The horizon of events of a Schwarzschild black hole, defined by its Schwarzschild radius, will fluctuate in response to variations in the gravitational constant G. These random fluctuations, denoted as ±δ Rs, will cause corresponding changes in the kinetic energy of the orbiting plasma of ions within the accretion disk surrounding the black hole. As a result, the observed luminosity of the accretion disk near the black hole horizon will also exhibit fluctuations.