This article examines and discusses concepts within the field of quantum mechanics. Specifically, this paper focuses on the idea of wave-particle duality within this field, by further examining the nature of light. The basic premise is rooted in MM theory, previously introduced and expanded upon in literature. Per MM theory, light is viewed as a wave of motion of momenta conveyed by an ensemble of M particles propagating harmonically in space. Through a deep analysis of the double-slit experiment, this paper aims to illustrate the manner by which MM theory provides a complete and thorough understanding of the nature of light and the basic fundamentals of quantum physics.The discussion centres on highlighting how the MM theory offers a comprehensive interpretation of various observations such as interreference patterns and illuminates the underlying mechanisms at play. By viewing light as a wave of momenta, seemingly contradictory observations are logically addressed and reconciled. The theory further demonstrates how the detection process can disrupt the wave pattern and leads to the collapse of the interference patterns observed. Furthermore, this article challenges the fundamental aspects of quantum mechanics, such as indeterminism and the role of measurement. Via MM theory’s examination of quantum measurements, the concepts of observer dependency and hidden variables are challenged. This ultimately suggests that quantum phenomena are inherently deterministic and can be predefined using known variables. In conclusion, this paper challenges the fundamental framework of quantum mechanics, offering deeper insights into the nature of light and the wave-particle duality via the deterministic approach derived from the MM theory and paves the way for further experimentation and study in this field.