Ioffe's subject was on the elementary photoelectric effect, the magnetic field of cathode rays and related investigations. In 1917 Theremin wrote that Ioffe talked of electrons, the photoelectric effect and magnetic fields as parts of an objective reality that surrounds us everyday, unlike others that talked more of somewhat abstract formula and symbols. Theremin wrote that he found this explanation revelatory and that it fit a scientific – not abstract – view of the world, different scales of magnitude, and matter.[5] From then on Theremin endeavoured to study the microcosm, in the same way he had studied the macrocosm with his hand-built telescope.[6] Later, Kyrill introduced Theremin to Ioffe as a young experimenter and physicist, and future student of the university.