Alexandru Proca (1897-1955)

Alexandru Proca

1897 Alexandru Proca was born at Bucharest and was son of a building engineer. He was a Romanian physicist who studied and worked in France. He developed the vector meson theory of nuclear forces and the relativistic quantum field equations that bear his name (Proca's equations) for the massive, vector spin-1 mesons.[2] His father, Alexandru Proca, was one of South Railway Station’s makers in Ploiesti. Young Alexandru attended real sector of Lazar High School.

1915 He enrolled to Faculty of Sciences within University of Bucharest.

1917 During World War I, after graduating Genius Officers School, he was sent to the front where he took part in fights.

1918 He attended Roads and Bridges School in Bucharest, fact that gave him the possibility to travel to USA in order to study.

1923 Returned to Romania, he was given electromechanical engineering degree, as valedictorian of the same school that had been turned into a Polytechnic School in 1920.

Proca joined as an engineer “Electra” Society being in the same time Assistant of Professor N. Vasilescu Karpen at Polytechnic. “Electra” Society in Campina sent him to Paris for specialization studies. Here he enrolled to Faculty of Sciences at Sorbonne and attended Paul Langevin, Jean Pierre, Marcel Brillouin and Maria Curie’s courses. Obtaining his degree in Physics brilliantly, he moved to Radium Institute which was led by Maria Curie; she had praise words for him.

1924 As an engineer, he published a volume about “Electricity Use within Oil Industry”, in which he expected oil industry electrification.

1930 Proca moved to H. Poincare Institute. At the beginning he worked together with Leon and Marcel Brillouin, but also with Louis of Broblie.

1933 He presented in front of a commission composed of Jean Perrin, Louis of Broglie and P. A. M. Dirac his Ph.D. thesis in Physics: “About Relativistic Theory of Dirac’s Electron in a Null Field”. Proca continued his activity to “Henri Poincare” Institute where he drew up “Revue d’Acustique” and newly established “Annales de l’Institute Henri Poincare”.

1935 At the beginning of the year he made a study trip to Denmark where he worked for N. Bohr.

1939 After World War II outbreak, Proca asked and got French citizenship. During German occupation, Proca supported the resistance against Nazis then he took refuge in Portugal, at Oporto, then he left to England. At the end of the war he returned to France, resuming his activities within “Henri Poincare” Institute. Soon, he was appointed scientific Director of “Centre national des recherché scientifiques” and Head of theoretical Physics Seminar at Sorbonne, positions he had until the end of his life.

1951 He represented French Academy of Sciences to General Assembly of International Union of Pure and Applied Physics at Copenhagen.

1954 He was invited to Tokyo, where he held a series of conferences about meson fields.

1955 Alexandru Proca passed away because of a neck cancer.

Proca’s scientific activity was a very productive one. The list of his works, done by Professor Engineer G. St. Andonie, consists of 49 researching works and 6 teaching works.

They were started while he was a student and are mainly regarding theoretical Physics issues. His first work, published in “Bulletin of Polytechnic Society in Romania” (1923) is related to relativity. This was followed by long string of analytical mechanics, relativistic mechanics, relativistic Mechanics of electron, spinorial Mechanics, statistical Mechanics, quantum Mechanics, elementary particles, nuclear Physics, electronics, radioactivity, structure of matter works.

Proca’s foremost scientific merit is his theoretical demonstration (in the same time with Japanese physicist Yukava) the possibility of mesons’ existence. Romanian physicist succeeded to determine equations of vector meson field that were resumed later by Louis of Broglie who called them “Proca’s equations”. Their importance for nuclear interactions study was barely found after their author’s death. Within his relative and quantum Physics he introduced, except the four coordinates of space and time, the fifth one: conjugate variable of mass. His works on this subject led him to the idea of action atomization, of space-time, namely to the granular structure of space and time and made him assign to light both wave properties and granular structure.

Proca’s multilateral and vast spirit did not limit to theoretical Physics, but it drove him to other subjects, too, like knowledge theory, Maths and Physics philosophy.[1]

 

 

Bibliography:

    1. Alexandru Proca (1897-1955), ro.biography.name
    2. Alexandru Proca, en.wikipedia.org