Max Planck originally produced his Black body radiation law on 19 October 1900 as an improvement upon the Wien approximation, published in 1896 by Wilhelm Wien, which fit the experimental data at short wavelengths (high frequencies) but deviated from it at long wavelengths (low frequencies). Read more
Title: New insights into black bodies Authors: F. J. Ballesteros
Planck's law describes the radiation of black bodies. The study of its properties is of special interest, as black bodies are a good description for the behaviour of many phenomena. In this work a new mathematical study of Planck's law is performed and new properties of this old acquaintance are obtained. As a result, the exact form for the locus in a colour-colour diagrams has been deduced, and an analytical formula to determine with precision the black body temperature of an object from any pair of measurements has been developed. Thus, using two images of the same field obtained with different filters, one can compute a fast estimation of black body temperatures for every pixel in the image, that is, a new image of the black body temperatures for all the objects in the field. Once these temperatures are obtained, the method allows, as a consequence, a quick estimation of their emission in other frequencies, assuming a black body behaviour. These results provide new tools for data analysis.
Title: The Early Universe and Planck's Radiation Law Authors: Rainer Collier
The classical Friedmann-Lemaitre equations are solved using a corrected version of Planck's radiation law. The function curves of the scale parameter a(t) and the variations with temperature a(T) and t(T) are given. It is shown that a reasonable cosmological evolution is only possible in case of flat spatial slices (k=0). The initial singularity is avoided. Horizon and flatness problems do not exist. For low temperatures compared with the Planck Temperature, the equations yield the usual course of expansion of the standard FLRW model for a radiation universe with k=0 and p=u(T)/3.
A well-established physical law describes the transfer of heat between two objects, but some physicists have long predicted that the law should break down when the objects are very close together. Scientists had never been able to confirm, or measure, this breakdown in practice. For the first time, however, MIT researchers have achieved this feat, and determined that the heat transfer can be 1,000 times greater than the law predicts.