A major part of Einstein’s 1905 light quantum paper is devoted to arguing that high frequency heat radiation bears the characteristic signature of a microscopic energy distribution of independent, spatially localized components. The content of his light quantum proposal was precarious in that it contradicted the great achievement of nineteenth century physics, the wave theory of light and its a...

Parainitraceras pickardcanibridgei sp. nov. and Paramitraceras tzotzil sp. nov. from Chiapas, Mexico are described based on specimens previously determined as Paramitraceras granulatum Pickard-Cambridge, 1905 by Goodnight and Goodnight. The male genitalia of the new species and P. granulatum are illustrated with scanning electronic micrographs (SEMs) or drawings derived from them. The importanc...