Rest Energy vs. Kinetic Energy in Extended Classical Mechanics (ECM): Beyond Classical and Relativistic Views.

Soumendra Nath Thakur                                                DOI
June, 01, 2025

The reinterpretation of the relativistic energy equation E = mc² within the Extended Classical Mechanics (ECM) framework offers deeper insight into the role of mass displacement during energy transitions. In ECM, the relativistic mass m is redefined as the displaced mass component, denoted ΔMᴍ. This effective mass Mᵉᶠᶠ includes not only the transition of ΔMᴍ from the original matter mass Mᴍ (i.e., a loss of −ΔMᴍ), but also encapsulates the interactional and energetic transformations that occur in high-energy phenomena such as nuclear reactions.

In standard relativistic physics, the rest mass m in E = mc² is often interpreted as being wholly converted into energy. However, in actual nuclear reactions, this is not entirely the case. The by-products of such reactions—alpha particles, beta particles, and residual nuclei—all retain a portion of the original rest mass. Hence, not all of the rest mass is converted into pure rest energy. Instead, a portion remains as bound rest mass ΔMᴍ, while the remainder is distributed into kinetic energy and radiative emission, particularly in the form of electromagnetic radiation.

Importantly, this emission includes particles traditionally considered massless—such as gamma rays and photons—which, in ECM, are interpreted as carrying apparent negative mass −ΔMᴍ, originating from internal energetic displacement rather than conventional rest mass.

Thus, in nuclear splitting:

Mᴍ_ɴᴜᴄᴇᴜꜱ = ΔMᴍ_ʀᴇꜱɪᴅᴜᴀʟ ɴᴜᴄᴇᴜꜱ + Mᴍ_ₐ,ᵦ + (−ΔMᴍ_ᵧ) + (−ΔMᴍ_ₚₕₒₜₒₙₛ)

This formulation reflects that both massive and massless reaction products arise from mass-energy redistribution, not from total annihilation or full rest-mass conversion. It also highlights that radiative products such as photons and gamma rays embody displaced energy with measurable effects, despite lacking rest mass in conventional terms.

In Classical Mechanics, energy is typically classified as either potential or kinetic. However, relativistic rest energy represents a more intricate form of transition—a fusion of potential-like binding effects and kinetic-like emissions—mediated through mass redistribution, emission of particles, and radiative losses. ECM captures this nuance by modelling rest energy release as a combination of physical mass displacement and interactional field effects, providing a coherent explanation for the emergence of both massive and massless products in high-energy processes.