ABSTRACT
Gustav Robert Kirchhoff suggested for making the measurements the use of a body, which he named the ‘blackbody’, which was able to absorb all the radiation incident upon it. While the Physikalisch-Technische Reichsanstalt was becoming increasingly involved in the preparations for absolute measurements of blackbody radiation, in June 1896, Wien left Berlin to take a professorship at Technische Hochschule of Aachen. The idea of Lord Rayleigh was to extend the statistical method to thermal radiation. The experimental study of the distribution of the frequencies emitted by a blackbody at a given temperature showed that the intensity has a maximum at a wavelength which changes with changing temperature, and becomes shorter and shorter as temperature increases. Friedrich Wilhelm Herschel, who was born in Hanover and later naturalized English, demonstrated early in the 19th century the heating effect of infrared radiation, showing that it may increase the temperature of a body.
