Relativistic Particle as Energy Source

Power is the rate at which energy is being used to do work. A negative sign of power indicates that it is an energy source. With this notion it is easy to explain photoelectric effect and nuclear reactions. Also, recent research indicates that speed of light is not a constant. In fact, the speed of light has been decreasing very very slowly over time. As a consequence of this fact, there is a potential ability of a relativistic particle (obeying Einstein's special theory of relativity) to be used as an energy source and this is highlighted in this paper.