Editing Uncertainty principle (section)

=== Terminology and translation ===
Throughout the main body of his original 1927 paper, written in German, Heisenberg used the word "Ungenauigkeit",<ref name=":0" />
to describe the basic theoretical principle. Only in the endnote did he switch to the word "Unsicherheit". Later on, he always used "Unbestimmtheit". When the English-language version of Heisenberg's textbook, ''The Physical Principles of the Quantum Theory'', was published in 1930, however, only the English word "uncertainty" was used, and it became the term in the English language.<ref>{{Citation |first1=David |last1=Cassidy |year=2009 |title=Beyond Uncertainty: Heisenberg, Quantum Physics, and the Bomb |location= New York |publisher=Bellevue Literary Press |page=185 |bibcode=2010PhT....63a..49C |bibcode-access=free |last2=Saperstein |first2=Alvin M. |volume=63 |issue=1 |journal=Physics Today |doi=10.1063/1.3293416 |doi-access=free }}</ref>