historical Caltech archives, Gottlieb [@2] recently discovered five handwritten pages of notes dated on Dec. 13, 1963 in which Richard P. Feynman sketched some ideas on an alternate way to handle electrodynamics. More recently, De Luca et al. [@3] have presented their version of how a part of Feynman’s ideas may be implemented so that they may be used as a supplementary material to usual treatments on electrodynamics. Following Feynman’s ideas to a certain extent, they heuristically obtained the Lorentz force and the homogeneous Maxwell’s equations. Their procedure can be briefly outlined as follows.

-   Following Feynman, De Luca et al. [@3] assume that the force on an electric charge $q$ moving with velocity $v_j$ is of the generic form $F_i=q(E_i+v_jB_{ij})$, where $E_i$ and $B_{ij}$ are functions of space and time to be determined (summation on repeated indices is understood). Next, this 3-force is assumed to be the spatial component of a 4-force. Considering the relativistic transformation of this 4-force, the form of the 3-force is found to be: $\mathbf{F}=q(\mathbf{E}+\mathbf{v}\times \mathbf{B})$ where $\textbf{B}$ represents the independent components of $B_{ij}$ (they make $c\!=\!1$). Through this procedure the relativistic transformations of the vectors $\mathbf{E}$ and $\mathbf{B}$ may be identified with those of 