Who introduced the quantum hypothesis for blackbody radiation in 1900?

Max Planck introduced the quantum hypothesis for blackbody radiation in 1900.

Planck proposed that oscillators exchanging energy with electromagnetic radiation could do so only in discrete amounts proportional to frequency. His formula successfully described the observed spectrum of thermal radiation and introduced the constant later named the Planck constant.

Planck initially treated quantization as a mathematical device rather than a complete description of nature. Albert Einstein later gave the idea a more physical interpretation by proposing that light itself could behave as packets of energy, now called photons.

The quantum hypothesis helped resolve the ultraviolet catastrophe, a failure of classical physics that predicted unlimited radiation at high frequencies. Planck’s work is therefore commonly regarded as the starting point of quantum theory, although the modern framework developed through later contributions from Einstein, Bohr, Heisenberg, Schrödinger, and others.