Firstly, I started working on the Theory of Metarelativity by expanding the Lorentz transformation equations of Einstein’s special relativity and assuming that the velocity of an inertial referential could be greater than the velocity of light. This idea is new in physics. I developed the new theory gradually and I did an extensive amount of reading and research over many years consequently since the year 1986 precisely in order to understand why astronomers have not observed yet particles that are moving with velocities greater than that of light as well as the nature of the mysterious and elusive dark matter and dark energy in the universe. This incited me to continue and to more elaborate the work below. In fact, no theory beholds and explains these observations in modern science since what we know in modern physics is the Albert Einstein’s model that is special relativity and its expansion which is the general theory of relativity. This new theory could be the new model and paradigm to take into account the superluminal particles undetected yet by our telescopes and observatories and to explain accordingly the existence of the obscure dark matter and dark energy.

Moreover, the Theory of Metarelativity takes its name from the original special relativity since the prefix ‘meta’ was added to the word ‘relativity’ and this means ‘what is beyond Einstein’s relativity’. Hence, this work affirms correspondingly the existence of a superluminal meta-matter and meta-energy beyond ‘ordinary’ matter and ‘ordinary’ energy. As a matter of fact, Einstein’s model states that light is the limit velocity that couldn’t be surpassed. The theory of Metarelativity develops more the theory of relativity which was divided by Einstein into two parts:

- The special relativity
- The general relativity

Also, relativity is an outstanding theory written at the beginning of the 20^{th} century. It deals with the velocity of light. The general one deals with gravitation and space-time. The latter is very elegant and is considered as a marvelous work of abstraction. The special one uses the Euclidean geometry and is very simple. The general one uses the non-Euclidean geometry and is very abstract. So, relativity uses both, the Euclidean and the non-Euclidean geometries. In the special relativity, we use the Lorentz transformation to compute the velocity of inertial systems of referential relatively to each other and relatively to light. In the general one, we study gravitation and the effect of matter on the structure of space-time. The latter is an expansion of the first theory in which space-time stops being flat but starts to be curved due to the effect of light, matter and energy. In fact, matter and energy are equivalent according to Einstein in his theory and this is shown by the famous equation put by him:

E = mc^{2}

Albert Einstein showed that light is the limit speed that a moving body could reach. In addition, matter affects the structure of space-time to make it curved and this is due to the interaction between matter and space-time. It is important to mention here that space and time are considered in the Einstein’s model as a unified continuum where all interacting bodies exist and move. What is more interesting is that energy converts into matter and matter into energy when acting in space-time like in stars nuclei and in black holes.

Furthermore, gravitation is shown by Einstein to be a fictitious force and is the consequence of inertia. In fact, the Principle of Inertia states that a moving body continues to move in a straight line if no action was done on the body (free motion). It is one of the fundamental principles in classical physics, and described by Isaac Newton in his first law of motion. Hence, Einstein confirmed and postulated in his general relativity that gravitational mass is equivalent to inertial mass and it is known as the Equivalence Principle. Accordingly, Albert Einstein was accurate in determining the effect of the curvature of space-time due to matter and energy and calculated this curvature near the sun and hence predicted the discrepancy in the position of distant stars and the anomalies in the motion of the planet Mercury which is the nearest planet to the sun in the solar system. Einstein used also his theory to estimate the form of the universe and the galaxies inside it.

Additionally, Einstein noted in his photoelectric theory that photons are the particles of light and that their velocity is accordingly the velocity of light denoted by ‘*c*’ for short. He excelled in his theory when he discovered the photoelectric effect where photons hit electrons like two moving balls or waves and this yields an electric current like in wires due to the action made by the photons on the electrons.

In addition, all the concepts used by Einstein were very easy and very clear except perhaps the identification of gravitation to inertia in accelerating systems of referential which needs considerable abstraction and meditation. What should be noted also is that both theories (the special and the general relativity) are expansions of the model created by Sir Isaac Newton in his mechanics and his theory of gravitation. As a matter of fact, all the three written theories: the mechanics of Isaac Newton in the 17^{th} century, the Einstein’s special relativity and general relativity in the 20^{th} century, were paradigms to represent and to understand the universe. They were in fact complex mathematical and physical theories and systems that try to explain the cosmos in its entirety and which have tremendous philosophical implications.

As well, the Theory of Metarelativity is an attempt to expand this paradigm another time and furthermore by increasing matter velocity to greater than the velocity of light like in outer space and in the whole universe and like artificially in gigantic accelerators which accelerate and smash particles to delve into the structure of modern particles and atomic physics and to study and to test thus their fundamental interactions.

Finally, and to conclude, mathematics is the most positive and the most certain branch of science due to its universality. It is considered worldwide as the ‘Esperanto’, that means the common and universal language, of all sciences. Certainly, the pleasure of doing and working mathematics and physics is everlasting. I hope that the reader will benefit from both and will share the pleasure of examining the present book. In fact, the combination of both mathematics and physics leads to amazing and ‘magical’ results and consequences and models, and the following manuscript is an illustration of this approach.