Mihajlo Idvorski Pupin (Serbian Cyrillic: Михајло Идворски Пупин, pronounced [miˈxǎjlo ˈîdʋoɾski ˈpǔpin]; October 4, 1858 – March 12, 1935), also known as Michael Pupin, was a Serbian-American electrical engineer, physicist and inventor.
Pupin is best known for his numerous patents, including a means of greatly extending the range of long-distance telephone communication by placing loading coils (of wire) at predetermined intervals along the transmitting wire (known as "pupinization"). Pupin was a founding member of National Advisory Committee for Aeronautics (NACA) on 3 March 1915, which later became NASA, and he participated in the founding of American Mathematical Society and American Physical Society.
In 1924, he won a Pulitzer Prize for his autobiography. Pupin was elected president or vice-president of the highest scientific and technical institutions, such as the American Institute of Electrical Engineers, the New York Academy of Sciences, the Radio Institute of America, and the American Association for the Advancement of Science. He was also an honorary consul of Serbia in the United States from 1912 to 1920 and played a role in determining the borders of newly formed Kingdom of Serbs, Croats and Slovenes.
Mihajlo Pupin was an ethnic Serb, born on 4 October (22 September, O.S.) in the village of Idvor (in the modern-day municipality of Kovačica, Serbia) in the region of Banat, in the Military Frontier of the Austrian Empire, 1858. He always remembered the words of his mother and cited her in his autobiography, From Immigrant to Inventor (1923):
My boy, If you wish to go out into the world about which you hear so much at the neighborhood gatherings, you must provide yourself with another pair of eyes; the eyes of reading and writing. There is so much wonderful knowledge and learning in the world which you cannot get unless you can read and write. Knowledge is the golden ladder over which we climb to heaven; knowledge is the light which illuminates our path through this life and leads to a future life of everlasting glory.
Pupin went to elementary school in his birthplace, to Serbian Orthodox school, and later to German elementary school in Perlez. He enrolled in high school in Pančevo, and later in the Real Gymnasium. He was one of the best students there; a local archpriest saw his enormous potential and talent, and influenced the authorities to give Pupin a scholarship.
Because of his activity in the "Serbian Youth" movement, which at that time had many problems with Austro-Hungarian police authorities, Pupin had to leave Pančevo. In 1872, he went to Prague, where he continued the sixth and first half of the seventh year. After his father died in March 1874, the twenty-year-old Pupin decided to cancel his education in Prague due to financial problems and to move to the United States.
When I landed at Castle Garden, forty-eight years ago, I had only five cents in my pocket. Had I brought five hundred dollars, instead of five cents, my immediate career in the new, and to me perfectly strange, land would have been the same. A young immigrant such as I was then does not begin his career until he has spent all the money which he has brought with him. I brought five cents, and immediately spent it upon a piece of prune pie, which turned out to be a bogus prune pie. It contained nothing but pits of prunes. If I had brought five hundred dollars, it would have taken me a little longer to spend it, mostly upon bogus things, but the struggle which awaited me would have been the same in each case. It is no handicap to a boy immigrant to land here penniless; it is not a handicap to any boy to be penniless when he strikes out for an independent career, provided that he has the stamina to stand the hardships that may be in store for him.
For the next five years in the United States, Pupin worked as a manual laborer (most notably at the biscuit factory on Cortlandt Street in Manhattan) while he learned English, Greek and Latin. He also gave private lectures. After three years of various courses, in the autumn of 1879 he successfully finished his tests and entered Columbia College, where he became known as an exceptional athlete and scholar. A friend of Pupin's predicted that his physique would make him a splendid oarsman, and that Columbia would do anything for a good oarsman. A popular student, he was elected president of his class in his Junior year. He graduated with honors in 1883 and became an American citizen at the same time.
After Pupin completed his studies, with emphasis in the fields of physics and mathematics, he returned to Europe, initially the United Kingdom (1883–1885), where he continued his schooling supervised by John Tyndall at the University of Cambridge. He obtained his Ph.D. at the University of Berlin under Hermann von Helmholtz with a dissertation titled "Osmotic Pressure and its Relation to Free Energy".
Professor at Columbia University
In 1889 Pupin returned to Columbia University, where he was offered a position as "Teacher of Mathematical Physics in the Department of Electrical Engineering". Shortly afterwards he was appointed associate professor, and in 1901 professor of electromechanics. Pupin's research pioneered carrier wave detection and current analysis.
He was an early investigator into X-ray imaging, but his claim to have made the first X-ray image in the United States is incorrect. He learned of Röntgen's discovery of unknown rays passing through wood, paper, insulators, and thin metals leaving traces on a photographic plate, and attempted this himself. Using a vacuum tube, which he had previously used to study the passage of electricity through rarefied gases, he made successful images on 2 January 1896. Edison provided Pupin with a calcium tungstate fluoroscopic screen which, when placed in front of the film, shortened the exposure time by twenty times, from one hour to a few minutes. Based on the results of experiments, Pupin concluded that the impact of primary X-rays generated secondary X-rays. With his work in the field of X-rays, Pupin gave a lecture at the New York Academy of Sciences. He was the first person to use a fluorescent screen to enhance X-rays for medical purposes. A New York surgeon, Dr. Bull, sent Pupin a patient to obtain an X-ray image of his left hand prior to an operation to remove lead shot from a shotgun injury. The first attempt at imaging failed because the patient, a well-known lawyer, was "too weak and nervous to be stood still nearly an hour" which is the time it took to get an X-ray photo at the time. In another attempt, the Edison fluorescent screen was placed on a photographic plate and the patient's hand on the screen. X-rays passed through the patients hand and caused the screen to fluoresce, which then exposed the photographic plate. A fairly good image was obtained with an exposure of only a few seconds and showed the shot as if "drawn with pen and ink." Dr. Bull was able to take out all of the lead balls in a very short time.
Pupin's 1899 patent for loading coils, archaically called "Pupin coils", followed closely on the pioneering work of the English polymath Oliver Heaviside, which predates Pupin's patent by some seven years. The importance of the patent was made clear when the American rights to it were acquired by American Telephone & Telegraph (AT&T), making him wealthy. Although AT&T bought Pupin's patent, it made little use of it, as it already had its own development in hand led by George Campbell and had up to this point been challenging Pupin with Campbell's own patent. AT&T was afraid it would lose control of an invention which was immensely valuable due to its ability to greatly extend the range of long-distance telephones and especially submarine ones.
When the United States joined the First World War in 1917, Pupin was working at Columbia University, organizing a research group for submarine detection techniques.
Together with his colleagues, professors Wils and Morcroft, he performed numerous experiments with the aim of discovering submarines at Key West and New London. He also conducted research in the field of establishing telecommunications between places. During the war, Pupin was a member of the state council for research and state advisory board for aeronautics. For his work he received acclamation from President Warren G. Harding, which was published on page 386 of his autobiography.