What is a photon?

Physics Teacher

Volumn 34, Issue 8, 1996, Pages 482-486

  Marburger, John H ^a  

^a STONY BROOK UNIVERSITY   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 85006274854     PISSN: 0031921X     EISSN: 19434928     Source Type: Journal    
DOI: 10.1119/1.2344538     Document Type: Article

References (11)

1. Quoted by Abraham Pais in Subtle in the Lord, The Science and the Life of Albert Einstein (Oxford University Press, Oxford, 1982), p. 382.
2. Richard P. Feynman, QED: The Strange Theory of Light and Matter (Princeton University Press, Princeton, NJ, 1985) pp. 14, 15 in 1988 paperback edition.
3. The attitude of Bohr and coworkers toward the photon in this period is described by Pais in Niels Bohr's Times in Physics, Philosophy, and Polity (Oxford University Press, Oxford, 1991), Chap. 11.
4. See Chap. 9 in L. Mandel and E. Wolf, Optical Coherence and Quantum Optics (Cambridge University Press, Cambridge, 1995).
5. To simplify the presentation, I have adopted what Bas C. van Fraassen would call a position of "naive scientific realism" in which "entities postulated in science really exist." Many physicists would agree with this position, at least until they read van Fraassen's The Scientific Image (Oxford University Press, Oxford, 1980), and then they would probably admit that his "constructive empiricism" is also reasonable. Physicists take such positions less seriously than philosophers would wish.
6. For an approach to the philosophy of science relative to this discussion that is congenial to how physicists actually work, see Robert Crease's The Play of Nature (Indiana University Press, Bloomington, 1993).
7. R.P. Feynman, The Character of Physical Law (MIT Press, Cambridge, MA, 1967), Chap. 6. Videos are available from Education Development Center, 55 Chapel Street, Newton, MA 02158.
8. Letter of May 27, 1926, H.S. Lorentz to E. Schödinger, reprinted in Letters on Wave Mechanics, translated by Martin J. Klein, edited by K. Przibram (Vision Press, London, 1967).
9. At low frequencies the electric field can be measured directly. At optical frequencies some subtle effects of the unexcited fields are observable, but not as light. See Ref. 4, Section 10.9.
10. An elementary discussion of this form of quantum mechanics may be found in R.P. Feynman and A.R Hibbs, Quantum Mechanics and Path Integrals (McGraw-Hill, New York, 1965). This book describes the quantization of fields that leads to photons(2′), but it does not use the strong particle language, i.e., photons(2), of QED.
11. Thus in a recent authoritative text: "... the temptation to interpret the electronic signal registered by a photodetector as due to a photon that is localized in some sense is quite strong" (Ref. 4, Section 12.11). Here "photon" means our "photon(2′)." The "electronic signal" is what we take as evidence of a "photon(1)." Section 12.11 reviews the history of unsuccessful attempts to make them the same.