Mechanics / Electrodynamics
Lenard, Planck, hν, Photoelectric effect, corpuscular theory of light, Compton phenomenon, Kantor, theory of elastic collisions
Semikov_About Classic Ideas[trans]_29Aug(2012)1-2.pdf
There are two theories to explain the photoelectric effect: P. Lenard's first theory (resonance theory) sees the cause of the effect in the mechanism of the atom, Einstein's second theory sees the reason in the special properties of light. According to the first theory, light, as O.D. Khvolson put it, plays the role of a release mechanism: each electron oscillates with its characteristic period, thanks to its inherent intra-atomic energy; when there is a resonance between its oscillation and the oscillation of light, the electron is ejected.