Vladimir Karapetoff (January 8, 1876 Saint Petersburg, Russian Empire - January 11, 1948) was a Russian-American electrical engineer, inventor, professor, and author.
He was the son of Nikita Ivanovich Karapetov and Anna Joakimovna Karapetova. Karapetoff first studied at Saint Petersburg's Institute of Ways and Communication, taking his first certification in 1897 and a second in 1902. During his studies he was a consultant to the Russian government and served as an instructor teaching electrical engineering and hydraulics in three of Saint Petersberg's colleges.
In 1899, he went to the Technische Hochschule Darmstadt to study power systems, he wrote Über Mehrphasige Stromsysteme in 1900.
In 1903 Karapetoff emigrated to the USA and apprenticed at Westinghouse Electric and Manufacturing Company. The following year he began his long association with Cornell University as professor of electrical engineering.
Karapetoff published the first part of his Engineering Applications of Higher Mathematics in 1911, and followed with parts two to five in 1916. That year he also published Electrical Measurements and Testing, Direct and Alternating Current.
The American Institute of Electrical Engineers made him a Fellow in 1912. He became a charter member of the American Association of University Professors in 1915. Karapetoff was a research editor for Electrical World from 1917 to 1926.
As a member of the Socialist Party of America, Karapetoff ran for the New York State Senate in 1910; and for New York State Engineer and Surveyor in the State elections of 1914, 1920 and 1924.
Karapetoff wrote several articles on special relativity to show that
In the first three articles in the journal of the Optical Society of America, Karapetoff used the notion of a "velocity angle" α which expressed the relation of a velocity v to the speed of light by sin α = v/c. In the later articles he used instead the hyperbolic angle u called rapidity in relativity, and determined by tanh u = v/c. As explained in a footnote on page 73 of the 1936 article, when sin α = tanh u, one says that α is the Gudermannian angle of u, and u is the anti-Gudermannian of α. Thus he explains, "the present treatment is in terms of the anti-Gudermannian of the velocity angle previously used." The diagramatic treatments given by Karapetoff are frequently called Minkowski diagrams in physical science.
In 1928 the Franklin Institute awarded him the Elliot Cresson Medal. Karapetoff was an accomplished cellist, and in 1934 was awarded an honorary doctorate in music by the New York College of Music. On November 25, 1936, he married Rosalie Margaret Cobb at Dobbs Ferry, New York. The Brooklyn Polytechnic Institute bestowed on him the degree of Doctor of Science in 1937. Karapetoff died in 1948, and is buried in Ithaca, Tompkins County, New York.
In his honor, since 1992 Eta Kappa Nu has celebrated significant work of electrical engineers with the Vladimir Karapetoff Outstanding Technical Achievement Award.