المرجع الالكتروني للمعلوماتية
المرجع الألكتروني للمعلوماتية

الرياضيات
عدد المواضيع في هذا القسم 9761 موضوعاً
تاريخ الرياضيات
الرياضيات المتقطعة
الجبر
الهندسة
المعادلات التفاضلية و التكاملية
التحليل
علماء الرياضيات

Untitled Document
أبحث عن شيء أخر المرجع الالكتروني للمعلوماتية


Lev Davidovich Landau  
  
278   01:57 مساءً   date: 3-11-2017
Author : A T Grigorian
Book or Source : Biography in Encyclopaedia Britannica
Page and Part : ...


Read More
Date: 22-10-2017 104
Date: 9-11-2017 234
Date: 14-11-2017 248

Born: 22 January 1908 in Baku, Azerbaijan, Russian Empire

Died: 1 April 1968 in Moscow, USSR


Lev Landau's mother, Lyubov Veniaminovna Harkavi (1876-1941), had trained in medicine and she had undertaken work in physiology. She went on holiday to Switzerland with her friend Anna and met Anna's cousin, David Lvovich Landau (born 1866). Both Lyubov and David were Jewish and they fell in love [81]:-

[David Lvovich] was a composed and restrained person, and never raised his voice; [Lyubov] was a bundle of energy, quick-tempered and excitable. But opposites are often compatible and complement each other.

They were married in 1905 and went to live in Baku where David Lvovich worked. He was a petroleum engineer with the Black Sea and Caspian Sea Stock Company who worked at the oil fields in Baku on the Caspian Sea. He was well-off and owned a six-room apartment in the centre of the city. Their daughter Sonya was born on 8 August 1906, and their son Lyova (the subject of this biography, known as Lev) in January 1908. After the birth of her children, Lyubov Veniaminovna worked as a midwife and gynecologist then, from 1911, was a physician in a girls' high school. After doing war service in 1915-16, she worked as a teacher of natural sciences in the Baku Jewish High School. In addition to his work as an engineer, David Lvovich undertook research, wrote scientific papers and was a highly competent mathematician. He taught his son Lev mathematics from a young age. Both Sonya and Lev were very bright but very stubborn children.

A Jewish high school opened in Baku in September 1916 and the eight year old Lev began his schooling there. The school was designed to teach Russian, Hebrew, and Biblical Studies to Jewish children but also taught a full range of other subjects. Lev was brilliant in science and mathematics but only mediocre in Hebrew and Yiddish. His fellow pupils described him at this time:-

He was a quiet, shy boy, although the manner in which he related to his classmates, and even to his teachers, was somewhat condescending.

From his mother, Lev learnt French and German and quickly became fluent. He had piano lessons which he hated so he was soon allowed to stop these and study more mathematics. While Lev was at high school, the Russian Revolution took place. Lev was a staunch believer in Communist principles but, as we will see below, came to hate the Soviet leadership. His achievements at school were such that by the age of thirteen he had completed his secondary schooling and had the qualifications to enter university. Although calculus wasn't part of the school syllabus, Lev had studied this own topic his own and, later in life, would say that he couldn't remember a time when he wasn't proficient at differentiation and integration. His parents did not like the idea that he should begin his university studies a such a young age, and this was almost certainly a wise decision on their part. David Lvovich wanted his son to have a career in finance or administration so Lev was sent to Baku Economic Technical School for a year to delay his entry to university studies.

Landau was still only fourteen years old when he entered Baku University (later called the Kirov Azerbaijan State University) in 1922 and by this time he was already enthusiastic about mathematics, physics and chemistry. There he studied physics in the department of Mathematics and Physics but he also studied chemistry and, although he did not carry his studies of this topic any further through his university education, it remained one of his life-long interests. In 1924, after two years at Baku University, he moved to the Leningrad State University, graduating in 1927 [66]:-

In Leningrad - that main centre of Soviet physics at the time - he first made the acquaintance of genuine theoretical physics, which was then going through a turbulent period. He devoted himself to its study with all his youthful zeal and enthusiasm and worked so strenuously that often he became so exhausted that at night he could not sleep because he was still turning over formulas in his mind. Later he used to describe how at that time he was entranced by the incredible beauty of the general theory of relativity (sometimes he even would declare that such a rapture on first making one's acquaintance with this theory should in general be a characteristic of any born theoretical physicist). He also described the state of ecstasy to which he was brought on reading the articles by Heisenberg and Schrödinger signaling the birth of the new quantum mechanics. He said that he derived from them not only delight in the glamour of genuine science but also an acute realization of the power of the human genius, whose greatest triumph is that man is capable of apprehending things beyond the pale of his imagination.

In fact his first publication On the Theory of the Spectra of Diatomic Molecules appeared in print in 1926, while he was an eighteen year old undergraduate, and his second paper The Problem of Damping in Wave Mechanics appeared in the year he graduated, being his first paper on quantum theory. He continued research at the Leningrad Physico-Technical Institute.

In 1929, supported with a Rockefeller Foundation Fellowship, Landau set off for eighteen months of foreign travel, visiting Germany, Switzerland, Holland, England, Belgium, and Denmark. The visits which were most valuable to his research were those to Göttingen, Leipzig and particularly to Copenhagen where he worked in Niels Bohr's Institute for Theoretical Physics on three occasions, 8 April to 3 May 1930, from 20 September to 22 November 1930, and from 25 February to 19 March 1931 [66]:-

This scientific atmosphere, magnified by the charm of the personality of Bohr himself, decisively influenced Landau in forming his own view of physics.

From that time on he considered himself a pupil of Bohr and it was Bohr's influence that dictated the direction of Landau's future work [49]:-

... he also learned his teaching and training methods from Bohr.

The visits to Copenhagen also seemed to mark a change in Landau's character [77]:-

Landau, then and for some years afterwards, was an extremely provocative young man, who liked to shock.

During his trip abroad he went to Zurich where he worked from December 1930 to January 1931. There he collaborated with Rudolf Peierls (1907-1995) on relativistic quantum mechanics and their joint paper Quantum Electrodynamics in Configuration Space was published in 1931. Landau and Peierls discussed, in German, many topics including astrophysics. Peierls said in an interview in May 1977:-

He obviously was a very impressive character. I mean, his way of working was - if he saw a paper that interested him, he would glance at it to see what the problem was, and as a result he would sit down and solve the problem himself, and see whether his answer agreed with the paper.

While in Zurich he wrote the paper On the theory of stars but did not submit it for publication until he had returned to Leningrad [44]:-

Landau opened his four-page paper by arguing that theoretical astrophysicists were wrong to analyse stellar structure with the aid of mathematically convenient, but physically unrealistic assumptions. He illustrated this point by commenting on Edward Arthur Milne's ongoing campaign to overthrow Arthur Stanley Eddington's orthodox model of stars as gas spheres in which inward gravitational pressure is counteracted by outward radiation pressure. ... Believing that he had demonstrated the irrationality of "astrophysical methods," Landau averred that it was "reasonable to try to attack the problem of stellar structure [with the] methods of theoretical physics."

In 1931 Landau returned to Leningrad to work at the Physical Technical Institute, but in the following year he was appointed as head of the Theory Division of the Ukrainian Technical Institute in Kharkov and he was also appointed to the chair of theoretical physics at the Kharkov Institute of Mechanical Engineering. He moved to Kharkov to take up these posts, receiving a doctorate in Physical and Mathematical Sciences in 1934. One of his first projects in Kharkov was to organise an international conference on theoretical physics, and Niels Bohr attended the meeting [77]:-

Landau presided; Bohr opened the discussions on all papers ...

Soon afterward Landau was back in Copenhagen at a conference organised by Bohr [77]:-

... wearing a red coat and still provocative. During the next two years he produced original scientific papers at an average rate of one every six weeks and covered an astonishing range of subjects.

This extraordinary productivity was soon rewarded for, in addition to his other positions, in 1935 he received the title of professor and was made head of Physics at the Kharkov Gorky State University. Landau soon made his School in Kharkov the centre of theoretical physics in the USSR. In Kharkov, Landau met Konkordiya Drobantseva, a chemistry graduate known as Kora. She was a food technologist and from 1935 they lived together in a civil marriage which, some years later in 1946, they made formal when their son Igor was born. In Karkov, Landau had a talented student Evgenii Mikhailovich Lifshitz who began studying for his Ph.D. under him in 1933. Lifshitz was an exceptionally talented writer and Landau teamed up with him to create the ten volume 'Course of Theoretical Physics'. We give more details below.

In 1937 Landau went to Moscow to become Head of the Theory Division of the Physical Institute of the USSR Academy of Sciences. He worked on atomic collisions, astrophysics, low-temperature physics, atomic and nuclear physics, thermodynamics, quantum electrodynamics, kinetic theory of gases, quantum field theory, and plasma physics. The work he did on the theory to explain why liquid helium was super-fluid earned him the 1962 Nobel Prize for Physics. The citation states that he received the Nobel Prize for Physic:-

... for his pioneering theories for condensed matter, especially liquid helium.

Perhaps some details of the strange behaviour of liquid helium at a temperature just above absolute zero would be useful. It had been noted experimentally that if liquid helium at these low temperatures was placed in a beaker, then it climbed out of the beaker until the level outside was equal to that inside. Similarly liquid helium would climb into the beaker if the level outside exceeded that in the beaker. Landau devised a theory to explain such behaviour which was published in 1941. It predicted a new phenomenon, namely a temperature wave described a "second sound", and three years later experimental evidence produced in Moscow confirmed the existence of "second sound".

As we noted above, Landau believed in Communist principles, writing in 1935 that there were [35]:-

... unprecedented opportunities for the development of physics in our country, provided by the Party and the government.

However, he became increasingly unhappy with the way that Joseph Stalin was leading the country. Beginning in 1935, Stalin began a systematic elimination of his opponents in the 'Great Purge'. Soon it was leading members of his party, of the military, and important people from all walks of life who were being sent to prison, penal camps or work camps. Soon Landau was under investigation by the KGB who had received information from informers that he was making anti-government statements. It is not known whether he was the author of a pamphlet attacking the regime which was produced in 1938 but, if he wasn't, nevertheless it is clear that he supported and helped in its production. It begins as follows [35]:-

The great cause of the October Revolution is being despicably betrayed. The country is inundated with torrents of blood and filth. Millions of innocent people are being thrown into prisons and no-one can tell when his own turn will come. It is clear, comrades, that the Stalinist clique has carried out a fascist coup. Socialism has remained only on the pages of the habitually lying newspapers. In his rabid hatred of genuine socialism, Stalin is not different from Hitler and Mussolini.

On 28 April 1938, Landau was arrested and taken to Lubyanka prison. After two months of being forced to stand for seven hours a day and threatened with transfer to Lefortovo prison (which was much worse than Lubyanka prison) he wrote and signed a confession. One cannot take seriously a document produced under such circumstances but, in fact, it does seem to give a true account of Landau's views. He wrote later:-

I spent a year in prison and it was clear that I would be unable to live for even another half year.

Russian scientists tried to force the authorities to release him, with the leading physicist Peter Kapitza claiming he would stop his scientific work unless Landau was released. Kapitsa and Niels Bohr both wrote letters to Stalin insisting that Landau must be released. He was released in 1939 and reinstated as a research fellow at the Institute of Physical Problems.

Landau did some work on the Soviet atomic bomb in the second half of the 1940s. He certainly undertook mathematical calculations for work on the project and published a couple of papers which were outcomes of this work. It was not work he wanted to do but felt obliged to undertake it, particularly after his arrest and imprisonment some years before.

We mentioned above that one major contribution made by Landau was the writing of a number of outstanding textbooks and research monographs. His most famous book is his ten volume Course of Theoretical Physics written jointly with E M Lifshitz who was Landau's research student. They began work on this in the 1930's and the first part of the book is based on lecture notes. Lifshitz continued to work on the book after Landau's death and it was not completed until 1979. The work includes many of the results of Landau and Lifshitz's research over many years including the results of many jointly written research papers. The chapters of the book indicates the main topics of their joint research: Mechanics, theory of fields, quantum mechanics, quantum electrodynamics, classical statistical physics, quantum statistical physics, fluid mechanics, theory of elasticity, electrodynamics of continuous media, and physical kinetics.

Let us give some information about Landau's seminar. Before being accepted as a member of Landau's school, a candidate had to pass Landau's 'theoretical minimum'. This was a series of examinations that Landau set for which students had to spend a long time preparing. For example, Boris Ioffe, the author of [45] and [46], took almost two years to pass Landau's 'theoretical minimum'. Ioffe writes in [46] about Landau's seminar:-

To be Landau's disciple implied no privileges, only obligations. That's because anybody could have scientific discussions with Landau and get his advice. Moreover, only a few among those who passed Landau's minimum became his graduate students (I did not). Landau's students enjoyed full rights as participants of Landau's seminar. But, again, anyone could participate in his seminar, ask questions and make remarks. The obligations of the "full-right" participants were to prepare, in a regular way, in alphabetical order, review talks for the seminar. After each seminar Landau would take a recent issue of Physical Review (at that time it was not divided into sections) and point out to a speaker-to-be which papers he was supposed to report on at the seminar. As a rule, he would choose a dozen such papers from all branches of physics. ... The speaker not only had to review the paper, i.e. present its basic idea and final results, but was supposed to understand well how the results were obtained, present and explain to the audience all necessary formulae, including experimental techniques, and have his own opinion, as to whether or not the results were reliable.... The presentation of a theoretical report would proceed differently. A person, who wanted to present a theoretical investigation at the seminar (his own or from the literature) was first supposed to tell the story to Landau privately. If Landau agreed with the basic points of the work, then the talk at the seminar would be allowed. During the talk, Landau gave clarifying comments and quite often his explanation of the work was strongly different from that of the author. A hot discussion would then often follow. One could hear from Landau: "The author, in fact, did not understand what he did." Landau's understanding in all cases was quite original and for normal people it was not easy to follow his line of reasoning.

On 7 January 1962, Landau was involved in a car accident on the road from Moscow to Dubna. The road was slippery and his car hit a truck coming in the opposite direction. Others in his car suffered only minor cuts and bruises but Landau suffered serious fractures and injuries to his internal organs. He was taken to hospital in Moscow where he was unconscious for six weeks. Several times doctors declared him clinically dead. Remarkably Landau regained consciousness and although in many ways he returned to normal, he could never again perform creative work. Having never completely recovered, he died six years after his accident following a major operation to free an intestinal blockage. Sadly, these last six years were ones of constant suffering and pain.

We have given some quotes above concerning Landau's character. Further remarks are given in [77]:-

His personal qualities are something of an enigma. He had a flaming sincerity for - and about - science. He attracted students by his enthusiasm and evident knowledge, but to a greater age than most retained aspects of the enfant terrible. He could also be hot and merciless in criticism. Yet those who knew him, from Niels Bohr to the writer of a Soviet appreciation of his 50th birthday, agreed that there was human warmth below his sharpness.

Peter Kapitza, who knew him well, writes in [49]:-

His uncompromising attitudes, typical of all distinguished scientists in their work, extended to Landau's personal relationships. However, those who knew him well were aware that behind the abruptness was a very kind and responsive man, always ready to help people who had been unjustly wronged. In his youth Landau was very shy and even shunned society; any contact with people required great effort. It would appear that with age shyness waned but Landau was never able to adjust to society. It was only the many-sided talents of Landau's personality which drew people to him, and as he got to know them they would begin to like him and find great pleasure in his company. Everyone at the Institute of Physical Problems loved landau and his loss is sorely felt by the whole staff and in particular by his students, whose feelings towards him were especially profound.

Landau received many international honours for his contributions. He was elected to the Royal Danish Academy of Sciences (1951), The Netherlands Academy (1956), The British Physical Society (1959) and the Royal Society of London (1960). Also in 1960 he was elected to the U.S. National Academy of Sciences and the American Academy of Arts and Sciences. In addition to the Nobel Prize in 1962, he received the Fritz London Prize in 1960 for research in low-temperature physics and, in the same year, the Max Planck Medal. In 1962 he was elected to the French Physical Society and the New York Academy of Sciences. He also received honours from his own country: he was elected to the USSR Academy of Sciences (1946), received the State Prize three times (1946, 1949, 1953), received the Lenin Prize in 1962 (jointly with Evgenii Mikhailovich Lifshitz for the 'Course of Theoretical Physics'), was given the title Hero of Socialist Labour (1953) and twice awarded the Order of Lenin.


 

  1. A T Grigorian, Biography in Encyclopaedia Britannica
    http://www.britannica.com/eb/article-9047038/Lev-Davidovich-Landau
  2. A T Grigorian, Biography in Dictionary of Scientific Biography (New York 1970-1990). 
    http://www.encyclopedia.com/topic/Lev_Davidovich_Landau.aspx

Books:

  1. A A Abrikosov, Academician L D Landau (Russian) (Izdat. 'Nauka', Moscow, 1965).
  2. M Bessarab, Landau. Pages of a life (Russian) (Rabochii, Moscow, 1978).
  3. A Dorozynski, The Man They Wouldn't Let Die (Macmillan, New York, 1965).
  4. V L Ginzburg, About Science, Myself and Others (CRC Press, 2004).
  5. F Janouch, Lev D Landau: his life and work (CERN - European Organization for Nuclear Research, Geneva, 1979).
  6. I M Khalatnikov (ed.), Landau : the physicist and the man: recollections of L D Landau (Pergamon Press, Oxford, 1989).
  7. I M Khalatnikov and V P Mineev (eds.), 30 years of the Landau Institute (World Scientific Publishing Co., Inc., River Edge, NJ, 1996).
  8. E M Lifshitz (ed.), L D Landau, Collected papers of L D Landau 1 (Russian) (Izdat. "Nauka", Moscow, 1969).
  9. E M Lifshitz and I M Halatnikov (eds), L D Landau, Collected papers of L D Landau 2 (Russian) (Izdat. "Nauka", Moscow, 1969).
  10. A Livanova, Landau : a great physicist and teacher (Oxford, 1980).
  11. D ter Haar, Men of Physics : L D Landau (Oxford, 1969).
  12. D ter Haar (ed.), L D Landau, Collected papers of L D Landau (Gordon and Breach Science Publishers, New York-London-Paris 1967).

Articles:

  1. A A Abrikosov, Recollections of L D Landau, in I M Khalatnikov (ed.), Landau : the physicist and the man: recollections of L D Landau (Pergamon Press, Oxford, 1989), 29-35.
  2. A I Akhiezer, Recollections of Lev Davidivich Landau, Physics today 47 (6) (1994), 35-42.
  3. A I Akhiezer, Teacher and friend, in I M Khalatnikov (ed.), Landau : the physicist and the man: recollections of L D Landau (Pergamon Press, Oxford, 1989), 36-56.
  4. O I Akhiezer, Landau and the Ukrainian Physical Engineering Institute (Ukrainian), Ukrain. Fiz. Zh. 43 (9) (1998), 1013-1019.
  5. N E Alekseevskii, Dau in the thirties, in I M Khalatnikov (ed.), Landau : the physicist and the man: recollections of L D Landau (Pergamon Press, Oxford, 1989), 57-59.
  6. E L Andronikashvili, The Leningrad period in the life of young Professor Landau, in I M Khalatnikov (ed.), Landau : the physicist and the man: recollections of L D Landau (Pergamon Press, Oxford, 1989), 60-62.
  7. V B Berestetskii, Studies on elementary particles, in I M Khalatnikov (ed.), Landau : the physicist and the man: recollections of L D Landau (Pergamon Press, Oxford, 1989), 63-66.
  8. H Casimir, Landau, in I M Khalatnikov (ed.), Landau : the physicist and the man: recollections of L D Landau (Pergamon Press, Oxford, 1989), 67-77.
  9. H Chang, Review: Course of Theoretical Physics, Vol 8 Electrodynamics of Continuous Media, by Lev Landau and Evgenii Lifshitz, American Scientist 49 (4) (1961), 408A; 410A.
  10. D S Danin, The passionate sobriety of youth, in I M Khalatnikov (ed.), Landau : the physicist and the man: recollections of L D Landau (Pergamon Press, Oxford, 1989), 78-83.
  11. D S Danin, If all the scientists in the world ..., in I M Khalatnikov (ed.), Landau : the physicist and the man: recollections of L D Landau (Pergamon Press, Oxford, 1989), 84-88.
  12. I E Dzyaloshinskii, Landau through a pupil's eyes, in I M Khalatnikov (ed.), Landau : the physicist and the man: recollections of L D Landau (Pergamon Press, Oxford, 1989), 89-96.
  13. I L Fabelinskii, Some meetings with L D Landau, in I M Khalatnikov (ed.), Landau : the physicist and the man: recollections of L D Landau (Pergamon Press, Oxford, 1989), 97-104.
  14. E L Feinberg, Landau and others, in I M Khalatnikov (ed.), Landau : the physicist and the man: recollections of L D Landau (Pergamon Press, Oxford, 1989), 105-116.
  15. A L Fetter, Review: Course of Theoretical Physics, Vol 5 Statistical Physics, by Lev Landau and Evgenii Lifshitz, American Scientist 69 (1) (1981), 88.
  16. E L Feinberg, Landau, Kapitsa and Stalin (on the 90th anniversary of the birth of L D Landau) (Russian), Priroda 1998 (1) (1998), 65-75.
  17. V L Ginzburg, Landau's attitude towards physics and physicists, Physics today 42 (5) (1989), 54-61.
  18. V L Ginzburg, A remarkable physicist, in I M Khalatnikov (ed.), Landau : the physicist and the man: recollections of L D Landau (Pergamon Press, Oxford, 1989), 117-121.
  19. V L Ginzburg, Further thoughts, in I M Khalatnikov (ed.), Landau : the physicist and the man: recollections of L D Landau (Pergamon Press, Oxford, 1989), 122-135.
  20. V L Ginzburg, The 'Course': in memory of L D Landau and E M Lifshitz, in I M Khalatnikov (ed.), Landau : the physicist and the man: recollections of L D Landau (Pergamon Press, Oxford, 1989), 298-307.
  21. G Gorelik, The top-secret life of Lev Landau. KGB archives reveal that the Soviet genius co-authored an anti-Stalin manifesto, Scientific American (August 1997), 72-77.
  22. G E Gorelik, How the 'Course of theoretical physics' was created (Russian), Priroda 2005 (8) (2005), 67-75.
  23. V I Gol'danskii, In the kaleidoscope of memory, in I M Khalatnikov (ed.), Landau : the physicist and the man: recollections of L D Landau (Pergamon Press, Oxford, 1989), 136-142.
  24. L P Gor'kov, The 'young people', in I M Khalatnikov (ed.), Landau : the physicist and the man: recollections of L D Landau (Pergamon Press, Oxford, 1989), 143-145.
  25. Z I Gorobets, By car into the mountains, in I M Khalatnikov (ed.), Landau : the physicist and the man: recollections of L D Landau (Pergamon Press, Oxford, 1989), 146-152.
  26. A T Grigor'yan, Lev Davidovich Landau (Russian). On the 80th anniversary of his birth, Studies in the history of physics and mechanics, 1988 (Russian) ('Nauka', Moscow, 1988), 139-143.
  27. A T Grigor'yan, Lev Davidovich Landau. On the 80th anniversary of his birth (Russian), Voprosy Istor. Estestvoznan. i Tekhm. 1988 (1) (1988), 116-119.
  28. K Hall, The schooling of Lev Landau: the European context of post-revolutionary Soviet theoretical physics, Osiris (2) 23 (2008), 230-259.
  29. J D Harris, Review: The Man They Wouldn't Let Die, by Alexander Dorozynski, Russian Review 25 (1) (1966), 98-99.
  30. K Hufbauer, Landau's youthful sallies into stellar theory: Their origins, claims, and receptions, Historical Studies in the Physical and Biological Sciences 37 (2) (2007), 337-354.
  31. B L Ioffe, If Landau were alive now, in I M Khalatnikov (ed.), Landau : the physicist and the man: recollections of L D Landau (Pergamon Press, Oxford, 1989), 153-156.
  32. B L Ioffe, Landau's Theoretical Minimum, Landau's Seminar, ITEP in the Beginning of the 1950's, QCD at the Threshold of the Fourth Decade/IOFFEFEST (2002).
  33. M I Kaganov, Landau as I knew him, in I M Khalatnikov (ed.), Landau : the physicist and the man: recollections of L D Landau (Pergamon Press, Oxford, 1989), 157-165.
  34. M I Kaganov, The harder you work, the better, in I M Khalatnikov (ed.), Landau : the physicist and the man: recollections of L D Landau (Pergamon Press, Oxford, 1989), 286-289.
  35. P L Kapitza and E M Lifshitz, Lev Davydovitch Landau (1908-1968), Biographical Memoirs of Fellows of the Royal Society 15 (1969), 141-158.
  36. I M Khalatnikov, Reminiscences of Landau, Physics today 42 (5) (1989),34-41.
  37. I M Khalatnikov, The pride of Soviet science. On the eightieth birthday of Academician L D Landau, in I M Khalatnikov (ed.), Landau : the physicist and the man: recollections of L D Landau (Pergamon Press, Oxford, 1989), 1-4.
  38. I M Khalatnikov, How the school of Landau was started, in I M Khalatnikov (ed.), Landau : the physicist and the man: recollections of L D Landau (Pergamon Press, Oxford, 1989), 166-172.
  39. I M Khalatnikov, How the Landau school was founded (Russian), Vestnik Akad. Nauk SSSR 1980 (7) (1980), 111-117.
  40. I M Khalatnikov, Some brushstrokes for a portrait not yet painted, in I M Khalatnikov (ed.), Landau : the physicist and the man: recollections of L D Landau (Pergamon Press, Oxford, 1989), 173-179.
  41. A K Kikoin, How I became a teacher at Kharkov University, in I M Khalatnikov (ed.), Landau : the physicist and the man: recollections of L D Landau (Pergamon Press, Oxford, 1989), 180-183.
  42. A K Kikoin, Landau's ten commandments, in I M Khalatnikov (ed.), Landau : the physicist and the man: recollections of L D Landau (Pergamon Press, Oxford, 1989), 284-285.
  43. A S Kompaneets, L D Landau as a teacher, in I M Khalatnikov (ed.), Landau : the physicist and the man: recollections of L D Landau (Pergamon Press, Oxford, 1989), 184-186.
  44. A G Kulikovskii, Some comments on the book 'Hydrodynamics' by L D Landau and E M Lifshitz (Russian), Prikl. Mat. Mekh. 50 (6) (1986), 1041-1042.
  45. J. Appl. Math. Mech. 50 (6) (1986), 806-807.
  46. Landau, Bohr, and Kapitza: letters 1936-41, in I M Khalatnikov (ed.), Landau : the physicist and the man: recollections of L D Landau (Pergamon Press, Oxford, 1989), 308-319.
  47. B G Lazarev, From my memories, in I M Khalatnikov (ed.), Landau : the physicist and the man: recollections of L D Landau (Pergamon Press, Oxford, 1989), 187-190.
  48. Lev Davidovich Landau, in Nobel lectures. Physics 1942-1962 (Elsevier Publishing Company, Amsterdam, 1964).
  49. Lev Davidovich Landau, in Who's Who in the Twentieth Century (Oxford University Press, Oxford, 1999).
  50. Lev Davidovich Landau, in A Dictionary of Scientists (Oxford University Press, Oxford, 1999).
  51. E M Lifshitz, Lev Davidovich Landau (1908-1968) (Russian), Usp. Fiz. Nauk 97 (1969), 169-186.
  52. E M Lifshitz, Lev Davidovich Landau (1908-1968), Soviet Physics Uspekhi 12 (1) (1969), 135-145.
  53. E M Lifshitz, Lev Davidovich Landau (1908-1968), in I M Khalatnikov (ed.), Landau : the physicist and the man: recollections of L D Landau (Pergamon Press, Oxford, 1989), 7-27.
  54. E M Lifshitz, The discovery and elucidation of superfluidity in liquid helium, in I M Khalatnikov (ed.), Landau : the physicist and the man: recollections of L D Landau (Pergamon Press, Oxford, 1989), 265-274.
  55. E M Lifshitz, Landau's plain talk to students of physics, in I M Khalatnikov (ed.), Landau : the physicist and the man: recollections of L D Landau (Pergamon Press, Oxford, 1989), 275-283.
  56. G Liljestrand (ed.), Speech by Mr Belokhvostikov, Ambassador of the Soviet Union on behalf of Lev Davidovich Landau, Les Prix Nobel en 1962 (Nobel Foundation, Stockholm, 1963).
  57. O I Martynova, From not very close, in I M Khalatnikov (ed.), Landau : the physicist and the man: recollections of L D Landau (Pergamon Press, Oxford, 1989), 191-193.
  58. W S McAfee, Review: Course of Theoretical Physics, Vol 1 Mechanics, by Lev Landau and Evgenii Lifshitz, American Scientist 50 (1) Frontiers of Zealous Research (March 1962), 109A-110A.
  59. R E Peierls, My recollections of Landau, in I M Khalatnikov (ed.), Landau : the physicist and the man: recollections of L D Landau (Pergamon Press, Oxford, 1989), 194-197.
  60. J R Pellam, Lev Davidovich Landau, in I M Khalatnikov (ed.), Landau : the physicist and the man: recollections of L D Landau (Pergamon Press, Oxford, 1989), 198-204.
  61. L P Pitaevskii, Lev Davidovich Landau, global talent (5 May 2010).
  62. V L Pokrovskii, Science and life: conversations with Dau, in I M Khalatnikov (ed.), Landau : the physicist and the man: recollections of L D Landau (Pergamon Press, Oxford, 1989), 207-209.
  63. Professor Lev Landau, The Times (1968).
  64. Yu N Ranyuk, L D Landau and L M Pyatigorskii (Russian), Voprosy Istor. Estestvoznan. i Tekhm. 1999 (4) (1999), 79-91; 157.
  65. M Rothman, Review: General Physics. Mechanics and Molecular Physics, by L D Landau, A I Akhiezer, and E M Lifshitz, Science, New Series 160 (3828) (1968), 667.
  66. Yu B Rumer, A page or two of reminiscences about L D Landau, in I M Khalatnikov (ed.), Landau : the physicist and the man: recollections of L D Landau (Pergamon Press, Oxford, 1989), 208-213.
  67. E Ryndina and A Gill, Family lines sketched in the portrait of Lev Landau, Physics Today 57 (2) (2004), 53-60.
  68. S M Rytov, My rare 'talks' with L D Landau, in I M Khalatnikov (ed.), Landau : the physicist and the man: recollections of L D Landau (Pergamon Press, Oxford, 1989), 214-219.
  69. J Sapristein, Review: Course of Theoretical Physics, Vol 4 Relativistic Quantum Theory, by Lev Landau and Evgenii Lifshitz, American Scientist 71 (3) (1983), 305.
  70. W R Schowalter, Review: Course of Theoretical Physics, Vol 6 Fluid Mechanics, by Lev Landau and Evgenii Lifshitz, American Scientist 49 (1) (1961), 66A; 68A.
  71. I S Shapiro, From my memories of L D Landau, in I M Khalatnikov (ed.), Landau : the physicist and the man: recollections of L D Landau (Pergamon Press, Oxford, 1989), 220-223.
  72. D Shoenberg, Recollections of Landau, in I M Khalatnikov (ed.), Landau : the physicist and the man: recollections of L D Landau (Pergamon Press, Oxford, 1989), 224-230.
  73. V A Shukov (ed.), Unknown letters of L D Landau to Niels Bohr (Russian), Voprosy Istor. Estestvoznan. i Tekhm. 1983 (1) (1983), 130-131.
  74. Ya A Smorodinskii, As memory dictates, in I M Khalatnikov (ed.), Landau : the physicist and the man: recollections of L D Landau (Pergamon Press, Oxford, 1989), 231-237.
  75. M A Styrikovich, Memories of Dau, in I M Khalatnikov (ed.), Landau : the physicist and the man: recollections of L D Landau (Pergamon Press, Oxford, 1989), 238-246.
  76. K A Ter-Martirosyan, Landau as I remember him, in I M Khalatnikov (ed.), Landau : the physicist and the man: recollections of L D Landau (Pergamon Press, Oxford, 1989), 247-256.
  77. V V Vorob'ev, Lev Landau and 'The anti-Soviet strike of physicists'. (Russian), Voprosy Istor. Estestvoznan. i Tekhm. 1999 (4) (1999), 92-101; 157.
  78. A Weinmann, Review: Course of Theoretical Physics, Vol 3 Quantum Mechanics: Non-Relativistic Theory, by Lev Landau and Evgenii Lifshitz, The Mathematical Gazette 43 (346) (1959), 305-306.
  79. G H Weiss, Review: Course of Theoretical Physics, Vol 3 Quantum Mechanics: Non-Relativistic Theory, by Lev Landau and Evgenii Lifshitz, Science, New Series 128 (3327) (1958), 767-768.
  80. Ya B Zel'dovich, Recollections of the teacher, in I M Khalatnikov (ed.), Landau : the physicist and the man: recollections of L D Landau (Pergamon Press, Oxford, 1989), 257-262.

 




الجبر أحد الفروع الرئيسية في الرياضيات، حيث إن التمكن من الرياضيات يعتمد على الفهم السليم للجبر. ويستخدم المهندسون والعلماء الجبر يومياً، وتعول المشاريع التجارية والصناعية على الجبر لحل الكثير من المعضلات التي تتعرض لها. ونظراً لأهمية الجبر في الحياة العصرية فإنه يدرّس في المدارس والجامعات في جميع أنحاء العالم. ويُعجب الكثير من الدارسين للجبر بقدرته وفائدته الكبيرتين، إذ باستخدام الجبر يمكن للمرء أن يحل كثيرًا من المسائل التي يتعذر حلها باستخدام الحساب فقط.وجاء اسمه من كتاب عالم الرياضيات والفلك والرحالة محمد بن موسى الخورازمي.


يعتبر علم المثلثات Trigonometry علماً عربياً ، فرياضيو العرب فضلوا علم المثلثات عن علم الفلك كأنهما علمين متداخلين ، ونظموه تنظيماً فيه لكثير من الدقة ، وقد كان اليونان يستعملون وتر CORDE ضعف القوسي قياس الزوايا ، فاستعاض رياضيو العرب عن الوتر بالجيب SINUS فأنت هذه الاستعاضة إلى تسهيل كثير من الاعمال الرياضية.

تعتبر المعادلات التفاضلية خير وسيلة لوصف معظم المـسائل الهندسـية والرياضـية والعلمية على حد سواء، إذ يتضح ذلك جليا في وصف عمليات انتقال الحرارة، جريان الموائـع، الحركة الموجية، الدوائر الإلكترونية فضلاً عن استخدامها في مسائل الهياكل الإنشائية والوصف الرياضي للتفاعلات الكيميائية.
ففي في الرياضيات, يطلق اسم المعادلات التفاضلية على المعادلات التي تحوي مشتقات و تفاضلات لبعض الدوال الرياضية و تظهر فيها بشكل متغيرات المعادلة . و يكون الهدف من حل هذه المعادلات هو إيجاد هذه الدوال الرياضية التي تحقق مشتقات هذه المعادلات.