This scientist tried unsuccessfully to use Riemannian quaternions to formulate a unified field theory.
The preface to J. D. Jackson's Classical Electrodynamics uses a "double relation" named for this man to place a bound on the mass of the photon. This scientist showed how a suspended iron rod rotates to oppose its own magnetization in an effect named for him and de Haas. This scientist tried unsuccessfully to use Riemannian quaternions to formulate a unified field theory. The relative rates of (*) absorption, spontaneous emission, and stimulated emission are described by this man's A and B coefficients. The energy of a photon equals h times nu according to a formula named for Planck and this man, who published the paper "On the Electrodynamics of Moving Bodies" in September 1905. For 10 points, name this physicist who followed that paper up with one on massÂ­energy equivalence, thus completing his theory of special relativity.
The preface to J. D. Jackson's Classical Electrodynamics uses a "double relation" named for this man to place a bound on the mass of the photon.
Albert  Einstein 