History
Quantum physics first dealt only with the quantization of the motion of particles, leaving the electromagnetic field classical, hence the name quantum mechanics.
Later the electromagnetic field was also quantized, and even the particles themselves were represented through quantized fields, resulting in the development of quantum electrodynamics (QED) and quantum field theory in general. Thus, by convention, the original form of particle quantum mechanics is denoted first quantization, while quantum field theory is formulated in the language of second quantization.
Read more about this topic: Canonical Quantization
Famous quotes containing the word history:
“It’s a very delicate surgical operation—to cut out the heart without killing the patient. The history of our country, however, is a very tough old patient, and we’ll do the best we can.”
—Dudley Nichols, U.S. screenwriter. Jean Renoir. Sorel (Philip Merivale)
“Jesus Christ belonged to the true race of the prophets. He saw with an open eye the mystery of the soul. Drawn by its severe harmony, ravished with its beauty, he lived in it, and had his being there. Alone in all history he estimated the greatness of man.”
—Ralph Waldo Emerson (1803–1882)
“The disadvantage of men not knowing the past is that they do not know the present. History is a hill or high point of vantage, from which alone men see the town in which they live or the age in which they are living.”
—Gilbert Keith Chesterton (1874–1936)