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Max Planck, a German physicist, is best known as the originator of the quantum theory of energy for which he was awarded the Nobel Prize in 1918.
Around the turn of the century, he realized that light and other electromagnetic waves were emitted in discrete packets of energy that he called “quanta” – “quantum” in the singlular – which could only take on certain discrete values (multiples of a certain constant, which now bears the name the “Planck constant”)
His work contributed significantly to the understanding of atomic and subatomic processes.
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