Max Planck short biography. Nobel laureates: Max Planck. The most constant of physicists Quantum physics max planck
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"Space detectives" - a new book by the writer, Doctor of Physical and Mathematical Sciences Nikolai Nikolayevich Gorkavy. Its characters are familiar to readers from the sci-fi trilogy The Astrovitan and science tales published in the magazine in 2010–2014. and in Nos. 1, 4, 5, 6, 2015
Once, a neat young man entered the office of Philipp von Jolly, a professor at the University of Munich, timidly knocking, and Princess Dzintara began to tell another evening fairy tale to her children.
I recently entered your university,” he said, “and I want to study theoretical physics.
Theoretical physics? - the professor was surprised. - I do not advise. In this science, all the discoveries have already been made, it remains to clean up a couple of holes.
The professor is understandable. It was 1874. By this time, theoretical physics had practically reached perfection, firmly based on Newton's mechanics, thermodynamics, and also on Maxwell's electrodynamics.
The young man answered modestly:
I am not going to make discoveries, I would just like to understand what has already been achieved in the field of theory.
Well, I will not dissuade you, you can attend my lectures. What is your name?
Max Plank.
A young man named Max Karl Ernst Ludwig Planck was from an old noble family who provided Germany with military men, lawyers and scientists. He was born in the city of Kiel in the family of civil law professor Johann Julius Wilhelm von Planck and Emma Planck. As a child, he studied piano and organ and made great strides. In 1867 the family moved to Munich, where Max entered the Royal Maximilian Gymnasium. There the young man became interested in the exact and natural sciences. From 1874, Planck studied physics and mathematics for three years at the University of Munich and for another year at Berlin.
After graduation, he did not have a permanent job, but he diligently studied theoretical physics, studied the articles of Hermann Helmholtz, Gustav Kirchhoff and other prominent physicists. He was fascinated by thermodynamics for a long time (this area of physics studies the phenomena of heat and the transformation of various types of energy into each other). In 1879, Planck defended his dissertation at the University of Munich on the second law of thermodynamics. After that, the young talented physicist began to quickly move up the career ladder and by the age of 34 he became a professor of theoretical physics at the University of Berlin and director of the Institute for Theoretical Physics.
One day, a well-known electrical company turned to Professor Planck with a proposal to conduct research and find out how to achieve the maximum luminosity of a light bulb with minimal energy consumption? Planck responded and began work that opened a new era in science.
What is the merit of Planck? It has long been known that the intensity of its glow, as well as the color of the radiation, depends on the temperature of a body (for example, a hot wire in an electric lamp).
Right! cried Galatea. - The candle burns yellow, and the flame of electric welding is blue!
For the mass production of electric lamps, it is important to know exactly under what conditions their light will be as bright as possible. Professor Planck set himself the task of determining the spectrum of the glow of hot bodies and finding out how this spectrum depends on temperature. By this time, two laws were derived that determine the glow of bodies as a function of wavelength. One of them - Wien's law - described well the brightness of the glow in the short-wave region, but did not correspond to the experimental data in the long-wavelength part of the spectrum. The other - the Rayleigh-Jeans law - on the contrary, perfectly coincided with the experiment for long waves, but in the region of short waves it hopelessly lied: according to it, the main radiation energy is contained in the shortest waves.
Getting down to business, Planck decided to derive a formula that would fit well with the observed dependence of the glow on the wavelength, without worrying about its theoretical justification. As a theoretical physicist, he took the path of obtaining an empirical formula, because the glow of lamps was a practically important issue and manufacturers needed a working formula, but they did not think about theories.
Planck succeeded in deriving a mathematical law that gave correct data for radiation in both long and short waves, which coincided with experiment. It remains to be seen whether this formula is just a mathematical trick with no deep justification, or it can be obtained on the basis of existing scientific principles.
In search of a scientific justification for the proposed law, Planck relied on the work of the Austrian physicist Ludwig Boltzmann, who, deeper than his contemporaries, understood the statistical nature of thermodynamic relationships and founded statistical mechanics. After much effort, Planck found out that his formula did not proceed from known principles. But it is perfectly derived if we assume that an elementary oscillator (a charge that oscillates) can emit waves only in portions proportional to the frequency of the wave. Planck wrote the energy of such a portion in the form
where h- a constant, which later became known in his honor as the Planck constant; ν - wave frequency.
It was a very strange expression that did not follow from the usual laws of physics.
What is his weirdness? - Andrey asked.
I'll try to explain. Hertz discovered that a circuit in which a stream of electrons moves back and forth emits radio waves. If we simplify the Hertz circuit to the limit, then we get an elementary oscillator - just an electric charge oscillating under the influence of some external force. A good example of such an oscillator is an electrically charged and swinging clock pendulum. Swinging or oscillating charged bodies or particles always emit electromagnetic waves. Maxwell's theory did not impose any restrictions on such radiation, and the condition that Planck was forced to base his formula on was that the oscillator cannot emit waves as it pleases: it must release energy only in separate portions (quanta). Whatever oscillators were considered, this condition did not change, they emitted energy as if by order in this way and not otherwise.
Planck published his theory in 1900, but neither he nor other scientists were in a hurry to admit the existence of the theory put forward by him. quantum theory. It was only through the efforts of Einstein and other physicists that the theory of light quanta began to gradually win its place in physical science.
Everything changed dramatically in 1913, when a young Dane named Niels Bohr came to the English city of Manchester to work in the laboratory of the outstanding British physicist Ernest Rutherford. Bohr proved that quanta are the foundation of the structure of matter, and thereby discovered new page in the history of science. And Max Planck discovered something that completely changed the building of world theoretical physics, which was so beautiful and seemed almost complete.
In 1918, Planck received the Nobel Prize for his work. Dozens of scientific institutions in Germany, which were engaged in fundamental science, united in the Max Planck Society. The country's highest award for achievements in the field of theoretical physics was the Max Planck medal. Well, the most impressive evidence of Planck's contribution to world science was that among the five world fundamental constants: the speed of light, the charge and mass of the electron, the gravitational constant and Planck's constant, only one bears the name of its discoverer.
Mom, - Galatea asked carefully, - is there any other unknown world constant?
Dzintara smiled:
I think it has. But the discoverer is the first to know about the existence of such a constant.
Empirical formulas are not derived from any theory. They are selected or constructed from mathematical functions in such a way as to best describe the experimental data.
Prominent German physicist Max Planck made a huge contribution to the development of quantum theory, thereby predetermining the main direction in the development of physics of the 20th century.
With early years Planck was brought up in an intellectually developed, educated and well-read family: great-grandfather Gottlieb Planck and grandfather Heinrich Planck were professors of theology, his father was a professor of law.
The decision to devote his life to physics was not easy for the future scientist: in addition to the natural disciplines, Planck was attracted by music and philosophy. The study of physics took place in Berlin and Munich. After defending his dissertation, the scientist taught in Kiel and Berlin.
Planck's research was mainly devoted to questions of thermodynamics. The scientist became famous after explaining the spectrum of the "absolutely black body", which became the basis for the development of quantum physics. A black body is an object whose radiation depends only on temperature and apparent surface area. Planck, in contrast to the theories of Newton and Leibniz, introduced the concept of the quantum nature of radiation: radiation is emitted and absorbed by quanta with an energy of each quantum equal to E \u003d h ∙ v,where h is Planck's constant. The result of this innovation was to obtain the correct formula for the spectral density of the radiation of a black body heated to a temperature T. Planck's constant also adorned the tombstone of its creator.
Using relativistic methods, Planck made a key discovery - he introduced the concept of the momentum of a photon. Later, this discovery of Planck was extended by de Broglie to all particles and became a fundamental element of quantum physics.
For his contribution to the development of quantum physics, Planck received the Nobel Prize in 1918.
The scientist made a significant contribution to the consideration of classical mechanics as the limiting case of quantum mechanics. Participating in the Solvay congresses, Planck shared his experienced opinion on the problems of modern physics.
Among other achievements of Planck, one cannot fail to note the derivation of the Fokker-Planck equation proposed by him, which describes the behavior of a system of particles under the action of small random impulses.
The fascist regime in Germany became a difficult test for the scientist. On the one hand, Planck accepted all the scientific and cultural achievements of a great country and did not stop working for the benefit of domestic science, on the other hand, the scientist could not come to terms with the policy of extermination pursued by the Reich, and repeatedly tried to convince Hitler of the impossibility of a holocaust. Fascism brought Planck and many personal tragedies: in 1944, the son of a scientist, Erwin, was executed for participating in a conspiracy against Hitler.
Planck was greatly influenced by Einstein's theory of relativity. The scientist fully supported Einstein's concept, which contributed to the acceptance of this theory by physicists. 
Planck could be proud of his students, who confidently continued the work of their mentor and made their own discoveries. One of the famous students of the physicist was Moritz Schlick. Schlick's story is interesting because of its balancing on the border of two completely unrelated sciences - physics and philosophy. Schlick's dissertation was defended in physics, and he devoted his entire life to philosophy, forming the ideological center of neopositivism. Schlick was shot at university by his psychopathic student.
Planck's name lives on in many objects and phenomena to this day: in addition to the Planck variable, there are also the Planck formula and the Max Planck Society. One of the craters on the Moon, as well as a satellite of the space agency, bears the name of a scientist.
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Why Max Planck, choosing between physics and music, preferred science, what do his studies and films about kung fu have in common, why did he quarrel with Einstein and how did he suffer from the First and Second World Wars, tells the column "How to get a Nobel Prize".
Nobel Prize in Physics 1918. The wording of the Nobel Committee: "In recognition of his merits in the development of physics through the discovery of energy quanta."
When you write biographies of Nobel laureates in chronological order, one has to wonder how different amounts of information are available about great scientists. In one case, one has to “dig into” journal articles, trying to understand texts in languages other than English and Russian, while in the other, on the contrary, there are so many important facts that one has to arrange a strict competition for them.
The case of the 1918 Nobel laureate in physics clearly falls into the second category. Max Planck has been nominated for the prize every year since 1910 and received the award relatively quickly, despite the fact that much of the physics community, including many of the original prize winners, was far from ready to acknowledge the advance. new physics. Even under the weight of accumulated facts.
Max Planck is a man whose name has now become a household name for German science (remember the Max Planck Society, an analogue of our Academy of Sciences). He was practically deified by German science during his lifetime (the Max Planck medal - the first was received by Planck himself and Einstein - and the Max Planck Institute of Physics appeared during the scientist's lifetime). Our hero was a "man of origin." His father, Wilhelm Planck, represented the ancient noble family, many of whose members were famous figures of science and culture. For example, Max's grandfather Heinrich Ludwig, like his great-grandfather Gottlieb Jakob, taught theology in Göttingen. Mom, Emma Patzig, came from a church family.
Entrance to the building of the Max Planck Society (Munich)
Wikimedia Commons
He was born on April 23, 1858 in Kiel, the capital of Holstein (it was from here that the emperor Peter III, husband of Catherine II). Germany and Denmark constantly argued for Kiel, even fought for it. The Planck family spent the first nine years of the life of the future great scientist in this city, and Max remembered for the rest of his life the entry of Prussian and Austrian troops into the city in 1864. In general, the wars constantly hit next to Planck - at the closest. In World War I, in 1916, his eldest son Karl died near Verdun, in January 1945 the Nazis hanged his second son Erwin (he was suspected of being involved in the conspiracy of Colonel Stauffenberg). Allied bombings almost killed him during a lecture, filling him up for several hours in a bomb shelter, at the end of the war they ruined his estate, his huge library disappeared somewhere ...
But for now, the year is 1867, and the father of the young Planck receives an invitation from Munich. The position of professor of law at the famous University of Munich turned out to be very tempting, and the family moved to Bavaria. Here Max Planck went to study at the very prestigious Maximilian Gymnasium, where he became the first student.
Maximilian Gymnasium
Wikimedia Commons
And right in the structure of Propp's fairy tale or a film about a kung fu master, it was here that a more experienced and wise adviser appeared, sharing some of his wisdom. Mathematics teacher Hermann Müller became such a fabulous mentor. He discovered a talent for mathematics in a young man and gave him the first lessons of the amazing beauty of the laws of nature: it was from Müller that Planck learned about the law of conservation of energy, which amazed him forever. It must be said that by the time he graduated from school, the outline of the fairy tale continued: he found himself at a crossroads. Of course, there was no stone with inscriptions, but, in addition to obvious abilities in physics and mathematics, Planck showed remarkable musical talent. Perhaps his choice was influenced by the fact that Max Planck, with an excellent voice and a wonderful technique of playing the piano, realized that he was not the best composer.
Planck chose physics and in 1874 entered the University of Munich. True, he did not quit playing, singing and conducting. Physics is physics. It also had to make a choice: in which of the areas of science to go.
Wilhelm Planck sent his son to Professor Philip Jolly. The young man gravitated towards theoretical physics and asked the famous scientist how he likes such a choice. Jolly, trying to dissuade him, told Planck the same phrase, which is now worn out to holes: they say, boy, don’t go into theoretical physics: all the discoveries have already been made here, all the formulas have been derived, there are a few details left to cover, and that’s it. True, this is usually quoted with intonation, they say, the young man heroically rushed to fight against the inertia of physics of that time. But no.
Max Planck in 1878
public domain
The young man was delighted: he was not at all going to make new discoveries. As Planck later explained his decision, he was only going to understand the knowledge already accumulated by physics and clarify inaccuracies. Who knew that in the course of the refinement, the entire building of physics of 1874 would collapse.
Here is how Planck himself wrote about himself as a young man in his Scientific Autobiography: “From my youth, I was inspired to engage in science by the realization of the far from self-evident fact that the laws of our thinking coincide with the laws that take place in the process of receiving impressions from the outside world, and that, therefore, a person can judge these regularities with the help of pure thinking. The essential thing here is that the external world is something independent of us, absolute, which we oppose, and the search for laws relating to this absolute seems to me the most beautiful task in the life of a scientist.
Theoretical physics brought him to Berlin, where he studied under the greats Helmholtz and Kirchhoff. True, Planck was disappointed with lectures on physics at the University of Berlin and sat down to the original work of his teachers. Works on the theory of heat by Rudolf Clausius were soon added to Helmholtz and Kirchhoff. This is how the area was defined. scientific works young theorist Max Planck - thermodynamics. He enthusiastically undertakes to "clarify" the details: he reformulates the second law of thermodynamics, writes new definitions of entropy ...
Portrait of Hermann Helmholtz
Hans Schadow/Wikimedia Commons
Here we take the liberty of quoting Max von Laue from 1947: “Today's physics bears a very different imprint than the physics of 1875, when Planck devoted himself to it; and in the greatest of these upheavals, Planck played the first decisive role. It was an amazing set of circumstances. To think, an eighteen-year-old applicant decided to devote himself to a science about which the most competent person he could ask would say that it had little promise. In the process of studying, he chooses a branch of this science, which is not at all respected by related sciences, but within this branch - a special area in which no one is interested. Neither Helmholtz, nor Kirchhoff, nor Clausius, who were closest to this, even read his first works, and yet he continues on his way, following an inner call, until he encounters a problem that many others already tried in vain to decide and for which - as it turns out - it was the path he had chosen that was the best preparation. As a result, he was able, based on measurements of radiation, to discover the law of radiation, which bears his name for all time. He communicated it on 19 October 1900 to the Physical Society in Berlin."
What did Planck discover and what problem did he solve?
Back in the 1860s, one of Planck's teachers, Gustav Kirchhoff, came up with a model object for thought experiments in thermodynamics - an absolutely black body. By definition, a blackbody is a body that absorbs absolutely all the radiation that falls on it. Kirchhoff showed that an absolute body is also the best possible radiator. But it radiates heat energy.
Rudolf Clausius
Wikimedia Commons
In 1896, the 1911 Nobel laureate, Wilhelm Wien, formulated his second law, which explained the shape of the black body radiation energy distribution curve based on Maxwell's equations. And this is where the controversy began. Wien's second law turned out to be valid for shortwave radiation. Regardless of Veen, William Strutt, Lord Rayleigh, got his formula, but it "worked" on long wavelengths.
Type of spectral curves given by Planck's and Wien's laws of radiation at various temperatures. It can be seen that the difference between the curves increases in the long-wavelength region
Planck was able, using the model of the simplest linear harmonic resonator, to derive a formula that combined the Wien formula and the Rayleigh formula. On this formula, which later became Planck's formula, he made a report on October 19. However, if Max Planck had done just that, he would hardly have been revered so highly. Yes, after the report in October, several physicists found him and told him: theory is ideally combined with practice. But this only meant that he had successfully chosen a formula that explained a highly specialized task. This was not enough for Planck, and he took up the theoretical justification of the empirically found formula. On December 14 of the same year, he again spoke at the Physical Society and made a report from which it follows: the energy of a completely black body should be emitted in portions. Quantum.
The outstanding French mathematician A. Poincare wrote: “Planck’s quantum theory is, without any doubt, the biggest and most profound revolution that natural philosophy endured since the time of Newton.
Max Karl Ernst Ludwig Planck was born on April 23, 1858 in the Prussian city of Kiel, in the family of civil law professor Johann Julius Wilhelm von Planck and Emma (nee Patzig) Planck.
In 1867 the family moved to Munich. Planck later recalled: "In the company of my parents and sisters, I happily spent my early years." At the Royal Maximilian Classical Gymnasium, Max studied well. His bright mathematical abilities also showed up early: in middle and high school, it became customary that he replaced sick mathematics teachers. Planck recalled the lessons of Hermann Müller, "a sociable, insightful, witty man who knew how to explain the meaning of those physical laws about which he told us, the students, using vivid examples."
After graduating from the gymnasium in 1874, he studied mathematics and physics for three years at the Munich University and for a year at the Berlin University. Physics was taught by Professor F. von Jolly. About him, as about others, Planck later said that he learned a lot from them and kept a grateful memory of them, "however, in scientific terms, they were, in essence, limited people." Max decided to complete his education at the University of Berlin. Although here he studied with such luminaries of science as Helmholtz and Kirchhoff, he did not receive full satisfaction here either: he was upset that the lectures of the luminaries were read poorly, especially Helmholtz. He gained much more from his acquaintance with the publications of these eminent physicists. They contributed to the fact that Planck's scientific interests focused for a long time on thermodynamics.
degree Planck received his doctorate in 1879, having defended his thesis at the University of Munich "On the second law of the mechanical theory of heat" - the second law of thermodynamics, stating that no continuous self-sustaining process can transfer heat from a colder body to a warmer one. A year later, he defended his dissertation "The equilibrium state of isotropic bodies at different temperatures", which earned him the position of junior assistant at the Faculty of Physics at the University of Munich.
As the scientist recalled: “Being a Privatdozent in Munich for many years, I waited in vain for an invitation to a professorship, which, of course, had little chance, since theoretical physics did not yet serve as a separate subject. All the more urgent was the need to advance one way or another in the scientific world.
With this intention, I decided to work out the problem of the essence of energy, put forward by the Goettingen Faculty of Philosophy for a prize in 1887. Even before the end of this work, in the spring of 1885, I was invited as an extraordinary professor of theoretical physics at the University of Kiel. This seemed to me a salvation; the day when the ministerial director Althof invited me to his hotel "Marienbad" and informed me in more detail about the conditions, I considered the happiest in my life. Although I led a carefree life in my parents' house, I still strove for independence ...
Soon I moved to Kiel; my Gottingen work was soon completed there and was crowned with a second prize.
In 1888, Planck became an adjunct professor at the University of Berlin and director of the Institute for Theoretical Physics (the post of director was created specifically for him).
In 1896, Planck became interested in the measurements made at the State Institute of Physics and Technology in Berlin. The experimental work on the study of the spectral distribution of the "black body" radiation, performed here, attracted the attention of the scientist to the problem thermal radiation.
By that time, there were two formulas for describing the radiation of a "black body": one for the short-wavelength part of the spectrum (Wien's formula), the other for the long-wavelength part (Rayleigh's formula). The challenge was to match them.
"Ultraviolet catastrophe" was called by the researchers the discrepancy between the theory of radiation and experiment. A discrepancy that could not be eliminated in any way. A contemporary of the “ultraviolet catastrophe”, the physicist Lorentz, sadly remarked: “The equations of classical physics turned out to be unable to explain why the fading furnace does not emit yellow rays along with radiation of large wavelengths ...”
Planck succeeded in "sewing" the Wien and Rayleigh formulas and deriving a formula that accurately describes the radiation spectrum of a black body.
Here is how the scientist writes about it:
“It was at that time that all outstanding physicists turned, both from the experimental and theoretical side, to the problem of energy distribution in the normal spectrum. However, they were looking for it in the direction of representing the intensity of radiation in its dependence on temperature, while I suspected a deeper connection in the dependence of entropy on energy. Since the significance of entropy had not yet found its due recognition, I was not in the least worried about the method I used and could freely and thoroughly carry out my calculations without fear of interference or advance on anyone's part.
Since the second derivative of its entropy with respect to its energy is of particular importance for the irreversibility of the exchange of energy between an oscillator and the radiation excited by it, I calculated the value of this quantity for the case that was then at the center of all interests of the Wien energy distribution, and found a remarkable result that for this case, the reciprocal of such a value, which I have here designated K, is proportional to the energy. This connection is so stunningly simple that for a long time I recognized it as completely general and worked on its theoretical foundation. However, the precariousness of such an understanding was soon revealed before the results of new measurements. It was precisely at the time that for small values of energy, or for short waves, Wien's law was perfectly confirmed later, for large values of energy, or for large waves, Lummer and Pringsheim first established a noticeable deviation, and the perfect deviations carried out by Rubens and F. Kurlbaum measurements with fluorspar and potassium salt revealed a completely different, but again simple relation, that the value of K is proportional not to energy, but to the square of energy when going to large values of energy and wavelengths.
Thus, two simple boundaries were established for the function by direct experiments: for small energies, the proportionality (of the first degree) of the energy, for large ones, to the square of the energy. It is clear that, just as any principle of energy distribution gives a certain value of K, so any expression leads to a certain law of energy distribution, and the question now is to find an expression that would give the energy distribution established by measurements. But now nothing was more natural than to compose for the general case a quantity in the form of a sum of two terms: one of the first degree, and the other of the second degree of energy, so that for small energies the first term will be decisive, for large energies - the second; at the same time, a new radiation formula was found, which I proposed at a meeting of the Berlin Physical Society on October 19, 1900, and recommended for research.
Subsequent measurements also confirmed the radiation formula, namely, the more accurately, the more subtle methods of measurement were used. However, the measurement formula, if we assume its absolutely exact truth, was in itself only a happily guessed law, having only a formal meaning.
Planck established that light must be emitted and absorbed in portions, and the energy of each such portion is equal to the oscillation frequency multiplied by a special constant, called Planck's constant.
The scientist reports how hard he tried to introduce an action quantum into the system classical theory: “But this value [the constant h] turned out to be obstinate and resisted all such attempts. As long as it can be considered infinitely small, that is, at higher energies and longer periods, everything was in perfect order. But in the general case here and there a gaping crack appeared, which became the more noticeable the faster the oscillations were considered. The failure of all attempts to bridge this abyss soon left no doubt that the quantum of action plays a fundamental role in atomic physics and that with its appearance a new era in physical science began, because it contains something, until then unheard of, which is called radically transform our physical thinking, built on the concept of the continuity of all causal relationships since the time when Leibniz and Newton created the infinitesimal calculus.
W. Heisenberg conveys the well-known legend of Planck's thoughts in this way: “His son Erwin Planck recalled this time, that he was walking with his father in Grunewald, that Planck excitedly and excitedly talked about the result of his research during the whole walk. He told him something like this: “Either what I am doing now is complete nonsense, or it is, perhaps, the biggest discovery in physics since the time of Newton.”
On December 14, 1900, at a meeting of the German Physical Society, Planck delivered his historic report "On the Theory of Energy Distribution of Normal Spectrum Radiation." He reported on his hypothesis and the new radiation formula. The hypothesis introduced by Planck marked the birth of quantum theory, which made a real revolution in physics. Classical physics, in contrast to modern physics, now means "physics before Planck."
The new theory included, in addition to Planck's constant, other fundamental quantities such as the speed of light and a number known as the Boltzmann constant. In 1901, based on experimental data on black body radiation, Planck calculated the value of the Boltzmann constant and, using other known information, obtained the Avogadro number (the number of atoms in one mole of an element). Based on the Avogadro number, Planck was able to find the electric charge of the electron with the highest accuracy.
The position of quantum theory was strengthened in 1905, when Albert Einstein used the concept of a photon - a quantum electromagnetic radiation. Two years later, Einstein further strengthened the position of quantum theory, using the concept of a quantum to explain the mysterious discrepancies between theory and experimental measurements of the specific heat of bodies. Another confirmation of Planck's theory came in 1913 from Bohr, who applied quantum theory to the structure of the atom.
In 1919 Planck was awarded Nobel Prize in physics for 1918 "in recognition of his services to the development of physics through the discovery of energy quanta." As stated by A.G. Ekstrand, member of the Royal Swedish Academy of Sciences at the award ceremony, "Planck's theory of radiation is the brightest of the guiding stars of modern physical research, and it will be, as far as one can tell, a long time before the treasures that were mined by his genius dry up." In a Nobel lecture given in 1920, Planck summed up his work and acknowledged that "the introduction of the quantum has not yet led to the creation of a genuine quantum theory."
Among his other achievements is, in particular, his proposed derivation of the Fokker-Planck equation, which describes the behavior of a system of particles under the action of small random impulses.
In 1928, at the age of seventy, Planck went into mandatory formal retirement, but did not break his ties with the Kaiser Wilhelm Society for Basic Sciences, of which he became president in 1930. And on the threshold of the eighth decade, he continued his research activities.
After Hitler came to power in 1933, Planck repeatedly spoke publicly in defense of Jewish scientists who were expelled from their posts and forced to emigrate. Later, Planck became more reserved and kept silent, although the Nazis were undoubtedly aware of his views. As a patriot who loves his motherland, he could only pray that the German nation would return to normal life. He continued to serve in various German learned societies, in the hope of saving at least some small amount of German science and enlightenment from total annihilation.
Planck lived on the outskirts of Berlin - Grunewald. In his house, located next to a wonderful forest, it was spacious, comfortable, everything had the stamp of noble simplicity. A huge, lovingly and thoughtfully curated library. A music room where the owner treated big and small celebrities with his exquisite playing.
His first wife, née Maria Merck, whom he married in 1885, bore him two sons and two twin daughters. Planck lived happily with her for more than twenty years. She died in 1909. It was a blow from which the scientist could not recover for a long time.
Two years later he married his niece Marga von Hesslin, with whom he also had a son. But since then, misfortune haunted Planck. During the First World War, one of his sons died near Verdun, and in subsequent years both of his daughters died in childbirth. The second son from his first marriage was executed in 1944 for participating in a failed plot against Hitler. The house and personal library of the scientist were destroyed during an air raid on Berlin.
Planck's strength was undermined, more and more suffering was caused by arthritis of the spine. For some time the scientist was in the university clinic, and then moved to one of his nieces.
Planck died in Göttingen on October 4, 1947, six months before his ninetieth birthday. Only his first and last name and the numerical value of Planck's constant are engraved on his tombstone.
In honor of his eightieth birthday, one of the minor planets was named Plankiana, and after the end of World War II, the Kaiser Wilhelm Society for Fundamental Sciences was renamed the Max Planck Society.
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The German physicist Max Karl Ernst Ludwig Planck was born in Kiel (then belonging to Prussia), in the family of civil law professor Johann Julius Wilhelm von Planck, professor of civil law, and Emma (nee Patzig) Planck. As a child, the boy learned to play the piano and organ, revealing extraordinary musical abilities. In 1867, the family moved to Munich, and there P. entered the Royal Maximilian Classical Gymnasium, where an excellent teacher of mathematics first aroused in him an interest in the natural and exact sciences. At the end of the gymnasium in 1874, he was going to study classical philology, tried his hand at musical composition, but then gave preference to physics.
For three years, P. studied mathematics and physics at Munich and a year - at the University of Berlin. One of his professors in Munich, experimental physicist Philipp von Jolly, turned out to be a bad prophet when he advised the young P. to choose another profession, since, according to him, there was nothing fundamentally new left in physics that could be discovered. This point of view, widely held at that time, arose under the influence of the extraordinary successes that scientists in the XIX century. achieved in increasing our knowledge of physical and chemical processes.
When he was in Berlin, P. acquired a broader view of physics through the publications of prominent physicists Hermann von Helmholtz and Gustav Kirchhoff, as well as articles by Rudolf Clausius. Acquaintance with their works contributed to the fact that the scientific interests of P. for a long time focused on thermodynamics - a field of physics in which, on the basis of a small number of fundamental laws, the phenomena of heat, mechanical energy and energy conversion are studied. Dr. P. received in 1879, having defended at the University of Munich a dissertation on the second law of thermodynamics, stating that no continuous self-sustaining process can transfer heat from a colder body to a warmer one.
The following year, P. wrote another work on thermodynamics, which earned him the position of junior assistant at the Faculty of Physics, University of Munich. In 1885 he became an adjunct professor at the University of Kiel, which strengthened his independence, strengthened his financial position and provided more time for scientific research. P.'s work on thermodynamics and its applications to physical chemistry and electrochemistry gained him international recognition. In 1888 he became associate professor at the University of Berlin and director of the Institute for Theoretical Physics (the post of director was created especially for him). He became a full (real) professor in 1892.
Since 1896, Mr.. P. became interested in the measurements made at the State Institute of Physics and Technology in Berlin, as well as the problems of thermal radiation of bodies. Any body containing heat emits electromagnetic radiation. If the body is hot enough, then this radiation becomes visible. When the temperature rises, the body first becomes red-hot, then becomes orange-yellow, and finally white. The radiation emits a mixture of frequencies (in the visible range, the frequency of the radiation corresponds to the color). However, the radiation of a body depends not only on temperature, but also to some extent on surface characteristics such as color and structure.
As an ideal standard for measurement and theoretical studies, physicists have adopted an imaginary absolute black body. By definition, a body is called absolutely black if it absorbs all radiation falling on it and reflects nothing. The radiation emitted by a completely black body depends only on its temperature. Although such an ideal body does not exist, a closed shell with a small hole (for example, a properly designed furnace, the walls and contents of which are in equilibrium at the same temperature) can serve as an approximation to it.
One of the proofs of the blackbody characteristics of such a shell is as follows. The radiation incident on the hole enters the cavity and, reflected from the walls, is partially reflected and partially absorbed. Since the probability that the radiation as a result of numerous reflections will go out through the hole is very small, it is almost completely absorbed. The radiation originating in the cavity and emerging from the hole is considered to be equivalent to the radiation emitted by a hole-sized area on the surface of a black body at the temperature of the cavity and shell. Preparing their own research, P. read the work of Kirchhoff on the properties of such a shell with a hole. An exact quantitative description of the observed distribution of radiation energy in this case is called the black body problem.
As experiments with a black body have shown, a plot of energy (brightness) versus frequency or wavelength is a characteristic curve. At low frequencies (large wavelengths), it is pressed against the frequency axis, then at some intermediate frequency it reaches a maximum (a peak with a rounded top), and then at higher frequencies (short wavelengths) it decreases. As the temperature rises, the curve retains its shape, but shifts towards higher frequencies. Empirical relationships were established between the temperature and frequency of a peak on a blackbody radiation curve (Wien's displacement law, named after Wilhelm Wien) and between temperature and all radiated energy (the Stefan-Boltzmann law, named after the Austrian physicists Josef Stefan and Ludwig Boltzmann ), but no one was able to derive the blackbody radiation curve from the basic principles known at the time.
Wien has succeeded in obtaining a semi-empirical formula that can be adjusted so that it describes the curve well at high frequencies, but misrepresents its behavior at low frequencies. J.W. Strett (Lord Rayleigh) and the English physicist James Jeans applied the principle of equal distribution of energy over the frequencies of oscillations of oscillators enclosed in the space of a black body, and came to another formula (the Rayleigh-Jeans formula). It reproduced the black body radiation curve well at low frequencies, but diverged from it at high frequencies.
P. under the influence of the theory of the electromagnetic nature of light by James Clerk Maxwell (published in 1873 and experimentally confirmed by Heinrich Hertz in 1887) approached the problem of a black body from the point of view of the distribution of energy between elementary electrical oscillators, the physical form of which is not specified in any way. Although at first glance it may seem that his chosen method resembles the conclusion of Rayleigh - Jeans, P. rejected some of the assumptions adopted by these scientists.
In 1900, after a long and persistent attempt to create a theory that would satisfactorily explain the experimental data, P. managed to derive a formula that, as found by experimental physicists from the State Institute of Physics and Technology, consistent with the measurement results with remarkable accuracy. The Wien and Stefan–Boltzmann laws also followed from Planck's formula. However, in order to derive his formula, he had to introduce a radical concept that runs counter to all established principles. The energy of Planck oscillators does not change continuously, as follows from traditional physics, but can only take on discrete values that increase (or decrease) in finite steps. Each energy step is equal to some constant (now called Planck's constant) multiplied by the frequency. Discrete portions of energy were subsequently called quanta. Introduced P. hypothesis marked the birth of quantum theory, which made a real revolution in physics. Classical physics, in contrast to modern physics, now means "physics before Planck."
P. was by no means a revolutionary, and neither he nor other physicists were aware of the deep meaning of the concept of "quantum". For P. quantum was just a means to derive a formula that gives satisfactory agreement with the radiation curve of a completely black body. He repeatedly tried to reach agreement within the classical tradition, but without success. At the same time, he noted with pleasure the first successes of quantum theory, which followed almost immediately. His new theory included, in addition to Planck's constant, other fundamental quantities such as the speed of light and a number known as the Boltzmann constant. In 1901, based on experimental data on blackbody radiation, P. calculated the value of the Boltzmann constant and, using other known information, obtained the Avogadro number (the number of atoms in one mole of an element). Based on the number of Avogadro, P. was able to find with remarkable accuracy the electric charge of the electron.
The position of quantum theory was strengthened in 1905, when Albert Einstein used the concept of a photon - a quantum of electromagnetic radiation - to explain the photoelectric effect (the emission of electrons from a metal surface illuminated by ultraviolet radiation). Einstein suggested that light has a dual nature: it can behave both like a wave (as all previous physics convinces us) and as a particle (as evidenced by the photoelectric effect). In 1907, Einstein further strengthened the position of quantum theory, using the concept of quantum to explain the mysterious discrepancies between theoretical predictions and experimental measurements of the specific heat of bodies - the amount of heat required to raise the temperature of one unit mass of a solid body by one degree.
Another confirmation of the potential power introduced by P. innovation came in 1913 from Niels Bohr, who applied quantum theory to the structure of the atom. In Bohr's model, electrons in an atom could only be at certain energy levels, determined by quantum restrictions. The transition of electrons from one level to another is accompanied by the release of the energy difference in the form of a radiation photon with a frequency equal energy photon divided by Planck's constant. In this way, the characteristic spectra of radiation emitted by excited atoms were given a quantum explanation.
In 1919, Mr.. P. was awarded the Nobel Prize in Physics for 1918. "in recognition of his merits in the development of physics through the discovery of energy quanta." As stated by A.G. Ekstrand, a member of the Royal Swedish Academy of Sciences, at the award ceremony, "P.'s radiation theory is the brightest of the guiding stars of modern physical research, and it will take, as far as one can judge, a lot of time before the treasures that were mined by his genius run out" . In the Nobel lecture given in 1920, P. summed up his work and admitted that "the introduction of the quantum has not yet led to the creation of a true quantum theory."
20s witnessed the development of Erwin Schrödinger, Werner Heisenberg, P.A.M. Dirac and others of quantum mechanics - equipped with a complex mathematical apparatus of quantum theory. P. did not like the new probabilistic interpretation of quantum mechanics, and, like Einstein, he tried to reconcile predictions based only on the principle of probability, with the classical ideas of causality. His aspirations were not destined to come true: the probabilistic approach withstood.
P.'s contribution to modern physics is not exhausted by the discovery of the quantum and the constant that now bears his name. Einstein's special theory of relativity, published in 1905, made a strong impression on him. special theory relativity by physicists. Among his other achievements is his proposed derivation of the Fokker-Planck equation, which describes the behavior of a system of particles under the action of small random impulses (Adrian Fokker is a Dutch physicist who improved the method first used by Einstein to describe Brownian motion - the chaotic zigzag motion of the smallest particles suspended in a liquid ). In 1928, at the age of seventy, Planck went into obligatory formal retirement, but did not sever his ties with the Kaiser Wilhelm Society for Fundamental Sciences, of which he became president in 1930. And into his eighth decade, he continued his research activities.
P.'s personal life was marked by tragedy. His first wife, née Maria Merck, whom he married in 1885 and who bore him two sons and two twin daughters, died in 1909. Two years later he married his niece Marga von Hesslin, by whom he also had a son. The eldest son P. died in the first world war and in later years both of his daughters died in childbirth. The second son from his first marriage was executed in 1944 for participating in a failed plot against Hitler.
As a person of established views and religious beliefs, and simply as a just person, P. after Hitler came to power in 1933 publicly defended Jewish scientists who were expelled from their posts and forced to emigrate. At a scientific conference, he hailed Einstein, who had been anathematized by the Nazis. When P. as president of the Kaiser Wilhelm Society for Fundamental Sciences paid an official visit to Hitler, he took advantage of this opportunity to try to stop the persecution of Jewish scientists. In response, Hitler launched a tirade against Jews in general. In the future, P. became more restrained and kept silent, although the Nazis, of course, knew about his views.
As a patriot who loves his motherland, he could only pray that the German nation would return to normal life. He continued to serve in various German learned societies in the hope of saving at least some small amount of German science and enlightenment from total annihilation. After his house and personal library were destroyed during an air raid on Berlin, P. and his wife tried to find refuge in the Rogetz estate near Magdeburg, where they found themselves between the retreating German troops and advancing forces allied forces. In the end, the Plancks were discovered by American units and taken to the then safe Göttingen.
P. died in Göttingen on October 4, 1947, six months before his 90th birthday. Only his first and last name and the numerical value of Planck's constant are engraved on his tombstone.
Like Bohr and Einstein, P. deeply interested philosophical problems causality, ethics, and free will, and has spoken on these topics in print and before professional and non-professional audiences. Acting pastor (but not having a priesthood) in Berlin, P. was deeply convinced that science complements religion and teaches truthfulness and respect.
Throughout his life, P. carried a love of music that flared up in him back in early childhood. An excellent pianist, he often played chamber works with his friend Einstein until he left Germany. P. was also a keen mountaineer and spent almost every vacation in the Alps.
In addition to the Nobel Prize, P. was awarded the Copley Medal of the Royal Society of London (1928) and the Goethe Prize in Frankfurt am Main (1946). The German Physical Society named its the highest award Planck medal, and P. himself was the first recipient of this honorary award. In honor of his 80th birthday, one of the minor planets was named Plankiana, and after the end of the Second World War, the Kaiser Wilhelm Society for Fundamental Sciences was renamed the Max Planck Society. P. was a member of the German and Austrian academies of sciences, as well as scientific societies and academies of England, Denmark, Ireland, Finland, Greece, the Netherlands, Hungary, Italy, Soviet Union, Sweden, Ukraine and the United States.
