The Origin and Development of the Quantum Theory
By Max Planck
Quantum theory was formulated by German physicist Max Planck while seeking the reason that radiation from a glowing body changes in color from red to orange and blue as its temperature rises. He postulated that energy exists in individual units in the same way that matter does, rather than as a constant electromagnetic wave, that it could therefore be quantified. He constructed a mathematical equation involving a figure to represent these individual units of energy, which he termed quanta, and presented his theory to the German Physical Society in 1900 as a basis for explaining the nature and behavior of matter and energy at the atomic and summertime and some subatomic levels. Also referred to as quantum physics and quantum mechanics, physicists gradually came to understand that the existence of quanta implied a completely new fundamental understanding of the laws of nature. Planck was awarded the Nobel prize in 1918 for his theory. This book is the address given at the awards ceremony in 1921. Quantum theory, together with Einstein’s relativity theory, form the basis for modern physics. Its premises have been repeatedly tested and applied in an increasingly number of areas including optics, chemistry, computing, and cryptography.
