Lamb and "The Photoelectric Effect Without Photons" I've recently been pointed by two different people to this paper by Lamb (yes, that Lamb) and Scully: http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19680009569_1968009569.pdf . The title is "The Photoelectric Effect Without Photons." Despite its famous first author, I think the paper is clearly bunk (and therefore it's not surprising it was never published in a refereed journal). Below is my analysis, cut and pasted from a FAQ I maintain at http://www.lightandmatter.com/cgi-bin/meki?physics/faq . I may, of course, be wrong. If you think so, let me know :-) Didn't Lamb and Scully show that you don't need photons to explain the photoelectric effect? No. There is a 1968 paper by Willis Lamb, Jr. and M.O. Scully, "The Photoelectric Effect Without Photons," that seems to have developed a life of its own on the internet. It was never published in a refereed journal. What you can find on the web is a pdf file made from scans of an internal publication of the Center for Theoretical Studies at the University of Miami. It may help to understand something about the historical context. Einstein hypothesized the photon in 1905, but his paper was ahead of its time and was not widely accepted. For decades afterward, even once the quantum-mechanical nature of the *atom* was assumed by all physicists, the quantum-mechanical nature of *light* was considered suspect. Bohr was influential in pushing a theory in which atoms were quantized, but the light they absorbed and emitted was classical. Lamb began his career during this era. If you read the Lamb-Scully paper, the first thing you notice is that they explicitly state that photons are absolutely necessary in order to explain phenomena such as blackbody radiation, Compton scattering, spontaneous emission, and the Lamb shift. Any internet kooks who are trying to quote Lamb as an authority against quantization of light are way off base. As in Bohr's old-fashioned dead-end approach, they then treat the atom as a quantum-mechanical system and the electromagnetic field as a classical one. They are able to reproduce the Einstein relation E=hf-W, where E is the maximum energy of the electron once it leaves the cathode, h is the quantum-mechanical Planck's constant, f is the frequency of the light, and W is the energy required for the electron to escape through the surface of the cathode. This is not particularly surprising or impressive in a bastardized quantum/classical calculation like this one; essentially it just says that the light wave has to have the energy taken out of it at a resonant frequency that matches its own frequency. They also show that the transition rate is nonzero even when the light is first turned on, saying that their transition rate "certainly does not imply the 'time delay' which some people used to expect for the photoelectrons produced by a classical e.m. field." This result is not as impressive as they make it sound, since the classical prediction is what one expects for a classical light wave impinging on *classical* atoms. In fact, the transition rate they derive shows the real problem with their calculation. Their calculation treats every atom as *independent* of all the other atoms. Therefore if a single photon illuminates the cathode, it may ionize more than one atom, violating conservation of energy. This unphysical result shows the opposite of what they claim; it shows that their mixed quantum-classical Frankenstein fails to provide a physically acceptable explanation of the photoelectric effect. What they really need is a quantum-mechanical entanglement between the different parts of the photon's wavefunction, so that if the photon is observed at atom A, it is guaranteed not to be observed at atom B. Without this quantum-mechanical "spooky action at a distance," their theory violates conservation of energy.