Pupin, Michael Idvorsky

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PUPIN, MICHAEL IDVORSKY

(b. Idvor, Banat [now Yugoslavia], 4 October 1858; d. New York, N. Y., 12 March 1935)

applied physics.

Pupin was born to a family of unlettered Serbian settlers in the Banat, a military buffar zone between the Ottoman and Austro-Hungarian empires. Because of his obvious gifts, his parents were encouraged to let him complete his secondary studies at a larger center. He was thus sent to Prague, where he stayed for more than a year; but before he was sixteen, he went alone to America, arriving in New York in 1874. During the next five years he worked at odd jobs on farms and in factories, studying at night to prepare himself for admission to Columbia University on a scholarship, an ambition he fulfilled in 1879.

Pupin graduated with distinction in 1883 and after additional study at the University of Cambridge went to Berlin, where he worked under Helmholtz and G. Kirchhoff, receiving the doctorate in 1889 with a dissertation on osmotic pressure. He then returned to Columbia to teach mathematical physics in the newly formed department of electrical engineering. He advanced repidly and in 1901 was made professor of electromechanics, a post he occupied until his retirement in 1931.

During his studies of the distortions that arise when iron is magnetized by an alternating current, Pupin developed electrical resonators (by analogy with resonators used to study complex sound waves) that peoved to be applicable to problems in telegraphy and telephony. His most important contribution grew out of a study of the electrical analogue of a vibrating string “loaded” at regular intervals. This work not only confirmed that the periodic insertion of inductance coils in telephone lines would improve their performance by reducing attenuation and distortion, but it also allowed him to calculate optimum coil size and spacing, an invention of considerable practical and commercial value. For a time such lines were called “pupinized.”

Pupin also made many other contributions of an applied nature, for instance, in X-ray fluoroscopy, design of early radio transmitters, and electrical network theory. He was a popular and outstanding teacher. Among his pupils were several of the pioneers of radio communications, the most notable of whom was E. H. Armstrong. Pupin also became prominent in public affairs and was an adviser to the Yugoslav delegation to the Paris Peace Conference in 1919. He was an accomplished writer; and his best-selling autobiography, From Immigrant to Inventor, received the Pulitzer Prize in 1924. He received many honors, including eighteen honorary degrees, and was elected to the National Academy of Sciences.. The physics laboratory at Columbia University is named in his honor.

In 1888 Pupin married a young widow, Sarah Katherine Jackson; she died in 1896. The couple had one daughter, Varvara.

BIBLIOGRAPHY

Pupin’s publuications follow his entries in Poggendorff, VI, 2094; and Biographical Memoirs. National Academy of Sciences, 19 (1938), 307–232. The latter (by Bergen Davis) also lists his many honors and thirty-four patents. Other biographical entries include National Cyclopaedia of American Biography, XXVI (1937), 5–6; and Dictionary of American Biography, XXI, supp. 1 (1944), 611–615.

Charles SÜsskind

Complete Dictionary of Scientific Biography

Michael Idvorsky Pupin

views updated Jun 08 2018

Michael Idvorsky Pupin

The Serbo-American physicist and inventor Michael Idvorsky Pupin (1858-1935) is recognized for his contributions to telephony and telegraphy, his invention of electrical tuning, and his discovery of secondary x-ray radiation.

Michael Pupin was born on Oct. 4, 1858, at Idvor in Banat Province, a part of Austria (now of Yugoslavia) settled by Serbs in 1690. The son of illiterate but highly intelligent parents who sacrificed to give their son an education, Pupin soon left the village school to study at Pančevo and then at Prague. Following the death of his father, Pupin sailed to the United States in 1874. Arriving without funds or friends, he held farm and factory jobs, learned English, and in 1879 entered Columbia College.

Pupin subsequently became the first holder of Columbia's Tyndall fellowship in physics. By then he was pursuing his studies abroad, at Cambridge and Berlin, studying mathematical physics and physical chemistry. Receiving his doctorate in 1889, he returned to Columbia as an instructor in its new department of electrical engineering. Pupin combined effective teaching with a program of experimental research. His preliminary work and first publications dealt with electrical charges passing through gases and then with distortions in alternating currents and a general theory of wave propagation. This work led to his development of the electrical resonator (1893), later used in radio tuning, and then to the Pupin coils, inductance coils which when spaced properly along telephone circuits reinforced the vibrations and permitted long-distance calls (1894). Subsequently Pupin expanded upon this work, developing multiplex telegraphy and means to overcome static in wireless communications.

When Wilhelm Roentgen announced his discovery of x-rays in December 1895, Pupin made an x-ray tube and, within 2 weeks, discovered secondary x-radiation; he used this discovery to make short-exposure x-ray photographs, a procedure of obvious medical importance later. The Bell Telephone Company acquired the rights to his line-loading coils in 1901, as did the Siemens and Halske Company in Germany, and long-distance telephony soon became a reality.

Concern over the people in his native land led Pupin to an increasingly active role in public affairs during the Balkan War and World War I, and he headed many philanthropic and humanitarian efforts on behalf of other Serbs. He was a popular and eloquent platform speaker and a skillful interpreter of scientific learning to laymen. Pupin published approximately 70 technical articles and reports during his lifetime, obtained 34 patents, and received many awards and distinctions. He died in New York City on March 12, 1935.