Soumendra Nath Thakur | August 27, 2025
In ECM, c is simply the photon’s own propagation speed that carries the Planck quantum hf. It is not imported from Lorentz transformations, γ-factors, or any relativity-based assumptions.
The ECM kinetic-energy law:
KEᴇᴄᴍ = (½ΔMᴍ⁽ᵈᵉ ᴮʳᵒᵍˡᶦᵉ⁾ + ΔMᴍ⁽ᴾˡᵃⁿᶜᵏ⁾)c² = hf
couples the displaced-mass operator directly to the photon’s speed, not to frame-dependent particle velocities.
Max Planck’s 1899 derivation of the natural units ℓₚ, tₚ and mₚ already fixed the ratio ℓₚ ⁄ tₚ = c without any reference to Lorentz transformations or the 1905 kinematics.
The constant c therefore entered physics as a purely electrodynamic/ thermodynamic scale, not as a relativistic postulate.
In the ECM reinterpretation step (v ↦ c) the symbol c is used only in this pre-relativistic, Planckian sense—i.e. as the speed that converts a quantum of action hf into a mass-equivalent hf ⁄ c².
No Lorentz covariance, time-dilation or length-contraction is invoked. Hence the claim “no reliance on relativity” stands.
For example, in the photoelectric effect, the same ΔMᴍ that liberates an electron also defines the emitted photon’s frequency (hf), with c acting only as the conversion link to mass-energy.
Thus, in ECM, c is a natural constant of propagation — exactly as Planck used it in 1899 — not a borrowed postulate from special relativity stands.
