Max Planck

max Karl Ernst Ludwig Planck (April 23rd 1858 - October 4th 1947) is a German Physicien , Nobel Prize of physics in 1918 and prize winner of the price Goethe in 1945.

Biography

Max Planck born on April 23rd, 1858 with Kiel, is resulting from an large family and middle-class woman. Its paternal great-grandfather and grandfathers are professors of Théologie, his father law professor (it took part in the drafting of the German Civil code), while his/her mother is resulting from a family of pastors.

Studies and beginnings

Max Planck makes its secondary studies with Munich where his/her father teaches. He is a good pupil, without more.

He hesitates then between devoting himself to science or the music. In 1874, it starts studies of mathematics and physics at the university. It obtains its baccalaureat at seventeen years and, three years later, it concludes its university course in Berlin with Hermann von Helmholtz and Gustav Kirchhoff as professors.

In 1878, it supports its thesis of doctorate on “the second principle of thermodynamics” and the concept of Entropie in perpetual increase. Its professors are hardly convinced. It passes nevertheless its enabling the following year (1881) on “the states of balance of the isotropic bodies at the various temperatures”, leading to the same results as those obtained before by American Josiah Willard Gibbs, whose work had remained confidential.

Until 1885, it seeks a post of teacher in theoretical physics, discipline little with the mode at the time. It will obtain finally a post of professor associated with Kiel in 1885.

With died of Kirchhoff, and on recommendation of Helmholtz, it is called with the Université of Berlin as assistant professor then titular in 1892. A station which it will keep for approximately forty years.

Research

In Berlin, it continues work in thermodynamics, electromagnetism and statistical physics.

Planck rejects, initially, the model nuclear physicist of gases of Maxwell and Boltzmann. For him, the atomic theory will crumble in the long term in favor of the assumption of the continuous matter. It joins in front of the obviousness with the atomism as from the years 1890.

At this same time Lord Kelvin identifies the Rayonnement of the black body like one of the problems to be solved. Jožef Stefan, Ludwig Boltzmann, Wilhelm Wien attack like Otto Richard Lummer, Ernst Pringsheim, Heinrich Rubens, Ferdinand Kurlbaum, Friedrich Paschen and Lord Rayleigh.

Working to formulate with exactitude the second principle of the Thermodynamic , Planck is interested as of 1894 in the electromagnetic radiation of the black body. It adopts the statistical methods of Boltzmann.

In 1899, it introduces the constant of Planck (H) and Boltzmann (K) at the same time as the notion of the quanta.

In October 1900, it determines the law of spectral distribution of the thermal radiation of the black body, without controlling physical interpretation of it.

It is at the end of 1900 qu' it presents its discovery to the company of physics of Berlin. It is the birth of the quantum theory, with the deepening of which it will take part little, letting Einstein support it firmly. Planck has evil to accept its own assumption, making the matter “discontinuous”. It becomes, thereafter, one of the first supports of Einstein, although this last was very critical with respect to the theories of Planck before recognizing its innovative positions.

It takes part in the first Congrès Solvay in Brussels in November 1911 which joins together the celebrities of the physics of this time. About the same time, he is opposed to the logical Positivisme of Ernst Mach.

He takes his university retirement in 1927 but continues to teach thereafter.

Honors

Since 1894, he is member of the Academy of Prussia from which he is named perpetual secretary of the committee of physics in 1912, impelling a certain dynamics at this institution. It in particular made there admit Einstein.

After having failed twice in 1907 and 1908, it receives for its work the Nobel Prize of physics in 1919 (in fact, it is about the Nobel Prize 1918, not decreed for reason of war, that of 1919 being allotted to Johannes Stark, anti-semite notorious and close to the ideas of the Nazis thereafter).

In 1913, it is named vice-chancellor of the university of Berlin.

In 1927, he is prize winner of the Franklin Médaille for his concept of quantum of energy, then of the Médaille Copley in 1929.

The medal “max Planck” of physics is created, which is jointly allotted to him with Einstein in 1929.

The following year, with died of von Harnack, Planck is named president of the company KWG ( Kaiser Wilhelm Gesellschaft , in the honor of Kaiser Guillaume) which will become after the Second world war the Société max Planck ( Max-Planck-Gesellschaft ), one of the great institutions of German research.

In same time, it writes treaties of theoretical physics, and works on popularizing works considered for their accessibility. It is interested much in pedagogy. He was the reader of two " Nobel Prize " , max von Laue in 1903 and Walther Bothe in 1914, but also of the philosopher Moritz Schlick (1904).

Max Planck dies on October 4th 1947 with Göttingen.

Planck is recognized by the largest scientists, even before his death. Einstein known as of him which it is a man with whom it was given to equip the world with a great creative idea . As for Louis de Broglie, he affirms: the work which it achieved is those which ensure their author an immortal glory and, if some cataclysm does not come to destroy our civilization, physicists of the centuries to come will always speak about the Planck's constant and will not cease repeating with admiration the name of that which revealed with the men the existence of the quanta .

Private life of Planck

He Marie with Marga in 1887 and becomes father as of 1888. They settle then in Grunewald, in the suburbs of Berlin. It will on the whole have four children of which three died at the time of the First World War, his/her oldest son, Karl, in front of Verdun in 1916 and its two binoculars in 1917 and 1919, at the time of continuations of layer. Erwin, its junior, is made prisoner in France. This last remained very near to his/her father during the inter-war period, occupant of the important administrative offices in the mode of Weimar. It is stopped in 1944, shown attempted murder on Hitler. Erwin is carried out in February 1945.

His first wife dies in 1909 and it remarie with Marga von Hoesslon, the cousin of the latter.

Planck always preserved its youth an attraction marked for the music: it composed thus some parts and controls the piano with which it plays sometimes with the violonist Joseph Joachim, or later with Albert Einstein.

Defender of a certain tradition or progressist?

Planck was always respectful of the hierarchy but does not hesitate to defend its convictions against the opinions of the moment. He testified on several occasions to his patriotism and his support for monarchy before and during the First World War.

It defends the academic Léo Arons in 1895 whose only fault is to belong to an opposition party, and this, against the opinion of and the Education minister of religion of the time. In the same way, it supports the access to higher education with the women, of which most famous remainder Lise Meitner.

In 1914, it signs, with eighty thirteen German intellectuals “the Call to the civilized people of the world”, proclaiming its solidarity with the German army. He reiterates patriotic speeches on several occasions but moderates as of 1915 his attitude by refusing the boycott of the British publications recommended by Vienna. He thinks then of the post-war period by evoking the disastrous situation of German science in the event of defeat and fight against all the attempts at isolationism by showing moderation. In the inter-war period, it takes an active part in the rebuilding of the German intellectual life while succeeding in obtaining important State grants or private foundations. Politically, there remains rather preserving, defending the capacity in place and being unfavourable by the vote for all. He refuses however, on several occasions, to be expressed in connection with subjects apart from the scientific sphere. He strongly pleads in favor of the basic research, being opposed in that to Stark whose influence grows with the influence of the Nazis.

The rise of the anti-semitism starts to reach several large scientists of which the most famous Einstein remainder. In 1933, Hitler becomes chancellor of Reich. Planck occupies then of the key post offices in several institutions, of which the institute Kaiser-Wilhem , learned society having some financial capacity. He then thinks of being able to moderate the policy of Führer by a certain degree of pragmatism. He is thus not opposed directly to the capacity in place and preaches discretion even if several of its public interventions are impregnated of moderation. In March 1933, Einstein, travels to the United States, announces from there that it will not turn over to Germany for political reasons. Manifest Planck into private its dissension with this decision, estimating that its effects were likely to be noxious for the Jewish scientists still on the spot. It meets in May 1933 Adolf Hitler to try to defend his colleagues Jews in the interest of Germany, without success. Its later speeches remain in the line chosen, mixing a certain ambiguity in the opposition: it thus makes several praises on relativity without however quoting the author of it. The results are nevertheless positive in the first years: it ruins the nomination of Stark the head of an important institute, manages to obtain funds for research and to preserve Jewish members. Under the pressure, the learned society under the direction of Planck must be however aligned gradually on the capacity, the scientist being obliged to discourse in the honor of Führer and to make Nazi safety. Planck ends up giving up any official function in 1938. It however continues to give conferences on significant topics like " Science and religion" where he acknowledges to believe in a God but not in that of the Christians.

Its house, in Grunewald, is destroyed by an air raid on February 15th 1944 whereas it resided at Rogatz, close to Magdeburg. With more than 80 years, it is obliged to flee the allied bombardments. With the release, it takes refuge with Göttingen with his wife and her niece. At the request of the survivors, it becomes a time the president of the institute Kaiser-Wilhem , transformed into Institut max Planck on November 11th 1946

Discovered

In 1900, max Planck discovers the spectral law of the radiation of a black Corps (published in 1901) while trying to reconcile the Loi of Rayleigh-Jean which functions with large the wavelengths (low frequencies) and the Loi of Wien which functions with the small wavelengths (high frequencies). It finds that its own function corresponded remarkably well to the data for all the wavelengths.

The correction of the law of Rayleigh-Jean is particularly important, because it is built on a strong theoretical basis: thermodynamics such as it was known at the time; but suffers from a major defect to the short wavelengths: the ultraviolet Catastrophe. This point suggests that thermodynamics is false. Planck thus tries to produce a new fundamental theory intended to replace thermodynamics.

The law of Rayleigh-Jean and the law of Planck use the Théorème of equal division and make correspond a Oscillateur to each frequency. Rayleigh supposes that all the oscillators are also excited, its law predicts that the oscillators very short wavelengths are strongly excited even with room temperature.

Planck deduces its law in an empirical way. It justifies it while postulating that the energy emitted or absorptive by the oscillators is not made that by small packages of energy E. These packages would be directly connected to the frequency of the oscillations according to the formula which it exposes the December 14th 1900:

$E = H \ naked ~$

where,

H is the Constante of Planck

ν is the Fréquence electromagnetic Rayonnement.

This assumption makes it possible to limit the energization of the oscillators to the short wavelengths, since it can absorb only one energy at least equal to $h \ nu$ .

Although it is easy maintaining to interpret that in term of quantification of the light in Photon S, Planck does not propose this quantification.

That appears clearly in its article of 1901, in the references which it gives in this article on work that it carried out on the subject, as in its book Theory off Heat Radiation ( Théorie of the radiation of heat ) where it explains why its constant relates to the oscillators.

At the time, this relation is regarded only as one artifice of mathematical calculation . The idea of quantification is developed by others, in particular Einstein which by studying the photoelectric Effet proposes a model and an equation in which the light is not only emitted but also absorptive per packages or photons; the introduction of the corpuscular nature of the light.

See too

Note

In 1914, it was one of the signatories of the Manifeste of the 93.

Constant of quantum Planck
Max-Planck-Institute
Mechanical
satellite Planck of ESA. This satellite will be to be launched to the second half-year 2008, jointly with a second scientific satellite, the Space telescope Herschel by a rocket ARIANE V.
Units of Planck

External bond

Biography of max Planck

Reference

Planck, the quantum revolution , JL Heilbron, geniuses of science, 2006,27, p32-120

Simple: Max Planck

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