Planck and Quantum Nature of Light

"A perfect blackbody is one that absorbs and re-emits all radiated energy that is incident upon it." "The disconnect between theory and reality was termed the **ultraviolet catastrophe**." "This theory, which created the branch of physics called quantum mechanics, speculated that the energy radiated by the blackbody could exist only in specific numerical, or **quantum**, states. This theory is described by the equation $E = nhf,$ where *n* is any nonnegative integer (0, 1, 2, 3, …) and *h* is Planck's constant, given by $h = 6.626 \times 10^{-34}\ \text{J·s},$ and *f* is frequency." "Atoms, molecules, and fundamental electron and proton charges are all examples of physical entities that are **quantized**—that is, they appear only in certain discrete values and do not have every conceivable value."