So forces are not only active agencies, but also passive agencies. Inertial forces, opposing any agency and efficiency, are the universal and inherent power of physical entities and systems to resist physical changes, mechanical, thermal, magnetic, or electric. Such resistive forces are opposing changes in the initial state of equilibrium, in motion, in electrical current, in magnetic fields, in electrical fields, in electromagnetic fields, etc. There are then mechanical inertia measured by mass, electrical inertia measured by conductivity and resistance, magnetic inertia by inductance and magnetic resistance, electromagnetic inertia by induction and permeability, etc.
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.