Subrahmanyan Chandrasekhar
Subrahmanyan Chandrasekhar FRS (19 October 1910 – 21 August 1995) was an Indian-American astrophysicist who spent his professional life in the United States. He was awarded the 1983 Nobel Prize for Physics with William A. Fowler for "...theoretical studies of the physical processes of importance to the structure and evolution of the stars". His mathematical treatment of stellar evolution yielded many of the current theoretical models of the later evolutionary stages of massive stars and black holes. The Chandrasekhar limit is named after him.
Chandrasekhar worked on a wide variety of physical problems in his lifetime, contributing to the contemporary understanding of stellar structure, white dwarfs, stellar dynamics, stochastic process, radiative transfer, the quantum theory of the hydrogen anion, hydrodynamic and hydromagnetic stability, turbulence, equilibrium and the stability of ellipsoidal figures of equilibrium, general relativity, mathematical theory of black holes and theory of colliding gravitational waves. At the University of Cambridge, he developed a theoretical model explaining the structure of white dwarf stars that took into account the relativistic variation of mass with the velocities of electrons that comprise their degenerate matter. He showed that the mass of a white dwarf could not exceed 1.44 times that of the Sun – the Chandrasekhar limit. Chandrasekhar revised the models of stellar dynamics first outlined by Jan Oort and others by considering the effects of fluctuating gravitational fields within the Milky Way on stars rotating about the galactic centre. His solution to this complex dynamical problem involved a set of twenty partial differential equations, describing a new quantity he termed "dynamical friction", which has the dual effects of decelerating the star and helping to stabilize clusters of stars. Chandrasekhar extended this analysis to the interstellar medium, showing that clouds of galactic gas and dust are distributed very unevenly.
Chandrasekhar studied at Presidency College, Madras (now Chennai) and the University of Cambridge. A long-time professor at the University of Chicago, he did some of his studies at the Yerkes Observatory, and served as editor of The Astrophysical Journal from 1952 to 1971. He was on the faculty at Chicago from 1937 until his death in 1995 at the age of 84, and was the Morton D. Hull Distinguished Service Professor of Theoretical Astrophysics.
Narinder Singh Kapany
Narinder Singh Kapany (31 October 1926 – 4 December 2020) was an Indian-American physicist best known for his work on fiber optics. He is credited with coining of the term fiber optics and is considered the 'Father of Fiber Optics'. Fortune named him one of seven 'Unsung Heroes' in their 'Businessmen of the Century' issue in 1999. He was awarded India's second highest civilian award the Padma Vibhushan posthumously in 2021.
As an entrepreneur and business executive, Kapany specialized in the processes of innovation and the management of technology and technology transfer. In 1960, he founded Optics Technology Inc. and was chairman of the board, President, and Director of Research for twelve years. In 1967 the company went public with numerous corporate acquisitions and joint-ventures in the United States and abroad. In 1973, Kapany founded Kaptron Inc. and was president and CEO until 1990 when he sold the company to AMP Incorporated. For the next nine years, Kapany was an AMP Fellow, heading the Entrepreneur & Technical Expert Program and serving as Chief Technologist for Global Communications Business. He founded K2 Optronics. He also served on the boards of various companies. He was a member of the Young Presidents Organization and later a member of the World Presidents Organization.
As an academic, Kapany taught and supervised research activity of postgraduate students. He was a Regents Professor at the University of California, Berkeley (UCB) and at the University of California, Santa Cruz. He founded the Center for Innovation and Entrepreneurial Development (CIED) at UCSC and served as Director for seven years. At Stanford University, he was a Visiting Scholar in the Physics Department and Consulting Professor in the Department of Electrical Engineering.
As an author and lecturer, Kapany published over 100 scientific papers and four books on opto-electronics and entrepreneurship. He lectured to various national and international scientific societies.