Raj Kumar Pathria (born March 30, 1933) is a

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

, a Distinguished Professor Emeritus at

University of Waterloo The University of Waterloo (UWaterloo, UW, or Waterloo) is a public research university with a main campus in Waterloo, Ontario Waterloo is a city in the Canadian province of Ontario. It is one of three cities in the Regional Municipality ...

, and an

Urdu Urdu (;"Urdu"
''

Men of Sciences & Technology in India, Edited by Raj K Khosla, Premier Publishers (India), New Delhi, 1967, page P-20.Men of Education in India (Distinguished Who's Who), Compiled by C L Khosla, Premier Publishers (India), New Delhi, 1965, page 211. Pathria is known for his work on

superfluidity Superfluidity is the characteristic property of a fluid with zero viscosity which therefore flows without any loss of kinetic energy. When stirred, a superfluid forms vortices that continue to rotate indefinitely. Superfluidity occurs in two i ...

liquid helium Liquid helium is a physical state of helium at very low temperatures at standard atmospheric pressures. Liquid helium may show superfluidity. At standard pressure, the chemical element helium exists in a liquid form only at the extremely low temp ...

Lorentz transformation In physics, the Lorentz transformations are a six-parameter family of linear transformations from a coordinate frame in spacetime to another frame that moves at a constant velocity relative to the former. The respective inverse transformation i ...

thermodynamic Thermodynamics is a branch of physics that deals with heat, work, and temperature, and their relation to energy, entropy, and the physical properties of matter and radiation. The behavior of these quantities is governed by the four laws of ther ...

quantities, an exact evaluation of lattice sums and finite-size effects in

phase transitions In chemistry, thermodynamics, and other related fields, a phase transition (or phase change) is the physical process of transition between one state of a medium and another. Commonly the term is used to refer to changes among the basic states of ...

. Pathria is also the author of a graduate textbook on

statistical mechanics In physics, statistical mechanics is a mathematical framework that applies statistical methods and probability theory to large assemblies of microscopic entities. It does not assume or postulate any natural laws, but explains the macroscopic be ...

, whose fourth edition appeared in the year 2021. He also wrote a book on relativity that was published as a Dover edition in the year 2003.

Early life

Pathria was born in a middle-class Punjabi family to parents Ramji Das Pathria and Mela Devi Pathria in a small town named Ramdas, 28 miles to the north of Amritsar. He received his early education in a local high school and then joined the Hindu College, Amritsar for his FSc studies. He was placed on the 'Role of Honour' of that college in the year 1950.

Career

Pathria obtained his BSc Honours and MSc Honours degrees from

Panjab University Panjab University (PU) is a Collegiate university, collegiate public state university located in Chandigarh, Punjab. Funded through both Punjab, India, State and Government of India, Union governments, it is considered a state university (Indi ...

Hoshiarpur Hoshiarpur () is a city and a Municipal corporations in India, municipal corporation in Hoshiarpur district in the Doaba region of the Indian state of Punjab, India, Punjab. It was founded, according to tradition, during the early part of the ...

in July 1953 and July 1954, respectively, and soon thereafter, at the invitation of Professor F.C. Auluck, joined the graduate school of Physics at the

University of Delhi Delhi University (DU), formally the University of Delhi, is a collegiate central university located in New Delhi, India. It was founded in 1922 by an Act of the Central Legislative Assembly and is recognized as an Institute of Eminence (IoE) ...

for his doctoral studies – which he completed in March 1957. In February 1958, he joined the

as a lecturer in

physics Physics is the natural science that studies matter, its 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 which r ...

and in April 1961 got promoted to readership. In August 1964, he left Delhi to take up a visiting professorship at

McMaster University McMaster University (McMaster or Mac) is a public research university in Hamilton, Ontario, Canada. The main McMaster campus is on of land near the residential neighbourhoods of Ainslie Wood and Westdale, adjacent to the Royal Botanical Ga ...

in Canada. Even though his field of research at the

was primarily

, Pathria, during that time, got fascinated with the subject of relativity and in 1963, with the friendly cooperation of the Hindustan Publishing Corporation (India), produced a book entitled ''The Theory of Relativity''. This maiden attempt at book-writing resulted in fabulous reviews from far and wide, especially from Professor William McCrea – who himself was a celebrated author on this subject. In 1974, the Pergamon Press, Oxford produced a second edition of that book and in 2003

Dover Publications Dover Publications, also known as Dover Books, is an American book publisher founded in 1941 by Hayward and Blanche Cirker. It primarily reissues books that are out of print from their original publishers. These are often, but not always, books ...

of New York took that book under their wings. In Canada, Pathria continued his research in the diverse field of

; at the same time, he gave graduate courses on that subject at

Hamilton Hamilton may refer to: People * Hamilton (name), a common British surname and occasional given name, usually of Scottish origin, including a list of persons with the surname ** The Duke of Hamilton, the premier peer of Scotland ** Lord Hamilt ...

and the

University of Alberta The University of Alberta, also known as U of A or UAlberta, is a public research university located in Edmonton, Alberta, Canada. It was founded in 1908 by Alexander Cameron Rutherford,"A Gentleman of Strathcona – Alexander Cameron Rutherfor ...

, Edmonton. In 1967, he returned to

India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...

to take up professorship of

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 natural phenomena. This is in contrast to experimental physics, which uses experim ...

at the

, Chandigarh, where (apart from conducting research in a variety of subjects in

mathematical physics Mathematical physics refers to the development of mathematics, mathematical methods for application to problems in physics. The ''Journal of Mathematical Physics'' defines the field as "the application of mathematics to problems in physics and t ...

) he continued his mission of teaching the fundamentals of

. In 1969 Pathria returned to Canada and, in addition to his other academic pursuits, continued to teach a variety of courses at the

and the

University of Windsor , mottoeng = Goodness, Discipline and Knowledge , established = , academic_affiliations = CARL, COU, Universities Canada , former_names = Assumption College (1857-1956)Assumption University of Windsor (1956-1963) , type = Public universit ...

. In 1972 the Pergammon Press, Oxford, published his classic text ''Statistical Mechanics'', which became an instant success on the international scene. In the early 1990s, when his new publishers (Butterworth-Heinemann) persuaded Pathria to produce a second edition of this text, he sought the help of Surjit Singh, a former student of his from the

Chandigarh Chandigarh () is a planned city in India. Chandigarh is bordered by the state of Punjab to the west and the south, and by the state of Haryana to the east. It constitutes the bulk of the Chandigarh Capital Region or Greater Chandigarh, which al ...

days (who had also been a postdoctoral fellow with him at Waterloo during the years 1983–87). The result of this joint effort was a brand new edition of this book that came out in July 1996 and, like its predecessor, continued to be a bestseller. Pathria retired from the

in August 1998 and, soon thereafter, moved to the west coast of the US and became an adjunct professor of physics at the

University of California The University of California (UC) is a public land-grant research university system in the U.S. state of California. The system is composed of the campuses at Berkeley, Davis, Irvine, Los Angeles, Merced, Riverside, San Diego, San Francisco, ...

San Diego San Diego ( , ; ) is a city on the Pacific Ocean coast of Southern California located immediately adjacent to the Mexico–United States border. With a 2020 population of 1,386,932, it is the List of United States cities by population, eigh ...

– a position he continued to hold till 2010. In 2009, Pathria's newest publishers (Elsevier/Academic) prevailed upon him to produce a third edition of this book. He now sought the help of Paul Beale, of the

University of Colorado The University of Colorado (CU) is a system of public universities in Colorado. It consists of four institutions: University of Colorado Boulder, University of Colorado Colorado Springs, University of Colorado Denver, and the University of Co ...

at Boulder, whose co-authorship resulted in another brand new edition in March 2011. Ten years later, in 2021, Pathria and Beale produced a fourth edition of this book.

Research interests

Raj Pathria has published over 110 research papers in a variety of international journals of repute. These papers are mainly spread over the following topics. #Superfluidity in liquid helium II --- one of the topics of Pathria’s Ph.D. thesis. #Lorentz transformation of thermodynamic quantities --- another topic of Pathria’s Ph.D. thesis. #Polymers and the Theory of Numbers --- a fascinating subject pursued in collaboration with V.S. Nanda. #Finite-size effects in systems undergoing phase transitions --- the main topic of Pathria's life-long pursuit. #An exact evaluation of ‘lattice sums’ using Poisson’s summation formula. #A study of ‘stochastic phenomena in sociology’ --- pursued in collaboration with Karmeshu. #Finite-time thermodynamics --- a new ripple in an old pond. #Relativity and Cosmology. Pathria's complete list of publications can be seen here.

Honours

* Fellowship of the American Physical Society, 1976 * Recipient of the "Distinguished Teacher award", University of Waterloo, 1977 – the citation for this award was presented at the UW convocation held on May 27, 1977 * Distinguished professor emeritus, University of Waterloo, 1999 – this honor was bestowed upon Pathria at the UW convocation held on June 18, 1999

Personal life

Pathria is married to a former student of his, named Raj Kumari (nee Gulati). They were blessed with two daughters and a son, as well as five grandchildren; unfortunately, they lost their younger daughter to Cancer in 2011. Pathria's current hobbies are 'contemporary world affairs' and 'Urdu poetry'. Right from his childhood, Pathria was nurtured in an atmosphere replete with

Urdu language Urdu (;"Urdu"
''Random House Webster's Unabridged Dictionary''. ur, , link=no, ) is an Indo-Aryan languages, In ...

, Urdu idiom and

Urdu poetry Urdu poetry ( ur, ) is a tradition of poetry and has many different forms. Today, it is an important part of the cultures of South Asia. According to Naseer Turabi there are five major poets of Urdu which are Mir Taqi Mir (d.1810), Mirza Ghalib ...

. Having read and imbibed dozens of classics emanating from stalwarts like

Mir ''Mir'' (russian: Мир, ; ) was a space station that operated in low Earth orbit from 1986 to 2001, operated by the Soviet Union and later by Russia. ''Mir'' was the first modular space station and was assembled in orbit from 1986 to&n ...

Ghalib Mirza Beg Asadullah Khan (Urdu, fa, مرزا بیگ اسد اللہ خان; 27 December 1797 – 15 February 1869) also known as Mirza Ghalib (Urdu, fa}) was an Urdu and Persian language, Persian shayar (poet), poet of the 19th century Mughal Em ...

Zauq Sheikh Muhammad Ibrahim Zauq (1790–1854) was an Urdu poet and scholar of literature, poetry and religion. He wrote poetry under the pen name "Zauq", and was appointed poet laureate of the Mughal Empire, Mughal Court in Delhi just at the age ...

, Momin,

Hali Hali may refer to: *Hali I of the Maldives (died 1268), Sultan of Maldives from 1266 to 1268 * Hali II of the Maldives (died 1288), Sultan of Maldives from 1278 to 1288 *a medieval Latinisation of Arabic Ali (also ''Haly'') ** Haly Abenragel, com ...

, Dagh and

Iqbal Iqbal, Eqbal, Ikbal, or Eghbal may refer to: Geography Iran * ''Eqbal, Iran'', a village in West Azerbaijan Province *''Eqbaliyeh'', rural district in Iran * ''Eqbal-e Gharbi Rural District'', western provincial district in Qazvin, Iran * ''Eqbal- ...

, down to modernists like AsGhar, Fani,

Hasrat Hasrat is a popular name predominantly used in Indian subcontinent. It is also a popular pen name for Urdu poets in India and Pakistan. It's an Urdu word, meaning "wish" or "desire". Notable Urdu poets that use this pen name include: Muhammad A ...

Jigar ''Jigar'' is a 1992 Indian Hindi-language martial arts film directed by Farogh Siddique. It was released during the Diwali weekend and proved to be a successful hit. The plot is inspired by the 1989 American film '' Kickboxer''. Plot Raju an ...

Firaq Raghupati Sahay (28 August 1896 – 3 March 1982), also known by his pen name Firaq Gorakhpuri, was an Indian writer, Literary criticism, critic, and, according to one commentator, one of the most noted contemporary Urdu poets from India. He ...

and

Faiz ''Fāʾiz'' () is a male Arabic name meaning "successful" and "victorious" overflowing, plenty. It is derived from its root word ''Faʾz'' ( which means "successful". People with the name * Faiz Mohammad Katib Hazara (1862/63–1929), a Hazar ...

, Pathria finally turned to writing Urdu poetry himself – but only around the year 1993 when he was close to retirement from

Physics Physics is the natural science that studies matter, its 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 which r ...

. Pathria – now pen-named '

Qais Qais ( ar, قیس) is an Arabic given name. 'Qays' and 'Qai' are alternatives of Qais. Notable people with the name include: *Imru' al-Qais, Arabic poet in the 6th century *Kais Saied (born 1958), Tunisian President *Qais Ashfaq (born 1993), Britis ...

' (after the legendary lover of the Arabic damsel Laila) – is now known for his latest compilation of Urdu

Ghazal The ''ghazal'' ( ar, غَزَل, bn, গজল, Hindi-Urdu: /, fa, غزل, az, qəzəl, tr, gazel, tm, gazal, uz, gʻazal, gu, ગઝલ) is a form of amatory poem or ode, originating in Arabic poetry. A ghazal may be understood as a ...

s entitled ''Sahraa Sahraa''.Hindi edition
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References