Editing Canonical quantization (section)

==History==

When it was first developed, [[quantum physics]] dealt only with the [[quantization (physics)|quantization]] of the [[motion (physics)|motion]] of particles, leaving the [[electromagnetic field]] [[Classical electromagnetism|classical]], hence the name [[quantum mechanics]].<ref name="van der Waerden">{{cite book|last=van der Waerden|first= B.L.|author-link=Bartel Leendert van der Waerden|title=Sources of quantum mechanics|publisher=Dover Publications|location= New York|isbn=0486618811|year=1968}}</ref>

Later the electromagnetic field was also quantized, and even the particles themselves became represented through quantized fields, resulting in the development of [[quantum electrodynamics]] (QED) and [[quantum field theory]] in general.<ref name="Schweber">{{cite book|last=Schweber|first= S.S. |title=QED and the men who made it|url=https://archive.org/details/qedmenwhomadeitd0000schw|url-access=registration|publisher=Princeton University Press|location= Princeton|isbn=0691033277|year=1983}}</ref> 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]].