Childhood & Early Life
Julian Seymour Schwinger was born on February 12, 1918, in New York City in a well to do Jewish family. His father, Benjamin Schwinger, was a successful clothing manufacturer. His mother’s name was Belle (née Rosenfeld) Schwinger.
Julian had an elder brother named Harold. Both the children were enrolled at Townsend Harris High School for their secondary education. Born a child progeny, Julian became interested in physics at an early age.
He later said that he had been reading Encyclopedia Britannica at home and got stuck when he reached ‘Physics’. Soon he began to visit public libraries to gain additional knowledge in that subject. In fact, most of his knowledge of physics at that time was gathered outside the formal educational system.
After passing out from school in 1933, Julian first entered the City College of New York with physics as his major. By this time he had formed the habit of studying at night. More than his text books, he kept reading outside publications and thus gained in depth knowledge on the subject.
Julian published his first paper in physics in 1934 at the age of sixteen and by the age of seventeen he was doing advanced calculations. Yet, because he did not attend classes and were more interested in solving higher problems, he began to have difficulties with his instructors and started failing in examinations.
Fortunately for him, one of his letters published in the ‘Letters to the Editor’ section in ‘Physical Review’ caught the attention of Professor Isidor Isaac Rabi of Columbia University. He was more impressed when he met young Julian face to face.
On Rabi’s advice, Julian left City College of New York and joined University of Columbia. He received his B.S. degree from the University of Columbia in 1936. By this time, he had started working on a paper titled ‘Magnetic Scattering of Neutrons’ and once completed, submitted it to the ‘Physical Review’.
The paper caught the attention of renowned theoretical physicists Edward Teller. On his advice, Julian developed the thesis further and submitted it as his PhD dissertation. However, he did not immediately get his degree.
At that time, it was mandatory for doctoral students to attend mathematics classes, which Julian had failed to do, mainly because those classes were held in early morning. To compensate that, he had to sit for an examination.
The mathematics professor, on the advice of Isidor Isaac Rabi, set up an extraordinary tough paper. In spite of that, Julian passed out with flying colors and received his doctoral degree in 1939. He was only twenty-one years old then.
Continue Reading Below
Career
After receiving his PhD in 1939, Julian Schwinger joined University of California, Berkeley as National Research Council Fellow. Next year in 1940, he began to work as the research associate of J Robert Oppenheimer.
He received his regular academic appointment in the summer of 1941 as an instructor of physics at the Purdue University, Indiana. The following year he was promoted to the post of Assistant Professor at the same University.
At that time, an active program in semiconductor research was being carried out at Purdue for the Radiation Laboratory of the Massachusetts Institute of Technology. Schwinger joined the program in 1942 and worked on the propagation of microwave radiation in microwave cavities.
In the beginning of 1943, Oppenheimer asked Schwinger to join him at Los Alamos National Laboratory, where an atomic bomb was being built. Schwinger refused; instead he joined the Radiation Laboratory at MIT later in the same year.
Being a night bird and a loner, Schwinger chose to become a night research staff. This allowed him to work in solitude. By applying his knowledge of nuclear physics on electromagnetic engineering, he arrived at the theory of nuclear scattering, which ultimately provided important inputs in the design of radars.
While working at Radiation Laboratory, he also solved a wide variety of microwave problems. The results of these works were later used by him to formulate many of his famous theories. At the same time, he gave a number of lectures on wave guides. These were attended by a selected group of colleagues.
His lectures during this period exhibited his astounding analytical power as well as his depth of knowledge in varied branches of science. However, the war ended before, he could finish the series. Much later in 1968, these lectures were compiled in a book called ‘Discontinuities in Waveguides’
As the war ended in 1945, Schwinger received offers from many established universities. Ultimately, he left Purdue to join Harvard University as an Associate Professor and remained there until 1972.
In 1947, he was promoted to the post of full professor. In the same year in September, Schwinger developed the concept of renormalization, which was able to explain the phenomenon called Lamb Shift in the magnetic field of an electron.
Continue Reading Below
During his tenure at Harvard, Schwinger worked on various aspects of modern theoretical physics and until mid 1950s, was considered an authority on that subject. In 1948-1949, he submitted a series of papers titled ‘Quantum Electrodynamics’ (Parts I, II, and III) to ‘Physics Review’, which earned him great acclaim.
In 1951, he presented his formulation of the equations for the Green’s functions of quantum fields in Proceedings of the National Academy of Sciences. He also gave many innovative lectures, which contained many new results. Although he did not bother to publish many of them, some were later printed by his students.
From the middle of 1950s, some of his theories began to be challenged. Nonetheless, he continued exploring new paths and from 1966, he began to develop his ‘source theory’, which was a reformulation of quantum electrodynamics theory. However, the theory was not accepted by many of colleagues at Harvard.
In 1972, Schwinger left Harvard to join University of California, Los Angeles. There he continued with his work on source theory, which according to him was the mathematical symbolism of human manipulations in high-energy physics.
Starting in the 1980s, Schwinger began a series of papers on the Thomas-Fermi model of atoms. Then from 1989, he began to take interest in the non-mainstream research of cold fusion. However, his papers were not accepted for publications. His last published paper was on sonoluminescence.
All through his working life, Schwinger had published around 200 papers and had penned number of books. He also acted as academic advisor to around 73 doctoral students and 20 post doctoral students. Many of them had later become well known physicists and three of them had won Nobel Prize. Through them his theories continue to influence modern physics.
Awards & Achievements
Julian Schwinger shared the 1965 Nobel Prize in Physics along with Richard Feynman and Shinichiro Tomonaga. Although three of them worked separately, their fundamental work in quantum electro dynamics injected new ideas in the field of QED, which had far reaching consequences.
Other than the Nobel Prize, Schwinger also received the Nature of Light Award of the U.S. National Academy of Sciences in 1949, Albert Einstein Award in 1951 and the U.S. National Medal of Science in 1964.
He also received honorary D.Sc. degrees from Purdue University in 1961 and from Harvard University in 1962.
