Heinrich Rudolf Hertz

During his work on electromagnetism, Heinrich reported another important phenomenon known as the Photoelectric effect. He noticed that UV rays made the metal lose charges faster than otherwise, which led him to publish his findings in the journal Annalen der Physik. He did not investigate this effect further on. Later, in 1905, Albert Einstein proposed that light came in discrete packets of energy known as the photons. This discovery led to the development of Quantum mechanics.