The Experience Principle and the Propagation Model—A Constructive Reformulation of Electromagnetic Force

This paper presents a constructive reformulation of electromagnetism grounded in the "experience principle," which posits that electromagnetic forces are determined by the physical interaction between charges and propagating fields, rather than by observer-dependent coordinate transformations. The work addresses the foundational puzzle of why the transverse force on a moving charge is reduced by the Lorentz factor, offering an alternative to the conventional relativistic explanation. The proposed propagation model is built on five postulates, leading to a geometric derivation of the effective field propagation speed using a velocity triangle and the law of sines. From this, the force law F = F_s √(1 - β²sin² θ) is obtained, from which the Lorentz factor emerges naturally from geometry. The magnetic field is introduced as a derived quantity, B = (1/c²)(v_\perp × E_s) , and is shown to represent the transverse component of the electric interaction. The model further reveals the relation E_m = c × B, demystifying magnetism as a velocity-dependent effect. Philosophically, the work advocates for interaction-dependent realism, where physical quantities are defined by participant interactions rather than observer perspectives. Force is shown to be invariant, and the electric field is treated as an absolute quantity. This paper is the first in a three-part series; subsequent parts will unify potentials and derive time-dependent Maxwell's equations.