Electron interference, part deux
In a recent letter entitled “Electron Interference?” (OPN, June 2013), J.H. Eberly correctly and studiously refers to Dirac’s description of interference, which is also known as Dirac’s dictum. In the same letter, he points toward “instructors in engineering-related courses” as propagating an erroneous description of interference, divergent from Dirac’s dictum.
This is a topic that has surfaced time and time again in the literature. In 1998, I participated in a written discussion that was published not in an engineering journal, but in the American Journal of Physics; it defended Dirac’s description of interference. My new book, Quantum Optics for Engineers, which is now in press, treats this topic in detail and reaffirms Dirac’s perspective as well. Incidentally, Dirac himself was an engineer prior to becoming a physicist.
Rochester, N.Y. , U.S.A.
Women in physics
I read with interest your recent President’s Message (OPN, May 2013). The fact that our president is Donna Strickland demonstrates that OSA is flexible and future-oriented. However, to her discussion of underrepresentation of women and other groups, I don’t believe it is helpful to compare the absolute or relative numbers of male, female and minority professors. The number of women within the physical community is very much smaller than that of men. Similarly, the number of African Americans within OSA is substantially fewer than European or Anglo Americans.
A given number of hired women—compared with the total number of women within the physical community—results in a higher percentage than the same number of men, because the total group of men is much larger. One should therefore compare how many applicants of various groups are hired as professors, for example; that would help us to find the right measure for change. Probably the number of hired women compared with the total number of women physicists is not so small. What needs to be changed is the total number of women within the physical community. That means that women must be promoted in school and during study at universities.
Bose and Einstein, the sequel
In a recent letter (OPN, June 2013), Edward Collett states that Einstein did not invite Bose to be a co-author of his paper on what is now known as Bose–Einstein statistics. Actually, Einstein gave full credit to Bose. When he received Bose’s manuscript, he translated it from English into German and then sent it to the editor of the Zeitschrift für Physik along with a letter that included the following remark: “In my opinion, Bose’s derivation of Planck’s formula signifies an important advance. The method used also yields the quantum theory of the ideal gas as I will show elsewhere.” The comment was printed at the end of the paper as well.
Rochester, N.Y., U.S.A.
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