there are lots of equivalent formulations of maxwell's equations (cf. https://en.wikipedia.org/wiki/Mathematical_descriptions_of_t... for a few); the ∇× ∇· one we most commonly use is quite a bit more compact and usable than maxwell's own formulation because vector calculus was, to a significant degree, invented to systematize maxwell's equations. there's apparently an even more compact form of them in terms of clifford algebras that i don't understand yet, \left(\frac{1}{c} \dfrac{\partial}{\partial t} + \boldsymbol\nabla \right) \mathbf F = \mu_0 c (c \rho - \mathbf J).

similarly there are lots of equivalent formulations of universal computation. lisp and the λ-calculus are analogous to the geometric-algebra formulation above and the more commonly used form in terms of vector field derivatives: they look very different, and they make different problems easy, but ultimately they all model the same thing, just like the various formulations of maxwell's equations

maxwell's equations are the maxwell's equations of classical electrodynamics, not of physics. without a lot of extra assumptions they won't get you very far in understanding why solid things are solid (which depends on the pauli exclusion principle) or why some nuclei break down or how transistors work or how stars can burn or why mercury's orbit precesses or why hot things go from red to orange to yellow when you heat them further

my point about modeling maxwell's equations in lisp (etc.) is that lisp (etc.) can model maxwell's equations (at least, as well as any other effective means of calculation we know of can model them — discretization and rounding error also happen when you numerically integrate with pencil and paper), so if we're looking for incredible accuracy, wide applicability, and concision, lisp (etc.) would seem to trump maxwell's equations — but good luck trying to build a computer without electromagnetism, maybe you can in some sense do it on a neutron star but not with atoms