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:
“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)
“The history of all countries shows that the working class exclusively by its own effort is able to develop only trade-union consciousness.”
—Vladimir Ilyich Lenin (1870–1924)
“History is the present. That’s why every generation writes it anew. But what most people think of as history is its end product, myth.”
—E.L. (Edgar Lawrence)