The speed of light is widely acknowledged as a fundamental constant of nature and as being central to the theories of special and general relativity. This research explores the potential for the acceleration or deceleration of the speed of light in a vacuum via a new machine denoted here as the Rotary Magnet Accelerator (RMA). The RMA, designed and created based on the MM Theory, is shown to induce specific effects on the M particles, which are stated to impact the speed and the direction of propagation of light. The primary objective of this study, then, is to present experimental results and novel theoretical perspectives on this interaction, challenging the traditional notions regarding light's behavior.While recent advancements in optics have shown that light's speed can be altered in various media due to their refractive indices, direct manipulation of light’s speed in a vacuum has not been previously experimented on. Previous experiments conducted by the author, demonstrated that the speed of light can indeed be altered utilizing an alternative longitudinal magnet. Despite this, broader empirical evidence and substantiation remains limited. As a result, in this paper, the aim will be to bridge this gap by utilizing the RMA to examine whether dynamic magnetic effects can influence the speed of light in a vacuum.The experimental setup and arrangements involve a system of rotating magnets to create specific effects on the M particles and consequently on light. Results from trials conducted under various experimental conditions are presented, demonstrating that the speed and the direction of light can be altered in a vacuum. As such, it is suggested that there may be a need for reassessing the foundations of special and general relativity based on these outcomes. Additionally, these findings hold significant implications for cosmology and astrophysics that would potentially revolutionize our comprehension of how the universe operates. By aiming to redefine our understanding of light propagation, this study marks a bold stride into unexplored scientific domains with an ambition to refine our knowledge about light behaviors.