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Which scientists contributed to the initial development of quantum theory?

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photoelectric effect: Einstein's Nobel Prize-winning discovery — quantum mechanics Brian Greene discusses the key formula in the photoelectric effect, an insight that helped launch the quantum revolution. This video is an episode in his *Daily Equation* series.

The initial development of quantum theory was significantly shaped by the contributions of several key scientists. Max Planck is credited with discovering the quantum of action, now known as Planck's constant, in 1900. This groundbreaking work, which suggested that energy is emitted in discrete packets called quanta, laid the foundation for quantum theory and earned him the Nobel Prize in Physics.12

Albert Einstein extended Planck's hypothesis in 1905 to explain the photoelectric effect, proposing that light itself consists of discrete particles called photons. This concept was crucial in establishing the wave-particle duality of light and matter, a cornerstone of quantum mechanics.345

Niels Bohr further developed quantum theory by proposing a model of the atom where electrons occupy specific orbits, a concept that incorporated quantum principles to explain atomic structure and spectral lines. These contributions collectively revolutionized the understanding of atomic and subatomic processes.651