in Introduction to Lasers, [F. J. Duarte, Tunable Laser Optics, Elsevier Academic, 2003, 0-12-222696-8, 3]
“Neither Dirac nor von Neumann discussed his measurements in physical terms.”
W. E. Lamb, Classical measurements on a quantum mechanical system, Nuclear Phys. B 6, 197-201 (1989).
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Willis Lamb 5
American Physicist 1913–2008Related quotes
W. E. Lamb, Sequential measurements in quantum mechanics, in Quantum Measurements and Chaos, E. R. Pike and S. Sarkar, eds. (Plenum, New York, 1987) pp. 183-193.
Scientific American (1971), volume 225, page 180.
Explaining why he named his uncertainty function "entropy".
“The welfare of a child is not to be measured by money only, nor by physical comfort only.”
In re McGrath (Infants), L. R. 1 C. D. (1893), p. 148.
Source: The Emperor's New Mind (1989), Ch. 6, Quantum Magic and Quantum Mastery, p. 269.
Context: It seems to me that we must make a distinction between what is "objective" and what is "measurable" in discussing the question of physical reality, according to quantum mechanics. The state-vector of a system is, indeed, not measurable, in the sense that one cannot ascertain, by experiments performed on the system, precisely (up to proportionality) what the state is; but the state-vector does seem to be (again up to proportionality) a completely objective property of the system, being completely characterized by the results it must give to experiments that one might perform.
R. H. Dalitz, Another side to Paul Dirac, in Paul Adrien Maurice Dirac (Cambridge University, Cambridge, 1987) Chapter 10.
With that, the conversation was over.
"A meeting with Enrico Fermi" in Nature 427 (22 January 2004), p. 297 (subscription required) http://dx.doi.org/10.1038/427297a