Einstein never really got on board the quantum mechanics train 🚂 God doesn’t roll dice 🎲 🎲 . But he won the Nobel Prize for his early 1905 paper explaining the Photoelectric Effect, including the idea of quantization of light, a precursor to quantum mechanics 🧰. Ironic, huh?
In 1887, Heinrich Hertz[2][3] discovered that electrodes illuminated with ultraviolet light create electric sparks more easily. In 1900, while studying black-body radiation, the German physicist Max Planck suggested that the energy carried by electromagnetic waves could only be released in "packets" of energy. In 1905, Albert Einstein published a paper advancing the hypothesis that light energy is carried in discrete quantized packets to explain experimental data from the photoelectric effect. This model contributed to the development of quantum mechanics. In 1914, Millikan’s experiment supported Einstein’s model of the photoelectric effect. Einstein was awarded the Nobel Prize in 1921 for "his discovery of the law of the photoelectric effect",[4] and Robert Millikan was awarded the Nobel Prize in 1923 for "his work on the elementary charge of electricity and on the photoelectric effect".[5]