Magnetic fields are among the most familiar yet conceptually elusive physical phenomena. A permanent magnet has a definite shape and boundary, yet its magnetic field is formless, continuous, and diffuse. Traditional physics treats the magnet as the source of the field, but does not explain the ontological relationship between the two. This paper proposes an interpretive framework compatible with classical electromagnetism from the first principles of Energy-Efficiency Theory (EET): a magnet can be understood as constrained-state energy (ordered alignment of magnetic domains), while the magnetic field can be understood as the free-state unfolding of the same energy in space. Magnetization can be viewed as the conversion of free-state energy into constrained-state energy (energy investment); demagnetization as the release of constrained-state energy into free-state energy (energy dissipation); the hysteresis loop records the irreversible cost of the Energy-Efficiency Cycle; magnetic recording encodes information as energy texture; and geomagnetic navigation can be read as a life strategy for utilizing a free energy gradient at low cost. This paper introduces operational proxies and heuristic test directions, forming a closed loop with companion papers such as Unified Energy-Efficiency Interpretation of Fields, Information Is Not a Substance, and Inertia Does No Work.
Hongpu Yang (Thu,) studied this question.