variable and causes bending of particle-waves trajectories. The origin of gravitational and inertial forces is therefore in principle the same, as claimed by the &#x201c;principle of equivalence&#x201d; &#x2013; the cornerstone of GTR. This means that the description of inertia and gravitation within the EMST is similar to their description in the GTR and will probably lead to identical mathematical formulas.</p>
</list-item>
<list-item>
<p>The local variability of <italic>v</italic>
<sub>
<italic>4D</italic>
</sub>
<italic>&#x2019;</italic> in an accelerating system explains the inertial properties of bodies, e.g., Newton&#x2019;s law of inertia. However, it does not explain the general gravitational interaction between bodies (e.g., the gravitational action of the Sun on the planets). It is therefore necessary to find the source of gravitation, i.e., the source of variability of <italic>v</italic>
<sub>
<italic>4D</italic>
</sub>, as a consequence of the presence of matter.</p>
</list-item>
</list>
</p>
<p>A detailed description of the EMST (without gravitation) is given in [<xref ref-type="bibr" rid="B7">7</xref>, <xref ref-type="bibr" rid="B8">8</xref>]. For the purposes of this article, it will be necessary to recall the basic principles and differences from STR and the concept of spacetime (Minkowski space).</p>
<p>The original &#x201c;nongravitational&#x201d; version of the EMST is based on subsequent postulates:<list list-type="order">
<list-item>
<p>Physical space E<sub>4</sub>-B is four-dimensional Euclidean space with all dimensions being spacelike. The fourth space dimension is bounded (compactified).</p>
</list-item>
<list-item>
<p>The medium filling physical space (so called transmission medium) is non-dispersive, homogenous and isotropic. This medium does not move with respect to E<sub>4</sub>-B.</p>
</list-item>
<list-item>
<p>All matter has wave nature and moves through transmission medium in the form of traveling waves. The 4D speed of particles of matter (particle-waves) is determined by the properties of the transmission medium filling physical space and is equal to the speed of light in a vacuum.</p>
</list-item>
<list-item>
<p>The total energy of particles of matter (particle-waves) is given by Planck&#x2019;s relation <italic>E &#x3d; h f</italic>.</p>
</list-item>
</list>
</p>
<p>The meaning of specific terms used in the postulates will be clarified later in this chapter.</p>
<p>The postulates differ significantly from the postulates of GTR and cover both relativistic and, to some extent, also quantum physics. The justification for the postulates can be found in [<xref ref-type="bibr" rid="B7">7</xref>] (postulate 1) and in [<xref ref-type="bibr" rid="B8">8</xref>] (postulates 2, 3, Chap. 2). Postulate 4 is based on Planck&#x2019;s law and the photoelectric effect; the other postulates are not directly motivated by the interpretation of specific physical experiments. However, their interaction leads to the same results as the postulates of STR, i.e., they explain, for example, the zero result of the well-known Michelson&#x2013;Morley experiment [7, Sect. 5.1]. Postulates 2 and 3 replaced the original &#x201c;4D speed invariance postulate&#x201d; introduced in [7, Sect. 3.2].</p>
<p>The foundations of classical (i.e., non-relativistic) physics and the above postulates are the starting points for deriving all the mathematical relations of the EMST presented in this article.</p>
<p>The EMST assumes the existence of partially bounded Euclidean space E<sub>4</sub>-B. E<sub>4</sub>-B is the usual Euclidean space E<sub>3</sub> (<italic>x, y, z</italic>) supplemented by a fourth bounded (compactified) dimension <italic>w</italic>. This dimension is miniature compared to the other three and therefore invisible on a macroscopic scale. Elementary particles of matter (particle-waves) are so small that they can move even in this dimension. Their movement in it is cyclical. One cycle corresponds to a trajectory 2.43 &#xd7; 10<sup>&#x2212;12</sup> m [<xref ref-type="bibr" rid="B8">8</xref>], which is the wavelength of the lightest massive particle-wave, the electron. The topology of the fourth dimension and the shape of the path along which particle-waves move in this dimension are not important for the purposes of this article.</p>
<p>Macroscopically observable objects are composed of a large number of particle-waves. Their fourth dimension (<italic>w</italic>) is many orders of magnitude smaller (at the level of 10<sup>&#x2013;12</sup> m) than the other three and therefore imperceptible. As a result, the macroscopic objects have three dominant dimensions, and as a whole, can only move in three dimensions (<italic>x, y, z</italic>). All objects and the entire physical space therefore appear to be three-dimensional. To describe the behavior of macroscopic (i.e., composite) bodies, it suffices to consider velocities, accelerations, or potential fields only in three-dimensional space E<sub>3</sub>.</p>
<p>The transmission medium is a hypothetical medium filling the E<sub>4</sub>-B space. As a whole, the medium is at rest relative to the E<sub>4</sub>-B space, but it allows energy to move in the form of waves. These are real waves of the transmission medium, i.e., small cyclic displacements of the medium relative to its equilibrium position. The speed of energy motion in the form of traveling waves is determined by physical properties of the medium &#x2013; these are the same at all points of space E<sub>4</sub>-B (the transmission medium is homogeneous, isotropic, and non-dispersive), so the speed of wave motion is always the same (without the presence of gravitation). The nature of the transmission medium is not known; from the EMST point of view, it is not matter, but an environment through which matter in the form of waves moves.</p>
<p>The coordinate system associated with the transmission medium is referred to as the &#x201c;stationary coordinate system&#x201d; and is the preferred frame of reference. However, its existence does not preclude the existence of other seemingly equivalent coordinate systems as well as &#x201c;relativistic phenomena&#x201d; in the form they are observed. The subject is discussed in detail in [<xref ref-type="bibr" rid="B7">7</xref>].</p>
<p>From the EMST point of view, all matter has a wave nature. Matter is a wave motion of transmission medium, motion of energy in space E<sub>4</sub>-B in the form of localized wave packets (so-called particles-waves). The particle-waves are the fundamental building blocks of matter in all its forms (condensed matter, radiation, fields, etc.). It is irrelevant whether they are massive or massless, whether they are bosons or fermions; from the EMST perspective, they are all considered &#x201c;particles of matter.&#x201d; The particle-waves include leptons, quarks, as well as gauge bosons. The &#x201c;particle-waves&#x201d; is just another name for objects that we commonly refer to as &#x201c;particles.&#x201d; The altered name merely emphasizes their wave nature.</p>
<p>The speed of particle-waves in space E<sub>4</sub>-B (speed <italic>v</italic>
<sub>
<italic>4D</italic>
</sub>) is determined by the properties of the transmission medium (see above). Experiments with photons show that the <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> is equal to the speed of light (<italic>v</italic>
<sub>
<italic>4D</italic>
</sub> &#x3d; c). The speed <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> at which particle-waves move in the space E<sub>4</sub>-B, is not generally identical to the commonly observed &#x201c;three-dimensional speed&#x201d; <italic>v</italic>
<sub>
<italic>3D</italic>
</sub> in the space E<sub>3</sub>. The speed <italic>v</italic>
<sub>
<italic>3D</italic>
</sub> is the orthogonal projection of the <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> from the space E<sub>4</sub>-B into the space E<sub>3</sub>. The following formula applies:<disp-formula id="e1">
<mml:math id="m1">
<mml:mrow>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:msqrt>
<mml:mrow>
<mml:msubsup>
<mml:mi>v</mml:mi>
<mml:mi>x</mml:mi>
<mml:mn>2</mml:mn>
</mml:msubsup>
<mml:mo>&#x2b;</mml:mo>
<mml:msubsup>
<mml:mi>v</mml:mi>
<mml:mi>y</mml:mi>
<mml:mn>2</mml:mn>
</mml:msubsup>
<mml:mo>&#x2b;</mml:mo>
<mml:msubsup>
<mml:mi>v</mml:mi>
<mml:mi>z</mml:mi>
<mml:mn>2</mml:mn>
</mml:msubsup>
<mml:mo>&#x2b;</mml:mo>
<mml:msubsup>
<mml:mi>v</mml:mi>
<mml:mi>w</mml:mi>
<mml:mn>2</mml:mn>
</mml:msubsup>
</mml:mrow>
</mml:msqrt>
<mml:mo>&#x3d;</mml:mo>
<mml:msqrt>
<mml:mrow>
<mml:msubsup>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>3</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
<mml:mn>2</mml:mn>
</mml:msubsup>
<mml:mo>&#x2b;</mml:mo>
<mml:msubsup>
<mml:mi>v</mml:mi>
<mml:mi>w</mml:mi>
<mml:mn>2</mml:mn>
</mml:msubsup>
</mml:mrow>
</mml:msqrt>
</mml:mrow>
</mml:math>
<label>(1)</label>
</disp-formula>
</p>
<p>The quantities <italic>v</italic>
<sub>
<italic>x</italic>
</sub>, <italic>v</italic>
<sub>
<italic>y</italic>
</sub>, <italic>v</italic>
<sub>
<italic>z</italic>
</sub>, and <italic>v</italic>
<sub>
<italic>w</italic>
</sub> are velocities in the individual coordinate axes, where <italic>v</italic>
<sub>
<italic>x</italic>
</sub> <italic>&#x3d; &#x3b4;x/&#x3b4;t</italic>, <italic>v</italic>
<sub>
<italic>y</italic>
</sub> <italic>&#x3d; &#x3b4;y/&#x3b4;t</italic>, <italic>v</italic>
<sub>
<italic>z</italic>
</sub> <italic>&#x3d; &#x3b4;z/&#x3b4;t</italic> and <italic>v</italic>
<sub>
<italic>w</italic>
</sub> <italic>&#x3d; &#x3b4;w/&#x3b4;t</italic>. Here <italic>&#x3b4;x</italic>, <italic>&#x3b4;y</italic>, <italic>&#x3b4;z</italic> and <italic>&#x3b4;w</italic> are infinitesimal differences in coordinates, and <italic>&#x3b4;t</italic> is an infinitesimal increment in the coordinate time <italic>t</italic>. The terms &#x201c;4D speed&#x201d; and &#x201c;3D speed&#x201d; will be used in the text to distinguish <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> from ordinary speed <italic>v</italic>
<sub>
<italic>3D</italic>
</sub>.</p>
<p>From the perspective of E<sub>4</sub>-B, the particle-waves are always in motion, but from the perspective of macroscopically perceived space E<sub>3</sub>, this may not necessarily be so. The compactified dimension <italic>w</italic> allows motion of particle-waves without changing their <italic>x, y, z</italic> coordinates. Such particle-waves are at rest from the viewpoint of E<sub>3</sub>. On the contrary, photons and other particle-waves with zero rest mass do not move in dimension <italic>w</italic> (<italic>v</italic>
<sub>
<italic>w</italic>
</sub> &#x3d; 0). Their 3D speed is equal to their 4D speed (<italic>v</italic>
<sub>
<italic>3D</italic>
</sub> &#x3d; <italic>v</italic>
<sub>
<italic>4D</italic>
</sub>).</p>
<p>Time in the EMST is measured by the number of particle-wave cycles in dimension <italic>w</italic>. Each particle-wave thus represents a kind of clock &#x2013; it measures its own time. The speed at which these &#x201c;clocks&#x201d; run depends on their state of motion, as shown in [<xref ref-type="bibr" rid="B7">7</xref>]. Like STR, EMST distinguishes between two types of time &#x2013; coordinate time <italic>t</italic> and proper time <italic>&#x3c4;</italic>. Proper time is measured by the cycles of the relevant particle-wave, coordinate time by the cycles of a hypothetical particle-wave at the origin of the coordinate system. The relationship for kinematic time dilation is the same in EMST as in STR [7, Sect. 4.1].</p>
<p>Any particle-wave is a quantum of energy and is indivisible. Its dimensions are non-zero (it is a wave) and its total energy is given by the Planck relation,<disp-formula id="e2">
<mml:math id="m2">
<mml:mrow>
<mml:mi>E</mml:mi>
<mml:mo>&#x3d;</mml:mo>
<mml:mi>h</mml:mi>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mi>f</mml:mi>
</mml:mrow>
</mml:math>
<label>(2)</label>
</disp-formula>where <italic>f</italic> is its frequency and <italic>h</italic> is the Planck constant. Frequency is expressed as the number of cycles per unit of coordinate time. The same particle-wave can therefore have different frequencies depending on the rate of the reference clock. A change in the reference coordinate system (and thus the reference clock) causes a change in the energy of particle-waves. In physics, a change in the total energy of a particle-wave is interpreted as a change in its kinetic or potential energy (depending on the cause of the change).</p>
<p>It should be noted that the frequency of a particle-wave and the frequency of its cyclic motion in the fourth dimension are two different quantities. Their relationship is explained in [8, Sect. 4.3].</p>
<p>The relationship between energy <italic>E</italic> and 4D momentum <italic>p</italic>
<sub>
<italic>4D</italic>
</sub> of a particle-wave can be derived from the second law of motion. Let us consider the change in energy <italic>dE</italic> of a particle-wave due to a change in its momentum <italic>dp</italic>. The particle-wave moves at a speed <inline-formula id="inf1">
<mml:math id="m3">
<mml:mrow>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:mi>d</mml:mi>
<mml:mi>s</mml:mi>
<mml:mo>/</mml:mo>
<mml:mi>d</mml:mi>
<mml:mi>t</mml:mi>
</mml:mrow>
</mml:math>
</inline-formula>, and therefore <inline-formula id="inf2">
<mml:math id="m4">
<mml:mrow>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:mi>d</mml:mi>
<mml:mi>p</mml:mi>
<mml:mo>/</mml:mo>
<mml:mi>d</mml:mi>
<mml:mi>t</mml:mi>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mi>d</mml:mi>
<mml:mi>s</mml:mi>
<mml:mo>&#x3d;</mml:mo>
<mml:mi>F</mml:mi>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mi>d</mml:mi>
<mml:mi>s</mml:mi>
</mml:mrow>
</mml:math>
</inline-formula>. This relationship can be rewritten as <inline-formula id="inf3">
<mml:math id="m5">
<mml:mrow>
<mml:mi>d</mml:mi>
<mml:mi>p</mml:mi>
<mml:mtext>&#x2009;</mml:mtext>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:mi>d</mml:mi>
<mml:mi>E</mml:mi>
</mml:mrow>
</mml:math>
</inline-formula>. Since <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> is a constant in this case, the following formula holds:<disp-formula id="e3">
<mml:math id="m6">
<mml:mrow>
<mml:msub>
<mml:mi>p</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:mi>E</mml:mi>
<mml:mo>/</mml:mo>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
</mml:mrow>
</mml:math>
<label>(3)</label>
</disp-formula>
</p>
<p>Considering <inline-formula id="inf4">
<mml:math id="m7">
<mml:mrow>
<mml:msub>
<mml:mi>&#x3bb;</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
<mml:mo>/</mml:mo>
<mml:mi>f</mml:mi>
</mml:mrow>
</mml:math>
</inline-formula> and substituting (<xref ref-type="disp-formula" rid="e2">Equation 2</xref>) into (<xref ref-type="disp-formula" rid="e3">Equation 3</xref>), we obtain an alternative relationship<disp-formula id="e4">
<mml:math id="m8">
<mml:mrow>
<mml:msub>
<mml:mi>p</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:mi>h</mml:mi>
<mml:mo>/</mml:mo>
<mml:msub>
<mml:mi>&#x3bb;</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
</mml:mrow>
</mml:math>
<label>(4)</label>
</disp-formula>where <italic>&#x3bb;</italic>
<sub>
<italic>4D</italic>
</sub> is particle-wave wavelength in space E<sub>4</sub>-B. Relation (<xref ref-type="disp-formula" rid="e4">Equation 4</xref>) is a four-dimensional variant of the well-known de Broglie relation for particle momentum. Manifestations of this relation in E<sub>3</sub> space are described in [8, Sect. 3.1].</p>
<p>For the momentum of any body, the general relation <italic>p &#x3d; m v</italic> applies. In the case of four-dimensional space, we can write <inline-formula id="inf5">
<mml:math id="m9">
<mml:mrow>
<mml:msub>
<mml:mi>p</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:msub>
<mml:mrow>
<mml:mi>m</mml:mi>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mi>v</mml:mi>
</mml:mrow>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula>. By combining this relation with (<xref ref-type="disp-formula" rid="e3">Equation 3</xref>), we obtain an analogue of Einstein&#x2019;s relation between mass <italic>m</italic> and energy <italic>E:</italic>
<disp-formula id="e5">
<mml:math id="m10">
<mml:mrow>
<mml:mi>E</mml:mi>
<mml:mo>&#x3d;</mml:mo>
<mml:mi>m</mml:mi>
<mml:mtext>&#x2009;</mml:mtext>
<mml:msup>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
<mml:mn>2</mml:mn>
</mml:msup>
</mml:mrow>
</mml:math>
<label>(5)</label>
</disp-formula>
</p>
<p>The EMST is based on space and time, i.e., length and time quantities. From its perspective, mass is not an independent, fundamental quantity. It can be determined from the frequency and 4D velocity of a particle-wave, using relations (<xref ref-type="disp-formula" rid="e2">Equations 2</xref>, <xref ref-type="disp-formula" rid="e5">5</xref>). As will be shown below, both the inertial and gravitational properties of particle-waves can be defined within EMST on the basis of the general properties of wave motion, i.e., without using the concept of mass.</p>
<p>Kinematic transformations of frequencies and wavelengths are discussed in detail in [<xref ref-type="bibr" rid="B8">8</xref>], so they are not included in this article. The formulas for energy and momentum transformation are based on them. It suffices to consider <xref ref-type="disp-formula" rid="e2">Equations 2</xref>, <xref ref-type="disp-formula" rid="e3">3</xref>.</p>
<p>For transformations between the stationary coordinate system S and the moving coordinate system S&#x2032;, the Lorentz transformation extended by a fifth equation applies [<xref ref-type="bibr" rid="B7">7</xref>]:<disp-formula id="equ1">
<mml:math id="m11">
<mml:mrow>
<mml:mi>&#x3b4;</mml:mi>
<mml:msup>
<mml:mi>x</mml:mi>
<mml:mo>&#x2032;</mml:mo>
</mml:msup>
<mml:mo>&#x3d;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mrow>
<mml:mi>&#x3b4;</mml:mi>
<mml:mi>x</mml:mi>
</mml:mrow>
<mml:mo>&#x2212;</mml:mo>
<mml:mi>u</mml:mi>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mi>&#x3b4;</mml:mi>
<mml:mi>t</mml:mi>
</mml:mrow>
<mml:msqrt>
<mml:mrow>
<mml:mn>1</mml:mn>
<mml:mo>&#x2212;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:msup>
<mml:mi>u</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
</mml:mrow>
<mml:mrow>
<mml:msubsup>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
<mml:mn>2</mml:mn>
</mml:msubsup>
</mml:mrow>
</mml:mfrac>
</mml:mrow>
</mml:msqrt>
</mml:mfrac>
<mml:mo>,</mml:mo>
<mml:mspace width="1em"/>
<mml:mi>&#x3b4;</mml:mi>
<mml:msup>
<mml:mi>y</mml:mi>
<mml:mo>&#x2032;</mml:mo>
</mml:msup>
<mml:mo>&#x3d;</mml:mo>
<mml:mi>&#x3b4;</mml:mi>
<mml:mi>y</mml:mi>
<mml:mo>,</mml:mo>
<mml:mspace width="1em"/>
<mml:mi>&#x3b4;</mml:mi>
<mml:msup>
<mml:mi>z</mml:mi>
<mml:mo>&#x2032;</mml:mo>
</mml:msup>
<mml:mo>&#x3d;</mml:mo>
<mml:mi>&#x3b4;</mml:mi>
<mml:mi>z</mml:mi>
<mml:mo>,</mml:mo>
<mml:mspace width="1em"/>
<mml:mi>&#x3b4;</mml:mi>
<mml:msup>
<mml:mi>w</mml:mi>
<mml:mo>&#x2032;</mml:mo>
</mml:msup>
<mml:mo>&#x3d;</mml:mo>
<mml:mi>&#x3b4;</mml:mi>
<mml:mi>w</mml:mi>
<mml:mo>,</mml:mo>
<mml:mspace width="1em"/>
<mml:mi>&#x3b4;</mml:mi>
<mml:msup>
<mml:mi>t</mml:mi>
<mml:mo>&#x2032;</mml:mo>
</mml:msup>
<mml:mo>&#x3d;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mi>&#x3b4;</mml:mi>
<mml:mi>t</mml:mi>
<mml:mo>&#x2212;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mi>u</mml:mi>
</mml:mrow>
<mml:mrow>
<mml:msubsup>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
<mml:mn>2</mml:mn>
</mml:msubsup>
</mml:mrow>
</mml:mfrac>
<mml:mi>&#x3b4;</mml:mi>
<mml:mi>x</mml:mi>
</mml:mrow>
<mml:msqrt>
<mml:mrow>
<mml:mn>1</mml:mn>
<mml:mo>&#x2212;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:msup>
<mml:mi>u</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
</mml:mrow>
<mml:mrow>
<mml:msubsup>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
<mml:mn>2</mml:mn>
</mml:msubsup>
</mml:mrow>
</mml:mfrac>
</mml:mrow>
</mml:msqrt>
</mml:mfrac>
</mml:mrow>
</mml:math>
</disp-formula>
</p>
<p>The quantity <italic>u</italic> is the speed of motion of S&#x2032; with respect to S. It is a 3D speed since coordinate systems rigidly coupled to macroscopic objects cannot move in the fourth dimension.</p>
<p>In the space E<sub>4</sub>-B, the Euclidean metric is given by the following formula:<disp-formula id="e6">
<mml:math id="m12">
<mml:mrow>
<mml:msubsup>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
<mml:mn>2</mml:mn>
</mml:msubsup>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mi>&#x3b4;</mml:mi>
<mml:msup>
<mml:mi>t</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
<mml:mo>&#x3d;</mml:mo>
<mml:mi>&#x3b4;</mml:mi>
<mml:msup>
<mml:mi>x</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
<mml:mo>&#x2b;</mml:mo>
<mml:mi>&#x3b4;</mml:mi>
<mml:msup>
<mml:mi>y</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
<mml:mo>&#x2b;</mml:mo>
<mml:mi>&#x3b4;</mml:mi>
<mml:msup>
<mml:mi>z</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
<mml:mo>&#x2b;</mml:mo>
<mml:mi>&#x3b4;</mml:mi>
<mml:msup>
<mml:mi>w</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
</mml:mrow>
</mml:math>
<label>(6)</label>
</disp-formula>
</p>
<p>The quantity <inline-formula id="inf6">
<mml:math id="m13">
<mml:mrow>
<mml:mi>&#x3b4;</mml:mi>
<mml:mi>s</mml:mi>
<mml:mo>&#x3d;</mml:mo>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mi>&#x3b4;</mml:mi>
<mml:mi>t</mml:mi>
</mml:mrow>
</mml:math>
</inline-formula> is a measure of the distance between two infinitesimally close points in the space E<sub>4</sub>-B and, at the same time, a measure of the time necessary to travel it (<italic>&#x3b4;t</italic>). The increment of the coordinate <italic>w</italic>, which is connected to the flow of proper time <italic>&#x3c4;</italic>, has a specific meaning. In the case of zero motion in E<sub>3</sub> (<italic>&#x3b4;x &#x3d; &#x3b4;y &#x3d; &#x3b4;z &#x3d; 0</italic>), the following formula applies:<disp-formula id="e7">
<mml:math id="m14">
<mml:mrow>
<mml:mi>&#x3b4;</mml:mi>
<mml:mi>t</mml:mi>
<mml:mo>&#x3d;</mml:mo>
<mml:mi>&#x3b4;</mml:mi>
<mml:mi>&#x3c4;</mml:mi>
<mml:mo>&#x3d;</mml:mo>
<mml:mi>&#x3b4;</mml:mi>
<mml:mi>w</mml:mi>
<mml:mo>/</mml:mo>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
</mml:mrow>
</mml:math>
<label>(7)</label>
</disp-formula>
</p>
</sec>
<sec id="s2">
<label>2</label>
<title>Theory of gravitation</title>
<sec id="s2-1">
<label>2.1</label>
<title>Influence of variable <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> on the flow of time</title>
<p>Previous articles concerning EMST [<xref ref-type="bibr" rid="B7">7</xref>, <xref ref-type="bibr" rid="B8">8</xref>] were based on the assumption, that the value of <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> is constant, or more precisely, that <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> &#x3d; c, where <italic>c</italic> is the speed of light in a vacuum. For the theory of gravitation, it is necessary to abandon this assumption. Let us now assume that the speed <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> is locally and temporally variable in the stationary coordinate system S. Each point in space E<sub>4</sub>-B (<italic>x, y, z, w</italic>) at coordinate time <italic>t</italic> can be assigned a value <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> <italic>&#x3d; f(x, y, z, w, t)</italic>, where <italic>f</italic> is a continuous differentiable function. The quantity <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> is a scalar field in space E<sub>4</sub>-B.</p>
<p>The rate of flow of coordinate time <italic>t</italic> is directly related to the value of <italic>v</italic>
<sub>
<italic>4D</italic>
</sub>. This clearly arises from the metric (<xref ref-type="disp-formula" rid="e6">Equation 6</xref>). The time <italic>&#x3b4;t</italic> required to move a particle-wave by given values <italic>&#x3b4;x</italic>, <italic>&#x3b4;y</italic>, <italic>&#x3b4;z</italic>, <italic>&#x3b4;w</italic> is the greater, the lower the value of <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> is.</p>
<p>The same effect also affects the flow of proper time, and thus also the running of clocks. It follows from relation (<xref ref-type="disp-formula" rid="e7">Equation 7</xref>) that the value of <italic>&#x3b4;&#x3c4;</italic> increases as <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> decreases. Since we always measure proper time by the number of repetitions of a regularly recurring event (e.g., the oscillation of a quartz crystal, the frequency of radiation coming from the electron shell of cesium, etc.), there will be fewer repetitions when <italic>&#x3b4;&#x3c4;</italic> is larger, and the clock will show a smaller increase in time. This phenomenon affects all clocks regardless of their design &#x2013; the fact was first discussed by A. Einstein in [<xref ref-type="bibr" rid="B9">9</xref>]. In the terminology of Einstein&#x2019;s theory of relativity, this is a &#x201c;universal effect&#x201d; independent of the design of the clock.</p>
<p>Clocks affected only by universal effects, i.e., not affected by the specific design of the particular clock, will be referred to as &#x201c;ideal&#x201d;. All further considerations will be based on the use of ideal clocks for time measurements.</p>
<p>As an example of the ideal clock, we can use the so-called particle clock. It is a particle-wave moving cyclically in dimension w. One cycle of the particle-wave is equal to one &#x201c;tick&#x201d; of the clock. The time between ticks is given by the length of the particle-wave&#x2019;s path and the speed of its motion. It is clear that the speed of the clock&#x2019;s &#x201c;ticking&#x201d; is directly proportional to the value of <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> (for an invariant path), (<xref ref-type="fig" rid="F1">Figure 1</xref>).</p>
<fig id="F1" position="float">
<label>FIGURE 1</label>
<caption>
<p>Simplified geometric model of the particle clock. The clock is based on the motion of the particle-wave in dimension <italic>w</italic>. On the left, the clock is at rest (<italic>v</italic>
<sub>
<italic>3D</italic>
</sub> &#x3d; 0); on the right, the clock is moving in the direction of the <italic>x</italic>-axis. The time between ticks depends on the speed of the particle-wave (<italic>v</italic>
<sub>
<italic>4D</italic>
</sub>) and the 3D speed of the clock (<italic>v</italic>
<sub>
<italic>3D</italic>
</sub>).</p>
</caption>
<graphic xlink:href="fphy-14-1737947-g001.tif">
<alt-text content-type="machine-generated">Two diagrams depict velocity vectors. The left diagram shows a vertical arrow labeled \(v_{4D}\) with \(v_{3D} &#x3d; 0\) and &#x22;TICK!&#x22; at its base. The right diagram shows a triangle with vectors \(v_{3D}\), \(v_{4D}\), and \(v_w\). Both diagrams have horizontal lines at the top and base. Axes labeled \(w\) and \(x\) are present.</alt-text>
</graphic>
</fig>
<p>To consider the motion of clock in E<sub>3</sub>, we must replace <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> in relation (<xref ref-type="disp-formula" rid="e7">Equation 7</xref>) by <italic>v</italic>
<sub>
<italic>w</italic>
</sub> (<inline-formula id="inf7">
<mml:math id="m15">
<mml:mrow>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mi>w</mml:mi>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:msqrt>
<mml:mrow>
<mml:msubsup>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
<mml:mn>2</mml:mn>
</mml:msubsup>
<mml:mo>&#x2212;</mml:mo>
<mml:msubsup>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>3</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
<mml:mn>2</mml:mn>
</mml:msubsup>
</mml:mrow>
</mml:msqrt>
</mml:mrow>
</mml:math>
</inline-formula>, see <xref ref-type="disp-formula" rid="e1">Equation 1</xref>). The relation then takes the form <inline-formula id="inf8">
<mml:math id="m16">
<mml:mrow>
<mml:mi>&#x3b4;</mml:mi>
<mml:mi>&#x3c4;</mml:mi>
<mml:mo>&#x3d;</mml:mo>
<mml:msub>
<mml:mrow>
<mml:mi>&#x3b4;</mml:mi>
<mml:mi>w</mml:mi>
<mml:mo>/</mml:mo>
<mml:mi>v</mml:mi>
</mml:mrow>
<mml:mi>w</mml:mi>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula>. Alternatively, we can consider the prolongation of the particle-wave trajectory within a single cycle. In both cases, the result will be the same &#x2013; prolongation of the duration of a single tick means slower &#x201c;ticking&#x201d; rate.</p>
<p>The slowing down of the motion of particle-waves in E<sub>4</sub>-B and the slowing down of the clocks have the same origin and act against each other. If, in some part of space, the value of <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> is lower than <italic>c</italic> by, say, 1%, the particle-wave will travel the given path in objectively longer time (an increase of 1%), but the lower rate of the clock (a decrease of 1%) will completely compensate the effect. Therefore, the change in <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> speed will not be noticeable locally. The ratio of the path and the measured time will remain equal to c.</p>
<p>The change in speed <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> cannot be detected locally by any known method. It is the speed at which the fundamental building blocks of matter (i.e., the particle-waves) move, and therefore it affects all physical processes. It affects the speed of quarks, photons, and leptons, it determines the speed of electrons in the electron shells of atoms and the frequencies of their emitted photons. Since the time component of all ongoing processes is affected, as well as all related physical quantities (frequency, speed, acceleration, force, etc.), it is not possible to detect the change in <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> by their measurement and comparison.</p>
<p>However, the change in <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> can be detected at greater distances by comparison of the clock rates of a pair of ideal clocks 1 and 2. If these are located in areas with different <italic>v</italic>
<sub>
<italic>4D</italic>
</sub>, one clock will run slower than the other. The mutual ratio is given by<disp-formula id="e8">
<mml:math id="m17">
<mml:mrow>
<mml:mfrac>
<mml:mrow>
<mml:msub>
<mml:mrow>
<mml:mi>C</mml:mi>
<mml:mi>l</mml:mi>
<mml:mi>o</mml:mi>
<mml:mi>c</mml:mi>
<mml:mi>k</mml:mi>
<mml:mi>R</mml:mi>
<mml:mi>a</mml:mi>
<mml:mi>t</mml:mi>
<mml:mi>e</mml:mi>
</mml:mrow>
<mml:mn>1</mml:mn>
</mml:msub>
</mml:mrow>
<mml:mrow>
<mml:msub>
<mml:mrow>
<mml:mi>C</mml:mi>
<mml:mi>l</mml:mi>
<mml:mi>o</mml:mi>
<mml:mi>c</mml:mi>
<mml:mi>k</mml:mi>
<mml:mi>R</mml:mi>
<mml:mi>a</mml:mi>
<mml:mi>t</mml:mi>
<mml:mi>e</mml:mi>
</mml:mrow>
<mml:mn>2</mml:mn>
</mml:msub>
</mml:mrow>
</mml:mfrac>
<mml:mo>&#x3d;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
<mml:mo>,</mml:mo>
<mml:mn>1</mml:mn>
</mml:mrow>
</mml:msub>
</mml:mrow>
<mml:mrow>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
<mml:mo>,</mml:mo>
<mml:mn>2</mml:mn>
</mml:mrow>
</mml:msub>
</mml:mrow>
</mml:mfrac>
</mml:mrow>
</mml:math>
<label>(8)</label>
</disp-formula>where <italic>ClockRate</italic> is the number of &#x201c;ticks&#x201d; per selected time interval. By comparison of the mutual tick rates of remote clocks, regional variations in <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> can be determined. If an extensive network of ideal, mutually non-moving clocks were available, deviations in <italic>ClockRate</italic> would indicate regional variations in the value of <italic>v</italic>
<sub>
<italic>4D</italic>
</sub>, (<xref ref-type="fig" rid="F2">Figure 2</xref>).</p>
<fig id="F2" position="float">
<label>FIGURE 2</label>
<caption>
<p>A stationary clock located in a region of lower <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> runs provably slower than a stationary clock located in a region of higher <italic>v</italic>
<sub>
<italic>4D</italic>
</sub>. Variations may be caused, for example, by the presence of significant gravitational masses.</p>
</caption>
<graphic xlink:href="fphy-14-1737947-g002.tif">
<alt-text content-type="machine-generated">Diagram featuring a series of clocks with the notation \( v_{4D} &#x3d; c \). Most clocks are blue, indicating the speed \( v_{4D} \) equals the speed of light \( c \). One clock is red with \( v_{4D} &#x3C; c \) next to a circle labeled &#x22;M,&#x22; depicting a variation from the constant speed in four-dimensional space.</alt-text>
</graphic>
</fig>
</sec>
<sec id="s2-2">
<label>2.2</label>
<title>The relationship between <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> and particle-wave energy</title>
<p>In the following, we will assume that material bodies create a zone with a spatially variable value of <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> around themselves &#x2013; we will call this zone the gravitational field.</p>
<p>Let us consider a particle-wave, such as a photon, in the gravitational field. We will determine its frequency <italic>f</italic> using a clock (at rest) located in its immediate vicinity. If the photon moves freely downward in the gravitational field, its potential energy <italic>E</italic>
<sub>
<italic>p</italic>
</sub> will decrease, and its kinetic energy <italic>E</italic>
<sub>
<italic>k</italic>
</sub> will increase. According to the law of conservation of energy, its total energy <italic>E</italic> remains constant. The following generally applies to every particle-wave:<disp-formula id="e9">
<mml:math id="m18">
<mml:mrow>
<mml:mi>E</mml:mi>
<mml:mo>&#x3d;</mml:mo>
<mml:msub>
<mml:mi>E</mml:mi>
<mml:mn>0</mml:mn>
</mml:msub>
<mml:mo>&#x2b;</mml:mo>
<mml:msub>
<mml:mi>E</mml:mi>
<mml:mi>p</mml:mi>
</mml:msub>
<mml:mo>&#x2b;</mml:mo>
<mml:msub>
<mml:mi>E</mml:mi>
<mml:mi>k</mml:mi>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:mi>c</mml:mi>
<mml:mi>o</mml:mi>
<mml:mi>n</mml:mi>
<mml:mi>s</mml:mi>
<mml:mi>t</mml:mi>
</mml:mrow>
</mml:math>
<label>(9)</label>
</disp-formula>
</p>
<p>The quantity <italic>E</italic>
<sub>
<italic>0</italic>
</sub> is the rest energy of a particle-wave, which is zero (negligible) in the case of a photon. It should be noted that EMST does not distinguish between massive and massless particles and assigns potential energy to both. Its origin will be explained in Sect. 2.3.</p>
<p>Since the total energy <italic>E &#x3d; h f</italic> remains unchanged, <italic>f</italic> also remains unchanged. The frequency of a free-falling particle-wave does not change. However, its wavelength decreases together with decrease of <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> (<italic>&#x3bb;</italic>
<sub>
<italic>4D</italic>
</sub> <italic>&#x3d; v</italic>
<sub>
<italic>4D</italic>
</sub>
<italic>/f</italic>). The decrease in <italic>&#x3bb;</italic>
<sub>
<italic>4D</italic>
</sub> is accompanied by an increase in momentum <inline-formula id="inf9">
<mml:math id="m19">
<mml:mrow>
<mml:msub>
<mml:mi>p</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:mi>h</mml:mi>
<mml:mo>/</mml:mo>
<mml:msub>
<mml:mi>&#x3bb;</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula>, see (<xref ref-type="disp-formula" rid="e4">Equation 4</xref>), and an increase in mass<disp-formula id="e10">
<mml:math id="m20">
<mml:mrow>
<mml:mi>m</mml:mi>
<mml:mo>&#x3d;</mml:mo>
<mml:msub>
<mml:mi>p</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
<mml:mo>/</mml:mo>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:mi>h</mml:mi>
<mml:mi>f</mml:mi>
<mml:mo>/</mml:mo>
<mml:msubsup>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
<mml:mn>2</mml:mn>
</mml:msubsup>
</mml:mrow>
</mml:math>
<label>(10)</label>
</disp-formula>
</p>
<p>Although the frequency of a particle-wave does not change during free fall, the dependence of <italic>ClockRate</italic> on the local value of <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> causes the frequency determined by different reference clocks is different. Phenomena such as gravitational redshift and blueshift do not reflect a change in the energy of the particle-wave, but rather a change in the rate (<italic>ClockRate</italic>) of the reference clocks. For instance, a clock in interstellar space runs faster than an imaginary clock on the surface of a massive star. In other words, time on the surface of the star flows more slowly, and all physical processes, including photon emission, are also slower.</p>
<p>The dependence of the particle-wave frequency on the value of <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> at the location of the reference clock is not surprising. It expresses the relative nature of potential energy. It is always related to a specific reference level. The EMST shows that the reference level is given by the local value of <italic>v</italic>
<sub>
<italic>4D</italic>
</sub>. A change in the reference level corresponds to the relocation of the reference clock to a location with a different <italic>v</italic>
<sub>
<italic>4D</italic>
</sub>. The result is a change in the frequency of the observed particle-wave, and thus its energy.</p>
<p>Let us consider a space and a pair of identical particle-waves A and B (e.g., electrons) arbitrarily distributed in it, as well as a pair of identical clocks 1 and 2. The particle-waves and clocks are at rest (<italic>v</italic>
<sub>
<italic>3D</italic>
</sub> <italic>&#x3d; 0</italic>). The particle-waves would have the same energy if they were located in areas of the same <italic>v</italic>
<sub>
<italic>4D</italic>
</sub>, but the value of <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> is different in the given locations. The following applies: <inline-formula id="inf10">
<mml:math id="m21">
<mml:mrow>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
<mml:mo>,</mml:mo>
<mml:mi>B</mml:mi>
</mml:mrow>
</mml:msub>
<mml:mo>&#x3c;</mml:mo>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
<mml:mo>,</mml:mo>
<mml:mi>A</mml:mi>
</mml:mrow>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula>, <inline-formula id="inf11">
<mml:math id="m22">
<mml:mrow>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
<mml:mo>,</mml:mo>
<mml:mn>2</mml:mn>
</mml:mrow>
</mml:msub>
<mml:mo>&#x3c;</mml:mo>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
<mml:mo>,</mml:mo>
<mml:mn>1</mml:mn>
</mml:mrow>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula> (<xref ref-type="fig" rid="F3">Figure 3</xref>).</p>
<fig id="F3" position="float">
<label>FIGURE 3</label>
<caption>
<p>Example of the arrangement of a pair of identical clocks and a pair of identical particle-waves in a zone with variable <italic>v</italic>
<sub>
<italic>4D</italic>
</sub>.</p>
</caption>
<graphic xlink:href="fphy-14-1737947-g003.tif">
<alt-text content-type="machine-generated">Cartoon of a person standing next to symbols illustrating a concept of four-dimensional space-time. A vertical arrow labeled &#x22;a&#x22; points downwards. Two clocks, labeled &#x22;1&#x22; and &#x22;2&#x22;, are associated with wave patterns &#x22;A&#x22; and &#x22;B&#x22;. Variables \( V_{4D,A} \), \( V_{4D,1} \), \( V_{4D,2} \), and \( V_{4D,B} \) are shown near the elements.</alt-text>
</graphic>
</fig>
<p>Let us denote the frequency of particle-wave A relative to clock 1 as <italic>f</italic>
<sub>
<italic>A,1</italic>
</sub>, and relative to clock 2 as <italic>f</italic>
<sub>
<italic>A,2</italic>
</sub>. The following applies:<disp-formula id="equ2">
<mml:math id="m23">
<mml:mrow>
<mml:mfrac>
<mml:mrow>
<mml:msub>
<mml:mi>E</mml:mi>
<mml:mrow>
<mml:mi>A</mml:mi>
<mml:mo>,</mml:mo>
<mml:mn>2</mml:mn>
</mml:mrow>
</mml:msub>
</mml:mrow>
<mml:mrow>
<mml:msub>
<mml:mi>E</mml:mi>
<mml:mrow>
<mml:mi>A</mml:mi>
<mml:mo>,</mml:mo>
<mml:mn>1</mml:mn>
</mml:mrow>
</mml:msub>
</mml:mrow>
</mml:mfrac>
<mml:mo>&#x3d;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mi>h</mml:mi>
<mml:mtext>&#x2009;</mml:mtext>
<mml:msub>
<mml:mi>f</mml:mi>
<mml:mrow>
<mml:mi>A</mml:mi>
<mml:mo>,</mml:mo>
<mml:mn>2</mml:mn>
</mml:mrow>
</mml:msub>
</mml:mrow>
<mml:msub>
<mml:mrow>
<mml:mi>h</mml:mi>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mi>f</mml:mi>
</mml:mrow>
<mml:mrow>
<mml:mi>A</mml:mi>
<mml:mo>,</mml:mo>
<mml:mn>1</mml:mn>
</mml:mrow>
</mml:msub>
</mml:mfrac>
<mml:mo>&#x3d;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:msub>
<mml:mrow>
<mml:mi>C</mml:mi>
<mml:mi>l</mml:mi>
<mml:mi>o</mml:mi>
<mml:mi>c</mml:mi>
<mml:mi>k</mml:mi>
<mml:mi>R</mml:mi>
<mml:mi>a</mml:mi>
<mml:mi>t</mml:mi>
<mml:mi>e</mml:mi>
</mml:mrow>
<mml:mn>1</mml:mn>
</mml:msub>
</mml:mrow>
<mml:mrow>
<mml:msub>
<mml:mrow>
<mml:mi>C</mml:mi>
<mml:mi>l</mml:mi>
<mml:mi>o</mml:mi>
<mml:mi>c</mml:mi>
<mml:mi>k</mml:mi>
<mml:mi>R</mml:mi>
<mml:mi>a</mml:mi>
<mml:mi>t</mml:mi>
<mml:mi>e</mml:mi>
</mml:mrow>
<mml:mn>2</mml:mn>
</mml:msub>
</mml:mrow>
</mml:mfrac>
<mml:mo>&#x3d;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
<mml:mo>,</mml:mo>
<mml:mn>1</mml:mn>
</mml:mrow>
</mml:msub>
</mml:mrow>
<mml:mrow>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
<mml:mo>,</mml:mo>
<mml:mn>2</mml:mn>
</mml:mrow>
</mml:msub>
</mml:mrow>
</mml:mfrac>
</mml:mrow>
</mml:math>
</disp-formula>
</p>
<p>It is clear from the formula that the frequency, and therefore also the energy of the particle-wave is greater relative to the slower clock 2.</p>
<p>A similar situation arises when comparing the frequencies of particle-waves A and B. If we relate them to clock 1, we get<disp-formula id="e11">
<mml:math id="m24">
<mml:mrow>
<mml:mfrac>
<mml:mrow>
<mml:msub>
<mml:mi>f</mml:mi>
<mml:mrow>
<mml:mi>A</mml:mi>
<mml:mo>,</mml:mo>
<mml:mn>1</mml:mn>
</mml:mrow>
</mml:msub>
</mml:mrow>
<mml:mrow>
<mml:msub>
<mml:mi>f</mml:mi>
<mml:mrow>
<mml:mi>B</mml:mi>
<mml:mo>,</mml:mo>
<mml:mn>1</mml:mn>
</mml:mrow>
</mml:msub>
</mml:mrow>
</mml:mfrac>
<mml:mo>&#x3d;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
<mml:mo>,</mml:mo>
<mml:mi>A</mml:mi>
</mml:mrow>
</mml:msub>
</mml:mrow>
<mml:mrow>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
<mml:mo>,</mml:mo>
<mml:mi>B</mml:mi>
</mml:mrow>
</mml:msub>
</mml:mrow>
</mml:mfrac>
</mml:mrow>
</mml:math>
<label>(11)</label>
</disp-formula>i.e., the particle-wave in the region of greater <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> has a higher frequency and thus also higher energy:<disp-formula id="e12">
<mml:math id="m25">
<mml:mrow>
<mml:mfrac>
<mml:mrow>
<mml:msub>
<mml:mi>E</mml:mi>
<mml:mrow>
<mml:mi>A</mml:mi>
<mml:mo>,</mml:mo>
<mml:mn>1</mml:mn>
</mml:mrow>
</mml:msub>
</mml:mrow>
<mml:mrow>
<mml:msub>
<mml:mi>E</mml:mi>
<mml:mrow>
<mml:mi>B</mml:mi>
<mml:mo>,</mml:mo>
<mml:mn>1</mml:mn>
</mml:mrow>
</mml:msub>
</mml:mrow>
</mml:mfrac>
<mml:mo>&#x3d;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mi>h</mml:mi>
<mml:mtext>&#x2009;</mml:mtext>
<mml:msub>
<mml:mi>f</mml:mi>
<mml:mrow>
<mml:mi>A</mml:mi>
<mml:mo>,</mml:mo>
<mml:mn>1</mml:mn>
</mml:mrow>
</mml:msub>
</mml:mrow>
<mml:msub>
<mml:mrow>
<mml:mi>h</mml:mi>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mi>f</mml:mi>
</mml:mrow>
<mml:mrow>
<mml:mi>B</mml:mi>
<mml:mo>,</mml:mo>
<mml:mn>1</mml:mn>
</mml:mrow>
</mml:msub>
</mml:mfrac>
<mml:mo>&#x3d;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
<mml:mo>,</mml:mo>
<mml:mi>A</mml:mi>
</mml:mrow>
</mml:msub>
</mml:mrow>
<mml:mrow>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
<mml:mo>,</mml:mo>
<mml:mi>B</mml:mi>
</mml:mrow>
</mml:msub>
</mml:mrow>
</mml:mfrac>
</mml:mrow>
</mml:math>
<label>(12)</label>
</disp-formula>
</p>
<p>When using clock 2, we obtain different frequencies, but their ratio will be the same. This shows that identical particle-waves (e.g., free electrons at rest) have different energies depending on the local value of <italic>v</italic>
<sub>
<italic>4D</italic>
</sub>.</p>
<p>Particle-waves A and B have different frequencies, but their wavelength <inline-formula id="inf12">
<mml:math id="m26">
<mml:mrow>
<mml:msub>
<mml:mi>&#x3bb;</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
<mml:mo>/</mml:mo>
<mml:mi>f</mml:mi>
</mml:mrow>
</mml:math>
</inline-formula> is the same, see (<xref ref-type="disp-formula" rid="e11">Equation 11</xref>). This corresponds to the same value of the momentum <italic>p</italic>
<sub>
<italic>4D</italic>
</sub> and all of its components. It should be noted that <italic>p</italic>
<sub>
<italic>4D</italic>
</sub> is a vector in E<sub>4</sub> with components <italic>p</italic>
<sub>
<italic>x</italic>
</sub>, <italic>p</italic>
<sub>
<italic>y</italic>
</sub>, <italic>p</italic>
<sub>
<italic>z</italic>
</sub>, and <italic>p</italic>
<sub>
<italic>w</italic>
</sub>, which correspond to the projections of the wavelength <italic>&#x3bb;</italic>
<sub>
<italic>4D</italic>
</sub> in the direction of the coordinate axes. For example, <italic>p</italic>
<sub>
<italic>x</italic>
</sub> <italic>&#x3d; h/&#x3bb;</italic>
<sub>
<italic>x</italic>
</sub>, see [<xref ref-type="bibr" rid="B8">8</xref>].</p>
<p>The wavelengths of identical particle-waves do not depend on the local value of <italic>v</italic>
<sub>
<italic>4D</italic>
</sub>. This fact can be used for distance measurement. The length of rigid measuring rods is determined by the distance between individual atoms in the crystal lattice. It can be reasonably assumed that these are fixed multiples of the wavelengths of electrons in the electron shells of atoms. That is, the dimensions of the rod do not depend on the local <italic>v</italic>
<sub>
<italic>4D</italic>
</sub>. The results of length measurements using rods will match the results of length measurements using light if local clocks are used for the transit time determination.</p>
<p>Using relations (<xref ref-type="disp-formula" rid="e10">Equation 10</xref>) and (<xref ref-type="disp-formula" rid="e12">Equation 12</xref>), we can write:<disp-formula id="e13">
<mml:math id="m27">
<mml:mrow>
<mml:mfrac>
<mml:mrow>
<mml:msub>
<mml:mi>m</mml:mi>
<mml:mi>A</mml:mi>
</mml:msub>
</mml:mrow>
<mml:mrow>
<mml:msub>
<mml:mi>m</mml:mi>
<mml:mi>B</mml:mi>
</mml:msub>
</mml:mrow>
</mml:mfrac>
<mml:mo>&#x3d;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mfrac>
<mml:mrow>
<mml:mi>h</mml:mi>
<mml:mtext>&#x2009;</mml:mtext>
<mml:msub>
<mml:mi>f</mml:mi>
<mml:mi>A</mml:mi>
</mml:msub>
</mml:mrow>
<mml:msubsup>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
<mml:mo>,</mml:mo>
<mml:mi>A</mml:mi>
</mml:mrow>
<mml:mn>2</mml:mn>
</mml:msubsup>
</mml:mfrac>
</mml:mrow>
<mml:mrow>
<mml:mfrac>
<mml:mrow>
<mml:mi>h</mml:mi>
<mml:mtext>&#x2009;</mml:mtext>
<mml:msub>
<mml:mi>f</mml:mi>
<mml:mi>B</mml:mi>
</mml:msub>
</mml:mrow>
<mml:msubsup>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
<mml:mo>,</mml:mo>
<mml:mi>B</mml:mi>
</mml:mrow>
<mml:mn>2</mml:mn>
</mml:msubsup>
</mml:mfrac>
</mml:mrow>
</mml:mfrac>
<mml:mo>&#x3d;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
<mml:mo>,</mml:mo>
<mml:mi>B</mml:mi>
</mml:mrow>
</mml:msub>
</mml:mrow>
<mml:mrow>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
<mml:mo>,</mml:mo>
<mml:mi>A</mml:mi>
</mml:mrow>
</mml:msub>
</mml:mrow>
</mml:mfrac>
</mml:mrow>
</mml:math>
<label>(13)</label>
</disp-formula>
</p>
<p>Particle-wave B has a higher mass than particle-wave A despite having lower energy.</p>
</sec>
<sec id="s2-3">
<label>2.3</label>
<title>Gravity potential</title>
<p>If the distribution of the <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> is constant in time, it can be used to define a potential field in space &#x2013; the gravity potential <italic>V</italic>. This term includes both gravitational potential (caused by the gravitational effects of matter) and inertial potential (caused by the acceleration of the reference frame); if both are present, it is their sum.</p>
<p>The gravity potential creates a scalar field in space E<sub>3</sub> (the compactified fourth dimension can be neglected when describing gravity). The function <italic>V &#x3d; V(x, y, z)</italic> is continuous and differentiable.</p>
<p>The gravity potential expresses the potential energy of a body of unit mass relative to a selected reference level (<inline-formula id="inf13">
<mml:math id="m28">
<mml:mrow>
<mml:mi>V</mml:mi>
<mml:mo>&#x3d;</mml:mo>
<mml:msub>
<mml:mi>E</mml:mi>
<mml:mi>p</mml:mi>
</mml:msub>
<mml:mo>/</mml:mo>
<mml:mi>m</mml:mi>
</mml:mrow>
</mml:math>
</inline-formula>). The potential decreases downward and increases upward. If the reference level of the potential is located outside the gravity field, the potential anywhere inside the field is negative.</p>
<p>Let us consider the potential of particle-wave A relative to clock 1 from the previous case. The energy of any particle-wave is given by <inline-formula id="inf14">
<mml:math id="m29">
<mml:mrow>
<mml:mi>E</mml:mi>
<mml:mo>&#x3d;</mml:mo>
<mml:mi>m</mml:mi>
<mml:mtext>&#x2009;</mml:mtext>
<mml:msubsup>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
<mml:mn>2</mml:mn>
</mml:msubsup>
<mml:mo>&#x3d;</mml:mo>
<mml:msub>
<mml:mi>p</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula>. The momentum <italic>p</italic>
<sub>
<italic>4D</italic>
</sub> is independent of the <italic>v</italic>
<sub>
<italic>4D</italic>
</sub>, so the infinitesimal change of <italic>E</italic> with <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> can be written as <inline-formula id="inf15">
<mml:math id="m30">
<mml:mrow>
<mml:mi>d</mml:mi>
<mml:mi>E</mml:mi>
<mml:mo>&#x3d;</mml:mo>
<mml:msub>
<mml:mi>p</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mi>d</mml:mi>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:mi>m</mml:mi>
<mml:mtext>&#x2009;</mml:mtext>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mi>d</mml:mi>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula>. The value <italic>dE</italic> represents the change in the potential energy of the particle-wave, i.e., <italic>dE &#x3d; dE</italic>
<sub>
<italic>p</italic>
</sub>. Therefore the change in potential is given by <inline-formula id="inf16">
<mml:math id="m31">
<mml:mrow>
<mml:mi>d</mml:mi>
<mml:mi>V</mml:mi>
<mml:mo>&#x3d;</mml:mo>
<mml:msub>
<mml:mrow>
<mml:mi>d</mml:mi>
<mml:mi>E</mml:mi>
</mml:mrow>
<mml:mi>p</mml:mi>
</mml:msub>
<mml:mo>/</mml:mo>
<mml:mi>m</mml:mi>
<mml:mo>&#x3d;</mml:mo>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mi>d</mml:mi>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula>.</p>
<p>The potential of particle-wave A relative to clock 1 is<disp-formula id="equ3">
<mml:math id="m32">
<mml:mtable class="align" columnalign="left">
<mml:mtr>
<mml:mtd columnalign="right"/>
<mml:mtd columnalign="right">
<mml:mrow>
<mml:msub>
<mml:mi>V</mml:mi>
<mml:mrow>
<mml:mi>A</mml:mi>
<mml:mo>,</mml:mo>
<mml:mn>1</mml:mn>
</mml:mrow>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:msubsup>
<mml:mo>&#x222b;</mml:mo>
<mml:mn>1</mml:mn>
<mml:mi>A</mml:mi>
</mml:msubsup>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
<mml:msub>
<mml:mrow>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mi>d</mml:mi>
<mml:mi>v</mml:mi>
</mml:mrow>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:msubsup>
<mml:mrow>
<mml:mfenced open="[" close="]" separators="&#x7c;">
<mml:mrow>
<mml:mfrac>
<mml:mrow>
<mml:msubsup>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
<mml:mn>2</mml:mn>
</mml:msubsup>
</mml:mrow>
<mml:mrow>
<mml:mn>2</mml:mn>
</mml:mrow>
</mml:mfrac>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
<mml:mn>1</mml:mn>
<mml:mi>A</mml:mi>
</mml:msubsup>
<mml:mo>&#x2b;</mml:mo>
<mml:mi>C</mml:mi>
</mml:mrow>
</mml:mtd>
</mml:mtr>
<mml:mtr>
<mml:mtd columnalign="right"/>
<mml:mtd columnalign="left">
<mml:mspace width="2em"/>
<mml:mrow>
<mml:mo>&#x3d;</mml:mo>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:mfrac>
<mml:mrow>
<mml:msubsup>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
<mml:mo>,</mml:mo>
<mml:mi>A</mml:mi>
</mml:mrow>
<mml:mn>2</mml:mn>
</mml:msubsup>
</mml:mrow>
<mml:mrow>
<mml:mn>2</mml:mn>
</mml:mrow>
</mml:mfrac>
<mml:mo>&#x2212;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:msubsup>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
<mml:mo>,</mml:mo>
<mml:mn>1</mml:mn>
</mml:mrow>
<mml:mn>2</mml:mn>
</mml:msubsup>
</mml:mrow>
<mml:mrow>
<mml:mn>2</mml:mn>
</mml:mrow>
</mml:mfrac>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
<mml:mo>&#x2b;</mml:mo>
<mml:mi>C</mml:mi>
<mml:mo>&#x3d;</mml:mo>
<mml:mo>&#x2212;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mn>1</mml:mn>
</mml:mrow>
<mml:mrow>
<mml:mn>2</mml:mn>
</mml:mrow>
</mml:mfrac>
<mml:msubsup>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
<mml:mo>,</mml:mo>
<mml:mn>1</mml:mn>
</mml:mrow>
<mml:mn>2</mml:mn>
</mml:msubsup>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:mn>1</mml:mn>
<mml:mo>&#x2212;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:msubsup>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
<mml:mo>,</mml:mo>
<mml:mi>A</mml:mi>
</mml:mrow>
<mml:mn>2</mml:mn>
</mml:msubsup>
</mml:mrow>
<mml:mrow>
<mml:msubsup>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
<mml:mo>,</mml:mo>
<mml:mn>1</mml:mn>
</mml:mrow>
<mml:mn>2</mml:mn>
</mml:msubsup>
</mml:mrow>
</mml:mfrac>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
<mml:mo>&#x2b;</mml:mo>
<mml:mi>C</mml:mi>
</mml:mrow>
</mml:mtd>
</mml:mtr>
</mml:mtable>
</mml:math>
</disp-formula>
</p>
<p>The integration constant <italic>C</italic> is determined by the choice of value of the potential at the location of the reference clock. The logical choice is <italic>V</italic>
<sub>
<italic>1</italic>
</sub> <italic>&#x3d; 0</italic>, which leads to <italic>C &#x3d; 0</italic>.</p>
<p>The gravity potential (of particle-wave) at point A relative to reference clock 1 located outside the gravity field (<inline-formula id="inf17">
<mml:math id="m33">
<mml:mrow>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
<mml:mo>,</mml:mo>
<mml:mn>1</mml:mn>
</mml:mrow>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:mi>c</mml:mi>
</mml:mrow>
</mml:math>
</inline-formula>) is<disp-formula id="e14">
<mml:math id="m34">
<mml:mrow>
<mml:msub>
<mml:mi>V</mml:mi>
<mml:mi>A</mml:mi>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:mo>&#x2212;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mn>1</mml:mn>
</mml:mrow>
<mml:mrow>
<mml:mn>2</mml:mn>
</mml:mrow>
</mml:mfrac>
<mml:msup>
<mml:mi>c</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:mn>1</mml:mn>
<mml:mo>&#x2212;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:msubsup>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
<mml:mo>,</mml:mo>
<mml:mi>A</mml:mi>
</mml:mrow>
<mml:mn>2</mml:mn>
</mml:msubsup>
</mml:mrow>
<mml:mrow>
<mml:msup>
<mml:mi>c</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
</mml:mrow>
</mml:mfrac>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
</mml:mrow>
</mml:math>
<label>(14)</label>
</disp-formula>
</p>
<p>This defines the functional dependence of <italic>V</italic> on the <italic>v</italic>
<sub>
<italic>4D</italic>
</sub>.</p>
<p>The inverse relationship gives the ratio of <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> to <italic>c,</italic>
<disp-formula id="e15">
<mml:math id="m35">
<mml:mrow>
<mml:mfrac>
<mml:mrow>
<mml:msub>
<mml:mi mathvariant="bold-italic">v</mml:mi>
<mml:mrow>
<mml:mn mathvariant="bold">4</mml:mn>
<mml:mi mathvariant="bold-italic">D</mml:mi>
<mml:mo>,</mml:mo>
<mml:mi mathvariant="bold-italic">A</mml:mi>
</mml:mrow>
</mml:msub>
</mml:mrow>
<mml:mrow>
<mml:mi mathvariant="bold-italic">c</mml:mi>
</mml:mrow>
</mml:mfrac>
<mml:mo>&#x3d;</mml:mo>
<mml:msqrt>
<mml:mrow>
<mml:mn mathvariant="bold">1</mml:mn>
<mml:mo>&#x2b;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mn mathvariant="bold">2</mml:mn>
<mml:msub>
<mml:mi mathvariant="bold-italic">V</mml:mi>
<mml:mi mathvariant="bold-italic">A</mml:mi>
</mml:msub>
</mml:mrow>
<mml:msup>
<mml:mi mathvariant="bold-italic">c</mml:mi>
<mml:mn mathvariant="bold">2</mml:mn>
</mml:msup>
</mml:mfrac>
</mml:mrow>
</mml:msqrt>
</mml:mrow>
</mml:math>
<label>(15)</label>
</disp-formula>which can be modified for the mutual ratio of clock rates<disp-formula id="e16">
<mml:math id="m36">
<mml:mrow>
<mml:mfrac>
<mml:mrow>
<mml:msub>
<mml:mrow>
<mml:mi mathvariant="bold-italic">C</mml:mi>
<mml:mi mathvariant="bold-italic">l</mml:mi>
<mml:mi mathvariant="bold-italic">o</mml:mi>
<mml:mi mathvariant="bold-italic">c</mml:mi>
<mml:mi mathvariant="bold-italic">k</mml:mi>
<mml:mi mathvariant="bold-italic">R</mml:mi>
<mml:mi mathvariant="bold-italic">a</mml:mi>
<mml:mi mathvariant="bold-italic">t</mml:mi>
<mml:mi mathvariant="bold-italic">e</mml:mi>
</mml:mrow>
<mml:mi mathvariant="bold-italic">A</mml:mi>
</mml:msub>
</mml:mrow>
<mml:mrow>
<mml:msub>
<mml:mrow>
<mml:mi mathvariant="bold-italic">C</mml:mi>
<mml:mi mathvariant="bold-italic">l</mml:mi>
<mml:mi mathvariant="bold-italic">o</mml:mi>
<mml:mi mathvariant="bold-italic">c</mml:mi>
<mml:mi mathvariant="bold-italic">k</mml:mi>
<mml:mi mathvariant="bold-italic">R</mml:mi>
<mml:mi mathvariant="bold-italic">a</mml:mi>
<mml:mi mathvariant="bold-italic">t</mml:mi>
<mml:mi mathvariant="bold-italic">e</mml:mi>
</mml:mrow>
<mml:mn mathvariant="bold">1</mml:mn>
</mml:msub>
</mml:mrow>
</mml:mfrac>
<mml:mo>&#x3d;</mml:mo>
<mml:msqrt>
<mml:mrow>
<mml:mn mathvariant="bold">1</mml:mn>
<mml:mo>&#x2b;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mn mathvariant="bold">2</mml:mn>
<mml:msub>
<mml:mi mathvariant="bold-italic">V</mml:mi>
<mml:mi mathvariant="bold-italic">A</mml:mi>
</mml:msub>
</mml:mrow>
<mml:msup>
<mml:mi mathvariant="bold-italic">c</mml:mi>
<mml:mn mathvariant="bold">2</mml:mn>
</mml:msup>
</mml:mfrac>
</mml:mrow>
</mml:msqrt>
</mml:mrow>
</mml:math>
<label>(16)</label>
</disp-formula>
</p>
<p>It can also be written in the form known from the GTR<disp-formula id="e17">
<mml:math id="m37">
<mml:mrow>
<mml:mi mathvariant="bold-italic">d</mml:mi>
<mml:mi mathvariant="bold-italic">&#x3c4;</mml:mi>
<mml:mo>&#x3d;</mml:mo>
<mml:mi mathvariant="bold-italic">d</mml:mi>
<mml:mi mathvariant="bold-italic">t</mml:mi>
<mml:msqrt>
<mml:mrow>
<mml:mn mathvariant="bold">1</mml:mn>
<mml:mo>&#x2b;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mn mathvariant="bold">2</mml:mn>
<mml:msub>
<mml:mi mathvariant="bold-italic">V</mml:mi>
<mml:mi mathvariant="bold-italic">A</mml:mi>
</mml:msub>
</mml:mrow>
<mml:msup>
<mml:mi mathvariant="bold-italic">c</mml:mi>
<mml:mn mathvariant="bold">2</mml:mn>
</mml:msup>
</mml:mfrac>
</mml:mrow>
</mml:msqrt>
</mml:mrow>
</mml:math>
<label>(17)</label>
</disp-formula>which gives the increment of proper time <italic>&#x3c4;</italic> at a point with gravity potential <italic>V</italic>
<sub>
<italic>A</italic>
</sub> relative to the independently flowing coordinate time <italic>t</italic> outside the gravity field. It can be seen that the EMST result is identical to the GTR result.</p>
<p>Regardless of the location of the reference clock, <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> &#x3d; <italic>c</italic> always applies in its vicinity. <xref ref-type="disp-formula" rid="e14">Equations 14</xref>&#x2013;<xref ref-type="disp-formula" rid="e17">17</xref> are therefore valid not only for reference clocks located outside the field, but for any location of the clock.</p>
</sec>
<sec id="s2-4">
<label>2.4</label>
<title>Influence of the variable <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> on particle-wave motion</title>
<p>In classical mechanics, the gradient of potential is acceleration<disp-formula id="e18">
<mml:math id="m38">
<mml:mrow>
<mml:mi mathvariant="bold-italic">g</mml:mi>
<mml:mi mathvariant="bold-italic">r</mml:mi>
<mml:mi mathvariant="bold-italic">a</mml:mi>
<mml:mi mathvariant="bold-italic">d</mml:mi>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:mi mathvariant="bold-italic">V</mml:mi>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
<mml:mo>&#x3d;</mml:mo>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:mfrac>
<mml:mrow>
<mml:mi mathvariant="bold-italic">&#x2202;</mml:mi>
<mml:mi mathvariant="bold-italic">V</mml:mi>
</mml:mrow>
<mml:mrow>
<mml:mi mathvariant="bold-italic">&#x2202;</mml:mi>
<mml:mi mathvariant="bold-italic">x</mml:mi>
</mml:mrow>
</mml:mfrac>
<mml:mo>,</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mi mathvariant="bold-italic">&#x2202;</mml:mi>
<mml:mi mathvariant="bold-italic">V</mml:mi>
</mml:mrow>
<mml:mrow>
<mml:mi mathvariant="bold-italic">&#x2202;</mml:mi>
<mml:mi mathvariant="bold-italic">y</mml:mi>
</mml:mrow>
</mml:mfrac>
<mml:mo>,</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mi mathvariant="bold-italic">&#x2202;</mml:mi>
<mml:mi mathvariant="bold-italic">V</mml:mi>
</mml:mrow>
<mml:mrow>
<mml:mi mathvariant="bold-italic">&#x2202;</mml:mi>
<mml:mi mathvariant="bold-italic">z</mml:mi>
</mml:mrow>
</mml:mfrac>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
<mml:mo>&#x3d;</mml:mo>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:msub>
<mml:mrow>
<mml:mo>&#x2212;</mml:mo>
<mml:mi mathvariant="bold-italic">a</mml:mi>
</mml:mrow>
<mml:mi mathvariant="bold-italic">x</mml:mi>
</mml:msub>
<mml:mo>,</mml:mo>
<mml:msub>
<mml:mrow>
<mml:mo>&#x2212;</mml:mo>
<mml:mi mathvariant="bold-italic">a</mml:mi>
</mml:mrow>
<mml:mi mathvariant="bold-italic">y</mml:mi>
</mml:msub>
<mml:mo>,</mml:mo>
<mml:mo>&#x2212;</mml:mo>
<mml:msub>
<mml:mi mathvariant="bold-italic">a</mml:mi>
<mml:mi mathvariant="bold-italic">z</mml:mi>
</mml:msub>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
<mml:mo>&#x3d;</mml:mo>
<mml:mo>&#x2212;</mml:mo>
<mml:mover accent="true">
<mml:mi mathvariant="bold-italic">a</mml:mi>
<mml:mo>&#x2192;</mml:mo>
</mml:mover>
</mml:mrow>
</mml:math>
<label>(18)</label>
</disp-formula>
</p>
<p>In the EMST, any accelerated motion is a consequence of the variable value of v<sub>4D</sub>. The above-mentioned relationship between acceleration and potential must, therefore, be verified and correctly interpreted. It will be shown that the vector <inline-formula id="inf18">
<mml:math id="m39">
<mml:mrow>
<mml:mover accent="true">
<mml:mi mathvariant="bold-italic">a</mml:mi>
<mml:mo>&#x2192;</mml:mo>
</mml:mover>
</mml:mrow>
</mml:math>
</inline-formula> does not represent kinematic acceleration in some situations. I will refer to it as the &#x201c;vector <inline-formula id="inf19">
<mml:math id="m40">
<mml:mrow>
<mml:mover accent="true">
<mml:mi mathvariant="bold-italic">a</mml:mi>
<mml:mo>&#x2192;</mml:mo>
</mml:mover>
</mml:mrow>
</mml:math>
</inline-formula>&#x201d; (instead of acceleration <inline-formula id="inf20">
<mml:math id="m41">
<mml:mrow>
<mml:mfenced open="" close=")" separators="&#x7c;">
<mml:mrow>
<mml:mover accent="true">
<mml:mi mathvariant="bold-italic">a</mml:mi>
<mml:mo>&#x2192;</mml:mo>
</mml:mover>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
</mml:math>
</inline-formula> in cases where confusion might arise.</p>
<p>The relationship between the potential <italic>V</italic> and the velocity <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> was derived above (<xref ref-type="disp-formula" rid="e15">Equation 15</xref>). It yields<disp-formula id="e19">
<mml:math id="m42">
<mml:mrow>
<mml:mfrac>
<mml:mrow>
<mml:mi mathvariant="bold-italic">d</mml:mi>
<mml:msub>
<mml:mi mathvariant="bold-italic">v</mml:mi>
<mml:mrow>
<mml:mn mathvariant="bold">4</mml:mn>
<mml:mi mathvariant="bold-italic">D</mml:mi>
</mml:mrow>
</mml:msub>
</mml:mrow>
<mml:mrow>
<mml:mi mathvariant="bold-italic">d</mml:mi>
<mml:mi mathvariant="bold-italic">V</mml:mi>
</mml:mrow>
</mml:mfrac>
<mml:mo>&#x3d;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mi mathvariant="bold-italic">d</mml:mi>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:mi mathvariant="bold-italic">c</mml:mi>
<mml:msqrt>
<mml:mrow>
<mml:mn mathvariant="bold">1</mml:mn>
<mml:mo>&#x2b;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mn mathvariant="bold">2</mml:mn>
<mml:mi mathvariant="bold-italic">V</mml:mi>
</mml:mrow>
<mml:msup>
<mml:mi mathvariant="bold-italic">c</mml:mi>
<mml:mn mathvariant="bold">2</mml:mn>
</mml:msup>
</mml:mfrac>
</mml:mrow>
</mml:msqrt>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
</mml:mrow>
<mml:mrow>
<mml:mi mathvariant="bold-italic">d</mml:mi>
<mml:mi mathvariant="bold-italic">V</mml:mi>
</mml:mrow>
</mml:mfrac>
<mml:mo>&#x3d;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mi mathvariant="bold-italic">c</mml:mi>
</mml:mrow>
<mml:mrow>
<mml:mn mathvariant="bold">2</mml:mn>
</mml:mrow>
</mml:mfrac>
<mml:mfrac>
<mml:mrow>
<mml:mn mathvariant="bold">1</mml:mn>
</mml:mrow>
<mml:mrow>
<mml:msqrt>
<mml:mrow>
<mml:mn mathvariant="bold">1</mml:mn>
<mml:mo>&#x2b;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mn mathvariant="bold">2</mml:mn>
<mml:mi>V</mml:mi>
</mml:mrow>
<mml:msup>
<mml:mi mathvariant="bold-italic">c</mml:mi>
<mml:mn mathvariant="bold">2</mml:mn>
</mml:msup>
</mml:mfrac>
</mml:mrow>
</mml:msqrt>
</mml:mrow>
</mml:mfrac>
<mml:mfrac>
<mml:mrow>
<mml:mn mathvariant="bold">2</mml:mn>
</mml:mrow>
<mml:mrow>
<mml:msup>
<mml:mi mathvariant="bold-italic">c</mml:mi>
<mml:mn mathvariant="bold">2</mml:mn>
</mml:msup>
</mml:mrow>
</mml:mfrac>
<mml:mo>&#x3d;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mn mathvariant="bold">1</mml:mn>
</mml:mrow>
<mml:mrow>
<mml:msub>
<mml:mi mathvariant="bold-italic">v</mml:mi>
<mml:mrow>
<mml:mn mathvariant="bold">4</mml:mn>
<mml:mi mathvariant="bold-italic">D</mml:mi>
</mml:mrow>
</mml:msub>
</mml:mrow>
</mml:mfrac>
</mml:mrow>
</mml:math>
<label>(19)</label>
</disp-formula>and so<disp-formula id="equ4">
<mml:math id="m43">
<mml:mrow>
<mml:mi>g</mml:mi>
<mml:mi>r</mml:mi>
<mml:mi>a</mml:mi>
<mml:mi>d</mml:mi>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
<mml:mo>&#x3d;</mml:mo>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:mfrac>
<mml:mrow>
<mml:mi>&#x2202;</mml:mi>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
</mml:mrow>
<mml:mrow>
<mml:mi>&#x2202;</mml:mi>
<mml:mi>x</mml:mi>
</mml:mrow>
</mml:mfrac>
<mml:mo>,</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mi>&#x2202;</mml:mi>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
</mml:mrow>
<mml:mrow>
<mml:mi>&#x2202;</mml:mi>
<mml:mi>y</mml:mi>
</mml:mrow>
</mml:mfrac>
<mml:mo>,</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mi>&#x2202;</mml:mi>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
</mml:mrow>
<mml:mrow>
<mml:mi>&#x2202;</mml:mi>
<mml:mi>z</mml:mi>
</mml:mrow>
</mml:mfrac>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
<mml:mo>&#x3d;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mi>&#x2202;</mml:mi>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
</mml:mrow>
<mml:mrow>
<mml:mi>&#x2202;</mml:mi>
<mml:mi>V</mml:mi>
</mml:mrow>
</mml:mfrac>
<mml:mi>g</mml:mi>
<mml:mi>r</mml:mi>
<mml:mi>a</mml:mi>
<mml:mi>d</mml:mi>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:mi>V</mml:mi>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
<mml:mo>&#x3d;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mn>1</mml:mn>
</mml:mrow>
<mml:mrow>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
</mml:mrow>
</mml:mfrac>
<mml:mi>g</mml:mi>
<mml:mi>r</mml:mi>
<mml:mi>a</mml:mi>
<mml:mi>d</mml:mi>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:mi>V</mml:mi>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
<mml:mo>&#x3d;</mml:mo>
<mml:mo>&#x2212;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mover accent="true">
<mml:mi>a</mml:mi>
<mml:mo>&#x2192;</mml:mo>
</mml:mover>
</mml:mrow>
<mml:mrow>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
</mml:mrow>
</mml:mfrac>
</mml:mrow>
</mml:math>
</disp-formula>
</p>
<p>The dependence of vector <inline-formula id="inf21">
<mml:math id="m44">
<mml:mrow>
<mml:mover accent="true">
<mml:mi mathvariant="bold-italic">a</mml:mi>
<mml:mo>&#x2192;</mml:mo>
</mml:mover>
</mml:mrow>
</mml:math>
</inline-formula> on the velocity <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> is given by the formula<disp-formula id="e20">
<mml:math id="m45">
<mml:mrow>
<mml:mover accent="true">
<mml:mi>a</mml:mi>
<mml:mo>&#x2192;</mml:mo>
</mml:mover>
<mml:mo>&#x3d;</mml:mo>
<mml:mo>&#x2212;</mml:mo>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mi>g</mml:mi>
<mml:mi>r</mml:mi>
<mml:mi>a</mml:mi>
<mml:mi>d</mml:mi>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
</mml:mrow>
</mml:math>
<label>(20)</label>
</disp-formula>
</p>
<p>For the analysis of particle-wave motion, it is convenient to decompose vector <inline-formula id="inf22">
<mml:math id="m46">
<mml:mrow>
<mml:mover accent="true">
<mml:mi mathvariant="bold-italic">a</mml:mi>
<mml:mo>&#x2192;</mml:mo>
</mml:mover>
</mml:mrow>
</mml:math>
</inline-formula> into two components &#x2013; a component parallel to the direction of particle-wave motion <inline-formula id="inf23">
<mml:math id="m47">
<mml:mrow>
<mml:mover accent="true">
<mml:msub>
<mml:mi mathvariant="bold-italic">a</mml:mi>
<mml:mo>&#x2225;</mml:mo>
</mml:msub>
<mml:mo>&#x2192;</mml:mo>
</mml:mover>
</mml:mrow>
</mml:math>
</inline-formula> and a component perpendicular to it <inline-formula id="inf24">
<mml:math id="m48">
<mml:mrow>
<mml:mover accent="true">
<mml:msub>
<mml:mi mathvariant="bold-italic">a</mml:mi>
<mml:mo>&#x22a5;</mml:mo>
</mml:msub>
<mml:mo>&#x2192;</mml:mo>
</mml:mover>
</mml:mrow>
</mml:math>
</inline-formula>. At the same time, we introduce an auxiliary coordinate system with its origin at the center of the particle-wave and axes <italic>&#x3be;</italic> and <italic>&#x3b7;</italic> (see <xref ref-type="fig" rid="F4">Figure 4a</xref>).</p>
<fig id="F4" position="float">
<label>FIGURE 4</label>
<caption>
<p>Decomposition of the acceleration vector into components related to the direction of motion of the particle-wave. <bold>(a)</bold> Plot in the &#x3be;-&#x3b7; plane, <bold>(b)</bold> plot in 4D space (space E<sub>3</sub> represented as two-dimensional).</p>
</caption>
<graphic xlink:href="fphy-14-1737947-g004.tif">
<alt-text content-type="machine-generated">Diagram (a) illustrates vector decomposition with vectors \(\overrightarrow{a}_\parallel\), \(\overrightarrow{a}_\perp\), and \(\overrightarrow{a}\), showing angles \(\gamma\) and directions \(\xi\) and \(\eta\). Diagram (b) depicts a spherical coordinate system in \(E_3\) space with vectors similar to (a), including angles \(\gamma\), \(\alpha\), \(\epsilon\), and \(\pi/2\), alongside vectors \(\overrightarrow{v}_{4D}\), \(\xi\), and \(\eta\).</alt-text>
</graphic>
</fig>
<p>In the coordinate system <italic>&#x3be;</italic>, <italic>&#x3b7;</italic>, the vector <inline-formula id="inf25">
<mml:math id="m49">
<mml:mrow>
<mml:mover accent="true">
<mml:mi mathvariant="bold-italic">a</mml:mi>
<mml:mo>&#x2192;</mml:mo>
</mml:mover>
</mml:mrow>
</mml:math>
</inline-formula> can be written as <inline-formula id="inf26">
<mml:math id="m50">
<mml:mrow>
<mml:mover accent="true">
<mml:mi mathvariant="bold-italic">a</mml:mi>
<mml:mo>&#x2192;</mml:mo>
</mml:mover>
<mml:mo>&#x3d;</mml:mo>
<mml:mi mathvariant="bold-italic">a</mml:mi>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:msub>
<mml:mi mathvariant="bold-italic">a</mml:mi>
<mml:mo>&#x2225;</mml:mo>
</mml:msub>
<mml:mo>,</mml:mo>
<mml:msub>
<mml:mi mathvariant="bold-italic">a</mml:mi>
<mml:mo>&#x22a5;</mml:mo>
</mml:msub>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
</mml:mrow>
</mml:math>
</inline-formula>, where<disp-formula id="e21">
<mml:math id="m51">
<mml:mrow>
<mml:msub>
<mml:mi>a</mml:mi>
<mml:mo>&#x2225;</mml:mo>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:mo>&#x2212;</mml:mo>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
<mml:mfrac>
<mml:mrow>
<mml:mi>&#x2202;</mml:mi>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
</mml:mrow>
<mml:mrow>
<mml:mi>&#x2202;</mml:mi>
<mml:mi>&#x3be;</mml:mi>
</mml:mrow>
</mml:mfrac>
<mml:mo>, </mml:mo>
<mml:mspace width="0.3em"/>
<mml:msub>
<mml:mi>a</mml:mi>
<mml:mo>&#x22a5;</mml:mo>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:mo>&#x2212;</mml:mo>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
<mml:mfrac>
<mml:mrow>
<mml:mi>&#x2202;</mml:mi>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
</mml:mrow>
<mml:mrow>
<mml:mi>&#x2202;</mml:mi>
<mml:mi>&#x3b7;</mml:mi>
</mml:mrow>
</mml:mfrac>
</mml:mrow>
</mml:math>
<label>(21)</label>
</disp-formula>
</p>
<p>The relationship of these components to the vector <inline-formula id="inf27">
<mml:math id="m52">
<mml:mrow>
<mml:mover accent="true">
<mml:mi mathvariant="bold-italic">a</mml:mi>
<mml:mo>&#x2192;</mml:mo>
</mml:mover>
</mml:mrow>
</mml:math>
</inline-formula> is given by formulas:<disp-formula id="e22">
<mml:math id="m53">
<mml:mrow>
<mml:msub>
<mml:mi mathvariant="bold">a</mml:mi>
<mml:mo>&#x2225;</mml:mo>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:mrow>
<mml:mfenced open="&#x2016;" close="&#x2016;" separators="&#x7c;">
<mml:mrow>
<mml:mover accent="true">
<mml:mi mathvariant="bold">a</mml:mi>
<mml:mo>&#x2192;</mml:mo>
</mml:mover>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
<mml:mi mathvariant="bold">cos</mml:mi>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mi mathvariant="bold">&#x3b5;</mml:mi>
<mml:mo>,</mml:mo>
<mml:mspace width="0.3em"/>
<mml:msub>
<mml:mi mathvariant="bold">a</mml:mi>
<mml:mo>&#x22a5;</mml:mo>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:mrow>
<mml:mfenced open="&#x2016;" close="&#x2016;" separators="&#x7c;">
<mml:mrow>
<mml:mover accent="true">
<mml:mi mathvariant="bold">a</mml:mi>
<mml:mo>&#x2192;</mml:mo>
</mml:mover>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mi mathvariant="bold">sin</mml:mi>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mi mathvariant="bold">&#x3b5;</mml:mi>
</mml:mrow>
</mml:math>
<label>(22)</label>
</disp-formula>
</p>
<p>The angle <italic>&#x3b5;</italic> between the 4D direction of particle-wave motion and the direction of vector <inline-formula id="inf28">
<mml:math id="m54">
<mml:mrow>
<mml:mover accent="true">
<mml:mi mathvariant="bold-italic">a</mml:mi>
<mml:mo>&#x2192;</mml:mo>
</mml:mover>
</mml:mrow>
</mml:math>
</inline-formula> can be calculated using formula:<disp-formula id="e23">
<mml:math id="m55">
<mml:mrow>
<mml:mi>cos</mml:mi>
<mml:mo>&#x2061;</mml:mo>
<mml:mi>&#x3b5;</mml:mi>
<mml:mo>&#x3d;</mml:mo>
<mml:mi>sin</mml:mi>
<mml:mo>&#x2061;</mml:mo>
<mml:mi>&#x3b1;</mml:mi>
<mml:mo>&#x2061;</mml:mo>
<mml:mi>cos</mml:mi>
<mml:mo>&#x2061;</mml:mo>
<mml:mi>&#x3b3;</mml:mi>
</mml:mrow>
</mml:math>
<label>(23)</label>
</disp-formula>
</p>
<p>Angle <italic>&#x3b3;</italic> is the analogue to <italic>&#x3b5;</italic> in ordinary space E<sub>3</sub>, while angle &#x3b1; is the inclination of the 4D direction of particle-wave motion relative to axis <italic>w</italic> (<xref ref-type="fig" rid="F4">Figure 4b</xref>). It holds that sin &#x3b1; &#x3d; v<sub>3D</sub>/v<sub>4D</sub>.</p>
<p>It might seem that the value <inline-formula id="inf29">
<mml:math id="m56">
<mml:mrow>
<mml:msub>
<mml:mi mathvariant="bold-italic">a</mml:mi>
<mml:mo>&#x2225;</mml:mo>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula> affects the speed of the particle-wave and the value <inline-formula id="inf30">
<mml:math id="m57">
<mml:mrow>
<mml:msub>
<mml:mi mathvariant="bold-italic">a</mml:mi>
<mml:mo>&#x22a5;</mml:mo>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula> affects its direction, but only the second part is true. The component <inline-formula id="inf31">
<mml:math id="m58">
<mml:mrow>
<mml:msub>
<mml:mi mathvariant="bold-italic">a</mml:mi>
<mml:mo>&#x2225;</mml:mo>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula> has no effect on the particle-wave speed. This is because the particle-wave is an undulation of the transmission medium and its speed is determined solely by the properties of this medium, specifically the value of <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> &#x2013; see (<xref ref-type="disp-formula" rid="e15">Equation 15</xref>). It is obvious that, with decreasing value of <italic>V</italic> (downward movement), the value of <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> also decreases. The quantity <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> is a 4D speed, which is not directly observable for most particle-waves, so we do not register the phenomenon. The <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> is identical to the commonly observed 3D speed only for photons (and other particle-waves with zero rest mass). It can be claimed that a photon falling into a gravitational well slows down. However, this paradox is not new. The decrease in the speed of light in a gravitational field (relative to a reference clock located outside the field) is generally known and accepted within GTR.</p>
<p>Regardless of the decrease in speed, the 4D momentum and mass of the particle-wave increase as it falls into the gravitational well (see Sect. 2.2 above).</p>
<p>The transverse component <inline-formula id="inf32">
<mml:math id="m59">
<mml:mrow>
<mml:mover accent="true">
<mml:msub>
<mml:mi mathvariant="bold-italic">a</mml:mi>
<mml:mo>&#x22a5;</mml:mo>
</mml:msub>
<mml:mo>&#x2192;</mml:mo>
</mml:mover>
</mml:mrow>
</mml:math>
</inline-formula> is a consequence of the change of <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> in the transverse direction. The particle-wave has non-zero dimensions and its individual parts move at different speeds - depending on the local value of <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> (<xref ref-type="fig" rid="F5">Figure 5</xref>). One side of the wave moves faster than the other, causing wavefronts to twist. The direction of the wave bends towards the area of lower <italic>v</italic>
<sub>
<italic>4D</italic>
</sub>. The situation is analogous to atmospheric refraction of light, where different speeds of light (different refractive indices) cause its path to curve. This is a manifestation of Fermat&#x2019;s principle, which states that waves do not propagate along the shortest path, but along the path with the shortest time.</p>
<fig id="F5" position="float">
<label>FIGURE 5</label>
<caption>
<p>Bending of the particle-wave trajectory due to different values of <italic>v</italic>
<sub>
<italic>4D</italic>
</sub>.</p>
</caption>
<graphic xlink:href="fphy-14-1737947-g005.tif">
<alt-text content-type="machine-generated">Illustration showing wave fronts with red and blue trajectories. Red trajectory labeled &#x22;Bend trajectory&#x22; curves downward, while the blue trajectory labeled &#x22;Straight trajectory&#x22; remains straight. Two regions have different velocities, with \(V_{4D,1}\) greater than \(V_{4D,2}\), indicated by arrows.</alt-text>
</graphic>
</fig>
<p>The radius of bending can be determined by the following consideration: The ratio of the path on the outer side of the arc to the path of the center of the particle-wave is equal to the ratio of local 4D speeds: <inline-formula id="inf33">
<mml:math id="m60">
<mml:mrow>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:mi>l</mml:mi>
<mml:mo>&#x2b;</mml:mo>
<mml:mi>d</mml:mi>
<mml:mi>l</mml:mi>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
<mml:mo>/</mml:mo>
<mml:mi>l</mml:mi>
<mml:mo>&#x3d;</mml:mo>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
<mml:mo>&#x2b;</mml:mo>
<mml:mi>d</mml:mi>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
<mml:mo>/</mml:mo>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula>.</p>
<p>The ratio of distances can be replaced by the ratio of radii <inline-formula id="inf34">
<mml:math id="m61">
<mml:mrow>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:mi>r</mml:mi>
<mml:mo>&#x2b;</mml:mo>
<mml:mi>d</mml:mi>
<mml:mi>r</mml:mi>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
<mml:mo>/</mml:mo>
<mml:mi>r</mml:mi>
</mml:mrow>
</mml:math>
</inline-formula>, where the increment of radius <italic>dr</italic> is equal to the negative increment of <italic>d&#x3b7;</italic>: <inline-formula id="inf35">
<mml:math id="m62">
<mml:mrow>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:mi>l</mml:mi>
<mml:mo>&#x2b;</mml:mo>
<mml:mi>d</mml:mi>
<mml:mi>l</mml:mi>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
<mml:mo>/</mml:mo>
<mml:mi>l</mml:mi>
<mml:mo>&#x3d;</mml:mo>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:mi>r</mml:mi>
<mml:mo>&#x2b;</mml:mo>
<mml:mi>d</mml:mi>
<mml:mi>r</mml:mi>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
<mml:mo>/</mml:mo>
<mml:mi>r</mml:mi>
<mml:mo>&#x3d;</mml:mo>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:mi>r</mml:mi>
<mml:mo>&#x2212;</mml:mo>
<mml:mi>d</mml:mi>
<mml:mi>&#x3b7;</mml:mi>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
<mml:mo>/</mml:mo>
<mml:mi>r</mml:mi>
</mml:mrow>
</mml:math>
</inline-formula>.</p>
<p>It can be written <inline-formula id="inf36">
<mml:math id="m63">
<mml:mrow>
<mml:mo>&#x2212;</mml:mo>
<mml:mi>d</mml:mi>
<mml:mi>&#x3b7;</mml:mi>
<mml:mo>/</mml:mo>
<mml:mi>r</mml:mi>
<mml:mo>&#x3d;</mml:mo>
<mml:mi>d</mml:mi>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
<mml:mo>/</mml:mo>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula>, hence<disp-formula id="e24">
<mml:math id="m64">
<mml:mrow>
<mml:mfrac>
<mml:mrow>
<mml:mn>1</mml:mn>
</mml:mrow>
<mml:mrow>
<mml:mi>r</mml:mi>
</mml:mrow>
</mml:mfrac>
<mml:mo>&#x3d;</mml:mo>
<mml:mo>&#x2212;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mi>d</mml:mi>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
</mml:mrow>
<mml:mrow>
<mml:mi>d</mml:mi>
<mml:mi>&#x3b7;</mml:mi>
</mml:mrow>
</mml:mfrac>
<mml:mfrac>
<mml:mrow>
<mml:mn>1</mml:mn>
</mml:mrow>
<mml:mrow>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
</mml:mrow>
</mml:mfrac>
</mml:mrow>
</mml:math>
<label>(24)</label>
</disp-formula>
</p>
<p>The radius depends on the rate of decrease in <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> (i.e., on <inline-formula id="inf37">
<mml:math id="m65">
<mml:mrow>
<mml:mi>d</mml:mi>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
<mml:mo>/</mml:mo>
<mml:mi>d</mml:mi>
<mml:mi>&#x3b7;</mml:mi>
</mml:mrow>
</mml:math>
</inline-formula>). By combining relations (<xref ref-type="disp-formula" rid="e24">Equation 24</xref>) and (<xref ref-type="disp-formula" rid="e21">Equation 21</xref>), it can be written<disp-formula id="e25">
<mml:math id="m66">
<mml:mrow>
<mml:mi>r</mml:mi>
<mml:mo>&#x3d;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:msubsup>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
<mml:mn>2</mml:mn>
</mml:msubsup>
</mml:mrow>
<mml:mrow>
<mml:msub>
<mml:mi>a</mml:mi>
<mml:mo>&#x22a5;</mml:mo>
</mml:msub>
</mml:mrow>
</mml:mfrac>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mo>&#x21d2;</mml:mo>
<mml:mtext>&#x2009;</mml:mtext>
<mml:msub>
<mml:mi>a</mml:mi>
<mml:mo>&#x22a5;</mml:mo>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:msubsup>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
<mml:mn>2</mml:mn>
</mml:msubsup>
</mml:mrow>
<mml:mrow>
<mml:mi>r</mml:mi>
</mml:mrow>
</mml:mfrac>
</mml:mrow>
</mml:math>
<label>(25)</label>
</disp-formula>
</p>
<p>The relationship (<xref ref-type="disp-formula" rid="e25">Equation 25</xref>) shows that the transverse component of the vector <inline-formula id="inf38">
<mml:math id="m67">
<mml:mrow>
<mml:mover accent="true">
<mml:mi mathvariant="bold-italic">a</mml:mi>
<mml:mo>&#x2192;</mml:mo>
</mml:mover>
</mml:mrow>
</mml:math>
</inline-formula> makes the particle-wave move in a circle with radius <italic>r</italic>. Centripetal acceleration of the same magnitude would have the same effect. The variable value of <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> curves the trajectory of the particle-wave the same way as it would be curved by the acceleration <inline-formula id="inf39">
<mml:math id="m68">
<mml:mrow>
<mml:msub>
<mml:mi mathvariant="bold-italic">a</mml:mi>
<mml:mo>&#x22a5;</mml:mo>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula> caused by some acting force (inertial, gravitational, etc.).</p>
<p>The deviation from the straight line is equal to <italic>&#x3b7; &#x3d; &#x3be;</italic> <sup>
<italic>2</italic>
</sup>
<italic>/2r</italic>, which, after substituting <italic>r</italic> from (<xref ref-type="disp-formula" rid="e25">Equation 25</xref>) and <italic>&#x3be; &#x3d; v</italic>
<sub>
<italic>4D</italic>
</sub> <italic>t</italic>, leads to <inline-formula id="inf40">
<mml:math id="m69">
<mml:mrow>
<mml:mi mathvariant="bold-italic">&#x3b7;</mml:mi>
<mml:mo>&#x3d;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:msubsup>
<mml:mi mathvariant="bold-italic">v</mml:mi>
<mml:mrow>
<mml:mn mathvariant="bold">4</mml:mn>
<mml:mi mathvariant="bold-italic">D</mml:mi>
</mml:mrow>
<mml:mn mathvariant="bold">2</mml:mn>
</mml:msubsup>
<mml:msup>
<mml:mi mathvariant="bold-italic">t</mml:mi>
<mml:mn mathvariant="bold">2</mml:mn>
</mml:msup>
<mml:msub>
<mml:mi mathvariant="bold-italic">a</mml:mi>
<mml:mo>&#x22a5;</mml:mo>
</mml:msub>
</mml:mrow>
<mml:mrow>
<mml:mn mathvariant="bold">2</mml:mn>
<mml:msubsup>
<mml:mi mathvariant="bold-italic">v</mml:mi>
<mml:mrow>
<mml:mn mathvariant="bold">4</mml:mn>
<mml:mi mathvariant="bold-italic">D</mml:mi>
</mml:mrow>
<mml:mn mathvariant="bold">2</mml:mn>
</mml:msubsup>
</mml:mrow>
</mml:mfrac>
<mml:mo>&#x3d;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mn mathvariant="bold">1</mml:mn>
</mml:mrow>
<mml:mrow>
<mml:mn mathvariant="bold">2</mml:mn>
</mml:mrow>
</mml:mfrac>
<mml:msub>
<mml:mi mathvariant="bold-italic">a</mml:mi>
<mml:mo>&#x22a5;</mml:mo>
</mml:msub>
<mml:msup>
<mml:mi mathvariant="bold-italic">t</mml:mi>
<mml:mn mathvariant="bold">2</mml:mn>
</mml:msup>
</mml:mrow>
</mml:math>
</inline-formula>.</p>
<p>It can be seen that the quantity <inline-formula id="inf41">
<mml:math id="m70">
<mml:mrow>
<mml:msub>
<mml:mi mathvariant="bold-italic">a</mml:mi>
<mml:mo>&#x22a5;</mml:mo>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula> is the actual kinematic acceleration with which the particle-wave moves in space E<sub>3</sub>.</p>
<p>In non-relativistic cases, the difference between <inline-formula id="inf42">
<mml:math id="m71">
<mml:mrow>
<mml:mover accent="true">
<mml:msub>
<mml:mi mathvariant="bold-italic">a</mml:mi>
<mml:mo>&#x22a5;</mml:mo>
</mml:msub>
<mml:mo>&#x2192;</mml:mo>
</mml:mover>
</mml:mrow>
</mml:math>
</inline-formula> and <inline-formula id="inf43">
<mml:math id="m72">
<mml:mrow>
<mml:mover accent="true">
<mml:mrow>
<mml:mi mathvariant="bold-italic">a</mml:mi>
<mml:mtext>&#x2009;</mml:mtext>
</mml:mrow>
<mml:mo>&#x2192;</mml:mo>
</mml:mover>
</mml:mrow>
</mml:math>
</inline-formula> can be neglected, since particle-waves moving at non-relativistic 3D speeds (<italic>v</italic>
<sub>
<italic>3D</italic>
</sub> &#x3c;&#x3c; <italic>v</italic>
<sub>
<italic>4D</italic>
</sub>) perform their 4D motion primarily in the <italic>w</italic> dimension. The direction of their motion is therefore practically perpendicular to any acceleration vector <inline-formula id="inf44">
<mml:math id="m73">
<mml:mrow>
<mml:mover accent="true">
<mml:mi mathvariant="bold-italic">a</mml:mi>
<mml:mo>&#x2192;</mml:mo>
</mml:mover>
<mml:mo>&#x3d;</mml:mo>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:msub>
<mml:mi mathvariant="bold-italic">a</mml:mi>
<mml:mi mathvariant="bold-italic">x</mml:mi>
</mml:msub>
<mml:mo>,</mml:mo>
<mml:msub>
<mml:mi mathvariant="bold-italic">a</mml:mi>
<mml:mi mathvariant="bold-italic">y</mml:mi>
</mml:msub>
<mml:mo>,</mml:mo>
<mml:msub>
<mml:mi mathvariant="bold-italic">a</mml:mi>
<mml:mi mathvariant="bold-italic">z</mml:mi>
</mml:msub>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
</mml:mrow>
</mml:math>
</inline-formula>. In these cases, the last formula can be rewritten into the familiar form<disp-formula id="e26">
<mml:math id="m74">
<mml:mrow>
<mml:mi>&#x3b7;</mml:mi>
<mml:mo>&#x3d;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mn>1</mml:mn>
</mml:mrow>
<mml:mrow>
<mml:mn>2</mml:mn>
</mml:mrow>
</mml:mfrac>
<mml:msup>
<mml:mrow>
<mml:mi>a</mml:mi>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mi>t</mml:mi>
</mml:mrow>
<mml:mn>2</mml:mn>
</mml:msup>
</mml:mrow>
</mml:math>
<label>(26)</label>
</disp-formula>
</p>
<p>It expresses the change in position of the particle-wave in E<sub>3</sub> under the influence of acceleration <inline-formula id="inf45">
<mml:math id="m75">
<mml:mrow>
<mml:mi mathvariant="bold-italic">a</mml:mi>
<mml:mo>&#x3d;</mml:mo>
<mml:mo>&#x2212;</mml:mo>
<mml:mi mathvariant="bold-italic">g</mml:mi>
<mml:mi mathvariant="bold-italic">r</mml:mi>
<mml:mi mathvariant="bold-italic">a</mml:mi>
<mml:mi mathvariant="bold-italic">d</mml:mi>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:mi mathvariant="bold-italic">V</mml:mi>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
</mml:mrow>
</mml:math>
</inline-formula>. The <xref ref-type="disp-formula" rid="e26">Equation 26</xref> applies to all non-relativistically moving particles of matter, as well as composite bodies. The change in the state of motion of a body is independent of its mass, 3D velocity, direction of motion, or composition. And, as will be shown later, it does not depend on the way in which the gravity field was created.</p>
<p>In relativistic cases, the kinematic acceleration <inline-formula id="inf46">
<mml:math id="m76">
<mml:mrow>
<mml:msub>
<mml:mi mathvariant="bold-italic">a</mml:mi>
<mml:mo>&#x22a5;</mml:mo>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula> is given by <xref ref-type="disp-formula" rid="e22">Equations 22</xref>, <xref ref-type="disp-formula" rid="e23">23</xref>. The term <italic>sin &#x3b1;</italic> in <xref ref-type="disp-formula" rid="e23">Equation 23</xref> acts equivalently as a relativistic mass increase in GTR.</p>
<p>The derivation of gravitational acceleration given above applies to any particle-wave (photon, neutrino, electron, muon, &#x2026;) moving in any direction and at any (permissible) 3D velocity. It should be noted that the accelerated motion of particle-waves in the gravity field is not the result of acceleration or force acting at a distance, but rather the result of different values of <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> in the immediate vicinity of the particle-wave. Acceleration or force is only a useful mathematical aid, not the real cause of the change in the particle&#x2019;s state of motion. Moreover, the usefulness of this aid is limited &#x2013; see the component <inline-formula id="inf47">
<mml:math id="m77">
<mml:mrow>
<mml:msub>
<mml:mi mathvariant="bold-italic">a</mml:mi>
<mml:mo>&#x2225;</mml:mo>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula> mentioned above.</p>
</sec>
<sec id="s2-5">
<label>2.5</label>
<title>Variable <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> in non-inertial systems</title>
<p>Once it has been clarified that the cause of the curvature of particle-waves trajectories is the variable value of <italic>v</italic>
<sub>
<italic>4D</italic>
</sub>, the question inevitably arises: What is the cause of this variability? It is useful to follow Einstein&#x2019;s approach here and focus on the similarity between gravitational and inertial forces.</p>
<p>Let us consider space E<sub>4</sub>-B filled with a homogeneous isotropic medium in which all particle-waves move at the same 4D speed, namely, speed <italic>c</italic>. In this space, there is a flat rotating disk that rotates at an angular velocity <italic>&#x3c9;</italic> relative to the stationary coordinate system S (x, y, z). The coordinate system S<italic>&#x2032;</italic> (<italic>x&#x27;, y&#x27;, z&#x27;</italic>) is rigidly connected to the disk. The axis of rotation is the common axis <italic>z &#x2261; z&#x27;</italic>.</p>
<p>Any point on the disk moves relative to S at a speed <inline-formula id="inf48">
<mml:math id="m78">
<mml:mrow>
<mml:msub>
<mml:mi mathvariant="bold-italic">v</mml:mi>
<mml:mi mathvariant="bold-italic">s</mml:mi>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:msub>
<mml:mi mathvariant="bold-italic">r</mml:mi>
<mml:mi mathvariant="bold-italic">s</mml:mi>
</mml:msub>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mi mathvariant="bold-italic">&#x3c9;</mml:mi>
</mml:mrow>
</mml:math>
</inline-formula>, where <italic>r</italic>
<sub>
<italic>s</italic>
</sub> is the distance from the <italic>z</italic>-axis, <inline-formula id="inf49">
<mml:math id="m79">
<mml:mrow>
<mml:msub>
<mml:mi mathvariant="bold-italic">r</mml:mi>
<mml:mi mathvariant="bold-italic">s</mml:mi>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:msqrt>
<mml:mrow>
<mml:msup>
<mml:mi mathvariant="bold-italic">x</mml:mi>
<mml:mn mathvariant="bold">2</mml:mn>
</mml:msup>
<mml:mo>&#x2b;</mml:mo>
<mml:msup>
<mml:mi mathvariant="bold-italic">y</mml:mi>
<mml:mn mathvariant="bold">2</mml:mn>
</mml:msup>
</mml:mrow>
</mml:msqrt>
</mml:mrow>
</mml:math>
</inline-formula>. The non-zero value of <italic>v</italic>
<sub>
<italic>s</italic>
</sub> causes the speed of particle-waves relative to the rotating system S&#x2032; to be lower than relative to the system S. This refers to the average two-way speed. The formula <inline-formula id="inf50">
<mml:math id="m80">
<mml:mrow>
<mml:msub>
<mml:mi mathvariant="bold-italic">v</mml:mi>
<mml:mrow>
<mml:mn mathvariant="bold">4</mml:mn>
<mml:mi mathvariant="bold-italic">D</mml:mi>
</mml:mrow>
</mml:msub>
<mml:mo>&#x2032;</mml:mo>
<mml:mo>&#x3d;</mml:mo>
<mml:msqrt>
<mml:mrow>
<mml:msup>
<mml:mi mathvariant="bold-italic">c</mml:mi>
<mml:mn mathvariant="bold">2</mml:mn>
</mml:msup>
<mml:mo>&#x2212;</mml:mo>
<mml:msubsup>
<mml:mi mathvariant="bold-italic">v</mml:mi>
<mml:mi mathvariant="bold-italic">s</mml:mi>
<mml:mn mathvariant="bold">2</mml:mn>
</mml:msubsup>
</mml:mrow>
</mml:msqrt>
</mml:mrow>
</mml:math>
</inline-formula> holds. It obviously holds for cases where <inline-formula id="inf51">
<mml:math id="m81">
<mml:mrow>
<mml:msub>
<mml:mi mathvariant="bold-italic">v</mml:mi>
<mml:mi mathvariant="bold-italic">s</mml:mi>
</mml:msub>
<mml:mo>&#x22a5;</mml:mo>
<mml:msub>
<mml:mi mathvariant="bold-italic">v</mml:mi>
<mml:mrow>
<mml:mn mathvariant="bold">4</mml:mn>
<mml:mi mathvariant="bold-italic">D</mml:mi>
</mml:mrow>
</mml:msub>
<mml:mo>&#x2032;</mml:mo>
</mml:mrow>
</mml:math>
</inline-formula>, i.e., in cases where the particle-wave motion is perpendicular to <italic>v</italic>
<sub>
<italic>s</italic>
</sub>. The validity for other directions of particle-wave motion is not obvious, but it also holds for them. A detailed justification can be found in [<xref ref-type="bibr" rid="B7">7</xref>].</p>
<p>The formula <inline-formula id="inf52">
<mml:math id="m82">
<mml:mrow>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
<mml:mo>&#x2032;</mml:mo>
<mml:mo>&#x3d;</mml:mo>
<mml:msqrt>
<mml:mrow>
<mml:msup>
<mml:mi>c</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
<mml:mo>&#x2212;</mml:mo>
<mml:msubsup>
<mml:mrow>
<mml:msup>
<mml:mi>&#x3c9;</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
<mml:mi>r</mml:mi>
</mml:mrow>
<mml:mi>s</mml:mi>
<mml:mn>2</mml:mn>
</mml:msubsup>
</mml:mrow>
</mml:msqrt>
</mml:mrow>
</mml:math>
</inline-formula> shows that in the rotating coordinate system, the velocity <italic>v</italic>
<sub>
<italic>4D</italic>
</sub>&#x2019; is variable. It can be speculated that this variability causes the curvature of the trajectories of free particle-waves, and such curvature is identical to the effect of centrifugal acceleration <inline-formula id="inf53">
<mml:math id="m83">
<mml:mrow>
<mml:msub>
<mml:mi>a</mml:mi>
<mml:mi>c</mml:mi>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:msup>
<mml:mi>&#x3c9;</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>s</mml:mi>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula>.</p>
<p>Derivation of the above formula for <inline-formula id="inf54">
<mml:math id="m84">
<mml:mrow>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
<mml:mo>&#x2032;</mml:mo>
</mml:mrow>
</mml:math>
</inline-formula> with respect to radius <italic>r</italic>
<sub>
<italic>s</italic>
</sub> gives<disp-formula id="equ5">
<mml:math id="m85">
<mml:mrow>
<mml:mfrac>
<mml:mrow>
<mml:mi>d</mml:mi>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
<mml:mo>&#x2032;</mml:mo>
</mml:mrow>
<mml:mrow>
<mml:mi>d</mml:mi>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>s</mml:mi>
</mml:msub>
</mml:mrow>
</mml:mfrac>
<mml:mo>&#x3d;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mo>&#x2212;</mml:mo>
<mml:mn>2</mml:mn>
<mml:msup>
<mml:mi>&#x3c9;</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>s</mml:mi>
</mml:msub>
</mml:mrow>
<mml:mrow>
<mml:mn>2</mml:mn>
<mml:msqrt>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:msup>
<mml:mi>c</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
<mml:mo>&#x2212;</mml:mo>
<mml:msubsup>
<mml:mrow>
<mml:msup>
<mml:mi>&#x3c9;</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
<mml:mi>r</mml:mi>
</mml:mrow>
<mml:mi>s</mml:mi>
<mml:mn>2</mml:mn>
</mml:msubsup>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
</mml:msqrt>
</mml:mrow>
</mml:mfrac>
<mml:mo>&#x3d;</mml:mo>
<mml:mo>&#x2212;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:msup>
<mml:mi>&#x3c9;</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>s</mml:mi>
</mml:msub>
</mml:mrow>
<mml:mrow>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
<mml:mo>&#x2032;</mml:mo>
</mml:mrow>
</mml:mfrac>
</mml:mrow>
</mml:math>
</disp-formula>
</p>
<p>By substituting into (<xref ref-type="disp-formula" rid="e21">Equation 21</xref>) and considering <inline-formula id="inf55">
<mml:math id="m86">
<mml:mrow>
<mml:mfrac>
<mml:mrow>
<mml:mi>d</mml:mi>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
<mml:mo>&#x2032;</mml:mo>
</mml:mrow>
<mml:mrow>
<mml:mi>d</mml:mi>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>s</mml:mi>
</mml:msub>
</mml:mrow>
</mml:mfrac>
<mml:mo>&#x2261;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mi>d</mml:mi>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
</mml:mrow>
<mml:mrow>
<mml:mi>d</mml:mi>
<mml:mi>&#x3b7;</mml:mi>
</mml:mrow>
</mml:mfrac>
</mml:mrow>
</mml:math>
</inline-formula> (these are identical variables with different notation), we obtain the formula<disp-formula id="equ6">
<mml:math id="m87">
<mml:mrow>
<mml:msub>
<mml:mi>a</mml:mi>
<mml:mo>&#x22a5;</mml:mo>
</mml:msub>
<mml:mo>&#x2032;</mml:mo>
<mml:mo>&#x3d;</mml:mo>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
<mml:mo>&#x2032;</mml:mo>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mfrac>
<mml:mrow>
<mml:msup>
<mml:mi>&#x3c9;</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>s</mml:mi>
</mml:msub>
</mml:mrow>
<mml:mrow>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
<mml:mo>&#x2032;</mml:mo>
</mml:mrow>
</mml:mfrac>
<mml:mo>&#x3d;</mml:mo>
<mml:msup>
<mml:mi>&#x3c9;</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>s</mml:mi>
</mml:msub>
</mml:mrow>
</mml:math>
</disp-formula>
</p>
<p>Clearly, <inline-formula id="inf56">
<mml:math id="m88">
<mml:mrow>
<mml:msub>
<mml:mi mathvariant="bold-italic">a</mml:mi>
<mml:mi mathvariant="bold-italic">c</mml:mi>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:msub>
<mml:mi mathvariant="bold-italic">a</mml:mi>
<mml:mo>&#x22a5;</mml:mo>
</mml:msub>
<mml:mo>&#x2032;</mml:mo>
</mml:mrow>
</mml:math>
</inline-formula> applies, i.e., the acceleration <inline-formula id="inf57">
<mml:math id="m89">
<mml:mrow>
<mml:msub>
<mml:mi mathvariant="bold-italic">a</mml:mi>
<mml:mi mathvariant="bold-italic">c</mml:mi>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula> caused by the rotation of the disk is equal to the acceleration <inline-formula id="inf58">
<mml:math id="m90">
<mml:mrow>
<mml:msub>
<mml:mi mathvariant="bold-italic">a</mml:mi>
<mml:mo>&#x22a5;</mml:mo>
</mml:msub>
<mml:mo>&#x2032;</mml:mo>
</mml:mrow>
</mml:math>
</inline-formula> of a particle-wave caused by the local change in <italic>v</italic>
<sub>
<italic>4D</italic>
</sub>
<italic>&#x27;</italic>.</p>
<p>It is important to note that the change in <italic>v</italic>
<sub>
<italic>4D</italic>
</sub>
<italic>&#x2019;</italic> with the spatial position, and thus also the acceleration <inline-formula id="inf59">
<mml:math id="m91">
<mml:mrow>
<mml:msub>
<mml:mi mathvariant="bold-italic">a</mml:mi>
<mml:mo>&#x22a5;</mml:mo>
</mml:msub>
<mml:mo>&#x2032;</mml:mo>
</mml:mrow>
</mml:math>
</inline-formula>, are phenomena tied to the rotating system S&#x27;. From the perspective of the stationary system S, the <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> is the same everywhere (<italic>v</italic>
<sub>
<italic>4D</italic>
</sub> &#x3d; <italic>c</italic>) and particle-waves move without acceleration (inertial motion). That is, the spatial variability of <inline-formula id="inf60">
<mml:math id="m92">
<mml:mrow>
<mml:msubsup>
<mml:mi mathvariant="bold-italic">v</mml:mi>
<mml:mrow>
<mml:mn mathvariant="bold">4</mml:mn>
<mml:mi mathvariant="bold-italic">D</mml:mi>
</mml:mrow>
<mml:mo>&#x2032;</mml:mo>
</mml:msubsup>
</mml:mrow>
</mml:math>
</inline-formula> is a consequence of the motion of the coordinate system S<italic>&#x2032;</italic> relative to S.</p>
<p>The acceleration <inline-formula id="inf61">
<mml:math id="m93">
<mml:mrow>
<mml:msub>
<mml:mi mathvariant="bold-italic">a</mml:mi>
<mml:mo>&#x22a5;</mml:mo>
</mml:msub>
<mml:mo>&#x2032;</mml:mo>
</mml:mrow>
</mml:math>
</inline-formula> can also be determined in another way, namely, by means of the function <italic>V&#x27; &#x3d; f(x&#x27;, y&#x27;, z&#x27;)</italic> describing the distribution of potential in the system <italic>S&#x2032;</italic> and subsequently by the relationship between acceleration and gradient of <italic>V&#x2019;</italic>. For a rotating disk <inline-formula id="inf62">
<mml:math id="m94">
<mml:mrow>
<mml:msup>
<mml:mi mathvariant="bold-italic">V</mml:mi>
<mml:mo>&#x2032;</mml:mo>
</mml:msup>
<mml:mo>&#x3d;</mml:mo>
<mml:mo>&#x2212;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mn mathvariant="bold">1</mml:mn>
</mml:mrow>
<mml:mrow>
<mml:mn mathvariant="bold">2</mml:mn>
</mml:mrow>
</mml:mfrac>
<mml:msup>
<mml:mi mathvariant="bold-italic">&#x3c9;</mml:mi>
<mml:mn mathvariant="bold">2</mml:mn>
</mml:msup>
<mml:msubsup>
<mml:mi mathvariant="bold-italic">r</mml:mi>
<mml:mi mathvariant="bold-italic">s</mml:mi>
<mml:mn mathvariant="bold">2</mml:mn>
</mml:msubsup>
</mml:mrow>
</mml:math>
</inline-formula> applies. In the cylindrical coordinates (<italic>r</italic>, <italic>&#x3c6;</italic>, <italic>z</italic>), the parameters of the acceleration vector can be determined from the potential <italic>V&#x27;</italic>:<disp-formula id="equ7">
<mml:math id="m95">
<mml:mrow>
<mml:mover accent="true">
<mml:mi>a</mml:mi>
<mml:mo>&#x2192;</mml:mo>
</mml:mover>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:msub>
<mml:mi>a</mml:mi>
<mml:mi>r</mml:mi>
</mml:msub>
<mml:mo>,</mml:mo>
<mml:msub>
<mml:mi>a</mml:mi>
<mml:mi>&#x3c6;</mml:mi>
</mml:msub>
<mml:mo>,</mml:mo>
<mml:msub>
<mml:mi>a</mml:mi>
<mml:mi>z</mml:mi>
</mml:msub>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
<mml:mo>&#x3d;</mml:mo>
<mml:mo>&#x2212;</mml:mo>
<mml:mi>g</mml:mi>
<mml:mi>r</mml:mi>
<mml:mi>a</mml:mi>
<mml:mi>d</mml:mi>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:msup>
<mml:mi>V</mml:mi>
<mml:mo>&#x2032;</mml:mo>
</mml:msup>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
<mml:mo>&#x3d;</mml:mo>
<mml:mo>&#x2212;</mml:mo>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:mfrac>
<mml:mrow>
<mml:mi>&#x2202;</mml:mi>
<mml:msup>
<mml:mi>V</mml:mi>
<mml:mo>&#x2032;</mml:mo>
</mml:msup>
</mml:mrow>
<mml:mrow>
<mml:mi>&#x2202;</mml:mi>
<mml:mi>r</mml:mi>
</mml:mrow>
</mml:mfrac>
<mml:mo>,</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mn>1</mml:mn>
</mml:mrow>
<mml:mrow>
<mml:mi>r</mml:mi>
</mml:mrow>
</mml:mfrac>
<mml:mfrac>
<mml:mrow>
<mml:mi>&#x2202;</mml:mi>
<mml:msup>
<mml:mi>V</mml:mi>
<mml:mo>&#x2032;</mml:mo>
</mml:msup>
</mml:mrow>
<mml:mrow>
<mml:mi>&#x2202;</mml:mi>
<mml:mi>&#x3c6;</mml:mi>
</mml:mrow>
</mml:mfrac>
<mml:mo>,</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mi>&#x2202;</mml:mi>
<mml:msup>
<mml:mi>V</mml:mi>
<mml:mo>&#x2032;</mml:mo>
</mml:msup>
</mml:mrow>
<mml:mrow>
<mml:mi>&#x2202;</mml:mi>
<mml:mi>z</mml:mi>
</mml:mrow>
</mml:mfrac>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
<mml:mo>&#x3d;</mml:mo>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:msup>
<mml:mi>&#x3c9;</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>s</mml:mi>
</mml:msub>
<mml:mo>,</mml:mo>
<mml:mn>0</mml:mn>
<mml:mo>,</mml:mo>
<mml:mn>0</mml:mn>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
</mml:mrow>
</mml:math>
</disp-formula>i.e., the acceleration has a radial direction and is equal to <inline-formula id="inf63">
<mml:math id="m96">
<mml:mrow>
<mml:msub>
<mml:mi mathvariant="bold-italic">a</mml:mi>
<mml:mi mathvariant="bold-italic">c</mml:mi>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula>. We have arrived at the same result as above, but the given procedure is usually easier.</p>
<p>The advantage of utilizing potential can be demonstrated in another typical situation &#x2013; linear accelerated motion. Consider a system S&#x2032; moving with acceleration relative to the stationary system S. Assume constant acceleration <italic>a</italic>
<sub>
<italic>S</italic>
</sub> in the direction of the common axis <italic>x &#x2261; x&#x27;</italic>.</p>
<p>In this case, it is difficult to directly determine the change in <italic>v</italic>
<sub>
<italic>4D</italic>
</sub>
<italic>&#x2019;</italic> with position (<inline-formula id="inf64">
<mml:math id="m97">
<mml:mrow>
<mml:mi mathvariant="bold-italic">d</mml:mi>
<mml:msub>
<mml:mi mathvariant="bold-italic">v</mml:mi>
<mml:mrow>
<mml:mn mathvariant="bold">4</mml:mn>
<mml:mi mathvariant="bold-italic">D</mml:mi>
</mml:mrow>
</mml:msub>
<mml:mo>&#x2032;</mml:mo>
<mml:mo>/</mml:mo>
<mml:mi mathvariant="bold-italic">d</mml:mi>
<mml:msup>
<mml:mi mathvariant="bold-italic">x</mml:mi>
<mml:mo>&#x2032;</mml:mo>
</mml:msup>
</mml:mrow>
</mml:math>
</inline-formula>). This is because of <italic>v</italic>
<sub>
<italic>4D</italic>
</sub>
<italic>&#x2019;</italic>s dependence on time and the simultaneous impossibility of mutual synchronization of remote clocks. Their time shift changes over time. However, it is possible to determine the ratio of the <italic>v</italic>
<sub>
<italic>4D</italic>
</sub>
<italic>&#x2019;</italic> flow at different points of S&#x2032; by comparison of the clocks (<italic>ClockRate</italic>) located there (<xref ref-type="disp-formula" rid="e8">Equation 8</xref>) or to calculate it using the gravity potential &#x2013; see (<xref ref-type="disp-formula" rid="e15">Equation 15</xref>). The potential in this case is given by <inline-formula id="inf65">
<mml:math id="m98">
<mml:mrow>
<mml:msup>
<mml:mi mathvariant="bold-italic">V</mml:mi>
<mml:mo>&#x2032;</mml:mo>
</mml:msup>
<mml:mo>&#x3d;</mml:mo>
<mml:msub>
<mml:mi mathvariant="bold-italic">a</mml:mi>
<mml:mi mathvariant="bold-italic">s</mml:mi>
</mml:msub>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mi mathvariant="bold-italic">x</mml:mi>
</mml:mrow>
</mml:math>
</inline-formula>
<italic>&#x27;</italic>, i.e., <inline-formula id="inf66">
<mml:math id="m99">
<mml:mrow>
<mml:mi mathvariant="bold-italic">&#x2202;</mml:mi>
<mml:msup>
<mml:mi mathvariant="bold-italic">V</mml:mi>
<mml:mo>&#x2032;</mml:mo>
</mml:msup>
<mml:mo>/</mml:mo>
<mml:mi mathvariant="bold-italic">&#x2202;</mml:mi>
<mml:msup>
<mml:mi mathvariant="bold-italic">x</mml:mi>
<mml:mo>&#x2032;</mml:mo>
</mml:msup>
<mml:mo>&#x3d;</mml:mo>
<mml:msub>
<mml:mi mathvariant="bold-italic">a</mml:mi>
<mml:mi mathvariant="bold-italic">s</mml:mi>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula>. Using (<xref ref-type="disp-formula" rid="e19">Equation 19</xref>), we obtain <inline-formula id="inf67">
<mml:math id="m100">
<mml:mrow>
<mml:mi mathvariant="bold-italic">&#x2202;</mml:mi>
<mml:msup>
<mml:msub>
<mml:mi mathvariant="bold-italic">v</mml:mi>
<mml:mrow>
<mml:mn mathvariant="bold">4</mml:mn>
<mml:mi mathvariant="bold-italic">D</mml:mi>
</mml:mrow>
</mml:msub>
<mml:mo>&#x2032;</mml:mo>
</mml:msup>
<mml:mo>/</mml:mo>
<mml:mi mathvariant="bold-italic">&#x2202;</mml:mi>
<mml:msup>
<mml:mi mathvariant="bold-italic">x</mml:mi>
<mml:mo>&#x2032;</mml:mo>
</mml:msup>
<mml:mo>&#x3d;</mml:mo>
<mml:msub>
<mml:mi mathvariant="bold-italic">a</mml:mi>
<mml:mi mathvariant="bold-italic">s</mml:mi>
</mml:msub>
<mml:msubsup>
<mml:mrow>
<mml:mo>/</mml:mo>
<mml:mi mathvariant="bold-italic">v</mml:mi>
</mml:mrow>
<mml:mrow>
<mml:mn mathvariant="bold">4</mml:mn>
<mml:mi mathvariant="bold-italic">D</mml:mi>
</mml:mrow>
<mml:mo>&#x2032;</mml:mo>
</mml:msubsup>
</mml:mrow>
</mml:math>
</inline-formula>. The known change in <italic>v</italic>
<sub>
<italic>4D</italic>
</sub>
<italic>&#x2019;</italic> with <italic>x&#x27;</italic> allows us to calculate the curvature of the path of a free particle-wave (<xref ref-type="disp-formula" rid="e24">Equation 24</xref>). Its acceleration relative to S<italic>&#x2032;</italic> can be determined using (<xref ref-type="disp-formula" rid="e20">Equation 20</xref>) or (<xref ref-type="disp-formula" rid="e18">Equation 18</xref>):<disp-formula id="equ8">
<mml:math id="m101">
<mml:mrow>
<mml:mover accent="true">
<mml:mi>a</mml:mi>
<mml:mo>&#x2192;</mml:mo>
</mml:mover>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:msub>
<mml:mi>a</mml:mi>
<mml:mi>x</mml:mi>
</mml:msub>
<mml:mo>,</mml:mo>
<mml:msub>
<mml:mi>a</mml:mi>
<mml:mi>y</mml:mi>
</mml:msub>
<mml:mo>,</mml:mo>
<mml:msub>
<mml:mi>a</mml:mi>
<mml:mi>z</mml:mi>
</mml:msub>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
<mml:mo>&#x3d;</mml:mo>
<mml:mo>&#x2212;</mml:mo>
<mml:mi>g</mml:mi>
<mml:mi>r</mml:mi>
<mml:mi>a</mml:mi>
<mml:mi>d</mml:mi>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:msup>
<mml:mi>V</mml:mi>
<mml:mo>&#x2032;</mml:mo>
</mml:msup>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
<mml:mo>&#x3d;</mml:mo>
<mml:mo>&#x2212;</mml:mo>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:mfrac>
<mml:mrow>
<mml:mi>&#x2202;</mml:mi>
<mml:msup>
<mml:mi>V</mml:mi>
<mml:mo>&#x2032;</mml:mo>
</mml:msup>
</mml:mrow>
<mml:mrow>
<mml:mi>&#x2202;</mml:mi>
<mml:mi>x</mml:mi>
</mml:mrow>
</mml:mfrac>
<mml:mo>,</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mi>&#x2202;</mml:mi>
<mml:msup>
<mml:mi>V</mml:mi>
<mml:mo>&#x2032;</mml:mo>
</mml:msup>
</mml:mrow>
<mml:mrow>
<mml:mi>&#x2202;</mml:mi>
<mml:mi>y</mml:mi>
</mml:mrow>
</mml:mfrac>
<mml:mo>,</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mi>&#x2202;</mml:mi>
<mml:msup>
<mml:mi>V</mml:mi>
<mml:mo>&#x2032;</mml:mo>
</mml:msup>
</mml:mrow>
<mml:mrow>
<mml:mi>&#x2202;</mml:mi>
<mml:mi>z</mml:mi>
</mml:mrow>
</mml:mfrac>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
<mml:mo>&#x3d;</mml:mo>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:msub>
<mml:mrow>
<mml:mo>&#x2212;</mml:mo>
<mml:mi>a</mml:mi>
</mml:mrow>
<mml:mi>s</mml:mi>
</mml:msub>
<mml:mo>,</mml:mo>
<mml:mn>0</mml:mn>
<mml:mo>,</mml:mo>
<mml:mn>0</mml:mn>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
</mml:mrow>
</mml:math>
</disp-formula>
</p>
<p>The acceleration <inline-formula id="inf68">
<mml:math id="m102">
<mml:mrow>
<mml:mover accent="true">
<mml:mi mathvariant="bold-italic">a</mml:mi>
<mml:mo>&#x2192;</mml:mo>
</mml:mover>
</mml:mrow>
</mml:math>
</inline-formula> with which the free particle-wave moves relative to S&#x2032; is, except for the sign, the same as the acceleration of S&#x2032; relative to S.</p>
<p>It has been shown that, in non-inertial systems, the speed <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> is a function of position. This applies to both linear accelerated as well as rotational motion. Since any motion of coordinate systems relative to each other can be understood as a combination of translations and rotations, it can be argued that <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> is a function of position in all non-inertial systems. Its change with position subsequently affects the direction of motion of particle-waves.</p>
<p>It is important to note that the acceleration of particle-waves caused by the variable value of <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> is exactly opposite to the acceleration of S&#x2032; relative to S. The inertia of matter is not a strange opposition of matter change its state of motion, but a natural property of waves (i.e., particle-waves) to move along the trajectory with the shortest time (Fermat&#x2019;s principle).</p>
</sec>
<sec id="s2-6">
<label>2.6</label>
<title>Undulation of the transmission medium as the source of gravitation</title>
<p>Since it has been shown that the spatially variable <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> is the cause of inertial acceleration, it can be expected to be the cause of gravitational acceleration as well. Logically, the question arises: What is the cause of the variability of <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> in the case of gravitation?</p>
<p>Based on the analogy between inertia and gravitation, one possibility is that the cause of the variable <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> is some motion of the reference frame relative to the stationary frame. However, the specific character of gravitation (e.g., the existence of a central gravitational field) does not allow us to find an adequate type of motion within the E<sub>3</sub> or E<sub>4</sub>-B space (for global Euclidean systems). Considering a hypothetical fifth spatial dimension, a suitable type of motion can be found &#x2013; it is the rotation of E<sub>4</sub>-B relative to the stationary space E<sub>5</sub>, where areas of lower potential are further from the axis of rotation (larger radius <italic>r</italic>
<sub>
<italic>V</italic>
</sub>) than areas of higher potential. For the speed <italic>v</italic>
<sub>
<italic>v</italic>
</sub> in the additional 5<sup>th</sup> dimension, <inline-formula id="inf69">
<mml:math id="m103">
<mml:mrow>
<mml:msub>
<mml:mi mathvariant="bold-italic">v</mml:mi>
<mml:mi mathvariant="bold-italic">V</mml:mi>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:msub>
<mml:mi mathvariant="bold-italic">r</mml:mi>
<mml:mi mathvariant="bold-italic">V</mml:mi>
</mml:msub>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mi mathvariant="bold-italic">&#x3a9;</mml:mi>
</mml:mrow>
</mml:math>
</inline-formula> applies. As a result, the speed <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> is lower in areas of lower potential, since <inline-formula id="inf70">
<mml:math id="m104">
<mml:mrow>
<mml:msub>
<mml:mi mathvariant="bold-italic">v</mml:mi>
<mml:mrow>
<mml:mn mathvariant="bold">4</mml:mn>
<mml:mi mathvariant="bold-italic">D</mml:mi>
</mml:mrow>
</mml:msub>
<mml:mo>&#x2032;</mml:mo>
<mml:mo>&#x3d;</mml:mo>
<mml:msqrt>
<mml:mrow>
<mml:msup>
<mml:mi mathvariant="bold-italic">c</mml:mi>
<mml:mn mathvariant="bold">2</mml:mn>
</mml:msup>
<mml:mo>&#x2212;</mml:mo>
<mml:msubsup>
<mml:mi mathvariant="bold-italic">v</mml:mi>
<mml:mi mathvariant="bold-italic">v</mml:mi>
<mml:mn mathvariant="bold">2</mml:mn>
</mml:msubsup>
</mml:mrow>
</mml:msqrt>
</mml:mrow>
</mml:math>
</inline-formula> applies. This model can be optimized to correspond to actual gravity, but the question is whether it corresponds to reality in general. It adds another large, yet undetected spatial dimension and, at the same time, assumes the existence of a yet undetected angular velocity <inline-formula id="inf71">
<mml:math id="m105">
<mml:mrow>
<mml:mi mathvariant="bold-italic">&#x3a9;</mml:mi>
</mml:mrow>
</mml:math>
</inline-formula>, at which the entire universe (space E<sub>4</sub>-B) rotates. However, the main disadvantage of this model is that it ignores the fundamental importance of mass as a source of gravitation.</p>
<p>Since Newton&#x2019;s time, it has been known that matter is the source of gravitation. The cause of local variability of <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> should therefore be the presence of matter, i.e., of particle-waves. These are packets of energy moving through space in the form of waves. Each particle-wave is, by its very nature, a source of motion of the transmission medium. The motion of the medium is cyclic &#x2013; after short time, the transmission medium returns to its initial position &#x2013; it does not shift anywhere. However, its average speed is non-zero.</p>
<p>The average speed of the transmission medium through which an undulation passes depends on the amplitude, frequency, waves shape, and type of undulation (sinusoidal, helical, etc.). Of these quantities, only the frequency is known with certainty (<italic>E &#x3d; h f</italic>). Therefore, a direct calculation of the average speed is not possible without further assumptions.</p>
<p>However, a different approach can be used: It is known that the energy of any wave motion consists of the elastic energy of the transmission medium and its kinetic energy. For example, in the case of waves on a string, the ratio of these energies is 1:1, i.e., half of the energy is kinetic and half is elastic [<xref ref-type="bibr" rid="B10">10</xref>, page 34]. For other types of wave motion, this ratio may be different. For our purposes, it suffices to assume that the wave motion of all particle-waves has the same character, and so the ratio of elastic and kinetic energy is the same. In that case, the ratio of the kinetic energies of particle-waves A and B will be equal to the ratio of their total energies. Since kinetic energy is proportional to the square of the velocity of the transmission medium, <inline-formula id="inf72">
<mml:math id="m106">
<mml:mrow>
<mml:msub>
<mml:mi mathvariant="bold-italic">E</mml:mi>
<mml:mi mathvariant="bold-italic">k</mml:mi>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:mn mathvariant="bold">1</mml:mn>
<mml:mo>/</mml:mo>
<mml:mn mathvariant="bold">2</mml:mn>
<mml:mi mathvariant="bold-italic">m</mml:mi>
<mml:msubsup>
<mml:mi mathvariant="bold-italic">v</mml:mi>
<mml:mi mathvariant="bold-italic">m</mml:mi>
<mml:mn mathvariant="bold">2</mml:mn>
</mml:msubsup>
</mml:mrow>
</mml:math>
</inline-formula>, the ratio of the mean square velocities <italic>v</italic>
<sub>
<italic>m</italic>
</sub> of the transmission medium as a result of the wave motion of particle-waves with energies <italic>E</italic>
<sub>
<italic>A</italic>
</sub> and <italic>E</italic>
<sub>
<italic>B</italic>
</sub> will be<disp-formula id="equ9">
<mml:math id="m107">
<mml:mrow>
<mml:mfrac>
<mml:mrow>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mi>m</mml:mi>
<mml:mo>,</mml:mo>
<mml:mi>A</mml:mi>
</mml:mrow>
</mml:msub>
</mml:mrow>
<mml:mrow>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mi>m</mml:mi>
<mml:mo>,</mml:mo>
<mml:mi>B</mml:mi>
</mml:mrow>
</mml:msub>
</mml:mrow>
</mml:mfrac>
<mml:mo>&#x3d;</mml:mo>
<mml:msqrt>
<mml:mfrac>
<mml:mrow>
<mml:msub>
<mml:mi>E</mml:mi>
<mml:mi>A</mml:mi>
</mml:msub>
</mml:mrow>
<mml:mrow>
<mml:msub>
<mml:mi>E</mml:mi>
<mml:mi>B</mml:mi>
</mml:msub>
</mml:mrow>
</mml:mfrac>
</mml:msqrt>
</mml:mrow>
</mml:math>
</disp-formula>
</p>
<p>Based on <inline-formula id="inf73">
<mml:math id="m108">
<mml:mrow>
<mml:msub>
<mml:mi mathvariant="bold-italic">v</mml:mi>
<mml:mrow>
<mml:mn mathvariant="bold">4</mml:mn>
<mml:mi mathvariant="bold-italic">D</mml:mi>
</mml:mrow>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:msqrt>
<mml:mrow>
<mml:msup>
<mml:mi mathvariant="bold-italic">c</mml:mi>
<mml:mn mathvariant="bold">2</mml:mn>
</mml:msup>
<mml:mo>&#x2212;</mml:mo>
<mml:msubsup>
<mml:mi mathvariant="bold-italic">v</mml:mi>
<mml:mi mathvariant="bold-italic">m</mml:mi>
<mml:mn mathvariant="bold">2</mml:mn>
</mml:msubsup>
</mml:mrow>
</mml:msqrt>
</mml:mrow>
</mml:math>
</inline-formula> and (<xref ref-type="disp-formula" rid="e14">Equation 14</xref>) it holds<disp-formula id="e27">
<mml:math id="m109">
<mml:mrow>
<mml:msub>
<mml:mi>V</mml:mi>
<mml:mi>A</mml:mi>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:mo>&#x2212;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mn>1</mml:mn>
</mml:mrow>
<mml:mrow>
<mml:mn>2</mml:mn>
</mml:mrow>
</mml:mfrac>
<mml:msubsup>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mi>m</mml:mi>
<mml:mo>,</mml:mo>
<mml:mi>A</mml:mi>
</mml:mrow>
<mml:mn>2</mml:mn>
</mml:msubsup>
</mml:mrow>
</mml:math>
<label>(27)</label>
</disp-formula>
</p>
<p>i.e., the ratio of the potentials is proportional to the ratio of the energies of the particle-waves<disp-formula id="equ10">
<mml:math id="m110">
<mml:mrow>
<mml:mfrac>
<mml:mrow>
<mml:msub>
<mml:mi>V</mml:mi>
<mml:mi>A</mml:mi>
</mml:msub>
</mml:mrow>
<mml:mrow>
<mml:msub>
<mml:mi>V</mml:mi>
<mml:mi>B</mml:mi>
</mml:msub>
</mml:mrow>
</mml:mfrac>
<mml:mo>&#x3d;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:msub>
<mml:mi>E</mml:mi>
<mml:mi>A</mml:mi>
</mml:msub>
</mml:mrow>
<mml:mrow>
<mml:msub>
<mml:mi>E</mml:mi>
<mml:mi>B</mml:mi>
</mml:msub>
</mml:mrow>
</mml:mfrac>
</mml:mrow>
</mml:math>
</disp-formula>
</p>
<p>The formula shows that particle-waves with <italic>n</italic> times greater energy create a gravitational field with <italic>n</italic> times greater potential.</p>
<p>From the known property of gravitational potential (Newton&#x2019;s relation <italic>V &#x3d; &#x2013; GM/r</italic>) and relation (<xref ref-type="disp-formula" rid="e27">Equation 27</xref>), it follows that<disp-formula id="e28">
<mml:math id="m111">
<mml:mrow>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mi>m</mml:mi>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:msqrt>
<mml:mfrac>
<mml:mrow>
<mml:mn>2</mml:mn>
<mml:mi>G</mml:mi>
<mml:mi>M</mml:mi>
</mml:mrow>
<mml:mi>r</mml:mi>
</mml:mfrac>
</mml:msqrt>
</mml:mrow>
</mml:math>
<label>(28)</label>
</disp-formula>
</p>
<p>i.e., <italic>v</italic>
<sub>
<italic>m</italic>
</sub> decreases with the growing distance <italic>r</italic> from the center of the particle-wave. It is a natural property of waves that they are not sharply outlined. Instead, they oscillate the surrounding medium, propagating not only forward, but also, to a certain extent, sideways. This also applies to particle-waves.</p>
<p>The motion of the transmission medium caused by a particle-wave is its motion relative to the stationary coordinate system S. This motion affects the local value of <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> (<inline-formula id="inf74">
<mml:math id="m112">
<mml:mrow>
<mml:msub>
<mml:mi mathvariant="bold-italic">v</mml:mi>
<mml:mrow>
<mml:mn mathvariant="bold">4</mml:mn>
<mml:mi mathvariant="bold-italic">D</mml:mi>
</mml:mrow>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:msqrt>
<mml:mrow>
<mml:msup>
<mml:mi mathvariant="bold-italic">c</mml:mi>
<mml:mn mathvariant="bold">2</mml:mn>
</mml:msup>
<mml:mo>&#x2212;</mml:mo>
<mml:msubsup>
<mml:mi mathvariant="bold-italic">v</mml:mi>
<mml:mi mathvariant="bold-italic">m</mml:mi>
<mml:mn mathvariant="bold">2</mml:mn>
</mml:msubsup>
</mml:mrow>
</mml:msqrt>
</mml:mrow>
</mml:math>
</inline-formula>), slows down other particle-waves, bends their trajectories, and simultaneously slows down the running of clocks.</p>
<p>The wave motion of the transmission medium caused by a single isolated particle-wave is understandably very small. The corresponding value of the mean square velocity can be determined using <xref ref-type="disp-formula" rid="e28">Equation 28</xref>. An electron at a distance of 1 m with a mass of <italic>m</italic>
<sub>
<italic>e</italic>
</sub> <italic>&#x3d; 9.1 x 10</italic>
<sup>
<italic>&#x2212;31</italic>
</sup>
<italic> kg</italic> causes the transmission medium to move at a mean velocity of <italic>v</italic>
<sub>
<italic>m</italic>
</sub> <italic>&#x3d; 1.1 x 10</italic>
<sup>
<italic>&#x2212;20</italic>
</sup>
<italic> m/s</italic>. This corresponds to a wave amplitude not exceeding <italic>10</italic>
<sup>
<italic>&#x2013;40</italic>
</sup>
<italic> m</italic> for a frequency of <inline-formula id="inf75">
<mml:math id="m113">
<mml:mrow>
<mml:mi>f</mml:mi>
<mml:mo>&#x3d;</mml:mo>
<mml:msub>
<mml:mi>m</mml:mi>
<mml:mi>e</mml:mi>
</mml:msub>
<mml:mfrac>
<mml:mrow>
<mml:msup>
<mml:mi>c</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
</mml:mrow>
<mml:mrow>
<mml:mi>h</mml:mi>
</mml:mrow>
</mml:mfrac>
<mml:mo>&#x3d;</mml:mo>
<mml:mn>1.2</mml:mn>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mi>x</mml:mi>
<mml:mtext>&#x2009;</mml:mtext>
<mml:msup>
<mml:mn>10</mml:mn>
<mml:mn>20</mml:mn>
</mml:msup>
</mml:mrow>
</mml:math>
</inline-formula> <italic>Hz</italic>. For more massive particles, the mean square velocity is higher, while the amplitude of the carrier medium is lower. For a proton with a mass of <italic>m</italic>
<sub>
<italic>p</italic>
</sub> <italic>&#x3d; 1.67 x 10</italic>
<sup>
<italic>&#x2212;27</italic>
</sup>
<italic> kg</italic>, the values are as follows: <italic>v</italic>
<sub>
<italic>m</italic>
</sub> <italic>&#x3d; 4.7 x 10</italic>
<sup>
<italic>&#x2212;19</italic>
</sup>
<italic> m/s</italic>, <inline-formula id="inf76">
<mml:math id="m114">
<mml:mrow>
<mml:mi>f</mml:mi>
<mml:mo>&#x3d;</mml:mo>
<mml:mn>2.3</mml:mn>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mi>x</mml:mi>
<mml:mtext>&#x2009;</mml:mtext>
<mml:msup>
<mml:mn>10</mml:mn>
<mml:mn>23</mml:mn>
</mml:msup>
</mml:mrow>
</mml:math>
</inline-formula> <italic>Hz</italic>, and the amplitude does not exceed <italic>10</italic>
<sup>
<italic>&#x2013;42</italic>
</sup>
<italic> m</italic>. However, there is a large number of particle-waves in space, and all the waves combine with each other. A superposition of waves occurs. This results in wave superposition, in which the velocities, as well as the actual displacements, add together.</p>
<p>The maximum displacement that the transmission medium can achieve as a result of Earth&#x2019;s gravitation can be determined by the following simplified reasoning:</p>
<p>The mean square velocity <italic>v</italic>
<sub>
<italic>m</italic>
</sub> for the Earth&#x2019;s mass of <italic>6 &#xd7; 10</italic>
<sup>
<italic>24</italic>
</sup>
<italic> kg</italic> is equal to <italic>2.8 &#xd7; 10</italic>
<sup>
<italic>7</italic>
</sup>
<italic> m/s</italic>. The frequencies of individual particle-waves range from <italic>10</italic>
<sup>
<italic>20</italic>
</sup>
<italic> Hz</italic> (electron) to <italic>10</italic>
<sup>
<italic>23</italic>
</sup>
<italic> Hz</italic> (proton and other baryons). Using the lowest of the frequencies mentioned, <italic>10</italic>
<sup>
<italic>20</italic>
</sup>
<italic> Hz</italic>, the displacement is approximately <italic>10</italic>
<sup>
<italic>&#x2013;13</italic>
</sup>
<italic> m</italic>. This is an upper (maximum) estimate. The displacements are, therefore, very small, which explains the inability to detect the wave motion (i.e., deformations) of the transmission medium in our surroundings.</p>
<p>The question arises: In which dimension the transmission medium oscillates? Based on the existence of polarization phenomena (polarization of photons, electrons, or neutrons), it can be assumed that particle-waves have the nature of transverse waves. However, this in itself does not fully answer the question of the direction of the transmission medium&#x2019;s displacements. It could be a wave motion in some fifth dimension, i.e., in such a way that E<sub>4</sub>-B is a hyperplane (membrane) in space E<sub>5</sub>. However, there are no indications for such an arrangement. It is more likely that the displacements of the transmission medium lie within E<sub>4</sub>-B, i.e., they have a very general direction in four-dimensional space. The existence of the intrinsic (spin) angular momentum of particles supports this arrangement. The wave motion of the transmission medium thus remotely resembles the propagation of the transverse waves through rigid bodies, such as S-waves through the Earth.</p>
<p>In wave superposition, the instantaneous displacements of the transmission medium are added together at each point in space. The same applies to the addition of velocities. The resulting velocity of the transmission medium depends on the magnitude and direction of the individual velocities. Let us now try to find a general relationship for calculating the mean square velocity <italic>v</italic>
<sub>
<italic>m</italic>
</sub> of the transmission medium caused by the wave motion of a large number of particle-waves. All these particle-waves act simultaneously at the same point in space.</p>
<p>The composition of the mean square velocities of the transmission medium requires, among other things, consideration of the nature of its oscillation. This may be oscillation in a straight line, in a plane, or in 3D space, in all cases perpendicular to the direction of motion of the particle-wave in E<sub>4</sub>-B. The specific variant depends on the polarization of the particle-wave. In any case, the mean square velocity can be decomposed into components in the direction of the coordinate axes. The components represent the mean square velocities in the individual dimensions &#x2013; <italic>x, y, z, w</italic>:<disp-formula id="equ11">
<mml:math id="m115">
<mml:mrow>
<mml:msubsup>
<mml:mi>v</mml:mi>
<mml:mi>m</mml:mi>
<mml:mn>2</mml:mn>
</mml:msubsup>
<mml:mo>&#x3d;</mml:mo>
<mml:msubsup>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mi>m</mml:mi>
<mml:mi>x</mml:mi>
</mml:mrow>
<mml:mn>2</mml:mn>
</mml:msubsup>
<mml:mo>&#x2b;</mml:mo>
<mml:msubsup>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mi>m</mml:mi>
<mml:mi>y</mml:mi>
</mml:mrow>
<mml:mn>2</mml:mn>
</mml:msubsup>
<mml:mo>&#x2b;</mml:mo>
<mml:msubsup>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mi>m</mml:mi>
<mml:mi>z</mml:mi>
</mml:mrow>
<mml:mn>2</mml:mn>
</mml:msubsup>
<mml:mo>&#x2b;</mml:mo>
<mml:msubsup>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mi>m</mml:mi>
<mml:mi>w</mml:mi>
</mml:mrow>
<mml:mn>2</mml:mn>
</mml:msubsup>
</mml:mrow>
</mml:math>
</disp-formula>
</p>
<p>In this way, we can decompose the mean square velocities of all acting particle-waves, and then sum their effects by components. In the summation, the contributions of individual particle-waves can be considered statistically uncorrelated (the mean square velocities corresponding to individual particle-waves are independent of each other, and the same applies to their components in the direction of the coordinate axes). This means that the mean square velocities can be added in the same way as other statistically independent quantities expressed by their mean square value. This is analogous to the propagation of standard deviations in statistical analysis. The <italic>x</italic>-components <inline-formula id="inf77">
<mml:math id="m116">
<mml:mrow>
<mml:msub>
<mml:mi mathvariant="bold-italic">v</mml:mi>
<mml:mrow>
<mml:mi mathvariant="bold-italic">m</mml:mi>
<mml:mi mathvariant="bold-italic">x</mml:mi>
<mml:mo>,</mml:mo>
<mml:mn mathvariant="bold">1</mml:mn>
</mml:mrow>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula>
<italic>,</italic> <inline-formula id="inf78">
<mml:math id="m117">
<mml:mrow>
<mml:msub>
<mml:mi mathvariant="bold-italic">v</mml:mi>
<mml:mrow>
<mml:mi mathvariant="bold-italic">m</mml:mi>
<mml:mi mathvariant="bold-italic">x</mml:mi>
<mml:mo>,</mml:mo>
<mml:mn mathvariant="bold">2</mml:mn>
</mml:mrow>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula>
<italic>, &#x2026;,</italic> <inline-formula id="inf79">
<mml:math id="m118">
<mml:mrow>
<mml:msub>
<mml:mi mathvariant="bold-italic">v</mml:mi>
<mml:mrow>
<mml:mi mathvariant="bold-italic">m</mml:mi>
<mml:mi mathvariant="bold-italic">x</mml:mi>
<mml:mo>,</mml:mo>
<mml:mi mathvariant="bold-italic">n</mml:mi>
</mml:mrow>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula> corresponding to individual particle-waves 1 to <italic>n</italic> are added according to the formula <inline-formula id="inf80">
<mml:math id="m119">
<mml:mrow>
<mml:msubsup>
<mml:mi mathvariant="bold-italic">v</mml:mi>
<mml:mrow>
<mml:mi mathvariant="bold-italic">m</mml:mi>
<mml:mi mathvariant="bold-italic">x</mml:mi>
</mml:mrow>
<mml:mn mathvariant="bold">2</mml:mn>
</mml:msubsup>
<mml:mo>&#x3d;</mml:mo>
<mml:mstyle displaystyle="true">
<mml:munderover>
<mml:mo>&#x2211;</mml:mo>
<mml:mrow>
<mml:mi mathvariant="bold-italic">i</mml:mi>
<mml:mo>&#x3d;</mml:mo>
<mml:mn mathvariant="bold">1</mml:mn>
</mml:mrow>
<mml:mi mathvariant="bold-italic">n</mml:mi>
</mml:munderover>
</mml:mstyle>
<mml:msubsup>
<mml:mi mathvariant="bold-italic">v</mml:mi>
<mml:mrow>
<mml:mi mathvariant="bold-italic">m</mml:mi>
<mml:mi mathvariant="bold-italic">x</mml:mi>
<mml:mo>,</mml:mo>
<mml:mi mathvariant="bold-italic">i</mml:mi>
</mml:mrow>
<mml:mn mathvariant="bold">2</mml:mn>
</mml:msubsup>
</mml:mrow>
</mml:math>
</inline-formula>. The same applies for components in other axes. The formula for the resulting mean square velocity can be derived as follows:<disp-formula id="equ12">
<mml:math id="m120">
<mml:mtable class="align" columnalign="left">
<mml:mtr>
<mml:mtd columnalign="right"/>
<mml:mtd columnalign="right">
<mml:mrow>
<mml:msubsup>
<mml:mi>v</mml:mi>
<mml:mi>m</mml:mi>
<mml:mn>2</mml:mn>
</mml:msubsup>
<mml:mo>&#x3d;</mml:mo>
<mml:mstyle displaystyle="true">
<mml:munderover>
<mml:mo>&#x2211;</mml:mo>
<mml:mrow>
<mml:mi>i</mml:mi>
<mml:mo>&#x3d;</mml:mo>
<mml:mn>1</mml:mn>
</mml:mrow>
<mml:mi>n</mml:mi>
</mml:munderover>
</mml:mstyle>
<mml:msubsup>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mi>m</mml:mi>
<mml:mi>x</mml:mi>
<mml:mo>,</mml:mo>
<mml:mi>i</mml:mi>
</mml:mrow>
<mml:mn>2</mml:mn>
</mml:msubsup>
<mml:mo>&#x2b;</mml:mo>
<mml:mstyle displaystyle="true">
<mml:munderover>
<mml:mo>&#x2211;</mml:mo>
<mml:mrow>
<mml:mi>i</mml:mi>
<mml:mo>&#x3d;</mml:mo>
<mml:mn>1</mml:mn>
</mml:mrow>
<mml:mi>n</mml:mi>
</mml:munderover>
</mml:mstyle>
<mml:msubsup>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mi>m</mml:mi>
<mml:mi>y</mml:mi>
<mml:mo>,</mml:mo>
<mml:mi>i</mml:mi>
</mml:mrow>
<mml:mn>2</mml:mn>
</mml:msubsup>
<mml:mo>&#x2b;</mml:mo>
<mml:mstyle displaystyle="true">
<mml:munderover>
<mml:mo>&#x2211;</mml:mo>
<mml:mrow>
<mml:mi>i</mml:mi>
<mml:mo>&#x3d;</mml:mo>
<mml:mn>1</mml:mn>
</mml:mrow>
<mml:mi>n</mml:mi>
</mml:munderover>
</mml:mstyle>
<mml:msubsup>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mi>m</mml:mi>
<mml:mi>z</mml:mi>
<mml:mo>,</mml:mo>
<mml:mi>i</mml:mi>
</mml:mrow>
<mml:mn>2</mml:mn>
</mml:msubsup>
<mml:mo>&#x2b;</mml:mo>
<mml:mstyle displaystyle="true">
<mml:munderover>
<mml:mo>&#x2211;</mml:mo>
<mml:mrow>
<mml:mi>i</mml:mi>
<mml:mo>&#x3d;</mml:mo>
<mml:mn>1</mml:mn>
</mml:mrow>
<mml:mi>n</mml:mi>
</mml:munderover>
</mml:mstyle>
<mml:msubsup>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mi>m</mml:mi>
<mml:mi>w</mml:mi>
<mml:mo>,</mml:mo>
<mml:mi>i</mml:mi>
</mml:mrow>
<mml:mn>2</mml:mn>
</mml:msubsup>
</mml:mrow>
</mml:mtd>
</mml:mtr>
<mml:mtr>
<mml:mtd columnalign="right"/>
<mml:mtd columnalign="left">
<mml:mspace width="1.25em"/>
<mml:mrow>
<mml:mo>&#x3d;</mml:mo>
<mml:mrow>
<mml:mstyle displaystyle="true">
<mml:munderover>
<mml:mo>&#x2211;</mml:mo>
<mml:mrow>
<mml:mi>i</mml:mi>
<mml:mo>&#x3d;</mml:mo>
<mml:mn>1</mml:mn>
</mml:mrow>
<mml:mi>n</mml:mi>
</mml:munderover>
</mml:mstyle>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:msubsup>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mi>m</mml:mi>
<mml:mi>x</mml:mi>
<mml:mo>,</mml:mo>
<mml:mi>i</mml:mi>
</mml:mrow>
<mml:mn>2</mml:mn>
</mml:msubsup>
<mml:mo>&#x2b;</mml:mo>
<mml:msubsup>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mi>m</mml:mi>
<mml:mi>y</mml:mi>
<mml:mo>,</mml:mo>
<mml:mi>i</mml:mi>
</mml:mrow>
<mml:mn>2</mml:mn>
</mml:msubsup>
<mml:mo>&#x2b;</mml:mo>
<mml:msubsup>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mi>m</mml:mi>
<mml:mi>z</mml:mi>
<mml:mo>,</mml:mo>
<mml:mi>i</mml:mi>
</mml:mrow>
<mml:mn>2</mml:mn>
</mml:msubsup>
<mml:mo>&#x2b;</mml:mo>
<mml:msubsup>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mi>m</mml:mi>
<mml:mi>w</mml:mi>
<mml:mo>,</mml:mo>
<mml:mi>n</mml:mi>
</mml:mrow>
<mml:mn>2</mml:mn>
</mml:msubsup>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
</mml:mrow>
<mml:mo>&#x3d;</mml:mo>
<mml:mstyle displaystyle="true">
<mml:munderover>
<mml:mo>&#x2211;</mml:mo>
<mml:mrow>
<mml:mi>i</mml:mi>
<mml:mo>&#x3d;</mml:mo>
<mml:mn>1</mml:mn>
</mml:mrow>
<mml:mi>n</mml:mi>
</mml:munderover>
</mml:mstyle>
<mml:msubsup>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mi>m</mml:mi>
<mml:mo>,</mml:mo>
<mml:mi>i</mml:mi>
</mml:mrow>
<mml:mn>2</mml:mn>
</mml:msubsup>
</mml:mrow>
</mml:mtd>
</mml:mtr>
</mml:mtable>
</mml:math>
</disp-formula>
</p>
<p>It is, therefore, a simple sum of the squares of the mean square velocities. The direction of oscillations has no effect on the result.</p>
<p>The resulting mean square velocity does not depend on the direction of motion, the polarization of individual particles-waves, or the number of dimensions in which the transmission medium oscillates. The formula also applies to the case of space E<sub>4</sub>-B as a membrane (hyperplane) in multidimensional space. The only limitations are given by the statistical nature of the formula, which assumes a large number of simultaneously acting particle-waves and their mutual uncorrelatedness (independence).</p>
<p>Using (<xref ref-type="disp-formula" rid="e27">Equation 27</xref>), the formula can be rewritten as<disp-formula id="e29">
<mml:math id="m121">
<mml:mrow>
<mml:mi>V</mml:mi>
<mml:mo>&#x3d;</mml:mo>
<mml:mstyle displaystyle="true">
<mml:munderover>
<mml:mo>&#x2211;</mml:mo>
<mml:mrow>
<mml:mi>i</mml:mi>
<mml:mo>&#x3d;</mml:mo>
<mml:mn>1</mml:mn>
</mml:mrow>
<mml:mi>n</mml:mi>
</mml:munderover>
</mml:mstyle>
<mml:msub>
<mml:mi>V</mml:mi>
<mml:mi>i</mml:mi>
</mml:msub>
</mml:mrow>
</mml:math>
<label>(29)</label>
</disp-formula>
</p>
<p>The <xref ref-type="disp-formula" rid="e29">Equation 29</xref> expresses the composition of the gravitational potentials of individual particle-waves. It is their simple sum at any point in space. This formula is identical to the formula valid in Newtonian gravitation, and simultaneously in the Newtonian limit of GTR.</p>
<p>Waves propagate in the transmission medium at speed <italic>v</italic>
<sub>
<italic>4D</italic>
</sub>, which determines the speed of gravitation. When calculating the potential, it is therefore necessary to take into account the time delay &#x2013; the time it takes for the waves to reach the given point in space.</p>
</sec>
<sec id="s2-7">
<label>2.7</label>
<title>Influence of variable <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> on space metric</title>
<p>The standard metric of space E<sub>4</sub> has the form<disp-formula id="e30">
<mml:math id="m122">
<mml:mrow>
<mml:mi>&#x3b4;</mml:mi>
<mml:msup>
<mml:mi>s</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
<mml:mo>&#x3d;</mml:mo>
<mml:mi>&#x3b4;</mml:mi>
<mml:msup>
<mml:mi>x</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
<mml:mo>&#x2b;</mml:mo>
<mml:mi>&#x3b4;</mml:mi>
<mml:msup>
<mml:mi>y</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
<mml:mo>&#x2b;</mml:mo>
<mml:mi>&#x3b4;</mml:mi>
<mml:msup>
<mml:mi>z</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
<mml:mo>&#x2b;</mml:mo>
<mml:mi>&#x3b4;</mml:mi>
<mml:msup>
<mml:mi>w</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
</mml:mrow>
</mml:math>
<label>(30)</label>
</disp-formula>where <italic>&#x3b4;s</italic> is the measure of the separation (distance) between two adjacent points in space. The separation is given in a measure of length (e.g., meters). However, the metric of space E<sub>4</sub>-B is given by a slightly different relation (<xref ref-type="disp-formula" rid="e6">Equation 6</xref>), where the spatial separation <italic>&#x3b4;s</italic> is replaced by the time separation <italic>&#x3b4;t</italic>. It applies<disp-formula id="e31">
<mml:math id="m123">
<mml:mrow>
<mml:mi>&#x3b4;</mml:mi>
<mml:mi>s</mml:mi>
<mml:mo>&#x3d;</mml:mo>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mi>&#x3b4;</mml:mi>
<mml:mi>t</mml:mi>
</mml:mrow>
</mml:math>
<label>(31)</label>
</disp-formula>
</p>
<p>The relationship (<xref ref-type="disp-formula" rid="e31">Equation 31</xref>) reflects the fact that length measurements are always related to the flow of time. In a situation where all matter takes the form of waves, it is not possible to define a unit of length that is independent of time. This is also reflected in the modern definition of the meter in the SI system. It includes not only time but also the speed of light, [<xref ref-type="bibr" rid="B11">11</xref>].</p>
<p>If the value of the speed of light was the same throughout the universe, there would be no fundamental difference between metrics (<xref ref-type="disp-formula" rid="e6">Equation 6</xref>) and (<xref ref-type="disp-formula" rid="e30">Equation 30</xref>). Both would be Euclidean. In the EMST, however, the speed of light (more precisely, the speed of particle-wave motion <italic>v</italic>
<sub>
<italic>4D</italic>
</sub>) is variable. Due to the presence of matter, the ratio between <italic>&#x3b4;s</italic> and <italic>&#x3b4;t</italic> changes and the Euclidean metric (<xref ref-type="disp-formula" rid="e6">Equation 6</xref>) ceases to be Euclidean. A logical contradiction arises &#x2013; if the metric (<xref ref-type="disp-formula" rid="e30">Equation 30</xref>) is used, space E<sub>4</sub>-B is Euclidean, but if (<xref ref-type="disp-formula" rid="e6">Equation 6</xref>) is used, it is not Euclidean. From a geometric point of view, the correct metric is (<xref ref-type="disp-formula" rid="e30">Equation 30</xref>), as it works with units of length and ignores the speed <italic>v</italic>
<sub>
<italic>4D</italic>
</sub>. From a physical point of view, however, we prefer the metric (<xref ref-type="disp-formula" rid="e6">Equation 6</xref>), because there is no such thing as a universal unit of length independent of the <italic>v</italic>
<sub>
<italic>4D</italic>
</sub>. This applies primarily to the measurement of lengths using the transit time of light. However, it also applies partially to &#x201c;rigid measuring rods.&#x201d; Our beliefs about them are misleading. These measuring rods are made up of waves, and their dimensions are derived from the wavelengths of the particle-waves that make them up. And as we know, wavelength depends on the <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> and the frequency &#x2013; that is, on the flow of time. So, we cannot <italic>a priori</italic> assume that they&#x2019;re independent of the <italic>v</italic>
<sub>
<italic>4D</italic>
</sub>.</p>
<p>The fact that the presence of matter affects the motion of particle-waves (changing both their speed and trajectory) gives the impression that space is curved by the influence of matter. The shortest line connecting two points (realized, for example, by the path of photons) is not identical to the shortest line according to Euclidean metrics (<xref ref-type="disp-formula" rid="e30">Equation 30</xref>), see <xref ref-type="fig" rid="F6">Figure 6</xref>. Gravitational effect influences transit times, wavelengths, and directions. It creates a perfect illusion of a curved space. However, if we consider the local values of <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> and rectify distances, wavelengths, and directions for their influence, i.e., if we switch to purely geometric units free from the influence of the variable <italic>v</italic>
<sub>
<italic>4D</italic>
</sub>, we find that space is still Euclidean and the metric (<xref ref-type="disp-formula" rid="e30">Equation 30</xref>) applies without any exception.</p>
<fig id="F6" position="float">
<label>FIGURE 6</label>
<caption>
<p>The apparent curvature of space due to the influence of matter. The case of a central spherical body with mass <italic>M</italic> is shown. The lines of shortest time (red) are not the shortest lines according to the Euclidean metric (blue). Near the body, the speed <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> is lower, so the lines of shortest time take a slight detour. Areas of equal gravitational potential <italic>V</italic> (equal <italic>v</italic>
<sub>
<italic>4D</italic>
</sub>) are marked in black.</p>
</caption>
<graphic xlink:href="fphy-14-1737947-g006.tif">
<alt-text content-type="machine-generated">Letter &#x22;M&#x22; centered inside a circle with concentric dotted rings around it. Overlaid on this are red and blue grid lines forming squares and rectangles, creating a complex geometric pattern.</alt-text>
</graphic>
</fig>
<p>In the following text, three types of lengths will be distinguished:</p>
<p>Euclidean lengths s<sub>E</sub> are purely geometric lengths independent of the v<sub>4D</sub> value. They are expressed in a standard length unit, which is the &#x201c;meter&#x201d; as defined by the SI, realized in an area outside the influence of the gravitational field. Here, I refer to the dependence of <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> and the flow of time on the gravitational potential, see (<xref ref-type="disp-formula" rid="e15">Equations 15</xref>&#x2013;<xref ref-type="disp-formula" rid="e17">17</xref>). The formula <italic>&#x3b4;s</italic>
<sub>
<italic>E</italic>
</sub> <italic>&#x3d;</italic> <inline-formula id="inf81">
<mml:math id="m124">
<mml:mrow>
<mml:mi mathvariant="bold">c</mml:mi>
</mml:mrow>
</mml:math>
</inline-formula> <italic>&#x3b4;t</italic> applies, where <italic>t</italic> represents coordinate time unaffected (not slowed) by the effect of gravitation.</p>
<p>Local lengths s<sub>L</sub>: The Euclidean meter, according to the SI definition, is, coincidentally, identical to the meter realized locally within a gravitational field. The requirement is that the gravitational potential of the reference clock and along the measured length are the same. As mentioned above, the rate of the clock depends on <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> &#x2013; see (<xref ref-type="disp-formula" rid="e8">Equation 8</xref>). For the same number of clock ticks (for the same amount of time), light travels the same distance. The wavelengths of particle-waves (electrons, locally emitted photons, etc.) will also be the same, i.e., length measuring tools will also have the same dimensions. Local lengths are therefore identical to Euclidean lengths, but unlike them, they are physically realizable in a gravitational field. However, their definition does not allow the measurement of lengths between points with different gravitational potential.</p>
<p>Corrected lengths <italic>s</italic>
<sub>
<italic>C</italic>
</sub>: To determine lengths passing through areas with different <italic>v</italic>
<sub>
<italic>4D</italic>
</sub>, the SI meter definition can be applied, except that the reference clock is not located at the same potential level as the measured length. It can be located outside the gravitational field (<italic>V &#x3d; 0</italic>, <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> <italic>&#x3d; c</italic>) or anywhere within it (<italic>V &#x3c; 0</italic>, <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> <italic>&#x3c; c</italic>). A different potential level at the location of the reference clock will affect the resulting lengths &#x2013; these will be different from Euclidean ones. A variable value of <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> in the area of the measured length, combined with a constant value of <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> at the location of the reference clock, will cause the length of the meter to be also variable. Corrected lengths in the area of variable <italic>V</italic> (i.e., variable <italic>v</italic>
<sub>
<italic>4D</italic>
</sub>) do not create a Euclidean system.</p>
<p>The increment of the corrected length <inline-formula id="inf82">
<mml:math id="m125">
<mml:mrow>
<mml:mi mathvariant="bold-italic">&#x3b4;</mml:mi>
<mml:msub>
<mml:mi mathvariant="bold-italic">s</mml:mi>
<mml:mi mathvariant="bold-italic">C</mml:mi>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula> is given by <inline-formula id="inf83">
<mml:math id="m126">
<mml:mrow>
<mml:mi>&#x3b4;</mml:mi>
<mml:msub>
<mml:mi>s</mml:mi>
<mml:mi>C</mml:mi>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
<mml:mi>&#x3b4;</mml:mi>
<mml:mi>t</mml:mi>
<mml:mo>&#x3d;</mml:mo>
<mml:msqrt>
<mml:mrow>
<mml:mn>1</mml:mn>
<mml:mo>&#x2b;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mn>2</mml:mn>
<mml:mi>V</mml:mi>
</mml:mrow>
<mml:msup>
<mml:mi>c</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
</mml:mfrac>
</mml:mrow>
</mml:msqrt>
<mml:mi>c</mml:mi>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mi>&#x3b4;</mml:mi>
<mml:mi>t</mml:mi>
<mml:mo>&#x3d;</mml:mo>
<mml:mi>k</mml:mi>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mi>&#x3b4;</mml:mi>
<mml:msub>
<mml:mi>s</mml:mi>
<mml:mi>E</mml:mi>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula>, where<disp-formula id="e32">
<mml:math id="m127">
<mml:mrow>
<mml:mi>k</mml:mi>
<mml:mo>&#x3d;</mml:mo>
<mml:msqrt>
<mml:mrow>
<mml:mn>1</mml:mn>
<mml:mo>&#x2b;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mn>2</mml:mn>
<mml:mi>V</mml:mi>
</mml:mrow>
<mml:msup>
<mml:mi>c</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
</mml:mfrac>
</mml:mrow>
</mml:msqrt>
</mml:mrow>
</mml:math>
<label>(32)</label>
</disp-formula>
</p>
<p>The values of <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> and <italic>V</italic> are related to the potential level of the reference clock. If this clock is located outside the gravitational field, then <inline-formula id="inf84">
<mml:math id="m128">
<mml:mrow>
<mml:mi mathvariant="bold-italic">V</mml:mi>
<mml:mo>&#x2264;</mml:mo>
<mml:mn mathvariant="bold">0</mml:mn>
</mml:mrow>
</mml:math>
</inline-formula>, <inline-formula id="inf85">
<mml:math id="m129">
<mml:mrow>
<mml:msub>
<mml:mi mathvariant="bold-italic">v</mml:mi>
<mml:mrow>
<mml:mn mathvariant="bold">4</mml:mn>
<mml:mi mathvariant="bold-italic">D</mml:mi>
</mml:mrow>
</mml:msub>
<mml:mo>&#x2264;</mml:mo>
<mml:mi mathvariant="bold-italic">c</mml:mi>
</mml:mrow>
</mml:math>
</inline-formula> applies throughout the entire space. Length increments <inline-formula id="inf86">
<mml:math id="m130">
<mml:mrow>
<mml:mi mathvariant="bold-italic">&#x3b4;</mml:mi>
<mml:msub>
<mml:mi mathvariant="bold-italic">s</mml:mi>
<mml:mi mathvariant="bold-italic">C</mml:mi>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula> inside the gravitational field (where <inline-formula id="inf87">
<mml:math id="m131">
<mml:mrow>
<mml:msub>
<mml:mi mathvariant="bold-italic">v</mml:mi>
<mml:mrow>
<mml:mn mathvariant="bold">4</mml:mn>
<mml:mi mathvariant="bold-italic">D</mml:mi>
</mml:mrow>
</mml:msub>
<mml:mo>&#x3c;</mml:mo>
<mml:mi mathvariant="bold-italic">c</mml:mi>
</mml:mrow>
</mml:math>
</inline-formula>) are smaller than <inline-formula id="inf88">
<mml:math id="m132">
<mml:mrow>
<mml:mi mathvariant="bold-italic">&#x3b4;</mml:mi>
<mml:msub>
<mml:mi mathvariant="bold-italic">s</mml:mi>
<mml:mi mathvariant="bold-italic">E</mml:mi>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula>. Any distance measured using increments <inline-formula id="inf89">
<mml:math id="m133">
<mml:mrow>
<mml:mi mathvariant="bold-italic">&#x3b4;</mml:mi>
<mml:msub>
<mml:mi mathvariant="bold-italic">s</mml:mi>
<mml:mi mathvariant="bold-italic">C</mml:mi>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula> will therefore be greater than the same distance measured using <inline-formula id="inf90">
<mml:math id="m134">
<mml:mrow>
<mml:mi mathvariant="bold-italic">&#x3b4;</mml:mi>
<mml:msub>
<mml:mi mathvariant="bold-italic">s</mml:mi>
<mml:mi mathvariant="bold-italic">E</mml:mi>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula> (i.e., by SI meter). The formula <inline-formula id="inf91">
<mml:math id="m135">
<mml:mrow>
<mml:msub>
<mml:mi mathvariant="bold-italic">s</mml:mi>
<mml:mi mathvariant="bold-italic">C</mml:mi>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mn mathvariant="bold">1</mml:mn>
</mml:mrow>
<mml:mrow>
<mml:mi mathvariant="bold-italic">k</mml:mi>
</mml:mrow>
</mml:mfrac>
<mml:msub>
<mml:mi mathvariant="bold-italic">s</mml:mi>
<mml:mi mathvariant="bold-italic">E</mml:mi>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula> applies.</p>
</sec>
<sec id="s2-8">
<label>2.8</label>
<title>Gravitational field of a central body</title>
<p>The finding that space is Euclidean, even in areas affected by gravitation, is useful in deriving the metric of the central gravitational field. This term refers to the gravitational field generated by a point object or a body with a spherically symmetric distribution of mass. Central gravitational fields are of great importance in physics, because they describe the gravitational influence of planets and stars on bodies in their vicinity.</p>
<p>For the derivation of the metric of the central gravitational field, we start with the Euclidean metric of four-dimensional space. Subsequently, we implement the influence of the variable <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> into it &#x2013; i.e., we move from a purely geometric model to a physical model.</p>
<p>The E<sub>4</sub> metric (as well as E<sub>4</sub>-B metric) in spherical coordinates (supplemented by the fourth coordinate <italic>w</italic>) is given by the relation<disp-formula id="equ13">
<mml:math id="m136">
<mml:mrow>
<mml:mi>&#x3b4;</mml:mi>
<mml:msubsup>
<mml:mi>s</mml:mi>
<mml:mi>E</mml:mi>
<mml:mn>2</mml:mn>
</mml:msubsup>
<mml:mo>&#x3d;</mml:mo>
<mml:mi>&#x3b4;</mml:mi>
<mml:msubsup>
<mml:mi>r</mml:mi>
<mml:mi>E</mml:mi>
<mml:mn>2</mml:mn>
</mml:msubsup>
<mml:mo>&#x2b;</mml:mo>
<mml:msubsup>
<mml:mi>r</mml:mi>
<mml:mi>E</mml:mi>
<mml:mn>2</mml:mn>
</mml:msubsup>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:mi>&#x3b4;</mml:mi>
<mml:msup>
<mml:mi>&#x3b8;</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
<mml:mo>&#x2b;</mml:mo>
<mml:msup>
<mml:mi mathvariant="italic">sin</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
<mml:mo>&#x2061;</mml:mo>
<mml:mi>&#x3b8;</mml:mi>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mi>&#x3b4;</mml:mi>
<mml:msup>
<mml:mi>&#x3d5;</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
<mml:mo>&#x2b;</mml:mo>
<mml:mi>&#x3b4;</mml:mi>
<mml:msubsup>
<mml:mi>w</mml:mi>
<mml:mi>E</mml:mi>
<mml:mn>2</mml:mn>
</mml:msubsup>
</mml:mrow>
</mml:math>
</disp-formula>
</p>
<p>Here, <inline-formula id="inf92">
<mml:math id="m137">
<mml:mrow>
<mml:msub>
<mml:mi mathvariant="bold-italic">r</mml:mi>
<mml:mi mathvariant="bold-italic">E</mml:mi>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula>, <inline-formula id="inf93">
<mml:math id="m138">
<mml:mrow>
<mml:mi mathvariant="bold-italic">&#x3b8;</mml:mi>
</mml:mrow>
</mml:math>
</inline-formula> and <inline-formula id="inf94">
<mml:math id="m139">
<mml:mrow>
<mml:mi mathvariant="bold-italic">&#x3d5;</mml:mi>
</mml:mrow>
</mml:math>
</inline-formula> are polar coordinates in E<sub>3</sub>, <inline-formula id="inf95">
<mml:math id="m140">
<mml:mrow>
<mml:msub>
<mml:mrow>
<mml:mi mathvariant="bold-italic">&#x3b4;</mml:mi>
<mml:mi mathvariant="bold-italic">r</mml:mi>
</mml:mrow>
<mml:mi mathvariant="bold-italic">E</mml:mi>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula>, <inline-formula id="inf96">
<mml:math id="m141">
<mml:mrow>
<mml:mi mathvariant="bold-italic">&#x3b4;</mml:mi>
<mml:mi mathvariant="bold-italic">&#x3b8;</mml:mi>
</mml:mrow>
</mml:math>
</inline-formula> and <inline-formula id="inf97">
<mml:math id="m142">
<mml:mrow>
<mml:mi mathvariant="bold-italic">&#x3b4;</mml:mi>
<mml:mi mathvariant="bold-italic">&#x3d5;</mml:mi>
</mml:mrow>
</mml:math>
</inline-formula> are their increments, and <inline-formula id="inf98">
<mml:math id="m143">
<mml:mrow>
<mml:msub>
<mml:mrow>
<mml:mi mathvariant="bold-italic">&#x3b4;</mml:mi>
<mml:mi mathvariant="bold-italic">w</mml:mi>
</mml:mrow>
<mml:mi mathvariant="bold-italic">E</mml:mi>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula> is the increment in the fourth coordinate. All length quantities are Euclidean.</p>
<p>For the transition to the physical model, it is necessary to include the influence of the variable <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> &#x2013; move to Corrected lengths. For the derivation, a mathematical model involving a pair of concentric circles <italic>C</italic> and <italic>C&#x2b;</italic> will be used. The centers of the circles are located in the central body and their radii are <inline-formula id="inf99">
<mml:math id="m144">
<mml:mrow>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>E</mml:mi>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula> and <inline-formula id="inf100">
<mml:math id="m145">
<mml:mrow>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mrow>
<mml:mi>E</mml:mi>
<mml:mo>&#x2b;</mml:mo>
</mml:mrow>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>E</mml:mi>
</mml:msub>
<mml:mo>&#x2b;</mml:mo>
<mml:mi>&#x3b4;</mml:mi>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>E</mml:mi>
</mml:msub>
<mml:mo>,</mml:mo>
<mml:mi>&#x3b4;</mml:mi>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>E</mml:mi>
</mml:msub>
<mml:mo>&#x2192;</mml:mo>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mn>0</mml:mn>
</mml:mrow>
</mml:math>
</inline-formula>. The reference level of gravitational potential for corrected lengths is the potential on circle <italic>C</italic> (<inline-formula id="inf101">
<mml:math id="m146">
<mml:mrow>
<mml:msub>
<mml:mi>V</mml:mi>
<mml:mi>R</mml:mi>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:mo>&#x2212;</mml:mo>
<mml:mi>G</mml:mi>
<mml:mi>M</mml:mi>
<mml:mo>/</mml:mo>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>E</mml:mi>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula>), i.e., the length of this circle expressed in Corrected lengths will be the same as in Euclidean lengths. The potential on circle <italic>C&#x2b;</italic> is <inline-formula id="inf102">
<mml:math id="m147">
<mml:mrow>
<mml:mi>V</mml:mi>
<mml:mo>&#x3d;</mml:mo>
<mml:mo>&#x2212;</mml:mo>
<mml:mi>G</mml:mi>
<mml:mi>M</mml:mi>
<mml:mo>/</mml:mo>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>E</mml:mi>
</mml:msub>
<mml:mo>&#x2b;</mml:mo>
<mml:mi>&#x3b4;</mml:mi>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>E</mml:mi>
</mml:msub>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
</mml:mrow>
</mml:math>
</inline-formula>. The circumferences of the circles in Corrected lengths relative to the reference potential <italic>V</italic>
<sub>
<italic>R</italic>
</sub> are</p>
<p>
<inline-formula id="inf103">
<mml:math id="m148">
<mml:mrow>
<mml:msub>
<mml:mi>O</mml:mi>
<mml:mi>C</mml:mi>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:msub>
<mml:mi>O</mml:mi>
<mml:mi>E</mml:mi>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:mn>2</mml:mn>
<mml:mi>&#x3c0;</mml:mi>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>E</mml:mi>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula> and <inline-formula id="inf104">
<mml:math id="m149">
<mml:mrow>
<mml:msub>
<mml:mi>O</mml:mi>
<mml:mrow>
<mml:mi>C</mml:mi>
<mml:mo>&#x2b;</mml:mo>
</mml:mrow>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:msub>
<mml:mi>k</mml:mi>
<mml:mi>R</mml:mi>
</mml:msub>
<mml:mo>/</mml:mo>
<mml:mi>k</mml:mi>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mn>2</mml:mn>
<mml:mi>&#x3c0;</mml:mi>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>E</mml:mi>
</mml:msub>
<mml:mo>&#x2b;</mml:mo>
<mml:mi>&#x3b4;</mml:mi>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>E</mml:mi>
</mml:msub>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
</mml:mrow>
</mml:math>
</inline-formula>, where <italic>k</italic> is given by (<xref ref-type="disp-formula" rid="e32">Equation 32</xref>) and<disp-formula id="e33">
<mml:math id="m150">
<mml:mrow>
<mml:msub>
<mml:mi>k</mml:mi>
<mml:mi>R</mml:mi>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:msqrt>
<mml:mrow>
<mml:mn>1</mml:mn>
<mml:mo>&#x2b;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mn>2</mml:mn>
<mml:msub>
<mml:mi>V</mml:mi>
<mml:mi>R</mml:mi>
</mml:msub>
</mml:mrow>
<mml:msup>
<mml:mi>c</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
</mml:mfrac>
</mml:mrow>
</mml:msqrt>
<mml:mo>&#x3d;</mml:mo>
<mml:msqrt>
<mml:mrow>
<mml:mn>1</mml:mn>
<mml:mo>&#x2212;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mn>2</mml:mn>
<mml:mi>G</mml:mi>
<mml:mi>M</mml:mi>
</mml:mrow>
<mml:msup>
<mml:mrow>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>E</mml:mi>
</mml:msub>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mi>c</mml:mi>
</mml:mrow>
<mml:mn>2</mml:mn>
</mml:msup>
</mml:mfrac>
</mml:mrow>
</mml:msqrt>
<mml:mo>&#x3d;</mml:mo>
<mml:msqrt>
<mml:mrow>
<mml:mn>1</mml:mn>
<mml:mo>&#x2212;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mi>R</mml:mi>
</mml:mrow>
<mml:mrow>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>E</mml:mi>
</mml:msub>
</mml:mrow>
</mml:mfrac>
</mml:mrow>
</mml:msqrt>
</mml:mrow>
</mml:math>
<label>(33)</label>
</disp-formula>
</p>
<p>Since <italic>k &#x2260; k</italic>
<sub>
<italic>R</italic>
</sub>, the circumference of circle <italic>O</italic>
<sub>
<italic>C&#x2b;</italic>
</sub> differs from the Euclidean <inline-formula id="inf105">
<mml:math id="m151">
<mml:mrow>
<mml:msub>
<mml:mi>O</mml:mi>
<mml:mrow>
<mml:mi>E</mml:mi>
<mml:mo>&#x2b;</mml:mo>
</mml:mrow>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:mn>2</mml:mn>
<mml:mi>&#x3c0;</mml:mi>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>E</mml:mi>
</mml:msub>
<mml:mo>&#x2b;</mml:mo>
<mml:mi>&#x3b4;</mml:mi>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>E</mml:mi>
</mml:msub>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
</mml:mrow>
</mml:math>
</inline-formula>.</p>
<p>The value of <italic>k</italic> can be expressed as a multiple of <italic>k</italic>
<sub>
<italic>R</italic>
</sub>, assuming <inline-formula id="inf106">
<mml:math id="m152">
<mml:mrow>
<mml:mi>&#x3b4;</mml:mi>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>E</mml:mi>
</mml:msub>
<mml:mo>&#x226a;</mml:mo>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>E</mml:mi>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula>.<disp-formula id="equ14">
<mml:math id="m153">
<mml:mtable class="align" columnalign="left">
<mml:mtr>
<mml:mtd columnalign="right"/>
<mml:mtd columnalign="right">
<mml:mrow>
<mml:mi>k</mml:mi>
<mml:mo>&#x3d;</mml:mo>
<mml:msqrt>
<mml:mrow>
<mml:mn>1</mml:mn>
<mml:mo>&#x2212;</mml:mo>
<mml:mfrac>
<mml:mi>R</mml:mi>
<mml:mrow>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>E</mml:mi>
</mml:msub>
<mml:mo>&#x2b;</mml:mo>
<mml:mi>&#x3b4;</mml:mi>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>E</mml:mi>
</mml:msub>
</mml:mrow>
</mml:mfrac>
</mml:mrow>
</mml:msqrt>
<mml:mo>&#x2248;</mml:mo>
<mml:msqrt>
<mml:mrow>
<mml:mn>1</mml:mn>
<mml:mo>&#x2212;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mi>R</mml:mi>
</mml:mrow>
<mml:mrow>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>E</mml:mi>
</mml:msub>
</mml:mrow>
</mml:mfrac>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:mn>1</mml:mn>
<mml:mo>&#x2212;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mi>&#x3b4;</mml:mi>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>E</mml:mi>
</mml:msub>
</mml:mrow>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>E</mml:mi>
</mml:msub>
</mml:mfrac>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
</mml:mrow>
</mml:msqrt>
<mml:mo>&#x3d;</mml:mo>
<mml:msqrt>
<mml:mrow>
<mml:mn>1</mml:mn>
<mml:mo>&#x2212;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mi>R</mml:mi>
</mml:mrow>
<mml:mrow>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>E</mml:mi>
</mml:msub>
</mml:mrow>
</mml:mfrac>
<mml:mo>&#x2b;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mi>R</mml:mi>
</mml:mrow>
<mml:mrow>
<mml:msubsup>
<mml:mi>r</mml:mi>
<mml:mi>E</mml:mi>
<mml:mn>2</mml:mn>
</mml:msubsup>
</mml:mrow>
</mml:mfrac>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mi>&#x3b4;</mml:mi>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>E</mml:mi>
</mml:msub>
</mml:mrow>
</mml:msqrt>
</mml:mrow>
</mml:mtd>
</mml:mtr>
<mml:mtr>
<mml:mtd columnalign="right"/>
<mml:mtd columnalign="left">
<mml:mspace width=".6em"/>
<mml:mrow>
<mml:mo>&#x3d;</mml:mo>
<mml:msqrt>
<mml:mrow>
<mml:msubsup>
<mml:mi>k</mml:mi>
<mml:mi>R</mml:mi>
<mml:mn>2</mml:mn>
</mml:msubsup>
<mml:mo>&#x2b;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mi>R</mml:mi>
</mml:mrow>
<mml:mrow>
<mml:msubsup>
<mml:mi>r</mml:mi>
<mml:mi>E</mml:mi>
<mml:mn>2</mml:mn>
</mml:msubsup>
</mml:mrow>
</mml:mfrac>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mi>&#x3b4;</mml:mi>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>E</mml:mi>
</mml:msub>
</mml:mrow>
</mml:msqrt>
<mml:mo>&#x3d;</mml:mo>
<mml:msub>
<mml:mi>k</mml:mi>
<mml:mi>R</mml:mi>
</mml:msub>
<mml:msqrt>
<mml:mrow>
<mml:mn>1</mml:mn>
<mml:mo>&#x2b;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mi>R</mml:mi>
</mml:mrow>
<mml:mrow>
<mml:msubsup>
<mml:mrow>
<mml:msubsup>
<mml:mi>k</mml:mi>
<mml:mi>R</mml:mi>
<mml:mn>2</mml:mn>
</mml:msubsup>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mi>r</mml:mi>
</mml:mrow>
<mml:mi>E</mml:mi>
<mml:mn>2</mml:mn>
</mml:msubsup>
</mml:mrow>
</mml:mfrac>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mi>&#x3b4;</mml:mi>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>E</mml:mi>
</mml:msub>
</mml:mrow>
</mml:msqrt>
<mml:mo>&#x2248;</mml:mo>
<mml:msub>
<mml:mi>k</mml:mi>
<mml:mi>R</mml:mi>
</mml:msub>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:mn>1</mml:mn>
<mml:mo>&#x2b;</mml:mo>
<mml:mfrac>
<mml:mi>R</mml:mi>
<mml:mrow>
<mml:mn>2</mml:mn>
<mml:mtext>&#x2009;</mml:mtext>
<mml:msubsup>
<mml:mrow>
<mml:msubsup>
<mml:mi>k</mml:mi>
<mml:mi>R</mml:mi>
<mml:mn>2</mml:mn>
</mml:msubsup>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mi>r</mml:mi>
</mml:mrow>
<mml:mi>E</mml:mi>
<mml:mn>2</mml:mn>
</mml:msubsup>
</mml:mrow>
</mml:mfrac>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mi>&#x3b4;</mml:mi>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>E</mml:mi>
</mml:msub>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
</mml:mrow>
</mml:mtd>
</mml:mtr>
<mml:mtr>
<mml:mtd columnalign="right"/>
<mml:mtd columnalign="left">
<mml:mspace width=".6em"/>
<mml:mrow>
<mml:mo>&#x2248;</mml:mo>
<mml:msub>
<mml:mi>k</mml:mi>
<mml:mi>R</mml:mi>
</mml:msub>
<mml:mfrac>
<mml:mn>1</mml:mn>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:mn>1</mml:mn>
<mml:mo>&#x2212;</mml:mo>
<mml:mfrac>
<mml:mi>R</mml:mi>
<mml:mrow>
<mml:mn>2</mml:mn>
<mml:mtext>&#x2009;</mml:mtext>
<mml:msubsup>
<mml:mrow>
<mml:msubsup>
<mml:mi>k</mml:mi>
<mml:mi>R</mml:mi>
<mml:mn>2</mml:mn>
</mml:msubsup>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mi>r</mml:mi>
</mml:mrow>
<mml:mi>E</mml:mi>
<mml:mn>2</mml:mn>
</mml:msubsup>
</mml:mrow>
</mml:mfrac>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mi>&#x3b4;</mml:mi>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>E</mml:mi>
</mml:msub>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
</mml:mfrac>
</mml:mrow>
</mml:mtd>
</mml:mtr>
</mml:mtable>
</mml:math>
</disp-formula>
</p>
<p>Subsequently, the increase in the radius in Corrected lengths can be compared with the same increase in Euclidean lengths:<disp-formula id="equ15">
<mml:math id="m154">
<mml:mrow>
<mml:mi>&#x3b4;</mml:mi>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>C</mml:mi>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mrow>
<mml:mi>C</mml:mi>
<mml:mo>&#x2b;</mml:mo>
</mml:mrow>
</mml:msub>
<mml:mo>&#x2212;</mml:mo>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>C</mml:mi>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:msub>
<mml:mi>O</mml:mi>
<mml:mrow>
<mml:mi>C</mml:mi>
<mml:mo>&#x2b;</mml:mo>
</mml:mrow>
</mml:msub>
<mml:mo>&#x2212;</mml:mo>
<mml:msub>
<mml:mi>O</mml:mi>
<mml:mi>C</mml:mi>
</mml:msub>
</mml:mrow>
<mml:mrow>
<mml:mn>2</mml:mn>
<mml:mi>&#x3c0;</mml:mi>
</mml:mrow>
</mml:mfrac>
<mml:mo>&#x3d;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:msub>
<mml:mi>k</mml:mi>
<mml:mi>R</mml:mi>
</mml:msub>
</mml:mrow>
<mml:mrow>
<mml:mi>k</mml:mi>
</mml:mrow>
</mml:mfrac>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>E</mml:mi>
</mml:msub>
<mml:mo>&#x2b;</mml:mo>
<mml:mi>&#x3b4;</mml:mi>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>E</mml:mi>
</mml:msub>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
<mml:mo>&#x2212;</mml:mo>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>E</mml:mi>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:mn>1</mml:mn>
<mml:mo>&#x2212;</mml:mo>
<mml:mfrac>
<mml:mi>R</mml:mi>
<mml:mrow>
<mml:mn>2</mml:mn>
<mml:mtext>&#x2009;</mml:mtext>
<mml:msubsup>
<mml:mrow>
<mml:msubsup>
<mml:mi>k</mml:mi>
<mml:mi>R</mml:mi>
<mml:mn>2</mml:mn>
</mml:msubsup>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mi>r</mml:mi>
</mml:mrow>
<mml:mi>E</mml:mi>
<mml:mn>2</mml:mn>
</mml:msubsup>
</mml:mrow>
</mml:mfrac>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mi>&#x3b4;</mml:mi>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>E</mml:mi>
</mml:msub>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>E</mml:mi>
</mml:msub>
<mml:mo>&#x2b;</mml:mo>
<mml:mi>&#x3b4;</mml:mi>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>E</mml:mi>
</mml:msub>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
<mml:mo>&#x2212;</mml:mo>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>E</mml:mi>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>E</mml:mi>
</mml:msub>
<mml:mo>&#x2b;</mml:mo>
<mml:mi>&#x3b4;</mml:mi>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>E</mml:mi>
</mml:msub>
<mml:mspace width="1em"/>
<mml:mo>&#x2212;</mml:mo>
<mml:mfrac>
<mml:mi>R</mml:mi>
<mml:mrow>
<mml:mn>2</mml:mn>
<mml:mtext>&#x2009;</mml:mtext>
<mml:msubsup>
<mml:mi>k</mml:mi>
<mml:mi>R</mml:mi>
<mml:mn>2</mml:mn>
</mml:msubsup>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>E</mml:mi>
</mml:msub>
</mml:mrow>
</mml:mfrac>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mi>&#x3b4;</mml:mi>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>E</mml:mi>
</mml:msub>
<mml:mo>&#x2212;</mml:mo>
<mml:mfrac>
<mml:mi>R</mml:mi>
<mml:mrow>
<mml:mn>2</mml:mn>
<mml:mtext>&#x2009;</mml:mtext>
<mml:msubsup>
<mml:mrow>
<mml:msubsup>
<mml:mi>k</mml:mi>
<mml:mi>R</mml:mi>
<mml:mn>2</mml:mn>
</mml:msubsup>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mi>r</mml:mi>
</mml:mrow>
<mml:mi>E</mml:mi>
<mml:mn>2</mml:mn>
</mml:msubsup>
</mml:mrow>
</mml:mfrac>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mi>&#x3b4;</mml:mi>
<mml:msubsup>
<mml:mi>r</mml:mi>
<mml:mi>E</mml:mi>
<mml:mn>2</mml:mn>
</mml:msubsup>
<mml:mo>&#x2212;</mml:mo>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>E</mml:mi>
</mml:msub>
<mml:mo>&#x2248;</mml:mo>
<mml:msub>
<mml:mrow>
<mml:mi>&#x3b4;</mml:mi>
<mml:mi>r</mml:mi>
</mml:mrow>
<mml:mi>E</mml:mi>
</mml:msub>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:mn>1</mml:mn>
<mml:mo>&#x2212;</mml:mo>
<mml:mfrac>
<mml:mi>R</mml:mi>
<mml:mrow>
<mml:mn>2</mml:mn>
<mml:mtext>&#x2009;</mml:mtext>
<mml:msubsup>
<mml:mi>k</mml:mi>
<mml:mi>R</mml:mi>
<mml:mn>2</mml:mn>
</mml:msubsup>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>E</mml:mi>
</mml:msub>
</mml:mrow>
</mml:mfrac>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
<mml:mo>&#x3d;</mml:mo>
<mml:msub>
<mml:mrow>
<mml:mi>&#x3b4;</mml:mi>
<mml:mi>r</mml:mi>
</mml:mrow>
<mml:mi>E</mml:mi>
</mml:msub>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:mn>1</mml:mn>
<mml:mo>&#x2212;</mml:mo>
<mml:mfrac>
<mml:mi>R</mml:mi>
<mml:mrow>
<mml:mn>2</mml:mn>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>E</mml:mi>
</mml:msub>
<mml:mo>&#x2212;</mml:mo>
<mml:mi>R</mml:mi>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
</mml:mrow>
</mml:mfrac>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
<mml:mo>&#x3d;</mml:mo>
<mml:msub>
<mml:mi>k</mml:mi>
<mml:mi mathvariant="italic">mod</mml:mi>
</mml:msub>
<mml:msub>
<mml:mrow>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mi>&#x3b4;</mml:mi>
<mml:mi>r</mml:mi>
</mml:mrow>
<mml:mi>E</mml:mi>
</mml:msub>
</mml:mrow>
</mml:math>
</disp-formula>where<disp-formula id="e34">
<mml:math id="m155">
<mml:mrow>
<mml:msub>
<mml:mi>k</mml:mi>
<mml:mi mathvariant="italic">mod</mml:mi>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:mn>1</mml:mn>
<mml:mo>&#x2212;</mml:mo>
<mml:mfrac>
<mml:mi>R</mml:mi>
<mml:mrow>
<mml:mn>2</mml:mn>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>E</mml:mi>
</mml:msub>
<mml:mo>&#x2212;</mml:mo>
<mml:mi>R</mml:mi>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
</mml:mrow>
</mml:mfrac>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
</mml:mrow>
</mml:math>
<label>(34)</label>
</disp-formula>
</p>
<p>In the transition from Euclidean lengths to Corrected lengths, only the increment of the radius changes (<inline-formula id="inf107">
<mml:math id="m156">
<mml:mrow>
<mml:mi>&#x3b4;</mml:mi>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>C</mml:mi>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:msub>
<mml:mi>k</mml:mi>
<mml:mi mathvariant="italic">mod</mml:mi>
</mml:msub>
<mml:mtext>&#x2009;</mml:mtext>
<mml:msub>
<mml:mrow>
<mml:mi>&#x3b4;</mml:mi>
<mml:mi>r</mml:mi>
</mml:mrow>
<mml:mi>E</mml:mi>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula>). The circumference of the circle <italic>O</italic>
<sub>
<italic>C</italic>
</sub> and thus also the derived radius <inline-formula id="inf108">
<mml:math id="m157">
<mml:mrow>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>C</mml:mi>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:msub>
<mml:mi>O</mml:mi>
<mml:mi>C</mml:mi>
</mml:msub>
<mml:mo>/</mml:mo>
<mml:mn>2</mml:mn>
<mml:mi>&#x3c0;</mml:mi>
</mml:mrow>
</mml:math>
</inline-formula> remain unchanged (<inline-formula id="inf109">
<mml:math id="m158">
<mml:mrow>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>C</mml:mi>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>E</mml:mi>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula>). The same applies to the increment in dimension <italic>w</italic>, which lies in the same potential as circle C (<inline-formula id="inf110">
<mml:math id="m159">
<mml:mrow>
<mml:mi mathvariant="normal">&#x3b4;</mml:mi>
<mml:msub>
<mml:mi mathvariant="normal">w</mml:mi>
<mml:mi mathvariant="normal">C</mml:mi>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:msub>
<mml:mrow>
<mml:mi>&#x3b4;</mml:mi>
<mml:mi mathvariant="normal">w</mml:mi>
</mml:mrow>
<mml:mi mathvariant="normal">E</mml:mi>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula>) We can write<disp-formula id="equ16">
<mml:math id="m160">
<mml:mrow>
<mml:mi>&#x3b4;</mml:mi>
<mml:msubsup>
<mml:mi>s</mml:mi>
<mml:mi>E</mml:mi>
<mml:mn>2</mml:mn>
</mml:msubsup>
<mml:mo>&#x3d;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mi>&#x3b4;</mml:mi>
<mml:msubsup>
<mml:mi>r</mml:mi>
<mml:mi>C</mml:mi>
<mml:mn>2</mml:mn>
</mml:msubsup>
</mml:mrow>
<mml:msubsup>
<mml:mi>k</mml:mi>
<mml:mi mathvariant="italic">mod</mml:mi>
<mml:mn>2</mml:mn>
</mml:msubsup>
</mml:mfrac>
<mml:mo>&#x2b;</mml:mo>
<mml:msubsup>
<mml:mi>r</mml:mi>
<mml:mi>C</mml:mi>
<mml:mn>2</mml:mn>
</mml:msubsup>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:mi>&#x3b4;</mml:mi>
<mml:msup>
<mml:mi>&#x3b8;</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
<mml:mo>&#x2b;</mml:mo>
<mml:msup>
<mml:mi mathvariant="italic">sin</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
<mml:mo>&#x2061;</mml:mo>
<mml:mi>&#x3b8;</mml:mi>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mi>&#x3b4;</mml:mi>
<mml:msup>
<mml:mi>&#x3d5;</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
<mml:mo>&#x2b;</mml:mo>
<mml:mi>&#x3b4;</mml:mi>
<mml:msubsup>
<mml:mi>w</mml:mi>
<mml:mi>C</mml:mi>
<mml:mn>2</mml:mn>
</mml:msubsup>
<mml:mo>.</mml:mo>
</mml:mrow>
</mml:math>
</disp-formula>
</p>
<p>The value <inline-formula id="inf111">
<mml:math id="m161">
<mml:mrow>
<mml:mi>&#x3b4;</mml:mi>
<mml:msub>
<mml:mi>w</mml:mi>
<mml:mi>C</mml:mi>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula> is, from a physical point of view, the increment of proper time determined by local clock <inline-formula id="inf112">
<mml:math id="m162">
<mml:mrow>
<mml:mi>&#x3b4;</mml:mi>
<mml:msub>
<mml:mi>w</mml:mi>
<mml:mi>C</mml:mi>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:mi>c</mml:mi>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mi>&#x3b4;</mml:mi>
<mml:mi>&#x3c4;</mml:mi>
</mml:mrow>
</mml:math>
</inline-formula>.</p>
<p>The increment <inline-formula id="inf113">
<mml:math id="m163">
<mml:mrow>
<mml:msub>
<mml:mrow>
<mml:mi>&#x3b4;</mml:mi>
<mml:mi>s</mml:mi>
</mml:mrow>
<mml:mi>E</mml:mi>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula> represents the distance between points in space E<sub>4</sub>-B. Its expression using the time of stationary reference clocks located outside the gravitational field leads to the formula <inline-formula id="inf114">
<mml:math id="m164">
<mml:mrow>
<mml:msub>
<mml:mrow>
<mml:mi>&#x3b4;</mml:mi>
<mml:mi>s</mml:mi>
</mml:mrow>
<mml:mi>E</mml:mi>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula> <italic>&#x3b4;t</italic> &#x2013; see (<xref ref-type="disp-formula" rid="e31">Equation 31</xref>). Considering the ratio between <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> and <italic>c</italic> (<xref ref-type="disp-formula" rid="e15">Equation 15</xref>) and the relationships (<xref ref-type="disp-formula" rid="e33">Equation 33</xref>), we obtain the metric of space in the area of the central gravitational field<disp-formula id="e35">
<mml:math id="m165">
<mml:mrow>
<mml:msup>
<mml:mi>c</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
<mml:mi>&#x3b4;</mml:mi>
<mml:msup>
<mml:mi>t</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
<mml:msubsup>
<mml:mi>k</mml:mi>
<mml:mi>R</mml:mi>
<mml:mn>2</mml:mn>
</mml:msubsup>
<mml:mo>&#x3d;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mi>&#x3b4;</mml:mi>
<mml:msubsup>
<mml:mi>r</mml:mi>
<mml:mi>C</mml:mi>
<mml:mn>2</mml:mn>
</mml:msubsup>
</mml:mrow>
<mml:msubsup>
<mml:mi>k</mml:mi>
<mml:mi mathvariant="italic">mod</mml:mi>
<mml:mn>2</mml:mn>
</mml:msubsup>
</mml:mfrac>
<mml:mo>&#x2b;</mml:mo>
<mml:msubsup>
<mml:mi>r</mml:mi>
<mml:mi>C</mml:mi>
<mml:mn>2</mml:mn>
</mml:msubsup>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:mi>&#x3b4;</mml:mi>
<mml:msup>
<mml:mi>&#x3b8;</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
<mml:mo>&#x2b;</mml:mo>
<mml:msup>
<mml:mi mathvariant="italic">sin</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
<mml:mo>&#x2061;</mml:mo>
<mml:mi>&#x3b8;</mml:mi>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mi>&#x3b4;</mml:mi>
<mml:msup>
<mml:mi>&#x3d5;</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
<mml:mo>&#x2b;</mml:mo>
<mml:msup>
<mml:mi>c</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
<mml:mi>&#x3b4;</mml:mi>
<mml:msup>
<mml:mi>&#x3c4;</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
</mml:mrow>
</mml:math>
<label>(35)</label>
</disp-formula>
</p>
<p>Coordinates and their increments are always real numbers in the EMST and can be both positive and negative. On the other hand, time increments <italic>&#x3b4;t</italic> and <italic>&#x3b4;&#x3c4;</italic> are always non-negative (they are related to the increments of the path or the number of clock ticks &#x2013; see [<xref ref-type="bibr" rid="B7">7</xref>]). The coefficients <italic>k</italic>
<sub>
<italic>R</italic>
</sub> and <italic>k</italic>
<sub>
<italic>mod</italic>
</sub> are given by <xref ref-type="disp-formula" rid="e33">Equations 33</xref>, <xref ref-type="disp-formula" rid="e34">34</xref>), where <inline-formula id="inf115">
<mml:math id="m166">
<mml:mrow>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>C</mml:mi>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>E</mml:mi>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula>. The quantity <inline-formula id="inf116">
<mml:math id="m167">
<mml:mrow>
<mml:mi>R</mml:mi>
<mml:mo>&#x3d;</mml:mo>
<mml:mn>2</mml:mn>
<mml:mi>G</mml:mi>
<mml:mi>M</mml:mi>
<mml:mo>/</mml:mo>
<mml:msup>
<mml:mi>c</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
</mml:mrow>
</mml:math>
</inline-formula> is known from the GTR as the Schwarzschild radius.</p>
<p>For <inline-formula id="inf117">
<mml:math id="m168">
<mml:mrow>
<mml:mi>R</mml:mi>
<mml:mo>&#x226a;</mml:mo>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>C</mml:mi>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula>, the difference between <italic>k</italic>
<sub>
<italic>R</italic>
</sub> and <italic>k</italic>
<sub>
<italic>mod</italic>
</sub> is negligible. We can write<disp-formula id="e36">
<mml:math id="m169">
<mml:mrow>
<mml:msub>
<mml:mi>k</mml:mi>
<mml:mi mathvariant="italic">mod</mml:mi>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:mn>1</mml:mn>
<mml:mo>&#x2212;</mml:mo>
<mml:mfrac>
<mml:mi>R</mml:mi>
<mml:mrow>
<mml:mn>2</mml:mn>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>C</mml:mi>
</mml:msub>
<mml:mo>&#x2212;</mml:mo>
<mml:mi>R</mml:mi>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
</mml:mrow>
</mml:mfrac>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
<mml:mo>&#x2248;</mml:mo>
<mml:msqrt>
<mml:mrow>
<mml:mn>1</mml:mn>
<mml:mo>&#x2212;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mi>R</mml:mi>
</mml:mrow>
<mml:mrow>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>C</mml:mi>
</mml:msub>
</mml:mrow>
</mml:mfrac>
</mml:mrow>
</mml:msqrt>
<mml:mo>&#x3d;</mml:mo>
<mml:msub>
<mml:mi>k</mml:mi>
<mml:mi>R</mml:mi>
</mml:msub>
</mml:mrow>
</mml:math>
<label>(36)</label>
</disp-formula>
</p>
<p>The metric (<xref ref-type="disp-formula" rid="e35">Equation 35</xref>) can be rewritten for <inline-formula id="inf118">
<mml:math id="m170">
<mml:mrow>
<mml:mi>R</mml:mi>
<mml:mo>&#x226a;</mml:mo>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>C</mml:mi>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula> in the form known from GTR<disp-formula id="equ17">
<mml:math id="m171">
<mml:mrow>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:mn>1</mml:mn>
<mml:mo>&#x2212;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mi>R</mml:mi>
</mml:mrow>
<mml:mrow>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>C</mml:mi>
</mml:msub>
</mml:mrow>
</mml:mfrac>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
<mml:msup>
<mml:mi>c</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
<mml:mi>&#x3b4;</mml:mi>
<mml:msup>
<mml:mi>t</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
<mml:mo>&#x3d;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mi>&#x3b4;</mml:mi>
<mml:msubsup>
<mml:mi>r</mml:mi>
<mml:mi>c</mml:mi>
<mml:mn>2</mml:mn>
</mml:msubsup>
</mml:mrow>
<mml:mrow>
<mml:mn>1</mml:mn>
<mml:mo>&#x2212;</mml:mo>
<mml:mfrac>
<mml:mrow>
<mml:mi>R</mml:mi>
</mml:mrow>
<mml:mrow>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>C</mml:mi>
</mml:msub>
</mml:mrow>
</mml:mfrac>
</mml:mrow>
</mml:mfrac>
<mml:mo>&#x2b;</mml:mo>
<mml:msubsup>
<mml:mi>r</mml:mi>
<mml:mi>C</mml:mi>
<mml:mn>2</mml:mn>
</mml:msubsup>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mrow>
<mml:mfenced open="(" close=")" separators="&#x7c;">
<mml:mrow>
<mml:mi>&#x3b4;</mml:mi>
<mml:msup>
<mml:mi>&#x3b8;</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
<mml:mo>&#x2b;</mml:mo>
<mml:msup>
<mml:mi mathvariant="italic">sin</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
<mml:mo>&#x2061;</mml:mo>
<mml:mi>&#x3b8;</mml:mi>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mi>&#x3b4;</mml:mi>
<mml:msup>
<mml:mi>&#x3d5;</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
</mml:mrow>
</mml:mfenced>
</mml:mrow>
<mml:mo>&#x2b;</mml:mo>
<mml:msup>
<mml:mi>c</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
<mml:mi>&#x3b4;</mml:mi>
<mml:msup>
<mml:mi>&#x3c4;</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
</mml:mrow>
</mml:math>
</disp-formula>i.e., in the form of the Schwarzschild metric. The meaning of the individual quantities is the same as in GTR. This also applies to the radius <inline-formula id="inf119">
<mml:math id="m172">
<mml:mrow>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>C</mml:mi>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula>, which is the radial coordinate calculated from the circumference of a circle. The corrected lengths form the same set of coordinates that was used by Schwarzschild in his solution.</p>
</sec>
<sec id="s2-9">
<label>2.9</label>
<title>Energy as a source of gravitation</title>
<p>As mentioned above, in the presented theory of gravitation, the principle source of gravitational attraction is the energy of matter, not its mass. The energy-mass ratio (which is constant in the GTR) is variable in the EMST &#x2013; it depends on the variable value of <italic>v</italic>
<sub>
<italic>4D</italic>
</sub>, <inline-formula id="inf120">
<mml:math id="m173">
<mml:mrow>
<mml:mi>E</mml:mi>
<mml:mo>&#x3d;</mml:mo>
<mml:mi>m</mml:mi>
<mml:mtext>&#x2009;</mml:mtext>
<mml:msubsup>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
</mml:mrow>
<mml:mn>2</mml:mn>
</mml:msubsup>
</mml:mrow>
</mml:math>
</inline-formula>, see (<xref ref-type="disp-formula" rid="e5">Equation 5</xref>). Therefore, it is not possible to interchange mass and energy in the formulas for gravitational potential or acceleration. As the potential decreases (moving down into the gravitational well), the energy of the particle-waves decreases, but their mass increases.</p>
<p>It is necessary to keep in mind the following when assessing the influence of gravitational potential on physical quantities:<list list-type="simple">
<list-item>
<label>-</label>
<p>The dimensions of objects are independent of potential (Local lengths are equal to Euclidean lengths,</p>
</list-item>
<list-item>
<label>-</label>
<p>Time flows more slowly in areas of lower potential (<xref ref-type="disp-formula" rid="e16">Equation 16</xref>),</p>
</list-item>
<list-item>
<label>-</label>
<p>The mass of bodies is higher in areas of lower potential (<xref ref-type="disp-formula" rid="e13">Equation 13</xref>).</p>
</list-item>
</list>
</p>
<p>The above is reflected in the implementation of the fundamental units of these quantities (meter, second, kilogram).</p>
<p>In general, physical quantities containing only length quantities (distance, area, volume, etc.) and quantities containing mass and time in the opposite power (momentum [<italic>kg m s</italic>
<sup>
<italic>-1</italic>
</sup>], angular momentum [<italic>kg m</italic>
<sup>
<italic>2</italic>
</sup>
<italic> s</italic>
<sup>
<italic>-1</italic>
</sup>], etc.) are not dependent on gravitational potential. For example, the value of Planck&#x2019;s constant <italic>h</italic> [<italic>kg m</italic>
<sup>
<italic>2</italic>
</sup>
<italic> s</italic>
<sup>
<italic>-1</italic>
</sup>] is also independent of <italic>V</italic>.</p>
<p>The formulas describing the effects of gravitation are similar to Newton&#x2019;s, but they are based on particle-wave energy as the principal source of gravitation. Energy refers to the total energy of a particle-wave (<inline-formula id="inf121">
<mml:math id="m174">
<mml:mrow>
<mml:mi>E</mml:mi>
<mml:mo>&#x3d;</mml:mo>
<mml:mi>h</mml:mi>
<mml:mtext>&#x2009;</mml:mtext>
<mml:mi>f</mml:mi>
<mml:mo>&#x3d;</mml:mo>
<mml:msub>
<mml:mi>E</mml:mi>
<mml:mn>0</mml:mn>
</mml:msub>
<mml:mo>&#x2b;</mml:mo>
<mml:msub>
<mml:mi>E</mml:mi>
<mml:mi>p</mml:mi>
</mml:msub>
<mml:mo>&#x2b;</mml:mo>
<mml:msub>
<mml:mi>E</mml:mi>
<mml:mi>k</mml:mi>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula>), see <xref ref-type="disp-formula" rid="e2">Equations 2</xref>, <xref ref-type="disp-formula" rid="e9">9</xref>. The two most fundamental gravitation formulas take the form<disp-formula id="e37">
<mml:math id="m175">
<mml:mrow>
<mml:mi>V</mml:mi>
<mml:mo>&#x3d;</mml:mo>
<mml:mo>&#x2212;</mml:mo>
<mml:mover accent="true">
<mml:mi>&#x3f0;</mml:mi>
<mml:mo>&#xaf;</mml:mo>
</mml:mover>
<mml:mfrac>
<mml:mrow>
<mml:mi>E</mml:mi>
</mml:mrow>
<mml:mrow>
<mml:msub>
<mml:mi>r</mml:mi>
<mml:mi>C</mml:mi>
</mml:msub>
</mml:mrow>
</mml:mfrac>
</mml:mrow>
</mml:math>
<label>(37)</label>
</disp-formula>
<disp-formula id="e38">
<mml:math id="m176">
<mml:mrow>
<mml:mi>a</mml:mi>
<mml:mo>&#x3d;</mml:mo>
<mml:mo>&#x2212;</mml:mo>
<mml:mover accent="true">
<mml:mi>&#x3f0;</mml:mi>
<mml:mo>&#xaf;</mml:mo>
</mml:mover>
<mml:mfrac>
<mml:mrow>
<mml:mi>E</mml:mi>
</mml:mrow>
<mml:mrow>
<mml:msubsup>
<mml:mi>r</mml:mi>
<mml:mi>C</mml:mi>
<mml:mn>2</mml:mn>
</mml:msubsup>
</mml:mrow>
</mml:mfrac>
</mml:mrow>
</mml:math>
<label>(38)</label>
</disp-formula>i.e., the product <italic>GM</italic> is substituted by the product of <inline-formula id="inf122">
<mml:math id="m177">
<mml:mrow>
<mml:mover accent="true">
<mml:mi>&#x3f0;</mml:mi>
<mml:mo>&#xaf;</mml:mo>
</mml:mover>
<mml:mi>E</mml:mi>
</mml:mrow>
</mml:math>
</inline-formula>.</p>
<p>It can be seen that the mass of the central body <italic>M</italic> is replaced by its energy <italic>E</italic>, and Newton&#x2019;s gravitational constant <italic>G</italic> is replaced by a new constant <inline-formula id="inf123">
<mml:math id="m178">
<mml:mrow>
<mml:mover accent="true">
<mml:mi>&#x3f0;</mml:mi>
<mml:mo>&#xaf;</mml:mo>
</mml:mover>
</mml:mrow>
</mml:math>
</inline-formula>. For weak gravitational fields, the value of <inline-formula id="inf124">
<mml:math id="m179">
<mml:mrow>
<mml:mover accent="true">
<mml:mi>&#x3f0;</mml:mi>
<mml:mo>&#xaf;</mml:mo>
</mml:mover>
</mml:mrow>
</mml:math>
</inline-formula> can be derived from <italic>G</italic> [<italic>kg</italic>
<sup>
<italic>-1</italic>
</sup> <italic>m</italic>
<sup>
<italic>3</italic>
</sup>
<italic> s</italic>
<sup>
<italic>-2</italic>
</sup>], <inline-formula id="inf125">
<mml:math id="m180">
<mml:mrow>
<mml:mover accent="true">
<mml:mi>&#x3f0;</mml:mi>
<mml:mo>&#xaf;</mml:mo>
</mml:mover>
<mml:mo>&#x3d;</mml:mo>
<mml:mi>G</mml:mi>
<mml:mo>/</mml:mo>
<mml:msup>
<mml:mi>c</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
<mml:mo>&#x3d;</mml:mo>
<mml:msup>
<mml:mrow>
<mml:mn>7</mml:mn>
<mml:mo>,</mml:mo>
<mml:mn>425</mml:mn>
<mml:mo>&#xd7;</mml:mo>
<mml:mn>10</mml:mn>
</mml:mrow>
<mml:mrow>
<mml:mo>&#x2212;</mml:mo>
<mml:mn>28</mml:mn>
</mml:mrow>
</mml:msup>
</mml:mrow>
</mml:math>
</inline-formula> [<italic>kg</italic>
<sup>
<italic>-1</italic>
</sup> <italic>m</italic>]. It is important to note that neither <italic>G</italic> nor <inline-formula id="inf126">
<mml:math id="m181">
<mml:mrow>
<mml:mover accent="true">
<mml:mi>&#x3f0;</mml:mi>
<mml:mo>&#xaf;</mml:mo>
</mml:mover>
</mml:mrow>
</mml:math>
</inline-formula> are constants in the true sense of the word. Both are functions of the gravitational potential <italic>V</italic>, and therefore also of <italic>v</italic>
<sub>
<italic>4D</italic>
</sub>. For reference clocks &#x201c;1&#x201d; and &#x201c;2&#x201d; in regions with different potentials (see example above), <inline-formula id="inf127">
<mml:math id="m182">
<mml:mrow>
<mml:msub>
<mml:mover accent="true">
<mml:mi>&#x3f0;</mml:mi>
<mml:mo>&#xaf;</mml:mo>
</mml:mover>
<mml:mn>2</mml:mn>
</mml:msub>
<mml:mo>/</mml:mo>
<mml:msub>
<mml:mover accent="true">
<mml:mi>&#x3f0;</mml:mi>
<mml:mo>&#xaf;</mml:mo>
</mml:mover>
<mml:mn>1</mml:mn>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
<mml:mo>,</mml:mo>
<mml:mn>2</mml:mn>
</mml:mrow>
</mml:msub>
<mml:mo>/</mml:mo>
<mml:msub>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
<mml:mo>,</mml:mo>
<mml:mn>1</mml:mn>
</mml:mrow>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula> and <inline-formula id="inf128">
<mml:math id="m183">
<mml:mrow>
<mml:msub>
<mml:mi>G</mml:mi>
<mml:mn>2</mml:mn>
</mml:msub>
<mml:mo>/</mml:mo>
<mml:msub>
<mml:mi>G</mml:mi>
<mml:mn>1</mml:mn>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:msubsup>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
<mml:mo>,</mml:mo>
<mml:mn>2</mml:mn>
</mml:mrow>
<mml:mn>3</mml:mn>
</mml:msubsup>
<mml:mo>/</mml:mo>
<mml:msubsup>
<mml:mi>v</mml:mi>
<mml:mrow>
<mml:mn>4</mml:mn>
<mml:mi>D</mml:mi>
<mml:mo>,</mml:mo>
<mml:mn>1</mml:mn>
</mml:mrow>
<mml:mn>3</mml:mn>
</mml:msubsup>
</mml:mrow>
</mml:math>
</inline-formula>. The constant <inline-formula id="inf129">
<mml:math id="m184">
<mml:mrow>
<mml:mover accent="true">
<mml:mi>&#x3f0;</mml:mi>
<mml:mo>&#xaf;</mml:mo>
</mml:mover>
</mml:mrow>
</mml:math>
</inline-formula> is less dependent on the value of the gravitational potential than <italic>G</italic>.</p>
<p>The gravitational potential of composite bodies is the sum of the gravitational potentials of individual particle-waves. The total value can be determined by simple addition &#x2013; see relation (<xref ref-type="disp-formula" rid="e29">Equation 29</xref>). At this stage, the different energies of identical particle-waves (e.g., free electrons at rest) in places with different potentials become significant. Particle-waves deeper in the gravitational well have lower energy than identical particle-waves higher up &#x2013; see Sect. 2.6.</p>
</sec>
</sec>
<sec sec-type="discussion" id="s3">
<label>3</label>
<title>Discussion</title>
<p>The concept of gravitation theory based on the EMST (GT-EMST) differs fundamentally from the one based on GTR. In particular, the foundations and mathematical notation of the two theories are completely different. The GT-EMST can be classified as a scalar theory of gravitation, i.e., a theory in which the source of gravitation is described by a scalar field. In this case by the <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> speed field. As a consequence, mathematical notation is considerably simpler in the GT-EMST. However, the resulting mathematical formulas of both theories are very similar or identical.</p>
<p>The GT-EMST explains the origin of gravitational time dilation and gives the functional dependence of this dilation on gravitational potential. It also explains the common origin of gravitational and inertial forces from the general properties of waves (Fermat&#x2019;s principle). It shows that gravitational and inertial forces have a common origin in the spatially variable value of <italic>v</italic>
<sub>
<italic>4D</italic>
</sub>, but the very reason is different. For (apparent) inertial forces, it is apparent differences in the speed <italic>v</italic>
<sub>
<italic>4D</italic>
</sub>; for (real) gravitation, it is a real decrease in <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> due to real waves in the transmission medium.</p>
<p>Eliminating the principle of relativity as a fundamental law of the universe removes the latent contradiction between the non-existence of a privileged reference frame for linear motion and the existence of such a frame for rotational motion. This contradiction, which originates in STR, does not exist in the EMST. The EMST assumes the existence of a privileged reference frame for all types of motion. It also explains why it is not possible to experimentally distinguish this frame from others for linear motion [<xref ref-type="bibr" rid="B7">7</xref>].</p>
<p>The GT-EMST is not just a theory of gravitation. The dependence of the trajectory of matter (particles-waves) on the variable <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> is simultaneously a theory of inertia. It explains the curvature of the trajectories of physical objects and the change in their energy due to the existence of apparent (inertial) forces. It shows that the acceleration of a body does not depend on its mass &#x2013; it explains the universal influence of inertial and gravitational forces on all matter.</p>
<p>The GT-EMST shows that the curvature of space due to gravitation is only apparent. It is a consequence of the interaction between Fermat&#x2019;s principle and the variable value of <italic>v</italic>
<sub>
<italic>4D</italic>
</sub> in space. Matter consisting of waves (particles-waves) moves along paths with the shortest time, not along geometrical straight lines. Although space appears curved in physical experiments, it is possible to consider the causes of this curvature, introduce numerical corrections, and show that space is Euclidean even in the presence of the gravitational influence of matter. This is analogous to the refraction of light in the Earth&#x2019;s atmosphere. Although light travels along curved paths and the measured directions and distances do not form a Euclidean system, no one doubts that the space in which light travels is Euclidean. It suffices to consider the local refractive indices (local speeds of light), correct the measured directions and distances for their influence, and the corrected quantities will form a Euclidean system. This is a common procedure used, for example, in geodetic measurements.</p>
<p>Numerical corrections can be also applied to clock rates of local clocks. The corrections are both gravitational (correction of clock rate depending on the local potential) and kinematic (correction based on the clock&#x2019;s speed of motion). It is therefore possible to numerically correct the clock&#x2019;s operation and recalculate it to the selected potential level and selected state of motion. This already happens, for example, when correcting the operation of atomic clocks on GNSS satellites, [<xref ref-type="bibr" rid="B12">12</xref>, <xref ref-type="bibr" rid="B13">13</xref>], and is also part of the definition of so-called coordinate times [<xref ref-type="bibr" rid="B14">14</xref>]. The corrections are identical in the EMST and the GTR.</p>
<p>The dependence of particle-wave frequency on local gravitational potential (see <xref ref-type="disp-formula" rid="e11">Equations 11</xref>, <xref ref-type="disp-formula" rid="e15">15</xref>) is the cause of the gravitational Aharonov&#x2013;Bohm effect [<xref ref-type="bibr" rid="B15">15</xref>].</p>
<p>Unlike the STR, the EMST assumes the existence of a preferred, so-called &#x201c;stationary coordinate system&#x201d;. It would therefore be possible, at least theoretically, to convert the time of an arbitrary clock to the time in the stationary gravitation-free system. This would give us a single time for the entire universe, time that is independent of the motion and location of clocks. This time can be considered as &#x201c;cosmological time&#x201d; &#x2013; an independent time parameter of the evolution of the universe. This possibility represents a fundamental departure from the theory of relativity, which considers all coordinate systems to be equivalent and therefore does not permit the definition of a single cosmological time.</p>
<p>Under usual physical conditions, the metric of the central gravitational field derived within the GT-EMST is identical to the Schwarzschild metric. This means that, in the case of a central field, the physical predictions of the EMST are the same as those of the GTR. The only difference is in the replacement of the coefficient <inline-formula id="inf130">
<mml:math id="m185">
<mml:mrow>
<mml:msub>
<mml:mi>k</mml:mi>
<mml:mi>R</mml:mi>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula> with the coefficient <inline-formula id="inf131">
<mml:math id="m186">
<mml:mrow>
<mml:msub>
<mml:mi>k</mml:mi>
<mml:mi mathvariant="italic">mod</mml:mi>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula> (<xref ref-type="disp-formula" rid="e36">Equation 36</xref>) in the radial term of the metric (<xref ref-type="disp-formula" rid="e35">Equation 35</xref>). The values of these coefficients are practically identical for usual situations where <italic>R</italic> &#x226a; <italic>r</italic>
<sub>
<italic>C</italic>
</sub>. The biggest difference within the solar system occurs on the surface of the Sun, where <inline-formula id="inf132">
<mml:math id="m187">
<mml:mrow>
<mml:msub>
<mml:mi>k</mml:mi>
<mml:mi>R</mml:mi>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:mn>0</mml:mn>
<mml:mo>,</mml:mo>
<mml:mn>997855</mml:mn>
</mml:mrow>
</mml:math>
</inline-formula> while <inline-formula id="inf133">
<mml:math id="m188">
<mml:mrow>
<mml:msub>
<mml:mi>k</mml:mi>
<mml:mi mathvariant="italic">mod</mml:mi>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:mn>0</mml:mn>
<mml:mo>,</mml:mo>
<mml:mn>997848</mml:mn>
</mml:mrow>
</mml:math>
</inline-formula> for the Sun&#x2019;s values <italic>R &#x3d; 3 &#xd7; 10</italic>
<sup>
<italic>6</italic>
</sup>
<italic> m</italic> and <italic>r</italic>
<sub>
<italic>C</italic>
</sub> <italic>&#x3d; 7 &#xd7; 10</italic>
<sup>
<italic>8</italic>
</sup>
<italic> m</italic>. Their ratio <inline-formula id="inf134">
<mml:math id="m189">
<mml:mrow>
<mml:msub>
<mml:mi>k</mml:mi>
<mml:mi>R</mml:mi>
</mml:msub>
</mml:mrow>
</mml:math>
</inline-formula>/ <inline-formula id="inf135">
<mml:math id="m190">
<mml:mrow>
<mml:msub>
<mml:mi>k</mml:mi>
<mml:mi mathvariant="italic">mod</mml:mi>
</mml:msub>
<mml:mo>&#x3d;</mml:mo>
<mml:mn>1</mml:mn>
<mml:mo>&#x2b;</mml:mo>
<mml:mn>7</mml:mn>
<mml:mo>.</mml:mo>
<mml:msup>
<mml:mn>10</mml:mn>
<mml:mrow>
<mml:mo>&#x2212;</mml:mo>
<mml:mn>6</mml:mn>
</mml:mrow>
</mml:msup>
</mml:mrow>
</mml:math>
</inline-formula>. This value is so close to 1 that detecting the deviation will be very difficult or even impossible with any existing technology. For the solar system, the GT-EMST and the GTR predictions can therefore be considered identical. However, differences occur in massive astronomical objects outside the solar system.</p>
<p>The GT-EMST concept is unique in that any particle-wave influences the motion of all surrounding particle-waves, reducing their speed <italic>v</italic>
<sub>
<italic>4D</italic>
</sub>, but does not affect its own speed. The particle-wave does not affect itself in any way. This eliminates the theoretical problem of Newton&#x2019;s classical solution, which has difficulty describing the gravitational effect of a point mass on itself.</p>
<p>The assumption that gravitation is caused by particle-waves, and thus by wave motion of the transmission medium, offers an answer to the question of how fast gravitation propagates. All waves move through the transmission medium at speed <italic>v</italic>
<sub>
<italic>4D</italic>
</sub>, and gravity propagates at the same speed. Changes in the distribution of gravitational masses manifest themselves at distant locations with a delay proportional to the distance. In the cases of dynamic sources of gravitation (e.g., close binary stars), areas of greater and lesser undulation of the transmission medium (areas of greater and lesser <italic>v</italic>
<sub>
<italic>4D</italic>
</sub>) arise, spreading through space from such sources. Such areas influence the actual gravitational effect &#x2013; they create so-called gravitational waves. These waves move at speed <italic>v</italic>
<sub>
<italic>4D</italic>
</sub>.</p>
<p>The fact that gravitation may not be caused by mass, but by the total energy of matter, see (<xref ref-type="disp-formula" rid="e37">Equations 37</xref>, <xref ref-type="disp-formula" rid="e38">38</xref>), can influence our understanding of the gravitation of very massive objects. Galaxies may be an example. The central part of a galaxy is located deeper in the gravitational well &#x2013; the mass here has less energy than similar mass at the periphery of the galaxy. This effect weakens the gravitational influence of the central regions of the galaxy, and at the same time, relatively strengthens the influence of the peripheral parts. This finding is important for modeling the rotation of galaxies and the effect of so-called dark matter on them.</p>
<p>The idea that gravitation is caused by a locally variable speed of light is not new. Albert Einstein considered it as the cause of the gravitational bending of light in his 1911 paper &#x201c;On the Influence of Gravitation on the Propagation of Light&#x201d; [<xref ref-type="bibr" rid="B16">16</xref>]. However, within the framework of classical or relativistic physics, the variable speed of light could not be a general cause of gravity, as it had no relation to the motion of ordinary (baryonic) matter. It could only affect particles moving at the speed of light, especially photons. For this reason, none of the theories of gravitation based on a variable speed of light [<xref ref-type="bibr" rid="B17">17</xref>, <xref ref-type="bibr" rid="B18">18</xref>] received much attention. An attempt was made to overcome this limitation by introducing a dual space metric, but this is an <italic>ad hoc</italic> solution without sufficient justification. It introduces free parameters whose physical interpretation is unclear [<xref ref-type="bibr" rid="B19">19</xref>, <xref ref-type="bibr" rid="B20">20</xref>]. A less radical approach separates the speed of light from the constant <italic>c</italic> as a parameter of the space-time metric [<xref ref-type="bibr" rid="B21">21</xref>]. However, even in this case, additional parameters without clear physical meaning have been introduced. It was the EMST and its prediction that all particles of matter move at the same 4D speed that permitted a fundamental shift in the understanding of gravity and the role of locally variable speed of light in it. It has made it possible to create a comprehensive theory of gravitation based on the natural properties of space, time, and matter.</p>
<p>A notable exception among works in this field is &#x201c;Flat Space Gravitation&#x201d; (FSG) by J.M.C. Montanus [<xref ref-type="bibr" rid="B22">22</xref>], which is based on relativity in uncurved Euclidean space. The so-called &#x201c;absolute Euclidean space-time&#x201d; used here is very similar to the EMST [<xref ref-type="bibr" rid="B23">23</xref>, <xref ref-type="bibr" rid="B24">24</xref>]. Montanus, just like the author of this article, concludes that the gravitational curvature of space is only apparent:</p>
<p>
<italic>&#x201c;The idea of a curved space&#x2013;time is based on the tacit assumption that the free space relation</italic> <inline-formula id="inf136">
<mml:math id="m191">
<mml:mrow>
<mml:mi mathvariant="normal">d</mml:mi>
<mml:msup>
<mml:mi mathvariant="normal">s</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
<mml:mo>&#x3d;</mml:mo>
<mml:msup>
<mml:mi mathvariant="normal">c</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
<mml:mi mathvariant="normal">d</mml:mi>
<mml:msup>
<mml:mi mathvariant="normal">&#x3c4;</mml:mi>
<mml:mn>2</mml:mn>
</mml:msup>
</mml:mrow>
</mml:math>
</inline-formula> <italic>also holds in the situation with gravitation. Without the latter assumption the concept of curvature becomes redundant.&#x201d;</italic> [22, p. 1561].</p>
<p>FSG has other similarities with the GT-EMST (e.g., a similar metric for the central gravitational field), but it completely omits the causes and mechanism of gravitational interaction. The derivation of FSG is purely mathematical and not entirely consistent (it does not consider the influence of the variable <italic>c</italic> on the ratio of mass and energy - <italic>E &#x3d; m c</italic>
<sup>
<italic>2</italic>
</sup>). Although very inspiring and pioneering, FSG lacks an explanation of the principles of gravitation offered by the GT-EMST. It also lacks clear justification for choosing the tensor field as the source of gravitation.</p>
<p>The GT-EMST is formulated to be relativistically invariant. It is based on the EMST, which is equivalent to the STR, it takes into account the finite speed of gravity propagation, the state of motion of the source of gravitation (its energy, including kinetic energy) and the state of motion of the object on which gravitation acts (the term sin &#x3b1; in (<xref ref-type="disp-formula" rid="e23">Equation 23</xref>) is equivalent to the relativistic increase in the mass of the object). In summary, it can be said that GT-EMST covers all areas of validity of GTR, leading to very similar, but not identical, physical predictions.</p>
<p>GT-EMST was derived using Newton&#x2019;s formula for potential (Sect. 2.6). This was modified in Sect. 2.9 by replacing the mass of the source by its total energy. For weak gravitational sources, the difference is negligible. Newtonian gravitation can be considered an approximation of the GT-EMST for weak stationary fields.</p>
<p>For many years, scalar theories of gravitation were not very popular, as there was no strictly scalar theory that would fit the experimental data [<xref ref-type="bibr" rid="B25">25</xref>]. However, this has changed recently, and there are at least two other scalar theories of gravitation claiming to fit all types of tests in the Solar System. These are the Geometric scalar theory of gravity [<xref ref-type="bibr" rid="B26">26</xref>] and A viable relativistic scalar theory of gravitation [<xref ref-type="bibr" rid="B27">27</xref>]. Both are based on flat Minkowski space and the assumption of a constant speed of light, i.e., on different foundations than GT-EMST. Nevertheless, both prove that scalar theories are not <italic>a priori</italic> excluded from the description of gravitation.</p>
<p>It must be admitted that there is currently no evidence that waves created by particles of matter are the cause of gravitation, nor is there any evidence that such waves exist at all. However, the author is not aware of any evidence indicating that such waves do not exist.</p>
</sec>
</body>
<back>
<sec sec-type="data-availability" id="s4">
<title>Data availability statement</title>
<p>The original contributions presented in the study are included in the article/supplementary material, further inquiries can be directed to the corresponding author.</p>
</sec>
<sec sec-type="author-contributions" id="s5">
<title>Author contributions</title>
<p>RM: Writing &#x2013; original draft, Writing &#x2013; review and editing.</p>
</sec>
<sec sec-type="COI-statement" id="s7">
<title>Conflict of interest</title>
<p>The author(s) declared that this work was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.</p>
</sec>
<sec sec-type="ai-statement" id="s8">
<title>Generative AI statement</title>
<p>The author(s) declared that generative AI was used in the creation of this manuscript. This was limited to the use of DeepL translator as a help for manuscript translation.</p>
<p>Any alternative text (alt text) provided alongside figures in this article has been generated by Frontiers with the support of artificial intelligence and reasonable efforts have been made to ensure accuracy, including review by the authors wherever possible. If you identify any issues, please contact us.</p>
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<sec sec-type="disclaimer" id="s9">
<title>Publisher&#x2019;s note</title>
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</sec>
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<fn fn-type="custom" custom-type="edited-by">
<p>Edited by: <ext-link ext-link-type="uri" xlink:href="https://loop.frontiersin.org/people/2208132/overview">Gerald Bryan Cleaver</ext-link>, Baylor University, United States</p>
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<fn fn-type="custom" custom-type="reviewed-by">
<p>Reviewed by: <ext-link ext-link-type="uri" xlink:href="https://loop.frontiersin.org/people/3274096/overview">Spyridon Vossos</ext-link>, National and Kapodistrian University of Athens, Greece</p>
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<ext-link ext-link-type="uri" xlink:href="https://loop.frontiersin.org/people/3278348/overview">Hilmi &#xdc;nl&#xfc;</ext-link>, Fatih Sultan Mehmet Waqf University, T&#xfc;rkiye</p>
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