The word quanta (singular quantum, Latin for how much) was used before 1900 to mean particles or amounts of different quantities, including electricity. In 1900, the German physicist Max Planck was studying black-body radiation, … See more

Photons obey the laws of quantum mechanics, and so their behavior has both wave-like and particle-like aspects. When a photon is detected by a measuring instrument, it is … See more

In 1916, Albert Einstein showed that Planck's radiation law could be derived from a semi-classical, statistical treatment of photons and … See more

The photon has no electric charge, is generally considered to have zero rest mass and is a stable particle. The experimental upper … See more

In most theories up to the eighteenth century, light was pictured as being made of particles. Since particle models cannot easily account for the See more

In 1924, Satyendra Nath Bose derived Planck's law of black-body radiation without using any electromagnetism, but rather by using a modification of coarse-grained counting of phase space. Einstein showed that this modification is equivalent to assuming that … See more

Quantization of the electromagnetic field
In 1910, Peter Debye derived Planck's law of black-body radiation from a relatively simple assumption. … See more