Singleness of surface and volume: Space–time non-symmetry of energy density

• STNS means physical processes in (+) direction are not the same as in (−) direction.
• Non-homogeneity and SVI are two aspects of the same effect.
• Inconsistency of body-field energy and surface-traction force can be erased by SVI.
• STNS corresponds to dissipated (past) and available (future) energy density.

Space–time non-symmetry means that physical processes in the (+) direction are not the same as those in the (−) direction. Non-homogeneity and surface–volume interaction (SVI) are two aspects of the same effect that attributes to directional dependency. While the Einstein tensor and stress-energy tensor (SET) of space–time curvature are reminiscence of SVI, non-homogeneity were forsaken such that stress-energy became non-tensorial. The inconsistency definition of body-field energy and surface-traction force can be erased by considering SVI. No less emphasizes can be placed on the interchange of energy, mass and matter. Energy and mass trade-off can occur as a quotient via square of the “velocity” and product via square of the “momentum”.SVI was also recognized in the ‘80s as the missing link to explain crack growth in fatigue and non-equilibrium and non-homogeneous (NENH) problems in mechanics. Space–time non-symmetry (STNS) corresponds, respectively, to dissipated (past) and available (future) energy density. Paradigm-breaking called for higher order mathematical solutions to lock non-homogeneity and non-symmetricity into the experimental data that would otherwise be interpreted with oversimplified assumptions. The trade-offs of energy, mass, matter are made possible for a wide range of the speed of space, larger and smaller than the speed of light. The speed of light is no longer the pillar of particle physics. Corrections to ordinary data can thus be made without knowing the composition of the atomic structures, which may not explain nature in its entity.In the language of fracture mechanics, any available fatigue crack growth data can be corrected to include NENH and STNS for different scale ranges. The “energy density” fits into the space–time non-symmetry (STNS) scheme of non-zero volume/area. Physicists and engineers are no longer next door neighbors, but they live under the same roof. In a nut shell, science has identified the cause of space non-symmetry (SNS) and time non-symmetry (TNS), while technology has recognized the effect of NENH.