This paper proposes a unified framework linking quantum phenomena, gravity, and computation through a redefinition of matter and particle behaviour based on the Principles of Matter or Laws of Unity. It argues that current physics leaves fundamental questions about the nature of a quantum unresolved, particularly regarding its origin and discrete magnitude. To address this, the paper introduces a model in which matter consists of potential-energy, sharing-energy, and excess-energy, whose interactions generate a unified force interpreted as inertia. In this framework, gravity (inertia-at-rest) arises from sharing-energy, while motion and heat (inertia-in-motion) arise from excess-energy. Building on this reinterpretation, the paper redefines a quantum not as an intrinsically discrete packet, but as a free particle that emerges when sufficient excess-energy overcomes its binding sharing-energy. This challenges the conventional assumption of intrinsic quantisation, suggesting instead that discreteness arises only from the threshold required to free a particle. Consequently, the foundations of quantum mechanics – and by extension quantum computing – require revision. The paper then examines the evolution and limitations of transistor computing, highlighting constraints such as energy consumption, heat dissipation, and scaling limits in integrated circuits. It critiques quantum computing for its reliance on probabilistic superposition and high error rates due to environmental interference, especially under the revised definition of a quantum. As a paradigm shift, the paper introduces “atom computing” that replaces transistors with atoms and uses controlled flows of single electrons or photons to achieve deterministic switching. Two implementations – electronic atom computing and photonic atom computing – are outlined, emphasizing reduced energy use, improved speed, and enhanced scalability. In parallel, analog optical computing is presented as another promising paradigm, leveraging optical processes for efficient, high-speed computation in specialized tasks. Overall, the work advocates a conceptual shift in both physics and computing, proposing that a deeper understanding of matter and energy interactions can lead to new computational architectures that transcend the limitations of current technologies.