How did Max Planck describe the emission and absorption of energy?

Max Planck revolutionized physics by proposing that energy is not continuous, but rather emitted and absorbed in discrete packets called quanta.12

In his 1900 study of blackbody radiation, Planck theorized that the oscillators within a material could not absorb or emit energy continuously. Instead, he posited that these oscillators could only interact with energy in specific, discrete amounts proportional to the frequency of the radiation. This relationship is expressed by the formula:132

$$E=h\nu$$

In this equation, $E$ represents the energy of the quantum, $\nu$ is the frequency of the radiation, and $h$ is a fundamental constant now known as Planck’s constant.345

By assuming that matter could only absorb or emit energy at these specific, equally spaced levels, Planck successfully resolved the "ultraviolet catastrophe" predicted by classical physics, providing the foundation for quantum mechanics.2