Einstein's famous equation, E=mc², relates energy (E) and mass (m) through the square of the speed of light (c). This equation shows that energy and mass are interchangeable and that a given amount of mass can be converted into an equivalent amount of energy, and vice versa.
However, this equation does not imply that all energy runs to decline. The conservation of energy is a fundamental principle in physics, which states that energy is neither created nor destroyed but can be transformed from one form to another. Energy can be transferred, converted, and utilized, but its total amount remains constant within a closed system.
In the context of Einstein's equation, when mass is converted into energy, such as in nuclear reactions or particle annihilation, the total energy in the system is conserved. Similarly, when energy is converted into mass, as in certain particle creation processes, the total energy is still conserved.
The notion of energy running to decline seems to imply a universal loss or degradation of energy, which is not supported by our understanding of physics. While energy can be dissipated or transferred in various ways, the total energy within a closed system remains constant.
It's important to note that there are cosmological theories that discuss the concept of the ultimate fate of the universe and the potential decline of usable energy in the distant future, such as the heat death of the universe. These ideas are based on current models and speculations about the behavior of the universe on very long timescales. However, they are still theoretical and subject to ongoing scientific investigation and refinement.