<human>:  Where does the Planck constant come from?
<bot>: The Planck constant comes from the equation E = h<unk>. The Planck constant is a physical constant that relates the energy of a quantum particle to its frequency. The Planck constant is a fundamental constant of nature that was discovered by Max Planck. The Planck constant is so named because it was discovered by Planck, who also invented the quantum theory of radiation.