Electric Charge
Electric charge is the property of matter that gives rise to electric and magnetic forces. In standard physics it is treated as an irreducible primitive: something particles have, described by a number with a sign, and not explained in terms of anything more basic.
The standard account
Charge comes in two signs, like signs repelling and unlike attracting, with the force between two static point charges given by Coulomb's law. It is conserved — the net charge of an isolated system never changes — and this conservation is not an empirical accident but a consequence, by Noether's theorem, of the U(1) gauge symmetry of electrodynamics. It is also quantized: all free particles carry integer multiples of the elementary charge e, which since the 2019 revision of the SI has the exact defined value 1.602176634 × 10−19 C. Millikan's oil-drop measurements of 1909–1913 established the quantization experimentally and gave the first good value.
Quarks are assigned charges of ±1/3 and ±2/3 of e, but no isolated quark has ever been observed; confinement means that the only free objects are combinations with integer charge. Searches for free fractional charges in bulk matter — in seawater, meteorites, niobium spheres and silicone oil drops — have been uniformly null, and set stringent upper limits on their abundance. The exactness of the electron–proton charge cancellation is separately tested by the observed electrical neutrality of bulk matter, which constrains any difference to fewer than one part in 1021.
What the standard account does not supply is any answer to why charge is quantized, why the quantum has the value it does, or what charge is. Dirac showed in 1931 that the existence of a single magnetic monopole anywhere in the universe would force charge quantization; no monopole has been found. Grand unified theories give quantization as a group-theoretic consequence; none has been confirmed. This is a genuinely open question in mainstream physics and should not be presented as settled.
On this wiki
It is precisely that gap that most of the work here aims at. A striking number of the models catalogued on this wiki refuse to take charge as primitive and derive it instead from structure, motion or a medium.
Charge from geometry and rotation. The Toroidal Ring tradition — Parson's magneton of 1915, revived by David L Bergman and Charles William Lucas in Common Sense Science — makes the electron a real ring of circulating charge, so that spin, magnetic moment and finite self-energy follow from the geometry. See Bergman's "Spinning Charged Ring Model of Elementary Particles" and the exchange in "Charged Ring Model of Elementary Particles: A Controversy" with Arnold G Gulko. Related ring and vortex constructions include Robert L Carroll's "The Toroidal Electron", Jaroslav G Klyushin's "On a Toroidal Model of the Neutron" and Valery Chalidze's "Mass and Electric Charge in the Vortex Theory of Matter". These models locate charge in the arrangement of something, not in a scalar label.
Charge from dipoles and dialectical structure. Peter Kohut builds matter from elementary "quantum dipoles" whose two poles are the origin of the two signs, so that bipolarity is structural rather than assumed — see "The Bipolar Structure of Particles and Interactions".
Charge from a medium. Rati Ram Sharma's unified theory derives interactions from a "sharmon" medium and predicts that no fermion can be strictly neutral; see "Unified Theory Composition-Structure of Electron, Proton & Neutron". John P Fernandez works from an aether in "Mechanisms of the Aether and Atomic Charges", and Osvaldo Domann's ""Emission & Regeneration" Unified Field Theory" builds particles from continuously emitted and reabsorbed sub-particles, with charge emerging as a property of that flux rather than of the particle.
Charge dissolved altogether. Ivor Catt takes the most radical line here, arguing in "The End of Electric Charge and Electric Current as We Know Them, Part 1" and "The End of Electric Charge and Electric Current as We Know Them, Part 2" that charge and current are redundant concepts and that transmission-line energy flow is the primitive. Harold Aspden connects charge to inertia in "Inertia as the Conservative Property of Electric Charge...", and Roland H Dishington ("Energy and Charge") and Arnold G Gulko ("An Analysis of Energy and Charge") pursue the relation between charge and energy — a discussion that connects to this wiki's argument about the reification of energy.
Charge and relativity. Sankar Hajra's "Electric charge, Light, Gravitation and Old Physics" and Vyacheslav N Streltsov's "How do Neutral Photons Carry the Sign & Value of Charge?" bear on whether charge is invariant under motion, which the standard theory asserts and this collection repeatedly questions.
What none of these models has yet done is predict the numerical value of e from independent principles. That would be the decisive test, and it is fair to hold them to it — as it is fair to note that the standard model does not predict it either.