For 10 points, name this German physicist famous for postulating that the rest energy of a particle equals its rest mass times the speed of light squared.
This scientist is the first namesake of a method where the magnetization of a bar is flipped, causing a change in angular momentum which allows for measurement of the gyromagnetic ratio. This namesake of that method with de Haas also names three parameters which characterize the rates of absorption, spontaneous emission, and stimulated emission in a two-level system. This scientist names a tensor equal to a constant times the stress-energy tensor minus the product of the (*) metric tensor and the cosmological constant by his namesake field equations. He won a Nobel Prize in Physics for his 1905 explanation of the photoelectric effect. For 10 points, name this German physicist famous for postulating that the rest energy of a particle equals its rest mass times the speed of light squared.
This scientist is the first namesake of a method where the magnetization of a bar is flipped, causing a change in angular momentum which allows for measurement of the gyromagnetic ratio.
Albert Einstein