In other words, the space is inverted (Parity or P-symmetry) and the direction of time is reversed (T-symmetry, or time symmetry) because there are symmetrical forces in their actions and directions, as active and retroactive forces. All the complex physical processes are reversed, converted, retroacted and there is R-symmetry (force-relation symmetry), both global and local, the fundamental principle of nature or the physical universe.

What’s Necessary for the Physical Science of the 21 Century

Our research in theoretical physics, mathematics of relationships and formal ontology has been leading to the necessity of formulation of the new integrative concepts of physical science of the 21^>st century: Force-Interaction, or Force-Interrelationship, and its Principle of Reversibility and Convertibility Laws, as being among the most basic principles and fundamental laws in nature. That also reflects the general fact that we live in the dynamic universe of force-interactions defining all ensuing regularities in the order of physical entities and processes, including the symmetries and conservation laws (Abdoullaev A., Reality, Universal Ontology and Knowledge Systems: Toward the Intelligent World, IGI Global, USA, 2008).

The enormous theoretical value and practical utility of Force-Interrelationship, Reversibility and Convertibility as the basic constructs and laws of physics and physical sciences are proved by the reverse force-relationships, reversible actions, of all natural effects and physical processes, of all interacting physical forces and fields.

As a consequence of the Reversibility and Convertibility of all physical forces, phenomena and energy forms, each real physical process must have its inverse counterpart, like as there are magneto-optical processes and there converse, opto-magnetic processes, otherwise their nature, law and description should be properly reviewed.

As another consequence, each real direct physical effect, when properly defined, must have its inverse counterpart, as the Faraday effect relating magnetism and optics has the inverse Faraday effect; otherwise its nature, law and description need a deeper study and should be properly reviewed.

Currently, there may be about 10000 physical effects specified by a multitude of physical materials, systems, or force fields, of which the most part happens to be represented by only one-side effect, see the Supplement 3.

On the intuitive level, the idea of convertibility/reversibility in nature complete with the concept of unity of natural forces were guiding principles in Faraday’s discovery of magnetic and electric effects and Maxwell’s prediction of electromagnetic fields caused by the mutual interactions of magnetic and electric force-fields.

If such is the case, many inverse effects are to be discovered under particular experimental conditions, thus giving new physical laws for new physical devices, technology systems, and machines performing the transformation of physical changes and energy (mechanical, thermal, electrical, magnetic, electromagnetic, nuclear) into each other.

Moreover, regardless their multitude and variety, all the existent and not yet uncovered physical effects are falling into one or another of a few physical processes, a self-consistent system of physical phenomena, distributed network of physical processes, first presented as an encyclopedic knowledge base for physical science in 1989 (А. Ш. Абдуллаев, База знаний энциклопедического искусственного интеллекта: Об исследовательском прототипе энциклопедической системы по физике, Москва, ВИНИТИ, 1989