In *Einstein's explanation* of the famous formula , there is nothing mentioned about a reason of entering the *speed of light c* in this formula. Modern physics is still unable to elucidate it as well. A new approach, in the framework of *Dynamic Model of Elementary Particles*, apparently, reveals this great mystery. Here is a summary of this approach.

Dynamic Model of Elementary Particles (DM)

Let us imagine an elementary particle as a dynamic spherical microobject of a complicated structure being in a dynamic equilibrium with environment through the wave process of the definite frequency *ω*. Longitudinal oscillations of its wave shell in the radial direction provide an interaction of the particle with other objects and the ambient field of matter-space-time.

(*dr* and *dS* are the thickness and area of an element of volume of the wave shell in a spherical field of ** exchange***: a particle - ambient field of matter-space-time; and are

*powers of exchange*of the field with the element of shell of the particle, is the two-dimensional

*density of exchange*, or the pressure of the field of exchange, is the wave number corresponding to the fundamental frequency

*ω*of the field of exchange at the subatomic level).

The spherical wave shell bounds the space of an elementary particle, separating it from the ambient wave field. It is the

*characteristic sphere*. The characteristic sphere restricts the

*main part of the microparticle*from its

*field part*merging gradually with the ambient field of matter-space-time.

The

*main part*(

*core*) is the

*basis of*a microparticle, whereas the

*field part*represents its

*superstructure*. Thus, the

*basis space*of a microparticle is restricted by the

*characteristic sphere*, beyond which there is the space of its

*superstructure*. Such a dynamic model interprets a microparticle as a particular discrete physical point of an arbitrary level of matter-space-time, restricted by the characteristic sphere and being in rest in the field-space.

The

*inner*geometrical space (spherical volume) of an elementary particle, restricted by its wave spherical shell, is the

*external world*of the particle. As the

*external world*of the Universe, this space (inside the spherical volume) naturally can be called the Anti-Universe. In this sense, the World (Being and Non-Being) is represented here through the Universe and Anti-Universe. Obviously, the spaces of the Universe and Anti-Universe are closed on each other. (Most probably, the main essence of life, its mystery, is hidden in the Anti-Universe).

The very important results have been obtained in the framework of this model. We will enumerate them; but before that, let us remind the readers the sad fact that since then the famous formula

E=m_{0}c^{2}

was obtained in Einstein's manipulation of the fictitious mathematical empty spaces, physics has no answer to the principal question:

**What is the cause of the relationship, which exists between the rest mass of a particle m _{0} and the speed of light c in the formula where motion is out of the question?** Or, in other words,

Why does the speed of light c play the fundamental role for the internal energy of a particle E?

*The Standard Model of Elementary Particles* (SM) is unable to explain it. By this reason, and not only, it is widely recognized, the SM "*will not be the final theory*" and "*any efforts should be undertaken to finds hints for new physics*"**. Experimentalists and theorists all over the world are actively trying to find ways to move beyond the current particle physics paradigm.

The SM was designed within the framework of Quantum Field Theory (QFT), consistent both with Quantum Mechanics and the Special Theory of Relativity. But QFT is not applied to General Relativity and, therefore, the SM cannot unify fundamental interactions with gravity.

There are many promising ideas to replace SM. In the SM, particles are considered to be points. In String Theory, a "*string*" is a single fundamental building block for all particles. There are five different theories of strings (three *superstrings* and two *heterotic strings*). There is also an underlying theory called *M-theory* of which all string theories are only. *M-theory* considers that all the matter in the Universe consists of combinations of tiny membranes, etc. However, many problems of the SM are still open.

One of the promising found "*hints for new physics*"** is the aforementioned Dynamic Model of Elementary Particles (DM).

The advantage of the DM over SM and its correctness are reinforced by the fact that from this model the naturally (and logically) originates the nature of mass and charge of elementary particles and, hence, the nature of energy **E=m _{0}c^{2}**, and other unexplained (or unknown) earlier properties of objects and phenomena of nature.

As follows from the DM:

** Mass** is the

*** of matter-space-time;**

*measure of exchange***is the**

*Electric charge**, or briefly, the*

**rate of exchange of matter-space-time***(of the dimensionality g/s);*

**rate of mass exchange***is the*

**The speed of light****c***.*

**basis speed of exchange of matter-space-time at the subatomic level**

*Energy*E=m_{0}c^{2}

is the energy of wave exchange of matter-space-time on the subatomic level

or

the dynamic energy of the subatomic level.

From the DM it also originates:

** The fundamental law of central exchange** (of the Coulomb kind), which unifies the fundamental interactions, distinguished in contemporary physics: electromagnetic, gravitational, and nuclear;

*, the frequency of the "electrostatic" field, which as we see is non-static;*

**The fundamental (carrying) frequency of exchange of matter-space-time of the subatomic level**, i.e.**, defining the average atomic diameters and, hence, the average distances (lattice parameters) in ordered material structures (crystals);**

*The fundamental wave radius***(where is the absolute unit density, G is the gravitational constant);**

*The fundamental gravitational frequency***;**

*The fundamental gravitational radius of elementary particles***shows the**

*The existence of the gravitational frequency and the gravitational radius of elementary particles***of the Universe in the unit complex of the Infinitely Small and Infinitely Big.**

*indissoluble bond of micro- and mega-objects***Thus, there are potentially enormous benefits in prospect from the further research within the DM.**

* An existence and interactions of the particles are, in essence, a continuous process of the wave ** exchange** of matter-space and motion-rest or, for brevity,

**. The wider notion**

*exchange of matter-space-time***(instead of interaction) is more correct for such a model because it reflects behavior of elementary particles in their dynamic equilibrium with the ambient field, at rest and motion, and interactions with other objects (and particles themselves). In other words, the notion**

*exchange***is more appropriate from the point of view of the physics of the complex behavior of elementary particles, as the dynamic formations, belonging to one of the interrelated levels of the multilevel Universe. This notion was first introduced in the work "Alternative Picture of the World" in 1995.**

*exchange*** A

**from [NuPECC report devoted to "Impact and Applications of Nuclear Science in Europe", 21-23 November, 2001 (France)].**

*quotation*