Which German theoretical physicist was the best known for enunciating the 'uncertainty principle'?
Uncertainty principle Uncertainty principle In quantum mechanics, the uncertainty principle (also known as Heisenberg's uncertainty principle) is any of a variety of mathematical inequalities asserting a fundamental limit to the precision with which certain pairs of physical properties of a particle, known as complementary variables, such as position "x" and momentum "p", can be known. Introduced first in 1927, by the German physicist Werner Heisenberg, it states that the more precisely the position of some particle is determined, the less precisely its momentum can be known, and vice versa. The formal inequality relating the standard deviation of position "σ" and the standard
Uncertainty principle , and , are the standard deviations of position and momentum. Heisenberg only proved relation () for the special case of Gaussian states. Throughout the main body of his original 1927 paper, written in German, Heisenberg used the word, "Ungenauigkeit" ("indeterminacy"), to describe the basic theoretical principle. Only in the endnote did he switch to the word, "Unsicherheit" ("uncertainty"). When the English-language version of Heisenberg's textbook, "The Physical Principles of the Quantum Theory", was published in 1930, however, the translation "uncertainty" was used, and it became the more commonly used term in the English language thereafter. The principle is quite