Annals of Library Science and Documentation 1983,30(3-4),177-184 CHANDRASEKHAR: WINNER OF THE 1983 NOBEL PRIZE FOR PHYSICS: A CITATION ANALYSIS STUDY OF HIS WORKS DA VENDRA K GUPTA Department of Library Studies University of Ibadan lbadan (Nigeria) A brief reference is made of the reward system in science and Nobel Prizes. Chandrasekhar shared the 1983 Nobel Prize for physics with William A. Fowler. A brief biographical account in respect of Cbandrasekbar is also given. The data collected from ti.e comprehensive volumes and annual cumulative volumes of the Science Citation Index were analysed. In all 401 works of Chandrasekhar were cited 10,359 times during 1965-1980. Out of all the contributions six could be identified as citation classics, having received about 53% of all the citations. Chandrasekhar received several prestigious awards during the last fifty years and reached to tl.e apex in 1983 having received Nobel Prize. The study of this analysis is concluded by stating that there is a high correlation in quantity, quality of works, citedness and receiuing honours and awards, and in the case of Cbandrasekbar the recognition appears to be belated. INTRODUCTION Awards ana prizes are important part of the reo ward systcrr of science and such rewards are determined primarily by merit, normally based on the original works of excellence contributed by the scientists for the advancement of science. Social aspects of the reward svstem of science are discussed by Merton in several of his writings [6,7}. Cole.md Cole, based on their studies conducted on American ",,'ademic physicists have produced an excellent work on the opera tion of the reward system in science [1]. The Noble Prizes The Noble Prizes, institu tcd :'y Alfred Nobel, the inventor of dynamite arc tr.e most notable, dramatic and prestigious awards in science. The prizes are unique in the reward system of science and have been awarded since 1901 in three fields of science: Physics, Chemistry and the composite of Physiology and Medicine. It was the only award that was known to all the 1300 American physicists queried by Cole and Cole and its. prestige was ranked First=-above that of all others in a long list of awards in physics [1]. Zuckerman has done an extensive sociological and quantitative analysis of Nobel Prize winners and mentioned that the prizes reflect the international character of science. They have been distributed on a larger and wider scale to 334 scientists from 26 different countries [9,10]. Assessment of quality of contributions Estimation and assessment of quality of scientists are not easy but to some reasonable extent this could be based on the assumption that the awards in a reward system of science are given on the quality of performance of scientists. The quality of performance which is the sole determinant is based on the quality of published works. Thus, the rewards, logically, closely parallel the distribution of publications. For measuring the quality of publications, citation counts as a measure of recognition, diffusion, the extent of diffusion and utilizatior. of scicntific works, have been Iound as useful and helpful took The number of citations a c;nrribution has received is taken as a measure of quality to represent the relative scientific significance among other contributions. The quality assessment in this case is based on the assumption that the most sic.niiigmt contributions will be most frequently cited by subsequent investigators. The potential of citatio» 177
GlTPTA analysis has been amply dcmonstrutcd by numerous studies reported on highly cited contrihution(s), contributor(s) and joumal(s) etc. Garfields writings on the subject are very rich [4]. In recent papers, Garfield has reported that there is a high correlation between citedness, Nobel Prizes and membership of National Academies [2,3]. Therefore, citation analysis techniques can be employed with reasonable confidence' to assess the quality of scientific contributions. For such analysis, Science Citation Index (=SCI), a rich data base, provides sufficiently good and reliable source of data. Utilizing the SCI, a citation analysis study was conducted to study the citation trends of the contributions of S. Chandrasekhar who won the 1983 Nobel Prize for physics. A brief biographical account ofs. Cbandrasekbar A brief biographical data of S. Chandrasekhar who won the 1983 Nobel Prize for physics is given here: Subramanyan Chandrasekhar was born in Lahore, then a part of India, on 19th October, 1910 in a prominent Hindu family (His uncle, Sir Chandrasekhar Raman was awarded Nobel Prize in 1930). He had education at the Presidency College, Madras (India) and Trinity College, Cambridge (U.K.) and obtained Fellowship of Trinity College, Ph.D. and Sc.D. He was Managing Editor of the Astrophysical Journal from 1952-1971 and gave Nehru Memorial Lecture, India in 1968. He is Member of the National Academy of Sciences, USA; Member of Americal Philosophical Society; Fellow, Royal Society London, U.K.; and Member of American Academy of Arts and Sciences, USA. Dr Chandrasekhar has received the following awards and prizes: Bruce Gold Medal (Astronomical Society of Pacific), 1952; Gold Medal (Royal Astronomical Society, London) 1953; Rumford Medal (American Academy of Arts and Sciences, USA) 1957; Royal Medal (Royal Society, London) 1966; National Medal of Science (USA) 1966; Henry Draper Medal (National Academy of Sciences, USA) 1971; Honorary D.Sc. Oxford University, 1972; Dannie Heineman Prize (American Institute of Physics, USA) 1974;and the Nobel Prize, 1983. Chandrasekhar went to America in 1936 and he is Professor of Theoretical Astrophysics 178 in the l.iniversii y of Chicago, USA since 1937. He was elected as Fellow of Royal Society, London in 1944 when he was only 31 years old. Chandrasekhar shared Nobel Prize with William A. Fowler.on their work on the evolution of stars in astrophysics which is the liveliest topic in Astrophysics. SCOPE OF THE STUDY In this study, an attempt has been made to analyse the citation trends of the citations received by Chandrasekhar for all his contribu-.tions during the period between 1964 and 1980. The main purpose of the study was to collect citation data of Chandrasekhar's contributions and other details of awards received by him and then to correlate them with each other to prove the hypothesis that there exists a correlation in citation density and awards received by a scientist. METHODOLOGY Data were collected from SCI data base by consulting comprehensive volumes for the periods, 1965-1969 and 1970-1974 and individual annual cumulative volumes for the years 1975 to 1980. Year of publication, and number of contributions against that year were noted and their citations against the year(s) of citations were noted. The data were computed and compiled and are presented in Table 1. The total number of cited items are shown against each year of publication with citations in specific years and periods. Total number of cited items and total number of citations to these items are also shown in the columns of specific years and periods. Citations were counted for all the contributions for all the years and periods. A few items were identified during this exercise which had 15 or more citations for one year. These items were separated and frequency of citations for these were counted for specific years and periods, as counting the frequency for all the items is a very tedious and time consuming job. The data for these super-cited items are given in Table 2 and bibliographical details are given in the Appendix. Keeping in view the limitations of using SCI data base, all Ann Lib Sci Doc
CHANDRASEKHAR: CITATION ANALYSIS STUDY possible duplications were avoided, specially for another physicist, S. Chandrasekhar, a specialist on liquid crystals. The task would have been easier if the facilities for computer search were available. Searching and analysing more than 10,000 citations manually is quite a tough job to do. CITATIOl'f ANALYSIS: DISCUSSIONS RESULTS AND Citation data collected from the SCI data base for the period 1965-1980 for all the contributions of Chandrasekhar from the first cited item in 1929 to the last cited items in 1979 were analysed. The results of analysis are presented in Table 1. First citable publication appeared in SCI data base in 1929 which indicates that Chandrasekhar became a citable contributor at the age of 19 years. But the impact started from his contributions of 1931. The items of 1931 are even being cited currently. In all, three of his contributions of 1931 have been cited even in 1979. A total of 33 items published during the period 1929-1940 were cited; 107 items during the period 1941-1950; 137 items during the period 1951-1960; 103 items during the period 1961-1970 and a total of 40 items for the period 1971-1979. The maximum citable items were contributed during the period 1951-1960 i.e. 137. A total and maximum for a year, 29 items for the year 1943 were cited during the period 1965-1969 and 1970-1974. Out of these this is the largest number of contributions of any year cited during one year. A total of 401 contributions were cited during 1970-1974, having received 3,416 citations during that period, which gives an average of 8.5 citations per item. The largest number of contributions cited in one single year is 193 for the year 1979 having received a total of 76!i citations or an average of 4.0 citations per item (compared to 1.96 citations per item for 1980 SCI data base) [5]. Chandrasekhar received a total of 10,359 citations to his contributions during the period 1965-1980, compared to 8,179 citations received by him during the period 1961-1975 [2] which makes a total of 11,993 or say roughly about 12,000 for the period 1961-1980. Vo! 30 No 3 4 Sept Dee 1983 He received an average of 518 citations per year during the period 1965-1969; 683 during the period 1970-1974; 726 during the period 1975-1980; an average of 545 citations for the period 1961-1975 and 647 for the period 1965-1980 (period under study). The average number of citations in the 1961 SCI to the life work of Nobel laureates who won prize in physics during 1955-1965 was 58, compared to an average of 5.5 citations to the other scientists cited in 1961. Only 1% of the quarter million scientists who appear in the 1961 SCI received 58 or more citations [2]. According to Cole and Cole, the average number of citations to the work of receipients of Nobel Prize in the last ten years was 199 in the 1965 SCI [1]. Compared to these figures, Chandrasekhar's standing is of a very high order. Chandrasekhar's rank among the 250 most cited authors during the period 1961-1975 is 38. According to number of citations received, among the Nobel Prize winners in physics during the period 1950 1977, his rank is fifth. L.D. Landau, a Soviet scientist who received his Nobel Prize in 1962 has to his credit the highest number i.e. 18,888 citations for that period; J.R.D. Jensen, a German scientist, 1963 Nobel Prize winner has exceptionally low number of citations, having only 79 for the same period. Lowery and others have exceptionally large number of citations, 58,304 for this period, and 50,016 for their single contribution: LOWERY, O.H.; ROSENBROUGH, N.J.; FAFF, A.L. and RANDALL, R.J. Protein measurement with the folin phenol reagent. J.Biol.Chem. 193; 256-265; 1951. For more detailed descriptions and data, Garfield's recent papers which are most relevant on the topic can be consulted [2,3]. Analysis of some heavily cited contributions While analysing the data, a few heavily and consistently cited items were identified. Citation data were collected and analysed separately in detail for these items. Analytical details are presented in Table 2 and bibliographical details of these contributions are given in Appendix. At least six such items were identified and it was found that this small fraction of the 401 119
GUPTA contributions cited, has received as many as 5,488 citations out of 10,359 or say 53% of the citations received by all the contributions. At least three out of these six can be classified as citation classics. Item 3,4 and 5 have received more than 1,000 citations each. In all, these three items have received a total of 4,472 citations which is more than 81% of the six heavily cited items or more than 41% of all the citations received by all the works of Chandrasekhar. Item no.2 and 3 have been cited with an annual average of 85 and item 3 with an average of 109 compared to 1.96 of SCI data base of 1980 [5], and compared to only 800 papers which have been cited over 500 times since the SCI was initiated [2]. Item 2 was cited 231 times during 1965-1969 or say at an average rate of 46 citations per year; 379 times during 1970-1974 or say 76 times annually; citation frequency in recent years was 159 in 1979 or say 125 citations per year during 1975-1980. This shows that the contribution has gained its visibility ann usability in recent years. Almost the same thing is true with item 3. Anyway, to study the impact and influence of these classic papers further investigation is needed, and this is not the scope of this paper. Another feature observed from this data is that citability of these classic papers suddenly increased during the years 1977 and 1978 when the average increased to 62.5 and 62.3 respectively from an average of 53. Chandrasekhar's paper published in 1943 (item 3 in Appendix) ranks 85 among all the contributions of primary author's most cited items during the period 1961-1975 [2]. This item was most heavily cited among all his works in 1979 and 1980. His book published in 1961 (item 5 in Appendix) was listed at rank 17 among all the most cited books in Physics for the period 1961-1972, having 235 citations to its credit for that period. This contribution among all the works is most cited having 1,748 citations to its credit for the period 1965-1980. CONCLUSIONS Chandrasekhar became a scientific citable contributor in the field of Astrophysics in 1929 with his original ideas about the dwarf star and evolution of stars. In all,401 of his contributions 180 received 10,359 for the period under study and abou t 12,000 citations since the initiation of SCI. Six of his contributions can be classified as citation classics.among them three are the most cited ones. These items are being cited even in the recent works. This confirms the theory that his contributions received wide recognition and have high visibility and usability. Chandrasekhar's works are not only cited heavily but consistently over the whole period of half a century.chandrasekhar was elected member of several National Academies and earliest recognition was in 1944 when he was elected as the Fellow of the Royal Society, London, only at the age of 34. He received several awards of high visibility (visibility; 79 in 1952; 44 in 1953; 37 in 1957; 16 in 1974 on the visibility scale of 100 as given in Appendix B of Cole and Cole [1]). The recent award of visibility rank First, received in 1983 and shared with Fowler can be said to be belated. As he himself expressed "Usually my work has become appreciated only after some length of time" [8]. This analysis confirms the hypothesis that it is not only the quantity of contributions, but in this case, the quality of contributions has been very widely recognized by the scientific community. The contributions were recognized to consider him for several prestigious awards, medals and other distinctions of high order, and these awards were given to him one after the other right from 1944 in very chronological order and in the order of merit. Therefore, conclusions can be drawn that there is a relationship in quantity, quality and recognition of original contributions of excellence which get diffused into the common stock of scientific knowledge; and that there is a good relationship of such contributions and number and kind of awards the contributor gets from the reward system of science; and finally that there is a positive relationship in rewards, citedness and quality of contributions. The study can be extended for further analysis to identify the network of scientists working on the topic and also tc identify the core journals by compiling a citography. A list of important and most cited items with bibliographical details is provided as Appendix, which may be found useful for collection d. velopment by the libraries and information centres :nterested on the aspect Ann Lib Sci Doc
CHANDRASEKHAR; CITATION ANALYSIS STUDY of evolution of stars - lively and current topic (4J in astrophysics. It is further recommended that somebody may attempt to compile a comprehensive bibliography for all the contributions of Chandrasekhar. [5J... Essays of information Scientist. Volume 1-4. Institute for Information Science, Philadelphia, Pa, 1977; 1980. Journal Citation Report 1980. Institute for Information Science, Philadelphia, Pa; 1981. REFERENCES [6 J Merton, Robert K. Priorities in scientific discoveries. p.639-4 7. [lj Cole, Jonathan R; and Cole, Stephen. Social [7 J stratification in science. Chicago; University of chicago Press, 1973; 283pp. [21 Garfield, Eugene. The 250 most- cited authors 1961-1975. Pt.I1. The correlation between citedness. Nobel Prizes and Academy membership. Current Contents. No.50 (December 12, 1977)(Reproduced in Garfield's Essays of Information Scientists, p.337-47). [9 J [3J... Are the 1979 Prizewinners of Nobel class? Current Contents. No.38 (September 22, 1980) (Reproduced in Garfield's Essays of [10 J Information Scientist; Vo1.3). [8J... Sociology of science. Chicago, III. University of Chicago Press, 1973. The 1983 Nobel Prize for Physics was shared by Subramanyan Chandrasekhar, 73, of the University of Chicago and William. A. Fowler, 72, of Caltech for their work on the evolution of stars. Time, October 31, 1983; No.44; pp.39. Zuckerman, Harriet A. The Sociology of the Nobel Prizes. Scientific American. No.217 (November, 1967); pp.25-33.... Scientific elites, Nobel Laureates in the United States. Free Press, New York, 1977,302p. Vol 30 No 34 Sept-Dee 1983 181
GUPTA Table 1 : Cited publications of Cbandrasekbar during the period 1929-1980 Year of Period during items publication were cited Year of publication ----_...----------------------------..---- of cited --..._---------------------------------_.._------_.._------------------------------------------- TOTAL items 1965-69 1970-74 1975 1976 1977 1978 1979 1980 (Max) Ie 11 1929 1 1 1930 1 1 1931 3 3 1 1 2 3 2 3 1932 1 2 1 2 2 1933 5 6 1 5 2 5 4 3 6 1934 7 6 2 2 1 1 1 7 1935 3 6 2 2 2 2 1 6 1936 2 1 2 1937 1 1 1 2 1 2 1938 3 5 2 2 1 1 5 1939 6 3 2 2 1 1 2 1 6 1940 - (32) - (33) - (10) - (14) - (9) 1 (12) - (20) - (14) 1 (33) 1941 9 7 1 1 1 2 4 1 9 1942 8 5 2 2 3 3 3 4 8 1943 29 29 10 12 12 8 12 16 29 1944 8 7 5 2 3 1 2 2 8 1945 7 12 5 4 4 3 5 3 12 1946 9 14 3 4 4 2 1 1 14 1947 7 11 2 1 3 5 5 3 11 1948 7 3 1 1 2 1 2 2 7 1949 6 8 1 1 3 4 4 3 8 1950 8 (98) 11 (107) 3 (33) 2 (30) 5 (40) 6 (35) 9 (47) 4 (29) 11 (107) 1951 6 10 2 2 1 3 1 1 10 1952 13 15 4 3 5 3 6 3 15 1953 17 16 9 4 3 7 4 8 17 1954 25 16 8 6 5 4 8 7 25 1955 15 12 2 4 5 2 1 4 15 1956 5 12 5 4 5 6 4 2 12 1957 19 12 8 3 4 4 5 2 19 1958 19 12 6 7 8 10 6 8 19 1959 5 2 1 2 1 2 1 5 1960 13 (137) 13 (119) 5 (50) 8 (43) 7 (44) 7 (48) 5 (40) 5 (41) 13 (137) 1961 13 10 2 3 2 3 3 2 13 1962 17 19 6 6 7 5 8 4 19 1963 18 10 6 5 5 3 3 1 18 1964 15 12 7 7 6 7 2 6 15 1965 12 11 5 2 3 3 3 3 12 1966 6 8 1 2 2 1 1 8 1967 12 7 3 6 2 5 4 3 12 1968 5 6 5 4 4 5 5 2 6 1969 5 17 13 8 10 13 9 8 17 1970 - (103) 13 (98) 10 (58) 8 (51) 7 (48) 6 (51) 7 (43) 8 (37) 13 (103) 1971 9 7 7 1 2 3 3 9 1972 17 12 7 7 6 8 7 17 182 Ann Lib Sci Doc
CHANDRASEKHAR: CITATION ANALYSIS STUDY Year of Period during items publication were cited Year of publication _ _ _ _~ n ---...-------... -----..---..-~..----------..-.. ~-------------------------------.....---_.._-----_... _.. _- I : cited TOTAL ;ems 1965-69 1970-74 1975 1976 1977 1978 1979 1980 (Max) 1973 5 (44) 5 9 3 5 1 6 9 1974 4 3 2 5 1 4 5 1975 3 (31) 5 4 5 9 6 9 1976 3 (34) 7 7 8 7 8 1977 2 (26) 6 4 3 6 1978 4 (40) 7 11 11 1979 4 (43) 10 10 (44) Total items 370 401 182 172 167 186 193 178 Total citations 2,589* 3,416** 640 679 709 741 765 820 10,359+ Average per item 3.5 3.9 4.2 4.0 4.0 4.6 Within parenthesis is given the SUb-total for decades * ** +Average citations per year = 647 Citations per year = 518 Citations per year = 683 Table 2 : Citation Analysis Data for some important contributions of Chandrasekhar Period of citations Year of citations Average Item No -------------------------------------------------------..------------------------------------..--------~-------------- Total citations 1965-69 1970-74 1975 1976 1977 1978 1979 1980 per year 1 155 144 36 18 26 28 25 35 467 (8.5) 29.2 2 71 80 14 17 29 26 15 16 268 (4.9) 16.8 3 231 379 93 102 118 "144 137 159 1,363 (24.8) 85.1 4 400 351 90 97 101 111 102 109 1,361 (24.8) 85.1 5 377 598 109 145 140 121 132 126 1,748 (31.9) 109.3 6 58 16 20 29 32 19 27 281 (5.1) 25.6 Total 1,234 1,610 358 399 443 462 430 472 5,488 Percentage 47.7 47.1 55.9 58.8 62.5 62.3 56.2 57.6 53.0 Note: Within parenthesis is given the percentage of the total Vol 30 No 34 Sept-Dee 1983 183
GUPTA APPENDIX Bibliographic details and citations analysis for some important contributions of Chandrasekhar for the period 1965-1980 Item No. Citations Received Bibliographic details Some other important contributions 1. 461 2. 268 3. 1,363 4. 1,361 5. 1,748 6. 281 An Introduction to the Study of Stellar Structures. New York; Dover; First published in 1939; 2nd edition in 1967. 509pp. (Astrophysical monograph; Sponsored by Astrophysical Journal). Principles of Stellar Dynamics. Chicago, Ill. The University of Chicago Press; 1942; 251 pp. (Astrophysical monograph; Sponsored by Astrophysical Journal). Stochastic Problems in Physics and Astronomy. 15; 1-89, 1943. (Also published by the American Institute of Physics for the American Physical Society). ~~~~~~YJ:y~ Radioactive Transfer. Oxford University Press; 1950; published second edition by Dover in 1960; 393 pp. (The International Series of monographs on Physics). Hydrodynamic and Hydromagnetic Stability. Oxford, Clarendon Press; 1961. Ellipsoidal Figures of Equilibrium. New Heaven, Yale University Press, 1969; 252pp. (Mrs Hepea Ely Stillman Memorial Lectures, 1963). 1. The Density of White Dwarf Stars. Phil. Mag. 31; 592-595; 1931. 2. The Illumination and Polarization of the Sunlit Sky on Rayleigh Scattering. Philadelphia. American Philosophical Society, 1954; 643-728. (Transactions of the American Philosophical Society; New Series v 44; pt 6). 3. New Methods in Stellar dynamics. New York, 1943 (New York Academy of Sciences, Annals; Vol. XLV, part 3). 4. The Normal Reflection of a blast Wave. Aberdeen Proving Ground. Md. Ballistic Research Laboratories, 1943). (US Ballistic Research Laboratories Report No.439). 5. Plasma Physics: A Course given at the University of Chicago. Notes compiled by S.K. Trehan. University of Chicago Press, 1960. (A Reproduction of Trehan's Note of 19 lectures with only minor amplifications at a few places). 184