In 1921, Albert Einstein was awarded the Nobel Prize in physics for his theoretical theories and his discovery of the law of the “photoelectric effect.” In 1905, Einstein considered that light has a nature of both a wave and a particle. This lead to the development of “photons,” or photo electrons, which gave light a wave-particle duality.
Now it must be noted that Nikola Tesla wasn’t just a theoretical physicist like Einstein, but was an experimental physicist as well. In 1896, Nikola Tesla was the first to propose that radiation had both particle-like and wavelike properties in his experiments with X-rays. In experiments with his newly developed high-vacuum tubes and his high-frequency disruptive coil (Tesla Coil), Tesla shot cathode, and other rays at different metals noting the differences in reflection the streams made upon the metals. Nikola Tesla preceded Einstein by 4 years on the law of the photoelectric effect publishing a patent titled “Apparatus of the Utilization of Radiant Energy.” filed in 1901.
Tesla still recieved no Nobel Prize.
Dr. Nikola Tesla