Yatendra Pal Varshni (born 21 May 1932) is a Canadian-Indian scientist in the areas of

physics Physics is the scientific study of matter, its Elementary particle, fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge whi ...

and

astrophysics Astrophysics is a science that employs the methods and principles of physics and chemistry in the study of astronomical objects and phenomena. As one of the founders of the discipline, James Keeler, said, astrophysics "seeks to ascertain the ...

Early life and education

Varshni studied at

Allahabad University The University of Allahabad is a Central University located in Prayagraj, Uttar Pradesh. It was established on 23 September 1887 by an act of Parliament and is recognised as an Institute of National Importance (INI). It is the 4th oldest mode ...

, where he obtained his B.Sc in 1950, his

M.Sc A Master of Science (; abbreviated MS, M.S., MSc, M.Sc., SM, S.M., ScM or Sc.M.) is a master's degree. In contrast to the Master of Arts degree, the Master of Science degree is typically granted for studies in sciences, engineering and medicine ...

in 1952, and his

Ph.D A Doctor of Philosophy (PhD, DPhil; or ) is a terminal degree that usually denotes the highest level of academic achievement in a given discipline and is awarded following a course of graduate study and original research. The name of the deg ...

in 1956. He published his first research paper in 1951 at the age of 19. He served as an assistant professor in the Physics Department of Allahabad University from 1955 to 1960.

Career

Varshni emigrated to Canada as a

postdoc A postdoctoral fellow, postdoctoral researcher, or simply postdoc, is a person professionally conducting research after the completion of their doctoral studies (typically a PhD). Postdocs most commonly, but not always, have a temporary academ ...

toral fellow at the National Research Council, Ottawa, Canada in July 1960, where he worked in

theoretical physics Theoretical physics is a branch of physics that employs mathematical models and abstractions of physical objects and systems to rationalize, explain, and predict List of natural phenomena, natural phenomena. This is in contrast to experimental p ...

under Ta-You Wu for two years. In July 1962, he was appointed as assistant professor in the Department of Physics at the

University of Ottawa The University of Ottawa (), often referred to as uOttawa or U of O, is a Official bilingualism in Canada, bilingual public research university in Ottawa, Ontario, Canada. The main campus is located on directly to the northeast of Downtown Ot ...

. He became associate professor in July 1965 and professor in July 1969. He retired in June 1997 and was then appointed as emeritus professor. Varshni worked in several areas of

and

. He proposed a semi-empirical relation for the temperature dependence of the energy gap in semiconductors which became known as the Varshni Equation. He developed the laser star model of quasars, which was not accepted by the astronomical community. He published more than 260 research papers in

peer-reviewed Peer review is the evaluation of work by one or more people with similar competencies as the producers of the work ( peers). It functions as a form of self-regulation by qualified members of a profession within the relevant field. Peer review ...

scientific journals, and contributed three biographies to the ''

Biographical Encyclopedia of Astronomers The ''Biographical Encyclopedia of Astronomers'' (''BEA'') is a two-volume biographical dictionary, first published in 2007, with a second edition released in 2014. The work covers astronomers from all geographies, born from antiquity to mid-191 ...

''. Varshni was the Ph.D. advisor of David Joseph Singh.

Honours

Varshni was made a Fellow of the

American Physical Society The American Physical Society (APS) is a not-for-profit membership organization of professionals in physics and related disciplines, comprising nearly fifty divisions, sections, and other units. Its mission is the advancement and diffusion of ...

Institute of Physics The Institute of Physics (IOP) is a UK-based not-for-profit learned society and professional body that works to advance physics education, physics research, research and applied physics, application. It was founded in 1874 and has a worldwide ...

(UK) and

Royal Astronomical Society The Royal Astronomical Society (RAS) is a learned society and charitable organisation, charity that encourages and promotes the study of astronomy, planetary science, solar-system science, geophysics and closely related branches of science. Its ...

(UK). He was also a member of the

American Astronomical Society The American Astronomical Society (AAS, sometimes spoken as "double-A-S") is an American society of professional astronomers and other interested individuals, headquartered in Washington, DC. The primary objective of the AAS is to promote the adv ...

and the

Astronomical Society of India The Astronomical Society of India (ASI) is an Indian society of professional astronomers and other professionals from related disciplines. It was founded in 1972, with Vainu Bappu being the founder president of the society, and as of 2010 has a m ...

References

External links

Varshni's homepage at U of OttawaPlasma Laser Star theory of quasars
{{DEFAULTSORT:Varshni, Y P 1932 births Living people 20th-century Canadian astronomers Canadian physicists 20th-century Indian physicists Indian astrophysicists University of Allahabad alumni Academic staff of the University of Allahabad