In March 1879, Austrian physicist Josef Stefan empirically discovered Stefan's Law, proving that total blackbody radiant power per unit area is directly proportional to the fourth power of absolute temperature (P = sigma T^4).

In October 1879, Johns Hopkins graduate student Edwin Hall discovered the Hall Effect, demonstrating that a perpendicular magnetic field induces a transverse voltage across a current-carrying gold strip.

Proposed Radiant Matter (Plasma) as the fourth state of matter in high vacuum.

In 1880, French physicists Pierre Curie and Jacques Curie discovered Piezoelectricity, demonstrating that applying mechanical pressure to quartz and Rochelle salt crystals generates surface electrical charges.

Estimated fundamental electric charge (e = F / N_A) and introduced the term Electron.

Argued Faraday electrolysis laws require indivisible electric atoms.

Invented amplitude-splitting optical interferometer to test ether drift.

Proved electrolytes spontaneously dissociate into free ions in water.

Proposed generating radio waves using high-frequency LC oscillating spark discharges.

Patented Edison Effect, discovering electron emission across vacuum.

Submitted Uppsala dissertation establishing electrical conductivity of electrolytes.

Derived u(T) = a T^4 combining Maxwell radiation pressure and thermodynamics.