The paper does not mention quanta of light (photons) and does not reference Einstein's 1905 paper on the photoelectric effect, but today the result can be interpreted by saying that less than one photon on average was present at a time.
O artigo non menciona os fotóns e non fai referencia o artigo de Einstein de 1905 sobre o efecto fotoeléctrico, pero o resultado aínda pode ser interpretado dicindo que menos de un fotón de media estaba presente no momento.