Who discovered Quantum Theory?

Niels Bohr and Max Planck, two of the founding fathers of Quantum Theory, each received a Nobel Prize in Physics for their work on quanta. Einstein is considered the third founder of Quantum Theory because he described light as quanta in his theory of the Photoelectric Effect, for which he won the 1921 Nobel Prize.

Its origins can be traced back to 1900, when physicist Max Planck put forward his controversial quantum theory to the German Physical Society

By combining equations derived by Wien and Rayleigh, in October 1900 Planck announced a result now known as Planck's radiation formula. Within two months, he explained why his formula worked – and it was a bold explanation. He renounced previous physics and introduced the concept of 'quanta' of energy.