Editing Aleksandr Lyapunov (section)

=== Teaching and research ===
A major theme in Lyapunov's research was the stability of a rotating fluid mass with possible astronomical application. This subject was proposed to Lyapunov by [[Pafnuty Chebyshev|Chebyshev]] as a topic for his masters thesis which he submitted in 1884 with the title ''On the stability of ellipsoidal forms of rotating fluids''. The main contribution was published in the celebrated  monograph  'A.M. Lyapunov, The general problem of the stability of motion. 1892. Kharkov Mathematical Society, Kharkov, 251p. (in Russian)'.<ref>{{cite book |last1=A.M. Lyapunov |title=The general problem of the stability of motion |date=1892 |publisher=Kharkov Mathematical Society |location=Kharkov |pages=1–251}}</ref> This led on to his 1892 doctoral thesis ''The general problem of the stability of motion''.{{sfn|Lyapunov|1892}} The thesis was defended in Moscow University on 12 September 1892, with [[Nikolay Yegorovich Zhukovsky|Nikolai Zhukovsky]] and V. B. Mlodzeevski as opponents. In 1908, the Kharkov edition was translated to French and republished by the [[University of Toulouse]]: 'Probleme General de la Stabilite du Mouvement, Par M.A. Liapounoff. Traduit du russe par M.Edouard Davaux'.
 
In 1885, Lyapunov became [[privatdozent]] and was proposed to accept the chair of mechanics at [[Kharkov University]], where he went the same year. About the initial stay at [[Kharkov]], Smirnov writes in his biography of Lyapunov:

{{quote|text=Here at first, the research activity of Lyapunov was cut short. It was necessary to work out courses and put together notes for students, which took up much time.{{sfn|Smirnov|1992}}}}

His student and collaborator, [[Vladimir Steklov (mathematician)|Vladimir Steklov]], recalled his first lecture in the following way: "A handsome young man, almost of the age of the other students, came before the audience, where there was also the old Dean, professor Levakovsky, who was respected by all students. After the Dean had left, the young man with a trembled voice started to lecture a course on the dynamics of material points, instead of a course on [[dynamical system]]s. This subject was already known to the students from the lectures of professor Delarue. But what Lyapunov taught us was new to me and I had never seen this material in any textbook. All antipathy to the course was immediately blown to dust. From that day students would show Lyapunov a special respect."{{sfn|Smirnov|1992}}