imported>Ganesh P Narayanan at 16:44, 3 August 2021

2021-08-03T16:44:38Z

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{{Use dmy dates|date=March 2019}}
{{Use Indian English|date=June 2017}}
{{Infobox scientist
| name = R.S. Krishnan
| image =
| alt =
| caption =
| birth_date = {{Birth date|1911|9|23|df=y}}
| birth_place = Rappal{{coord|10.4094515|76.2685119|type:city_region:IN|display=inline}}, [[Thrissur]], [[Kingdom of Cochin]], [[British Raj]]<br/>(now [[Kerala]], [[India]])
| death_date = {{Death date and age|1999|10|2|1911|09|23|df=y}}
| death_place = [[Bengaluru]], [[Karnataka]], India
| residence =
| nationality = [[Indian nationality|Indian]]
| fields = {{ublist | [[Colloids]] | [[Experimental physics]]}}
| workplaces = {{ublist | [[Indian Institute of Science]]}}
| alma_mater = {{ublist | [[St. Joseph's College, Tiruchirappalli]] | [[University of Cambridge]]}}
| doctoral_advisor = {{ublist | [[C.V. Raman]] | [[Norman Feather]]}}
| doctoral_students = {{ublist | [[P. T. Narasimhan]]}}
| known_for = Krishnan Effect
| awards = {{ublist | [[C. V. Raman]] Prize|[[Indian Institute of Science|IISc]] Platinum Jubilee Distinguished Alumni Award }}
}}

'''Rappal Sangameswaran Krishnan'''<ref name="Current_Science_obit"/> (23 September 1911 – 2 October 1999) was an Indian experimental physicist and scientist. He was the Head of the department of Physics at the [[Indian Institute of Science]] and the vice chancellor of the [[University of Kerala]]. He is known for his pioneering researches on colloid optics and a discovery which is now known as ''Krishnan Effect''.<ref name="Molecular Physics: Methods of Experimental Physics">{{cite book |url=https://books.google.com/books?id=RrQ3BQAAQBAJ&q=Krishnan+%28reciprocity%29+Effect&pg=PA420 |title=Molecular Physics: Methods of Experimental Physics |publisher=Academic Press |author=Dudley Williams (Ed.) |year=2013 |pages=420 of 500 |isbn=9781483191775}}</ref> He was a Fellow of the [[Indian Academy of Sciences]], [[Indian National Science Academy]] and the [[Institute of Physics]], London and a recipient of the [[C. V. Raman]] Prize.<ref name="Deceased Fellow">{{cite web |url=http://insaindia.org.in/deceaseddetail.php?id=N500397 |title=Deceased Fellow |publisher=Indian National Science Academy |date=2015 |access-date=5 December 2015}}</ref>
25 students were guided by RSKrishnan for Ph D.
Dr T N Vasudevan was the 25th. Prof Vasudevan retired from Physics Dept, Calicut University died on 2nd August 2021

== Biography ==
[[File:Cyclotron.jpg|thumb|140px|A modern [[Cyclotron]].]]
Krishnan was born in a small village named Rappal, in [[Thrissur district]], then in the [[Kingdom of Cochin]] and now in the South Indian state of [[Kerala]] on 22 September 1911.<ref name="Current_Science_obit">{{cite web |url=http://www.currentscience.ac.in/Downloads/article_id_077_11_1552_1553_0.pdf |title=R. S. Krishnan: an obituary |publisher=Current Science |date=1999 |access-date=25 December 2016}}</ref> He did his early schooling at local schools and, securing a scholarship, joined [[St. Joseph's College, Tiruchirappalli]] from where he completed his bachelor's degree with honours (BA Hons.) and a first rank in 1933.<ref name="Current_Science_obit"/> He subsequently joined the Indian Institute of Science, Bangalore as a research student under the physics Nobel laureate Sir [[C. V. Raman]].<ref name="Current_Science_obit"/> For his research, he received a doctorate from the [[University of Madras]] (DSc) in 1938, as the IISc did not then confer doctoral degrees.<ref name="Current_Science_obit"/> In 1938, he became a researcher at [[Cavendish Laboratory]] of [[Cambridge University]] under Sir [[John Cockcroft]].<ref name="Current_Science_obit"/> His researches at Cambridge is reported to have assisted in the development of the 37’ [[Cyclotron]] and to the observation of deuteron-induced [[Nuclear fission|fission]] in [[uranium]] and [[thorium]].<ref name="Deceased Fellow" /> The University awarded him PhD, in 1941, for his research work.<ref name="Current_Science_obit"/> He conducted his thesis research under [[Norman Feather]], a colleague of Cockcroft's and also a student of Lord Rutherford.<ref name="AIP_interview">{{cite web |url=https://www.aip.org/history-programs/niels-bohr-library/oral-histories/4559-2 |title=Norman Feather - Session II |publisher=American Institute of Physics |access-date=9 June 2016 |date=26 January 2015}}</ref>

Krishnan returned to India the same year and joined the Physics department of the [[Indian Institute of Sciences]], [[Bangalore]] in 1942<ref name="Great Teachers V.-R.S.Krishnan">{{cite web | url=http://creative.sulekha.com/great-teachers-v-r-s-krishnan_276200_blog | title=Great Teachers V.-R.S.Krishnan | publisher=Sulekha | date=2015 | access-date=5 December 2015}}</ref> where he returned to work under C.V. Raman's tutelage. After the retirement of Raman, Krishnan succeeded him as the Head of the Department of Physics in 1948. He served the institution till 1972 and, on his superannuation, he was appointed as the vice chancellor of the [[University of Kerala]], [[Thiruvananthapuram]] in 1973 and held the position till 1977.<ref name="Current_Science_obit"/> He is known to have been active during his retirement life in Bengaluru, involved with the compilation of research publications on [[Raman Effect]] and publishing a number of articles. During this period, he served as a visiting scientist at the [[National Aerospace Laboratories]] (1987–90)and was an Emeritus Scientist of the [[Council of Scientific and Industrial Research]] (CSIR).<ref name="Deceased Fellow" /> He was married to Narayani Krishnan and he died on 2 October 1999, at the age of 88, at [[Bengaluru]].{{citation needed|date=December 2015}}

== Legacy ==
Working further on the [[Raman Effect]], Krishnan discovered the reciprocity relations between the intensity of the horizontally polarised incident light getting scattered with horizontal polarization irrespective of the colloidal particles.<ref name="On the Theory of Scattering of Light">{{cite journal |jstor=97009 |title=On the Theory of Scattering of Light |author=Hans Mueller |journal=Proceedings of the Royal Society of London. Series A, Mathematical and Physical Sciences |date=June 1938 |volume=166 |issue=926 |pages=425–449 |doi=10.1098/rspa.1938.0102 |bibcode=1938RSPSA.166..425M|doi-access=free }}</ref> This is known as ''Krishnan (reciprocity) Effect''<ref name="History of Science, Philosophy and Culture in Indian Civilization: pt. 1. Science, technology, imperialism and war">{{cite book |url=https://books.google.com/books?id=lrx3wLz4itkC&q=R.+S.+Krishnan+Krishnan+effect&pg=PA923 |title=History of Science, Philosophy and Culture in Indian Civilization: pt. 1. Science, technology, imperialism and war |publisher=Pearson Education India |author=Debi Prasad Chattopadhyaya |year=1999 |pages=923 |isbn=9788131728185}}</ref> and the article was published in IISc journal on recommendation from [[C. V. Raman]] in 1936.<ref name="Scattering of light in optical glasses">{{cite journal |url=http://repository.ias.ac.in/30580/1/378.pdf |title=Scattering of light in optical glasses |author=R. S. Krishnan |journal=Proc. Indian Acad. Sci. |date=February 1936 |volume=3 |issue=211|pages=211–220 |doi=10.1007/BF03046252 |s2cid=198139008 }}</ref> He is credited with researches on Second Order Raman Spectra in diamond and in alkali halide crystals and is reported to have successfully recorded the phenomena for the first time, using the ultraviolet (mercury 2536 Å) technique of excitation for Raman spectroscopy, a technique he developed, on which he published a number of articles in peer reviewed journals.<ref name="Second-Order Raman Spectra of Crystals">{{cite journal |title=Second-Order Raman Spectra of Crystals |author=R. S. Krishnan |journal=Nature |date=August 1947 |volume=160 |issue=4059 |pages=230–231 |doi=10.1038/160230a0 |pmid=20256209 |bibcode=1947Natur.160..230K|s2cid=4126866 }}</ref><ref name="The Second Order Raman Spectrum on Diamond">{{cite journal |title=The Second Order Raman Spectrum on Diamond |author=R. S. Krishnan |journal=Proc. Indian Acad. Sci. |date=July 1946 |volume=24 |issue=1 |pages=25–32 |doi=10.1007/BF03170737|s2cid=91228159 }}</ref> This is known to have provided conformation of [[Born–Huang approximation|Born's lattice dynamical theory]].<ref name="Deceased Fellow" /> He was the first scientist to perform Brillouin scattering experiments in diamond, crystalline and fused quartz, alumina and alkali halides and is the author of a theory on [[Brillouin scattering]] in cubic and birefringent crystals, along with his student, Chandrasekhar.<ref name="Deceased Fellow" /> He also had documented investigations on thermal expansion, elastic constants and photoelastic constants of crystals and he initiated efforts on dating of Indian rock formations using nuclear geochronological techniques.<ref name="Deceased Fellow" /> He was the author of a monograph, two volumes of 'Source Book on Raman Effect' and contributed chapters to several scientific texts,<ref name="Deceased Fellow" /> besides delivering several orations.<ref name="Krishnan Memorial Lectures">{{cite web |url=http://www.nplindia.org/sites/default/files/Krishnan_Memorial_Lecture.pdf |title=Krishnan Memorial Lectures |publisher=National Physical Laboratory |date=2010 |access-date=5 December 2015}}</ref>

Krishnan served as a member of the International Committee on Ferro-electricity and sat in the International Advisory Committee for Conferences on Raman Spectroscopy.<ref name="Deceased Fellow" /> He represented India in several international conferences and seminars such as the 2nd International Conference on Crystallography in [[Stockholm]] in 1951, the International Science Conference at [[Edinburgh]], the 5th Australian Spectroscopic Conference, and the 1st International Conference on ''Raman Spectra on Crystals'' in [[Paris]] in 1965.{{citation needed|date=December 2015}} His researches have been documented by way of over 500 articles published in peer reviewed national and international journals and over 60 research scholars were mentored by him, in their doctoral studies.{{citation needed|date=December 2015}} Krishnan was a member of the council of the [[Indian Academy of Sciences]] from 1949 to 1955 and was its treasurer for a short period in 1955.<ref name="IAS Fellow">{{cite web |url=http://www.ias.ac.in/listing/fellows/deceased |title=IAS Fellow |publisher=Indian Academy of Sciences |date=2015 |access-date=5 December 2015}}</ref> He was also a member of the London Institute of Science, and the [[American Physical Society]] and was associated with several universities in Europe and the US, as a visiting professor.{{citation needed|date=December 2015}}

== Awards and honours ==
The [[Indian Academy of Sciences]] elected Krishnan as a Fellow in 1944<ref name="IAS Fellow" /> and the [[Indian National Science Academy]] followed suit in 1950.<ref name="Deceased Fellow" /> He was also a fellow of the [[Institute of Physics]], London and served as the president of the Physics Section of [[Indian Science Congress]] in 1949.<ref name="Deceased Fellow" /> He received the [[C. V. Raman]] Prize of the [[Indian Science Congress]] in 1988, four years after the [[Indian Institute of Science]] awarded him the 1984 Platinum Jubilee Distinguished Alumni Award.<ref name="Deceased Fellow" />

== Selected bibliography ==
* {{cite journal |title=Raman Effect of Conundrum |author=S. P. S. Porto, R. S. Krishnan |journal=J. Chem. Phys. |year=1957 |volume=47 |issue=3 |pages=1009–1012 |doi=10.1063/1.1711980 |bibcode=1967JChPh..47.1009P}}
* {{cite journal |title=Scattering of light in optical glasses |author=R. S. Krishnan |journal=Proc. Indian Acad. Sci. |date=February 1936 |volume=3 |issue=211|pages=211–220 |doi=10.1007/BF03046252 |s2cid=198139008 }}
* {{cite journal |title=Second-Order Raman Spectra of Crystals |author=R. S. Krishnan |journal=Nature |date=August 1947 |volume=160 |issue=4059 |pages=230–231 |doi=10.1038/160230a0 |pmid=20256209 |bibcode=1947Natur.160..230K|s2cid=4126866 }}
* {{cite journal |title=The Second Order Raman Spectrum on Diamond |author=R. S. Krishnan |journal=Proc. Indian Acad. Sci. |date=July 1946 |volume=24 |issue=1 |pages=25–32|doi=10.1007/BF03170737 |s2cid=91228159 }}

== See also ==
* [[R. S. Krishnan Higher Secondary School]]
* [[Raman Effect]]

==References==
{{reflist|colwidth=30em}}

{{authority control}}

{{DEFAULTSORT:Krishnan, R. S.}}
[[Category:1911 births]]
[[Category:1999 deaths]]
[[Category:20th-century Indian physicists]]
[[Category:Scientists from Kerala]]
[[Category:Fellows of the Indian National Science Academy]]
[[Category:Fellows of the Indian Academy of Sciences]]
[[Category:Fellows of the Institute of Physics]]
[[Category:Indian scientific authors]]
[[Category:People from Thrissur district]]
[[Category:20th-century Indian inventors]]
[[Category:Indian Institute of Science faculty]]
[[Category:St Joseph's College, Tiruchirappalli alumni]]
[[Category:University of Madras alumni]]
[[Category:Cavendish Laboratory]]
[[Category:Alumni of the University of Cambridge]]
[[Category:Heads of universities and colleges in India]]
[[Category:University of Kerala faculty]]
[[Category:People of the Kingdom of Travancore]]
[[Category:Fellows of the American Physical Society]]

R. S. Krishnan - Revision history

imported>Ganesh P Narayanan at 16:44, 3 August 2021