Thus, light and other waves were emitted in discrete packets of energy that he called " quanta". The previous year, though, in 1899, he had noted that the energy of photons could only take on certain discrete values which were always a full integer multiple of a certain constant, which is now known as the “ Planck constant”.
However, although it described the experimentally observed black body spectrum well, he realized that it was not perfect. After some initial frustrations, he derived the first version of his black body radiation law in 1900. the color of the light) and the temperature of the body.
In particular, he investigated how the intensity of the electromagnetic radiation emitted by a black body depends on the frequency of the radiation (e.g. In 1894, Planck turned his attention to the problem of black body radiation, the observation that the greatest amount of energy being radiated from a “ black body” (or any perfect absorber) falls near the middle of the electromagnetic spectrum, rather than in the ultraviolet region as classical theory would suggest. The Planck home in Berlin became a social and cultural center for academics, and many well-known scientists, including Albert Einstein, Otto Hahn and Lise Meitner, were frequent visitors. He had married Marie Merck in 1887, and they went on to have four children, Karl (1888), the twins Emma and Grete (1889) and Erwin (1893), of whom only Erwin was to survive past the First World War. In 1889, Planck moved to the University of Berlin, becoming a full professor in 1892. In April 1885, the University of Kiel appointed him as an associate professor of theoretical physics, and he continued to pursue work on heat theory and on Rudolph Clausius’ ideas about entropy and its application in physical chemistry. Having completed his habilitation thesis on heat theory in 1880, Planck became an unpaid private lecturer in Munich, waiting until he was offered an academic position. There, he came under the tutelage of Hermann Müller, who taught him astronomy and mechanics as well as mathematics, and awoke Planck’s early interest in physics.Īlthough a talented musician (he sang, played the piano, organ and cello, and composed songs and even operas), he chose to study physics at the University of Munich in 1874, soon transferring to theoretical physics, before going on to Berlin for a year of further study in 1877. In 1867, the family moved to Munich, where Planck attended the Ludwig Maximilians gymnasium school.
His family was traditional and intellectual (his father was a law professor and his grandfather and great-grandfather had been theology professors). Karl Ernst Ludwig Marx Planck, better known as Max, was born in Kiel in Holstein, northern Germany on 23 April 1858. This is generally regarded as the first essential stepping stone in the development of quantum theory, which has revolutionized the way we see and understand the sub-atomic world. Around the turn of the century, he realized that light and other electromagnetic waves were emitted in discrete packets of energy that he called " quanta" - "quantum" in the singlular - which could only take on certain discrete values (multiples of a certain constant, which now bears the name the “ Planck constant”). Max Planck was a German theoretical physicist, considered to be the initial founder of quantum theory, and one of the most important physicists of the 20th Century.