Pesic Sample

C. V. Raman and Colonial Physics:Acoustics and the Quantum

Somaditya Banerjee*

Presenting the social and historical context of Chandrasekhara Venkata Raman, this paperclarifies the nature and development of his work in early twentieth-century colonial India.Ramans early fascination with acoustics became the basis of his later insights into thenature of the light quantum. His work on light scattering played an important role in theexperimental verification of quantum mechanics. In general, Ramans worldview correctscertain Orientalist stereotypes about scientific practice in Asia.

Key words: Chandrasekhara Venkata Raman; Raman effect; Quantum theory;

Indian Association for the Cultivation of Science; Indian Institute of Science;

Physics in India; Orientalism.

Introduction

Speaking on the radio for the Indian public, Chandrasekhara Venkata Raman

(18881970) remarked:

I think it will be readily conceded that the pursuit of science derives its motive

power from what is essentially a creative urge In doing this, the man ofscience, like the exponents of other forms of art, subjects himself to a rigorous

discipline, the rules of which he has laid down for himself and which he calls

logic Intellectual beauty is indeed the highest kind of beauty. Science, inother words, is a fusion of mans aesthetic and intellectual functions devoted to

the representation of nature. It is therefore the highest form of creative art.1

Raman was a first generation bhadralok** scientist whose experiments at the

Indian Association for the Cultivation of Science (IACS) in Calcutta from 1922

onward led to his ground-breaking discovery in 1928 of the Raman effect, the

frequency-altering scattering of light by atomic systems for which he was awarded

a Nobel Prize in 1930, the first non-Western scientist to be so honored.2 This

* Somaditya Banerjee is an assistant professor in the Department of History at the Uni-versity of Idaho in Moscow, Idaho. He completed his doctorate in History of Science fromthe University of British Columbia.** A Bengali term denoting a well-mannered and educated man.

Phys. Perspect. 2014 Springer BaselDOI 10.1007/s00016-014-0134-8 Physics in Perspective

historic achievement in the sphere of science served as an important political

symbol and a catalyst for Indian strivings for independence. Though Raman

manifested a variety of national consciousness that was different than his col-

leagues Satyendranath Bose and Meghnad Saha, his remark shows his scientific

worldview, which integrated concepts of artistic and intellectual beauty. Like the

changing patterns on a kaleidoscope, Ramans intellectual interests in science also

showed a gradual change, covering a broad spectrum.

As was also the case for his mentor, the physicist and plant physiologist Jaga-

dish Chandra Bose, Ramans major research interests changed over the years:

acoustics (19091920), optics and scattering of light (19201930), ultrasonic dif-

fraction and the application of Brillouin scattering to liquids and Raman scattering

to crystals (19301940), diamonds and vibrations of crystal lattices (19401950),

optics of minerals (19501960), and thereafter the physiology of vision. In the

course of his academic career, Raman published more than four hundred and

eighty research papers (as a single author and coauthored), many of which

appeared in the Indian Journal of Physics, which he founded in 1928. He also

trained a large number of research students, many of whom went on to hold

important portfolios in administration, academia, and politics.

Because Ramans early life up to 1928 and the reception of his work has been

discussed by Rajinder Singh some years ago in this journal, the present paper is a

social history of how Raman established himself as a key figure of Indian science in

the early twentieth century, especially how he sought meaningful connections

between a modern scientific worldview and the indigenous knowledge of India,

combining his attachment to European science with local intellectual traditions

into a particular brand of Indian modernity.3 Specifically, I will explore the events

that led to the discovery of the Raman effect by Raman and Kariamanikam

Srinivasa Krishnan at the IACS in Calcutta in February 1928. I shall argue that,

though the Raman effect has generally been seen as providing a strong evidence

for the quantum nature of light, he himself was initially a staunch supporter of the

classical wave theory. Ramans faith in the wave theory, I suggest, came from his

initial interest in the physics behind several Indian musical instruments. This study

will also put Ramans work in the context of the alternate dispersion theories,

especially those of Hendrik Antoon Lorentz, Paul Drude, Peter Debye, Arnold

Sommerfeld, Charles Galton Darwin, Karl Herzfeld, Adolf Smekal, as well as

scattering experiments by Rudolf Ladenburg and Fritz Reiche, culminating with

the dispersion theory of Hendrik A. Kramers.4

Raman scattering played an important role in the experimental verification of

the quantum dispersion theory of Kramers, which formed a conceptual bridge

between Niels Bohrs and Arnold Sommerfelds old quantum theory and Wer-

ner Heisenbergs matrix mechanics. The scattering experiments of Russian

physicists Leonid Issakovich Mandelstam and Grigory Landsberg, done at around

the same time in 1928 as Raman, are also analyzed in this context. Finally, this

paper breaks from the tradition of hagiographic writings5 on Raman and argues

S. Banerjee Phys. Perspect.

that because he had strong networks in the international scientific community, he

became better known and more popular in India than Satyendranath Bose or

Meghnad Saha. The life trajectory of Raman also shows the multilayered nature of

Indian science and the subtleties that surround any consideration of science and

nationalism in early twentieth century India.6 This becomes especially evident

when Ramans intellectual style is compared to those of Bose and Saha.

Biographical Comments

Born to a middle class bhadralok Brahmin family on November 7, 1888, in Ti-

ruchirapalli in the state of Tamil Nadu in South India, Raman was the second of

eight children. His father, R. Chandrasekaran Aiyar, accepted the post of lecturer

in mathematics and physics at the A. V. N. College in Vizagapatam when Raman

was aged three. Aiyar also excelled in playing Indian musical instruments. After

receiving the first rank* in his bachelors degree in 1901, Raman was advised by his

teachers to go to England to compete for the Indian Civil Service (ICS) exami-

nation. When he failed the medical examination and the door to England was

closed, he felt relieved and remarked: I shall always be grateful to this man, the

medical officer.7 It can be inferred from this remark that either Raman was very

much attached to his country and did not want to serve the British in the ICS or

perhaps had already developed academic interests.

Raman returned to Presidency College in Madras to do his masters degree in

physics, during which he attended very few lectures and devoted most of his time

to independent research focusing mostly on Indian musical instruments. In 1906,

he published a short paper in the British Philosophical Magazine that analyzed the

phenomenon of oblique diffraction using the wave theory of light.8 Having care-

fully studied the double-slit diffraction pattern produced when light is normally

incident at the slits, Raman wondered what would happen when light struck the

slits obliquely. He came to the conclusion that when the incident angle was very

close to a right angle, the diffraction bands were no longer symmetric, as they

would have been in the case of normal incidence. He then performed simple

experiments to verify his conclusions. As Raman recalled later, he was able to

pursue such research because attending lectures was not mandatory.

After completing his masters degree in January 1907, Raman went to Calcutta

in eastern India, where he joined the Financial Civil Service as assistant accoun-

tant general. Though wanting to pursue a research career in physics, Raman saw

the utility of being in the administrative service. Such opportunities in adminis-

tration were open only to the British and those Indians who held British university

degrees, which Raman did not have. To pursue a research career in future and

make a living during the intervening period, he had to join the government service

after passing its entrance exam. Raman remarked, I took one look at all the

* Comparable to receiving first-class honours in Britain at that time.

C. V. Raman and Colonial Physics

candidates who had assembled there and I knew I was going to stand first, as he

indeed went on to do.9 His self-confidence, a marked trait of his character, turned

out to be well-founded in this case. Meanwhile, Raman also married a South

Indian woman named Lokasundari, a bhadramahila.*

Raman established contacts with the IACS,which had been founded in 1876 by

a noted Bengali bhadralok intellectual Mahendra Lal Sircar, a well-known medical

practitioner and philanthropist. Sircar saw scientific expertise and research as

important yardsticks for national awakening.10 Because Calcutta offered more job

opportunities than other provinces, Raman decided to move there in 1907, which

coincided with the rise of the nationalist movement in the city following the

partition of Bengal by the British in 1905.11 From 1907 until 1917, Raman spent his

days in the government office working as an assistant accountant and devoted his

mornings and nights to science. In this period as part-time clerk and part-time

researcher, Raman read Hermann von Helmholtzs The Sensations of Tone, which

had been translated into English by Alexander Ellis in 1885.12 Raman considered

Helmholtz the most inspirational scientific figure; The Sensations of Tone greatly

influenced his intellectual outlook.13 Helmholtzs work was presented in a lucid

form especially for the convenience of music students and dealt with sound as a

sensation, offering many insights that apparently were unclear to Raman, such as

that harmony and quality of tone differ only in degree or that the scale best

adapted to melody is not adapted to harmony.14 Wanting to explore the ramifi-

cations of Helmholtzian wave theories and interested in the aesthetics of art and

science, Raman decided to investigate the acoustics of Indian musical instruments

and check for himself whether the Helmholtzian doctrines of scale, harmony, and

melody worked for them, though he had difficulty in getting access to proper

laboratory facilities.

In 1909, Raman was promoted to the rank of currency officer in seemingly far-

away Rangoon. Frustrated by the lack of scientific equipment, he turned to the

theory governing the Indian musical instrument ectara and wrote a theoretical

paper that was accepted by the Journal of the Indian Math Club.15 Using basic

wave theory, Raman calculated the periodic variation of tension when the

vibrating wire has both ends fixed. Raman determined that the pitch of the ectaras

note was twice the frequency of oscillations of the wire and then verified the result

experimentally. Likewise, Raman studied other musical instruments: the violin,

sitar, tambura, and the veena, analyzed their frequency response and found the

dependence of the production of various frequencies on the bowing pressure, the

normal modes of vibration, and various harmonics.

Ramans early fascination with acoustics became the basis for his later insights

into the nature of light. His attachment to the wave theory stemmed from his

initial interests in the physics behind Indian musical instruments like the ectara.

Raman remarked about music, stringed instruments, and culture in ancient India:

* Female analogue of a bhadralok.


Music, both vocal and instrumental, undoubtedly played an important part in

the cultural life of ancient India. Sanskrit literature, both secular and reli-

gious, makes numerous references to instruments of various kinds, and it is, I

believe, generally held by archaeologists that some of the earliest mentions

of such instruments to be found anywhere are those contained in the ancient

Sanskrit works. Certain it is that at a very early period in the history of the

country, the Hindus were acquainted with the use of stringed instruments

excited by plucking or bowing, with the transverse form of the flute, with

wind and reed instruments of different types and with percussion

instruments.16

Speaking about percussion instruments as a wave theorist, Raman appreciated the

vibrations of a circular stretched membrane and especially the myriad overtones

that are excited to produce a discordant effect. Raman noted that, though many

European percussion instruments are basically non-musical but can be tolerated in

large orchestras, Indian percussion instruments have varied, subtle acoustic

properties that drew him to delve deeper into Indian music.17

Raman published thirty scientific papers during this period in such journals

as the Journal of the Indian Math Club, Nature, Philosophical Magazine, and

Physical Review.18 As a consequence, he was offered the Palit Professorship of

Physics at Calcutta University in 1917 by Ashutosh Mukherjee, the Vice

Chancellor. Though Ramans new position came with a considerably lower

salary than his job as an accountant, he accepted it. Now he could devote more

time to teaching and research at Calcutta University and to experimental work

at the IACS. Ramaseshan, a student of Raman, noted that: 5.30 a.m. Raman

goes to the Association. Returns at 9.45 a.m., bathes, gulps his food in haste

and leaves for office, invariably by taxi [horse-drawn carriage] so that he might

not be late. At 5 p.m., Raman goes directly to the Association [IACS] on the

way back from work. Home at 9.30 or 10 p.m. Sundays, whole day at the

Association.19

During that period, Raman also developed the odd habit of wearing a head-

band, though these were not customary in South India. Headbands or turbans, as

they are popularly called in India, are worn by people from the north, especially

the state of Punjab, parts of Rajasthan, and also the Kathiawari region in Gujarat

in the west. M. S. Swaminathan, one of Ramans contemporaries, recalled

Ramans ready wit when someone asked him why he wore a turban. Oh, if I did

not wear one, my head will swell. You all praise me so much and I need a turban to

contain my ego.20 This story is yet another indication of Ramans eagerness to be

different. For Raman, the turban symbolized Indianness or a distinctiveness that

made him look different from his colleagues, both Indian and non-Indian

(figure 1).


En Route to the Raman Effect

From isolated Rangoon, Raman was glad to get a transfer to Calcutta, where he

joined the up-and-coming IACS in 1911. Ramans travels involved sea voyages

during which he spent considerable time pondering the sea and its colors. At the

IACS, Raman wanted to diversify his research portfolio, for which making the

transition from wave acoustics to optics made sense. The diversity of Ramans

interests in optics ranged from the visualizations of the sea to astronomical optics.

For example, he studied Saturn and gave two lectures on his observations of the

interference fringes and diffraction patterns of two light sources using the wave

theory of light. In 1912, Raman helped mount a telescope on the small wooden

observatory on the roof of the IACS and then studied Jupiters surface: I think

the problem of scattering of light by a planetary body is not altogether an easy one

and there may be room for further investigations here.21

Hence, Ramans initial interests in acoustics and his research on the ectara and

Indian percussion instruments, using the wave theory, served as the background

for his later interests in light scattering at the IACS. As G. N. Ramachandran

noted,

The study of acoustics is intimately connected with the study of vibrations and

waves, and it is not surprising that Ramans interests passed from his early love

Fig. 1. Raman wearing his turban. Credit: Raman Research Institute.


for acoustics on to a life-long devotion to optics, the other great domain of

classical wave mechanics. In fact, if one may talk of a unifying trend in the

scientific work of Raman, it may be said to reside in the study of wave

phenomena.22

While Raman was working in Calcutta at the IACS, he had only one assistant,

Ashutosh Dey (another bhadralok), who helped him set up and carry out exper-

iments. In the wake of the partition of Bengal, many Indians sought education as

part of the general movement for national improvement. The distinguished edu-

cator Ashutosh Mukherjee played an important role in this crucial period.

Mukherjees efforts led philanthropists like Taraknath Palit, Rashbehari Ghosh,

the Maharaja of Darbhanga, and the Maharaja of Khaira to open the University

College of Science (UCS) and subsequently endow chairs to be held by Indian

scientists. Raman made a name for himself in acoustics and astronomical optics; he

became a stalwart in the institutional milieu of the IACS. Despite that, he was not

the best choice for Mukherjee, compared to Jagadish Chandra Bose, who already

established himself as a celebrated scientist and a physics professor at Presidency

College in Calcutta.

Ramans position at the UCS also entailed teaching, which he longed to do.23

He got involved in a conflict with scientists from Bengal like J. C. Bose, who wrote

to the Vice Chancellor of Calcutta University complaining that Raman was

offering increased salaries to lure away J. C. Boses research assistants.24 These

grievances against Raman were part of a larger problem in the history of Indian

science, the regionalism that identified him as a South Indian attempting to make

his way in Bengal (figure 2).

In 1914, Raman accepted appointment as Sir Taraknath Palit Professor of

Physics at Calcutta University.25 Consequently, he resigned from his government

position, but due to the requirements of the Palit endowment could not join

immediately. The colonial government intervened, reluctant to fund endowed

chairs in India occupied by native Indians. By 1917, however, Raman was already

the Palit Professor. With a well-equipped lab and research grants to build

instruments, Raman started a new chapter in his life in optics and light scattering.

He also gained access to the labs at IACS, where he had worked part-time when

was a financial clerk. A research group was beginning to grow around Raman in

Calcutta. As he earned nationwide fame for his research and teaching prowess in

Calcutta at UCS and IACS, several students came and joined his group from South

India (University of Madras), which included his key collaborator Kariamanikam

Srinivasa Krishnan and also K. R. Ramanathan, L.A. Ramdas, K. S. Rao, Sund-

eraraman, V. S. Tamma, Y. Venkataramayya, A. Ananthakrishnan, S.

Bhagavantam, A. S. Ganesan, C. Ramaswamy, S. S. M. Rao, S. Paramasivan, N.

S. Nagendra Nath, C. S. Venkateswaran and S. Venkateswaran, who became

Ramans research assistants.26 Most of them, like Raman, not coincidentally were


South Indians, showing the pervasiveness of regional favoritism in Indian science

during the early twentieth century.

While at the IACS, Raman came into conflict with Meghnad Saha, beginning in

1917, when Raman attempted to limit the membership of IACS only to South

Indians, creating problems for the Institute and other senior members like J.

C. Bose, Kedareswar Banerjee, Panchanon Das, and Manindra Nath Mitra, who

were not from the South.27 As leader of this group opposing Raman, Saha

expressed his annoyance on several occasions regarding Ramans regionalistic

favoritism and was also apprehensive that Raman could jeopardize the future

prospects of Sahas students. Thus, he advised Pratap K. Kichlu, an upcoming

scientist from North India: When you submit [your] thesis for [the] DSc theexaminers ought to be Professor [Ralph H.] Fowler, Lord Rayleigh, and myself.

Do not allow Raman or [John W.] Nicholson to be put in28

Raman also came into conflict with the eminent Bengali mathematician D.

N. Mallik over an interpretation of Fermats Law in optics that Mallik published in

1913.29 Raman objected that this statement of Dr. Mallik is most seriously in

error.30 He advised that Dr. Mallik should read Huyghens own statement of the

case in his original treatises on Light [Malliks] assumption is wholly unnec-essary and leads to results which are quite meaningless.31 This episode suggests

Ramans grasp in theoretical optics in his early days as a scientist, quite well read

Fig. 2. Ramans lone assistant at IACS: Ashutosh Dey. Credit: Raman Research Institute.


in classical optics including the works of Huygens. On the personal level, this

conflict shows the commanding and dismissive tone Raman took towards a senior

Indian (Bengali) colleague like Mallik. While this incident shows Ramans fear-

lessness, it can also be interpreted as a growing regionalistic trend in his

personality even as a young man.

Though showing his mastery over theoretical topics in classical optics, Raman

wasted no time in planning an experimental research program. Now having a good

number of assistants, Raman consolidated his research program in Calcutta by

building instruments and probing the subtleties of wave optics to understand the

molecular basis of the macroscopic phenomenon of refraction. In 1919, he began

developing an interest in the molecular diffraction of light. With B. B. Ray, Raman

published a paper on a light scattering problem in which a beam of light was sent

through a solution in which sulphur suspension particles were formed. Here a

counterintuitive phenomenon was observed: The intensity of the transmitted light

decreased as the solution became gradually turbid, as seems intuitively under-

standable, but with further passage of time there was a gradual reappearance of

transmitted light passing through the suspension.32 Raman tried to explain this

apparently strange phenomenon with the help of Fresnel and Huygens wave

theory by arguing that the reappearance of transmitted light occurs when the

growth in size of the suspension particles lead to forward scattering and inter-

ference in the forward direction. These studies formed the background for

Ramans later researches into light scattering.

In 1921, Raman had his first opportunity to visit England and attend the

University Congress at Oxford as a representative of Calcutta University. When

Raman was transferred to Rangoon early in his life, he took a sea voyage during

which he pondered the optics of the sea in relation to his research experiences in

music and acoustics. On his return voyage from England, Raman further con-

templated the seas color.33 Explaining it was a natural outgrowth of Ramans

initial interest in beauty, aesthetics, and the connections between art and science.

In 1899, Lord Rayleigh had explained the blue color of the sky by giving a scat-

tering formula for a gas, arguing further that the sea was blue because it reflected

the color of the sky.34 Rayleigh scattering involved scattered radiation having the

same frequency as the incident radiation. After having himself taken a long sea

voyage, Rayleigh argued that

the much admired dark blue of the deep sea has nothing to do with the colour of

water, but is simply the blue of the sky seen by reflection. When the heavens are

overcast the water looks grey and leaden; and even when the clouding is partial,

the sea appears grey under the clouds, though elsewhere it may show colour. It

is remarkable that a fact so easy of observation is unknown to many even of

those who have written from a scientific point of view.35

From his own experience, Rayleighs explanation of the color of the sea seemed

discordant to Raman, who noted that


observations made in this way in the deeper waters of the Mediterranean and

Red seas showed that the color, so far from being impoverished by suppression

of sky-reflection, was wonderfully improved thereby It was abundantly clearfrom the observations that the blue color of the deep seas is a distinct phe-

nomenon in itself, and not merely an effect due to reflected sky-light Thequestion is: What is it that diffracts the light and makes its passage visible? An

interesting possibility that should be considered is that the diffracting particles

may, at least in part, be the molecules of the water themselves.36

His reasoning also relied on the EinsteinSmoluchowski formula (1910) that

explained critical opalescence, the strong scattering of light by a medium near a

phase transition.* Einsteins key insight was that the phenomena of critical op-

alescence and the blue color of the sky, though not related to each other, were

both due to density fluctuations caused by the molecular constitution of matter.37

What happened to light scattering when the medium was not close to a phase

transition? How should one understand light scattering from solids? These and

similar problems attracted Raman and his associates. In 1922, Raman combined

his observations with photometric determinations of Matthew Luckiesh to argue

that molecular scattering of light in seawater explained its color, which then led

him to study light scattering in liquids and thence to the discovery of the Raman

effect.38 In his work on light scattering in liquids, Raman studied density fluctu-

ations in a fluid and also the non-spherical nature of the molecules constituting the

fluid. Performing experiments at the IACS with his collaborators, Raman found

that scattering from transparent liquids always contained some radiation of fre-

quency lower than that of the incident light, now called Raman scattering.39 Thus,

Ramans interests in light scattering from a liquid (19191927) culminated in the

celebrated Raman effect.40

Building an International Image

Though Raman had a special fondness for India, his network of patrons led him to

think beyond the nation. As soon as he had a well-equipped laboratory with

logistical support and a research group, he started planning international trips.

Even while starting out as Palit Professor at UCS, he visited London to attend a

scientific meeting in 1924, now better placed than in 1921, when he was still

building up his reputation. He could travel undisturbed while his research groups

back home worked on the problems he had set for them. Receiving an invitation to

attend a meeting of the British Association for the Advancement of Science

(BAAS) in Canada, Ramans travels took him to North America for the first time.

* Approaching the critical point in a phase transition, such as between gas and liquid states,the sizes of the gas and liquid regions begin to fluctuate; when the density fluctuationsbecome comparable to the wavelength of impinging light, incoming light is scattered and thepreviously transparent fluid appears cloudy (opalescent).


In August 1924, he was in Toronto giving talks on his research at IACS on light

scattering. After his Canadian sojourn, he went to the Franklin Institute in Phil-

adelphia for its centenary celebrations. Robert Millikan invited him to visit

Caltech, where he stayed for three months. Here Raman remarked to astro-

physicist Svein Rosseland that his immediate scientific goal was to make a great

discovery and receive the Nobel Prize.41 After leaving California, he visited

Sweden, Denmark, and Germany, returning to Calcutta in March 1925.

The 1920s were a very fertile period for the development of physics on a

transnational scale. In late 1922, Arthur Holly Compton calculated that (unlike in

classical electromagnetism) a quantum of radiation undergoes a discrete change in

wavelength when it experiences a billiard-ball collision with an electron at rest in

an atom, which his X-ray scattering experiments confirmed.42 This phenomenon

provided an experimental proof for quanta and convinced most physicists of the

reality of light quanta. Yet these results were not universally accepted. The

Harvard physicist William Duane, for instance, expressed doubts regarding

Comptons results at the BAAS meeting in Toronto in 1924 that Raman atten-

ded.43 Speaking at this meeting, Duane apparently in the end conceded to

Compton, according to the ambiguous account published in Nature, (figure 3):

Duane found that, with his apparatus, he was unable to find evidence for the

existence of the effects observed by Compton. Compton, on the other hand,

could not repeat satisfactorily Duanes experiments. Each observer investigated

the apparatus used by the other and convinced himself of its trustworthinessDuane found to his surprise that, in addition to the effects he had previously

observed, a new peak appeared in approximately the position observed by

Compton Prof. Raman made an eloquent appeal against a too hasty aban-donment of the classical theory of scattering The fundamental differencebetween the two theories remain; Duane uses only the well-established quan-

tum energy equation, while Compton in addition introduces the idea of

conservation of momentum in the interaction between radiator [sic] and

matter.44

At this meeting, Raman took Compton to task: Compton, youre a very good

debater, but the truth isnt in you. This can be taken as evidence that Raman was

unmoved by Comptons arguments and continued to believe in waves.45 Though

he tried to downplay the Compton effect and its conceptual significance, Comp-

tons insights at the Toronto debate were very much present in Ramans work on

light scattering, which he conceptualized as an optical analogue of the Compton

effect, remarking that its real significance as a twin brother to the Compton

effect was clear to him by 1927.46 Compton himself remarked that it was

probably the Toronto debate that led him to discover the Raman effect two years

later.47

In 1927, Ramanathan observed that when sunlight passed through a scattering

medium, a small fraction of light scattered with a change of frequency. All of


Ramans collaborators agreed that the mechanism producing the modified radia-

tion was fluorescence primarily due to impurities in the scattering liquids (such as

benzene or glycene) acting as scattering centers. Attempts were made to purify the

material by distillation, yet the frequency-shifted radiation persisted. Ramanathan

called this radiation feeble fluorescence, though it was polarized, whereas

fluorescent radiation is not.48 Furthermore, Raman performed experiments to

study this feeble fluorescence, entailing a spectroscopic study that failed due to a

lack of a sufficiently powerful light source. Hence, his research group repeated

these experiments in more detail from February 528, 1928 and concluded that

what Ramanathan called feeble fluorescence was not fluorescence at all, but a

form of modified scattering.49

An obstacle in the way of speedy progress of Ramans scattering experiments

was the feebleness of his primary light source, sunlight filtered to select the parts of

the spectrum to be analyzed. Though a monochromatic source was needed to

isolate the frequency-shifted scattering, the introduction of any optical element

such as a prism or a phase retarder might have made the signal weaker. To

improve the intensity of the incident light, Raman acquired a seven-inch refracting

telescope, which in tandem with a lens with a small focal length could condense a

beam of sunlight into a high-intensity pencil of light. Using this, Raman and his

associates began to analyze the feeble fluorescence in early 1928.50

Explaining the Effect

The theoretical explanation of the Raman effect followed its experimental dis-

covery. According to current understanding, the Raman effect occurs when light

quanta of a certain frequency collides with the molecules of the liquid, either

giving up some energy or collecting some energy from it. The scattered radiation

Fig. 3. Raman with Compton in the center. Credit: Raman Research Institute.


includes both quanta of the same frequency as the incident light (Rayleigh scat-

tering), along with quanta of lower frequencies (Stokes terms) or higher

frequencies (anti-Stokes terms), illustrated in figures 4, 5 and 6. At the time, the

transitions with unchanged frequency were called coherent, those with changed

frequencies incoherent.*

The Rayleigh transition arises because of the polarizability of the molecule,

involving an excitation from the ground state to the excited state and a subsequent

de-excitation back to the original ground state, resulting in scattered radiation of

the same frequency as the incident one. Changes in polarizability (electric dipole

Fig. 4. Raman scattering. Credit: Andor Technology Ltd.

Fig. 5. Energy level diagram showing Rayleigh and Raman (Stokes and anti-Stokes) scattering.

The ground state and the excited states are shown as bands between which transitions are made.

Credit: Andor Technology Ltd.

* Note that the usage of the word coherent in the 1920s was slightly different than thecurrent use of the term, which refers more specifically to phase coherence.


moment) during molecular motions are responsible for the Stokes and anti-Stokes

line and hence the Raman effect. The Stokes transition can be explained by saying

that there is an excitation at a particular frequency from the ground state and a

subsequent de-excitation to a state of lower frequency (increased wavelength)

than the initial. This implies that the scattered photon has a lower energy than of

the incident photon, as proposed by Adolf Smekal in 1923.51

Smekal was a firm believer in Einsteins light quantum and suggested a corpus-

cular theory of dispersion. Smekal explained the anti-Stokes radiation by noting that

the exciting transition is already from an excited state, so that the subsequent de-

excitation is at a higher frequency and hence higher energy by the relation E = hm.Because the transition starts out from a state in which sufficient vibrationally excited

molecules might not be present, the anti-Stokes line is therefore weaker than the

Stokes line (figure 6).52 Classically, the Raman effect can be viewed as a perturba-

tion of the molecules electric field; the frequency shifts of the scattered light give a

measure of the rotational or vibrational frequencies of the molecule.

The newspaper announcement regarding the discovery of the Raman effect

appeared on February 28, 1928 (figure 7) and also mentioned the Compton effect

as a radical breakthrough for light quanta.53 Though Raman was influenced by

Comptons work, as we have seen earlier, he tried to downplay its revolutionary

aspect, especially in the verification of light-quantum in the Toronto debate. In

fact, when Krishnan informed Raman in 1927 that Compton had been awarded the

Nobel Prize, Raman remarked If this is true of X-rays, it must be true of light

tooWe must pursue it and we are on the right lines. It must and shall be found.The Nobel Prize must be won.54 As I will argue, the meanings of light quanta

were quite different in India than in Europe; Ramans interpretive lens disclosed a

manifest ambiguity whether his effect can be explained semiclassically using

continuous wave theory or only using discontinuous light quanta.

Raman Effect and Quantum Physics

How did Raman account for his effect? In February 1928, he noted that X-ray

Compton scattering without change of frequency corresponded to the average

Fig. 6. Comparison of Rayleigh with Raman spectrum with its Stokes and anti-Stokes lines.

Credit: Andor Technology Ltd.


state of atoms and molecules, while the frequency-changing scattering represented

fluctuations. Likewise, in the case of visible light there correspond two types of

scattering, one based on the normal optical properties of atoms and molecules and

the other representing the effect of fluctuations. Hence, light scattering in general

is a confluence of thermodynamics, molecular physics, and the wave theory of

radiation.55

As argued above, Ramans predilection for the wave theory may have come

from his early association with Indian musical instruments. Raman also re-derived

the Compton shift in 1928 using classical theory, analogizing it to the Doppler

effect, another example of Ramans faith in the wave theory. There is, however,

some ambivalence in his understanding of this novel effect, reflected in his remark

on March 16, 1928, at a lecture in Bangalore. In quite a cavalier fashion, Raman at

this lecture tried to explain the effect using light quanta and seemed to be aware of

the theoretical underpinnings as contemplated in the KramersHeisenberg the-

ory of dispersion.56

Fig. 7. First newspaper announcement of the discovery of the Raman effect. Credit: Raman

Research Institute.


Here, Raman seems to mean a light quantum as a quantity of energy in the

form of classical radiation, as Bohr also seems to imply in his 1913 paper.57 Even

so, Ramans remark really does not mean that he subscribed to the notion of the

light quantum. There is some disagreement about this in the extant sources.

Rajinder Singh says, Well before Raman discovered the Raman effect, he

accepted the quantum nature of light.58 However, Abha Sur claims that Raman

himself was a quintessential classical physicist certainly in his training and even

more so in his outlook.59 Above all, this disagreement raises larger questions

about the Raman effects connections to the experimental verification of the new

formalisms of quantum mechanics that were emerging in Europe.60

Quantum Dispersion and Matrix Mechanics: The Place of the Raman Effectin the History of Quantum Physics

During the mid-1920s, physicists were grappling with the Rayleigh-like coherent

terms in the scattered radiation in old quantum theory.61 In the classical Lorentz

Drude picture of dispersion, an electromagnetic wave of frequency m strikes a one-dimensional simple harmonic oscillator with resonant frequency m0. What happensnext depends on whether or not m is close to m0. As long as m is far removed fromm0, one is in the regime of so-called normal dispersion; close to m0, one is in theregime of anomalous dispersion.

In 1915, Peter Debye and Arnold Sommerfeld proposed a dispersion formula

similar to the classical LorentzDrude formula in the context of Bohrs new

quantum model of the atom. The resonances in the SommerfeldDebye formula

are at the orbital frequencies in the Bohr atom, yet the experimental data clearly

showed that these resonances should be at the radiation frequencies of the light,

which, in the Bohr model, differ sharply from the orbital frequencies of the atom.

In the early 1920s, several alternative dispersion theories addressed this problem.

In 1922, using light quanta, Charles Galton Darwin introduced a damping mech-

anism and argued that, though light from a single atom would have the orbital

frequency, the interference of an ensemble of waves led to scattered light waves

having the radiation frequency.62 Unfortunately, conservation of energy only held

statistically in his model. Furthermore, Bohr pointed out that Darwins theory

failed for low-intensity light.

Meanwhile, Karl Herzfeld had suggested a mechanism for obtaining non-

coherent scattered radiation.63 Using light quanta, Herzfeld argued that the sta-

tionary states allowed by the quantum conditions were not the only permissible

ones. Besides these, there were orbits of all sizes and shapes corresponding to all

values of the constants of integration, which resulted in a diffuse quantization

with indeterminate energy values. This was a variant of the work by Bohr and

Sommerfeld and their quantization condition. Hence, the orbits not obeying the

quantum conditions were assumed to have a very small a priori probability, so that

electrons could remain in them for about a femtosecond.64


In 1923, Smekal described a new type of quantum transition from scattering

monochromatic radiation from atoms, which he called translational quantum

transitions.65 He argued that there existed a certain probability per unit time that

the atom struck by the radiation frequency m1 passed from the state m to the staten and changed its velocity of translation along with a change of frequency. Smekal

noted that, because of the change in direction of the radiation effected by them

[i.e., by the translational quantum transitions], we shall speak in the case about

normal dispersion (m = n) and about anomalous dispersion (m = n).66 Note thatSmekal used the terms normal dispersion and anomalous dispersion in an

idiosyncratic way and that the distinction he made is usually labeled coherent

versus non-coherent. Smekals view opposed that held by Niels Bohr, who was a

stubborn supporter of the wave nature of radiation. This became important for the

later development of dispersion theory by Kramers and Heisenberg in 1925 and

later in 1928 when Raman and his associates made their discovery. It is however,

unknown when (if at all) Raman became aware of Smekals work, and how he

responded to it. It can be inferred that Ramans complete faith in wave theories

and natural distrust of the light quantum could have led him to ignore Smekals

work.

Subsequently, Smekals paper was often quoted in the literature as indicating a

prediction of the Raman effect.67 Ramdas, one of Ramans students at IACS,

commented in 1928 that Smekals paper did not appear to have been noticed by

any experimental physicist working in the field of light scattering, including the

group working under Raman.68 But Ramdas also noted that Kramers and Hei-

senberg took notice of Smekals idea and developed them in their 1925 treatment

of the quantum theory of scattering.69 Kramers and Heisenberg, like Raman, used

only the wave theory of light and the experiments on dispersion by Rudolf La-

denburg and Fritz Reiche at Breslau.70 Schrodinger remarked that the existence of

this remarkable kind of secondary radiation has not been demonstratedexperimentally.71 The main object of Kramers and Heisenbergs paper was to

account for the non-coherent scattering suggested by Smekal without taking

recourse to light quanta and using only the wave theory.72 The KramersHei-

senberg paper was also the first systematic exposition of the new theory for

coherent scattering Kramers had presented in 1924.

The theory of dispersion by Kramers and Heisenberg replaced the unsatisfac-

tory SommerfeldDebye theory using Einsteins 1916 theory of emission and

absorption, Bohrs correspondence principle, and the work of Ladenburg and

Reiche.73 Ladenburgs main contribution was to recognize that the oscillator

strengths corresponding to various transitions could all be interpreted in terms of

transition probabilities, as given by Einsteins 1916 theory.74 For the excited state,

one needed two terms, which Kramers later derived. Ladenburg replaced the

numbers of oscillators in the classical LorentzDrude formula by transition

probabilities in the Bohr atom given by Einsteins emission and absorption coef-

ficients.75 Ladenburgs extensive experiments since 1908 on dispersion in gases had


convinced him that the resonances of the dispersion formula had to be at the

radiation frequencies, even though he and Reiche saw no way of deriving this

result from quantum theory.

In 1924, Kramers finally accomplished this task on the basis of Bohrs corre-

spondence principle. Kramers found that the formula suggested by Ladenburg

needed to be supplemented by a second term, which would only contribute

appreciably to the dispersion if a substantial fraction of the atoms were in an

excited state. In the late 1920s, Ladenburg and his collaborators tried unsuccess-

fully to verify experimentally this second term in the Kramers dispersion formula,

which the Raman effect then confirmed. As the physicist Francis Low puts it,

Raman found that light scattered by certain substances may have a slightly

changed color from the original light beam. This effect is hard to account for

according to nineteenth century physics, whereas it may be definitely predicted

on the basis of the new quantum theory, of which it is therefore an important

experimental confirmation.76

In essence, Raman did associate his findings of light scattering with Kramers

dispersion formula. Krishnans personal diary recorded the exchange of views

between Raman and his associates before the discovery of the Raman effect. The

diary entry on February 7, 1928 reveals that Raman was overjoyed by his exper-

imental findings that morning and also realized how the modified scattering

corroborated the KramersHeisenberg effect.77

Hence, it is evident that Raman was aware of the work of Kramers and Hei-

senberg. There is no evidence that Raman was aware of Smekals theoretical

insights in the early 1920s. Rajinder Singh, however, has argued both ways. In an

earlier paper, he argued that Raman used Kramers theory to interpret the

experimental results, but later Singh argued that Raman was unaware of the work

of Kramers and Heisenberg and remarks none of this theoretical work (of Kra-

mers and Heisenberg) exerted a direct influence on the discovery of the Ramaneffect.78 This apparent uncertainty whether or not Raman was aware of earlier

theoretical work feeds into bigger questions of originality and recognition in the

history of science. While Raman might very well have been aware of the earlier

work of Kramers, as the diaries of Krishnan reveal, he tried to build an image that

showed the converse, especially in pursuit of the Nobel Prize.

Landsberg and Mandelstams Simultaneous Discovery and the Nobel Prizeof 1930

Often physicists and historians refer to the Nobel Prize as an index of a research

programs success and modernity. It has been recently argued that, as opposed to

the physics of principles (espoused by Einstein, Planck, and Bohr), the physics of

problems as practiced by the Sommerfeld school could make a strong claim to


have been the most successful research program for theoretical physics in the

twentieth century because at least eight Nobel laureates were associated with it.79

The Nobel Prize is commonly seen as the final authority to assess the success or

failure of a research program. This is, however, a highly reductionist view.

According to Robert Friedman, this stereotype overlooks the politics and the

hidden agendas associated with the prize. Friedman shows in his Politics of

Excellence how simplistic such stereotypical claims are about the Nobel Prize:

Without understanding the limitations and weaknesses of the process, the

recipients were afforded instant prestige as part of the Nobel cult.80 Behind the

Nobel Prize given to Raman were factors that corroborate Friedmans argument in

this case.

Though the Raman effect was discovered in Calcutta on February 28, 1928, this

very phenomenon was also discovered in Moscow on February 21. There, a group

of Russian physicists including Grigory Samuilovich Landsberg and Leonid Isaa-

kovich Mandelstam had been working on similar scattering experiments to those

of Raman.81 Unlike Raman, Landsberg and Mandelstam used quartz as their

scattering medium. Quartz was not as easy to find as benzene or the other aro-

matic compounds that Raman used.

The basic motivation for Landsberg was the work by R. J. Strutt (the fourth

Baron Rayleigh), who studied light scattering in quartz and concluded that what

he had observed was not light scattered from quartz molecules but light reflected

from false scattering centers. Landsberg took up this task of studying molecular

light scattering in a real crystal and proposed a criterion for the differentiation of

scattered light and reflected light from false scattering centers. Mandelstam the-

oretically calculated the change in the light frequency; they published their results

on July 13, 1928.82

Landsberg and Mandelstam argued that the non-Rayleigh modified scattering

terms were due to the interaction between the light and infrared molecular

vibrations. Immanuil L. Fabelinskii, a student of Mandelstam, reports that the first

observations of his mentors were on February 21, 1928, a week before those of

Raman and his collaborators. Landsberg and Mandelstam, however, published

their work on July 13, 1928, a few months after their discovery. Apparently the

main reason for the delay was that Gurevich, a relative of Mandelstam, was

arrested and sentenced to death. As a consequence, Mandelstam took a break

from research to mitigate the death sentence. In the end, he succeeded in reversing

the death sentence; instead, Gurevich was exiled to the city of Vyatka. Hence,

Gurevichs life was saved at the expense of the publication of the innovative work

of Mandelstam and Landsberg.83

Mandelstam wrote to physicist Orest Khvolson: We first noted the appearance

of the new lines on February 21, 1928. On a negative from an experiment of

February 2324 (exposure time 15 h) the new lines were clearly visible.84 Fab-

elinskii argues that Landsberg and Mandelstam reported their discovery at the

beginning of August 1928 at the sixth Congress of the Association of Russian


Physicists. Twenty-one of the four hundred participants at the Congress were

foreign scientists, including Born, Brillouin, Darwin, Debye, Dirac, Phol, Prings-

heim, Philip Frank, and Scheel. Darwin wrote, Perhaps the most interesting work

is that of Prof. Mandelstam and Landsberg. The latter described how they had

independently discovered Ramans phenomenon, the scattering of light with

changed frequency.85 Commenting on the identical nature of Ramans discovery

and that of Landsberg and Mandelstam, Born clarified that these discoveries were

made independently and nearly simultaneously on February 20, 1928. Such

identical yet separate nature of discoveries, Born thought, showed the transna-

tional nature of science at that time.86 In fact, two students of Raman, A.

Jayaraman and A. V. Ramdas, on his centenary wrote about this simultaneous

discovery as independently discovered by Landsberg and Mandelstam in calcite

and quartz crystals.87 Though Mandelstam and Landsberg saw the novel scattering

phenomenon a week before Raman, the Nobel Prize in Physics in 1930 went to the

latter. One may try to find out the reasons behind such an episode.

There were twenty-one nominations for the Nobel Prize in 1930 and Raman

was proposed ten times either as a single candidate or jointly with his collabora-

tors.88 Because Raman established contacts with scientists in Germany, England,

France, Sweden, and North America, he was better known internationally than

Mandelstam and Landsberg. M. Siegbahn and C. W. Oseen, both members of the

Nobel physics committee in 1930, knew Raman personally. An interesting

exchange of letters in 19281929 between Raman and Niels Bohr summarizes the

story. In a letter to Bohr in 1928, Raman remarked:

The great kindness you have shown me in the past encourages me to make a

request of a personal character. As you know, my work on the new radiation

effect has been received with enthusiasm in scientific circles, and I feel sure that

if you give your influential support, the Nobel Committee for physics may

recommend that the award for 1930 may go to India for the first time. The

proposal for the award has to reach the Nobel Committee before 31 January

1930. I have greatly hesitated in writing to you about this, and it is only because

I felt sure that you sympathise with the scientific aspirations of India that I have

ventured to do so.89

As a matter of fact, Bohr was influenced by Ramans letter and extended his

support for him through his nomination, which played a key role in Raman getting

the prize (figure 8).

Arnold Sommerfeld was also visiting India in 1928, which coincided with

Ramans explorations in light scattering.90 Sommerfeld repeated Ramans exper-

iments at the IACS and verified them. Through Sommerfeld, his colleagues in

Munich and Berlin came to be aware of Ramans work. Strangely enough, the

names of Mandelstam and Landsberg did not even figure in the Nobel acceptance

speech of Raman in 1930, though he refers twice to Bohr, who played an important


role in the prize process.91 The previous quotation also shows Ramans fondness

for classical wave theories, of which Bohr was a radical supporter.

Given Ramans fondness for classical wave theories, had he eventually accepted

the quantum, it would have been a hesitant acceptance with the disclaimer that

classical theories were more fundamental so that, in the case of large quantum

numbers, according to Bohrs correspondence principle quantum calculations had

to agree with classical calculations. Though the new quantum mechanics of the the

mid-1920s was mostly a German phenomenon, its leading exponents, such as

Arnold Sommerfeld, were keenly interested in Ramans works in light scattering.

Sommerfeld and the Reception of Ramans Work in Germany: Orientalismand Science

Sommerfeld was a great admirer and supporter of Indian physicists and their work.

He was attracted to J. C. Boses work in electrophysiology, Sahas work on stellar

spectra, Satyendranath Boses work on quantum statistics, and Ramans work on

light scattering. The Zeitschrift fur Physik was the channel through which Som-

merfeld gained familiarity with the work of Indian physicists. Sommerfeld

requested Saha to give a lecture in Munich in 1921, and Saha obliged. Raman,

along with Saha, invited Sommerfeld to visit India and give lectures at the Uni-

versity of Calcutta. Sommerfeld visited India in 1928 after the discovery of the

Raman effect and gave talks mostly on atomic structure and wave mechanics in

Calcutta. While in India, Sommerfeld wrote an article that praised modern Indian

Fig. 8. Raman (second from right) with Niels Bohr to Ramans left. The others from the left are

George Gamow, Thomas Lauritsen, T. B. Rasmussen, and Oskar Klein. Credit: Niels Bohr

Archive.


science and equated its quality to that of Europe and America. Sommerfeld

expressed special admiration for the discovery by Raman and for Sahas work in

astrophysics.92

The Raman effect, however, did not get a good reception within certain sec-

tions of the German physics community. Gottingen physicist Otto Blumenthal,

Georg Goos at the University of Jena, and Richard Gans were all skeptical about

Ramans work. Gans in particular had a negative view about Indian scientists,

writing to Sommerfeld from Jena on May 14, 1928: Do you think that Ramans

work on the optical Compton effect in liquids is reliable? To repeat the experi-

ment is not a big task and most probably we are going to do it. The sharpness of

the scattered lines in liquids seems doubtful to me.93 Goos based his ideas on an

unsuccessful repetition of the Raman effect at the University of Munich. As Singh

noted, Gans had a negative opinion about Indian scientists and had a skepticalattitude towards the quality of publications by Indian physicists and also toldSommerfeld that Indian physicists are not reliable.94

On June 9, 1928, Sommerfeld wrote to Joos that in my opinion Raman is

correct and important. He writes to me, that the difference between the lines is

exactly equal to the infra-red frequencies of the molecules under consideration.95

Thus, Sommerfelds response to Indian science provides an alternate perspective

that reconstructed the socio-scientific image of India as not exclusively spiritual

but also scientific. Following Raman, one can infer that Indian science did not

follow the Western trajectory to modernity, but an alternate path that encom-

passed ideas about the human spirit, the virtues of human endeavor and

achievement, and a search for truth for its own sake. Raman himself thought that

in my case strangely enough it was not the love of science, nor the love of

Nature, but an abstract idealization, the belief in the value of the Human Spirit

and the virtue of Human Endeavor and Achievement. When I read Edwin

Arnolds classic The Light of Asia, I was moved by the story of the Buddhas

great renunciation, of his search for truth, and of his final enlightenment. It

showed me that the capacity for renunciation in the pursuit of exalted aims is

the very essence of human greatness.96

This is striking because Raman was moved by a Western account of Oriental

wisdom, showing the contradictory nature of his personality; he seemed to have

developed an aversion for the British and yet was fond of other Europeans like

Sommerfeld and Arnold (British though he was). Ramans quotation and his

scientific work also puts in question certain stereotypes opposing Oriental to

Western thought.

If, as Singh asserts, Gans was prejudiced against Indian scientists, the contro-

versy among German physicists about Ramans work may have involved their

various preconceptions about Oriental science.97 In my view, the defining

characteristic of Raman was that, even though he was a major harbinger of

modernity in Indian society, he tended to reject the Oriental stereotypes in the


West that would separate and oppose modern science to traditional Oriental

knowledge. Upon his return to Calcutta after receiving the Nobel Prize, Lady

Raman remarked about her husband, he has sought to dispel the notions in

Europe that India was rather too Spiritual.98 Ramans interests in Indian clas-

sical musical instruments shows how he was bound to Indian tradition, yet his light

scattering experiments advanced the most modern European science.

Raman vacillated between tradition and modernity, but his characteristic

approach combined them. Before his discovery of the Raman effect in 1928,

he re-derived the Compton scattering wavelength using wave theory.

Ramans attitudes about the traditional and the modern were ambivalent,

even contradictory. His apparently strange outlook espoused a methodology

that broke away from negative stereotypes about Oriental science and

instead adopted a variant of what Richard G. Fox has called affirmative

orientalism.99 By this, Fox suggests that Orientalist narratives were appro-

priated by Indian intellectuals and applied in such a way as to undercut the

colonialist agenda. Hence, such narratives did not operate in straightforward

and orderly fashions but illustrate some of the ambiguities of colonial physics

in early twentieth century India.

Ramans extensive institutional, personal, and pedagogical networks were

similar to those of Western scientists, yet he developed them while working

in a colonized, non-Western nation. Then too, in contrast to Orientalistic

assumptions of Eastern inferiority, several Western scientists such as Som-

merfeld helped reconfigure myths about the East by highlighting the scientific

achievements of Raman and other scientists of his generation who were

working in the Orient. Sommerfeld convinced his colleagues in Germany of

the authenticity of Ramans works, especially after his visit to India. Som-

merfelds India visit paved the way for several collaborations between

physicists at the University of Calcutta and Sommerfelds Munich school.

Ramesh Chandra Majumdar, a graduate student in Calcutta University was

awarded the Zeiss scholarship by the Deutsche Akademie to do research at

Munich. Several Indian students from Calcutta studied at the University of

Munich under the guidance of Sommerfeld, Walther Gerlach, Thierfelder,

and Schmauss, the noted meteorologist. Sommerfeld received the honorary

degree DSc from the University of Calcutta in 1928.100

Raman himself visited Munich as a Nobel Laureate in 1930. In 1934,

when he became the director of the Indian Institute of Science (IISc),

Sommerfeld recommended one of his students named Ludwig Hopf, who

happened to be a Jewish refugee, to teach at the IISc. Ramans endeavor

was instrumental in the creation of a special readership in theoretical

physics at IISc from October 1935 to March 1936, which went to the Jewish

scientist Max Born, seeking refuge after his dismissal from the University

of Gottingen.101


Between Nationalism and Regionalism

Robert Anderson has argued that, while the national scientific community was

developing during the 1930s, communications among Indian scientists of different

regions increased considerably. Researchers were interacting with each other

frequently on a regional and national basis, travel by train was slightly easier and

more frequent, the postal and telegraphic system was improving, and opportunities

arose for both status and power that were not just local in character.102

In this way, Indian science started having a conglomeration of scientists from

different regions that went beyond the confines of regionalism. On the other hand,

regionalism played an important role in the IACS when Raman started roping in

South Indian scholars, notwithstanding the availability of qualified local candi-

dates. While at the IACS, Raman had occasional disagreements with Saha on the

issue of regionalism* in particular. As a result, scientists led by Saha expressed

their objections to this abject regionalism. Raman had conflicts with Western

scientists as well. In the 1930s and 1940s, he was involved in a controversy con-

cerning crystal dynamics with Max Born, a leading physicist in Europe, which led

Born to remark Raman is a very able physicist, full of enthusiasm There isreally no other Indian physicist who is of his rank. [His] European intensityalone would be enough to make Raman suspicious to the average Indian

professor.103

It is, however, debatable whether Raman was a nationalist, but his personality

had a peculiar brand of sensitivity for his nation that can be seen from his

exchanges with some of the institutions and colleagues in the West. Speaking at

the convocation address to the students of Benaras Hindu University in 1926,

Raman remarked about his speeches while he was in Europe and emphasized the

importance of traditional centers of Indian learning like Kashi** and its con-

comitant institutional set-up there as the living embodiment of the aspirations of

new India.104 Most importantly, Raman emphasized that the university should

aim not to grow bookworms but to train men to serve their country.105

On May 15, 1924 Raman was elected as Fellow of the Royal Society of London.

According to Kameshwar Wali, about 1967 Raman became unhappy about an

article published in the London Times about the Nobel Laureate Fellows of the

Royal Society, which did not mention his name. Raman blamed the omission on

the Society and wrote to P. M. S. Blackett, the president of the Society at that

time, saying that unless he would be given a satisfactory explanation for this

omission, he would resign, which he did in March 1968 after Blacketts

response.106 Rajinder Singh, however, argues that there was no communication

between Blackett and Raman and there was also no such list of Fellows of the

* By regionalism is meant the regional prioritizing of ideas and agency, which is not racialor religious in this context but more in the line of lobbying for recognition in a regionallydependent way.** A north Indian city also called Benaras on the banks of the river Ganges.


Royal Society who won a Nobel Prize published in the London Times between

1967 and 1968. Singh concludes, Ramans resignation remains a mystery.107

Though this is an apparently strange episode, Raman had developed a special

sensitivity regarding his nation, a sense of national identity not atypical of scien-

tists in late colonial India. In an undated quote on how he felt having received the

Nobel Prize, Raman remarked:

When the Nobel award was announced I saw it as a personal triumph, an

achievement for me and my collaboratorsa recognition for a very remarkable

discovery, for reaching the goal I had pursued for seven years. But when I sat in

that crowded hall and I saw the sea of faces surrounding me, and I, the only

Indian, in my turban and closed coat, it dawned on me that I was really rep-

resenting my people and my country. I felt truly humble when I received the

Prize from King Gustav; it was a moment of great emotion but I could restrain

myself. Then I turned round and saw the British Union Jack under which I had

been sitting and it was then that I realized that my poor country, India, did not

even have a flag of her ownand it was this that triggered off my complete

breakdown.108

Examining Ramans character closely, however, one can conclude that Ramans

nationalist inclinations about colonial India might have been a reason behind this

feeling. Hence, this act of Ramans resignation can also be viewed as a protest

against a seemingly discriminatory act on the part of the British. There is other

evidence, though, which shows that Raman was a difficult person to get along with

and also quite arrogant, which added a peculiar dimension to his character. Fab-

elinskii describes a personal incident in 1957, when Raman had visited Moscow to

receive the Lenin Peace Prize. Lecturing on the theory of solids, and getting

distracted by a remark by L. D. Landau, Raman started shouting, stamping his

feet, swinging his arms, insulting Landau and talking rot. At that point, Landau

left the lecture hall, to the utter astonishment of everyone present.109

Furthermore, when C. G. Darwin expressed skepticism during a visit to

Ramans laboratories in 1935, Raman remarked, It is far easier to straighten the

tail of a dog than to try to convince an Englishman of the correctness of [ones]

theories.110 As Raman pursued modern science in a colonial environment under

the British Raj, he might have developed a feeling of cynicism and a lack of

fondness towards the English in particular, as also revealed by his wearing a turban

to show his defiance towards colonial rule. Yet despite such occasional disagree-

ments and seemingly quarrelsome behavior, one should not be hasty to categorize

Raman as abhadra or ungentlemanly. These odd episodes, in my judgment, do

not outweigh his success in his early days as a scientist at the IACS, where he

successfully built a group of early-career scholars leading to his Nobel prize

winning work, and his later move to Bangalore at the Indian Institute of Science

and the Raman Research Institute.


Conclusion

Raman showed a fondness for his nation that is harder to classify as nationalist

compared to the sentiments of Satyendranath Bose and Saha.111 His nationalistic

sentiments were expressed through his emotions while accepting the Nobel Prize

in 1930 and his later resignation from the Royal Society; his symbolic gestures like

wearing an indigenous headgear projected an attitude that was nationalist but not

staunchly anticolonial.112

Interestingly, his world-view resonated with those of the German Helmholtz,

the Briton Rayleigh, and the Dane Bohr. Raman combined European science,

such as the classical wave theories of Huygens, Fresnel, Helmholtz, and Rayleigh,

with local intellectual traditions of Indian music, fusing them into a specific brand

of Indian modernity that emerged in the case of the Raman effect. His early

fascination with acoustics became the basis of his later insights into the nature of

light, especially his ardent support for the wave theory of light and his ambivalent

outlook towards the quantum.

The career trajectory of Raman also shows the multilayered and mul-

tidimensional nature of Indian science. Not all Indian scientists thought

alike, and there were occasional disagreements between Raman and

J. C. Bose, Saha, and Mallik and even with Western scientists like Born

and Compton. I consider these differences as regionalism (on a local and

global scale): the regional prioritizing of traditions, personal networks, and

solidarities. In spite of utilizing plenty of opportunities available for sci-

entific research and teaching at the Calcutta University and the IACS,

Raman never identified himself as a scientist from Bengal. Most of his

associates were from South India, so that when he was offered a position at

the IISc in Bangalore in 1931, he was quick to take it and leave his

established position in Calcutta.

This paper also locates the Raman effect in the history of quantum mechanics

by putting his work on the dispersion of light in the context of the alternative

dispersion theories of LorentzDrude, DebyeSommerfeld, C. G. Darwin, Herz-

feld, Smekal, and the scattering experiments by Ladenburg and Reiche,

culminating in the dispersion theory of Kramers and Heisenberg. Raman scat-

tering played an important role in the verification of quantum mechanics by

confirming experimentally the second term of the KramersHeisenberg dispersion

formula.

Scientific image-building was also a matter of concern for Raman. For this

purpose, he made educational pilgrimages to Europe and North America where he

developed a dialogue with his Western colleagues such as Compton, Millikan,

Rosseland, Bohr, and Sommerfeld. These apparently scientific internationalist

gestures helped Raman win the Nobel Prize in 1930, though the Russian physicists

Mandelstam and Landsberg observed the novel scattering mechanism before

Raman.


Finally, Ramans world-view reconfigured Orientalist stereotypes by presenting

his interest in science as a pursuit of truth for aesthetic and intellectual satisfaction.

More generally, science in India did not follow the Western trajectory to

modernity, but opened up an alternative path that encompassed ideas about

modernity along with Indian tradition.

Acknowledgements

I thank David Cassidy, Alexei Kojevnikov, Michel Janssen, Robert Brain, Sean

Quinlan, Daniel Kennefick, John Crepeau, Peter Pesic, Robert Crease, and Alexei

Pesic for suggestions and comments about this paper and mentoring help in

general. Thanks also goes to D. C. V. Mallik, Rajinder Singh, and Meera B. M. at

the Raman Research Institute, and Felicity Pors at the Niels Bohr Archive for

giving me access to the pictures used here. I acknowledge the support of the Office

of Research and Economic Development at the University of Idaho.

References1 C.V. Raman, New Physics: Talks on Aspects of Science. (Freeport, New York: Books for

Libraries Press, 1951), 135142.2 http://www.nobelprize.org/nobel_prizes/physics/laureates/1930/, accessed on January 10, 2012.3 Rajinder Singh, C. V. Raman and the Discovery of the Raman Effect, Physics in Perspective 4

(2002), 3994204 Peter Debye, Die Konstitution des Wasserstoff-molekuls, Sitzungsberichte der mathematisch-

physikalischen Klasse der Koniglichen Bayerischen Akademie der Wissenschaften zu Munchen

(1915), 126. See also, Paul Drude, Lehrbuch der Optik (Leipzig: S. Hirzel, 1900), English transl.:

The Theory of Optics. trans. C. R. Mann and R. A. Millikan (New York: Longmans, Green, 1902);

Arnold Sommerfeld, Die Drudesche Dispersionstheorie vom Standpunkte des Bohrschen

Modelles und die Konstitution von H2, O2, and N2, Annalen der Physik 53 (1917), 497550; K.

F. Herzfeld, Versuch einer quantenhaften Deutung der Dispersion, Zeitschrift fur Physik 23(1924), 341360; A. Smekal, Zur Quantentheorie der Dispersion, Die Naturwissenschaften 11

(1923), 873875; R. Ladenburg, Die quantentheoretische Dispersionsformel und ihre experi-

mentelle Prufung, Die Naturwissenschaften 14 (1926), 12081213; F. Reiche, and W. Thomas

Uber die Zahl der Dispersionselektronen, die einem stationaren Zustand zugeordnet sind,

Zeitschrift fur Physik 34 (1925), 510525; H. A. Kramers, and W. Heisenberg, Uber die Streuung

von Strahlung durch Atome, Zeitschrift fur Physik 31 (1925) 681707, translated in B. L. van der

Waerden, ed., Sources of Quantum Mechanics (New York: Dover, 1968), 223252.5 G. Venkataraman, Journey into Light: Life and Science of C. V Raman (New Delhi: Penguin

Books India Ltd., 1986); S. Ramaseshan, C. V. Raman: A Pictorial Biography. (Bangalore: The

Indian Academy of Sciences, 1988); Singh, Raman and the Discovery of the Raman Effect (ref.

3); Uma Parameswaran C. V. Raman: A Biography (New Delhi: Penguin Books 2011).6 Pratik Chakrabarty, Western Science in Modern India: Metropolitan Methods, Colonial Practices

(Delhi, Permanent Black, 2004), 180210. Chakrabarty argues that science and nationalism

blended into a single project in early twentieth-century India, especially as seen in the works of

Jagadish Chandra Bose, who was a mentor of Raman in Calcutta.7 Venkataraman, Journey into Light (ref. 5), 3.


8 C. V. Raman, Unsymmetrical Diffraction Bands Due to a Rectangular Aperture, Philo-

sophical Magazine 12, no. 6 (1906), 494498.9 Ibid.10 IACS Archives (see http://hdl.handle.net/10821/405, accessed April 26, 2014). Sircar also

established the Calcutta Journal of Medicine in 1868 and was an influential populariser of Indian

science. See Gyan Prakash, Another Reason (Princeton, NJ: Princeton University Press, 1999), 59.11 Calcutta was the capital of British India from 1772 to 1911, when, because of the revolutionary

campaigns in the city, the capital was shifted to Delhi in the north.12 A thoroughly revised and corrected edition, rendered conformable to the fourth and last

German edition of 1877, with numerous additional notes, and a new additional appendix bringing

down information to 1885 especially adapted to the use of musical students. The partition of

Bengal did not have any sustained impact on Raman; nothing in the archives shows otherwise. It

can be inferred that because Raman was from South India, far from Bengal, his response was not

atypical of South Indians.13 Raman, Books That Have Influenced Me: A Symposium (Madras: G. A. Natesan & Co., 1947),

2129.14 Hermann von Helmholtz, On the Sensations of Tone as a Physiological Basis for the Theory of

Music, trans. Alexander J. Ellis (London: Longmans, Green and Co. 1885), 481484.15 Raman, The Ectara, Journal of the Indian Math Club, 1909, 170175.16 Sir Ashutosh Mookherji Silver Jubilee Volume (Calcutta: Calcutta University Press, 1922),

2:179.17 Ibid., 180185.18 http://www.vigyanprasar.gov.in/scientists/cvraman/raman1.htm, accessed December 5, 2011.19 Venkataraman, Journey into Light (ref. 5), 6.20 http://www.thehindu.com/2006/06/21/stories/2006062107600200.htm, accessed March 5, 2007,

the online edition of one of Indias national newspapers, The Hindu. Ramans behavior can be

likened to Gandhi, an Indian nationalist who also used to wear a turban during his stay in South

Africa (between 1893 and 1914) as a form of defiance toward the West and colonial authority. See

for example Ramachandra Guha, Gandhi Before India (New York: Knopf, 2014).21 Report of Astronomical Society, April 1913. Parameswaran, Raman (ref. 5), 66.22 G. N. Ramachandran, Professor RamanThe Artist-Scientist, Current Science 40 (1971), 212.23 Singh, Raman and the discovery of the Raman effect (ref. 3).24 Raman apparently offered three times higher salary than Bose did. See J. C. Bose to D.

P. Sarbadhikari, August 30, 1917 (private copy) as quoted in Singh, Raman and the discovery of

the Raman effect (ref. 3).25 Parameswaram, Raman (ref. 5) 80.26 Ibid., 94.27 IACS online archives http://hdl.handle.net/10821/285, accessed January 6, 2012.28 M. N. Saha to P. K. Kichlu, August 15, 1927, Nehru Archives (Saha papers), New Delhi.29 D. N. Mallik, Fermats Law, Bulletin of the Indian Association for the Cultivation of Science 7

(1913), 14-16.30 To keep Hamiltons Principle and Fermats Law consistent, Mallik argued that we must have

for light propagation, T V = Constant, where T is the kinetic energy and V the potential energy.

Calcutta Mathematical Society Archives, Kolkata, Doc B.1913. Raman argued that inside the


variational equation d $ (T V) dt = 0 one could add terms like a sin(nt) whose variation was zeroand hence showed the non-uniqueness of (T V).31 Calcutta Mathematical Society Archives, Doc. B.1917.32 Raman and Ray, On the Transmission Colours of Sulphur Suspensions. Proceedings of the

Royal Society of London A100 (1921), 102109. The strange reappearance of color was as follows:at first indigo, then blue, blue-green, greenish-yellow, and finally white.33 Venkataraman, Journey into Light (ref. 5), 34.34 The scattering coefficient was inversely proportional to the fourth power of wavelength; see for

example Rodney Loudon, The Quantum Theory of Light (Oxford: Oxford University Press, 2000),

374.35 Lord Rayleigh, Colours of Sea and Sky in his Scientific Papers (Cambridge: Cambridge

University Press, 1900), 5:540.36 Raman, The colour of the sea, Nature 108 (1921), 367, responding to Rayleighs Colours of

Sea and Sky (ref. 35).37 Einstein, Theorie der Opaleszenz von homogenen Flussigkeiten und Flussigkeitsgemischen in

der Nahe des kritischen Zustandes. Annalen der Physik 33 (1910), 12751298. Using classicalelectromagnetic theory, Einstein and Smoluchowski argued that the mean square fluctuation in

density (and also the transverse scattering of light) increases near the critical temperature,

resulting in critical opalescence.38 Raman, Transparency of Liquids and Colour of the Sea, Nature 110 (1922), 280.39 His collaborators were K. R. Ramanathan (who joined Ramans lab in December 1921 from

South India and made important observations in 1923), Krishnan, Ramdas, Ganesan, Seshagiri

Rao, Venkateswaran, Kameswara Rao, Ramakrishsna Rao, and Ramachandra Rao.40 Krishnan observed the same effect in scattered light of sixty-five different purified liquids

leading to Ramans observation in glasses in late 1927. See Venkataraman, Journey into Light (ref.

5), 196-198.41 Kameshwar Wali, Chandra: A Biography of S. Chandrasekhar, (Chicago: University of Chicago

Press, 1990), 254.42 Roger Stuewer, The Compton effect: Turning Point in Physics. (New York: Science History

Publications, 1975), 223234. The Compton effect gives a change of wavelength k0 k

hmec

1 cos h where h is Plancks constant, c the speed of light, me is the mass of the electron atrest, h is the scattering angle.43 Ibid., 249273.44 Ibid., 268269.45 Ibid., 268. Several physicists accepted the Compton effect, but were just as happy to consider

light as waves. For the relevance of this in the development of matrix mechanics see Anthony

Duncan and Michel Janssen, On the Verge of Umdeutung: John Van Vleck and the Corre-

spondence Principle, Archive for History of Exact Sciences 61 (2007), 553624.46 Raman, A Classical Derivation of the Raman Effect. Indian Journal of Physics 3 (1929),

357369.47 Marjorie Johnston, ed., The Cosmos of Arthur Holly Compton (New York: Knopf, 1967), 37.

This is a valuable resource that contains Comptons Personal Reminiscences, a selection of his

writings on scientific and non-scientific subjects, and a bibliography of his scientific writings.48 C. V. Raman, A new radiation, Indian Journal of Physics 2 (1928), 387398.49 Quoted by P. R. Pisharoty in C. V. Raman (New Delhi: Publications Division, 1982), 40-44.


50 D. C. V. Mallik and S. Chatterjee, Kariamanikkam Srinivasa Krishnan: His Life and Work

(Hyderabad: Universities Press, 2011), 81.51 Adolf Smekal, Zur Quantentheorie der Dispersion, Die Naturwissenschaften 11 (1923),

873875.52 Figure 6 also illustrates that the Stokes and anti-Stokes lines are equally displaced from the

Rayleigh line because in both cases one vibrational quantum of energy is gained or lost.53 The announcement was in the Associated Press of India; RRI Archives Digital Repository,

Bangalore, http://hdl.handle.net/2289/3430, accessed October 4, 2012.54 G. H. Keswani, Raman and His Effect, (New Delhi: National Book Trust 1980), 44.55 RRI Archives Digital Repository, Bangalore, http://hdl.handle.net/2289/3430, accessed October

4, 2012.56 Ibid., 396.57 See Niels Bohr, I. On the constitution of atoms and molecules, Philosophical Magazine 26

(1913), 125.58 Singh, Raman and the Discovery of the Raman Effect (ref. 3), 409.59 Abha Sur, Aesthetics, Authority, and Control in an Indian Laboratory: The Raman-Born

Controversy on Lattice Dynamics, Isis 90 (1999), 2549.60 In a 1980 videotaped lecture at Harvard entitled The Crisis of the Old Quantum Theory,

192225, Thomas Kuhn remarked about the Kramers-Heisenberg paper and their treatment of

the Smekal-Raman incoherent scattering terms that you get what you would now recognize as

cross-products terms in a matrix expansion and that is what inspired matrix mechanics. I thank

Michel Janssen for giving me access to this videotape.61 John H. Van Vleck, Quantum Principles and Line Spectra (Washington, DC: National Research

Council, Bulletin of the National Research Council 10, Part 4, 1926), as cited in Duncan and

Janssen, On the Verge of Umdeutung (ref. 45), 623.62 C. G. Darwin, A quantum theory of optical dispersion, Nature 110 (1922), 841842.63 Herzfeld, Versuch einer quantenhaften Deutung der Dispersion, Zeitschrift fur Physik 23(1924), 341360.64 See ref. 61.65 Jagadish Mehra and Helmut Rechenberg, The Historical Development of Quantum Theory

(New York, Berlin: Springer, 2001), 6:354.66 Smekal, Quantentheorie der Dispersion (ref. 51).67 See, for example, K. W. F. Kohlrausch, Der Smekal-Raman-Effekt (Heidelberg: Springer, 1938).68 Ramdas was also the first to photograph the scattered spectrum successfully, as noted by R.

S. Krishnan and R. K. Shankar, Raman Effect: History of the Discovery, Journal of Raman

Spectroscopy 10 (1981), 18.69 L. A. Ramdas, Raman Effect in Gases and Vapours, Indian Journal of Physics 3 (1928), 131.70 Ladenburg had introduced one of two key ingredients needed for a satisfactory treatment of

dispersion in the old quantum theory: the emission and absorption coefficients of Einsteins

quantum theory of radiation. Ladenburg spent most of his career doing experiments on dispersion

in gases. See Duncan and Janssen On the Verge of Umdeutung (ref. 35).71 Erwin Schrodinger, Quantisierung als Eigenwertproblem, Annalen der Physik 81 (1926),109139.72 H. A. Kramers and W. Heisenberg, Uber die Streuung von Strahlung durch Atome, Zeits-

chrift fur Physik 31 (1925), 681707.


73 A. G. Shenstone, Ladenburg, Rudolf Walther in Charles Gillispie, ed., Dictionary of Scientific

biography (New York: Charles Scribners Sons, 1973), 7:552556.74 Rudolf Ladenburg, Die quantentheoretische Deutung der Zahl der Dispersionselektronen,

Zeitschrift fur Physik 4 (1921), 451468, translated in van der Waerden, Sources of Quantum

Mechanics (ref. 4), 139157. See also Duncan and Janssen, On the verge of Umdeutung (ref. 35).75 J. H. Van Vleck,The absorption of radiation by multiply periodic orbits, and its relation to the

correspondence principle and the Rayeigh-Jeans law. Part I. Some extensions of the correspon-

dence principle, Physical Review 24 (1924), 330346, in van der Waerden, Sources of QuantumTheory (ref. 4), 203222, at 219, eq. 17.76 Francis Lows introduction to Raman, The New Physics (ref. 1).77 IACS archives, Kolkata, Raman Correspondence File.78 Singh, Raman and the Discovery of the Raman Effect (ref. 3), 14. See also Singh, Seventy

Years Ago: The Discovery of the Raman Effect as Seen From German Physicists, Current

Science 74 (1998), 11121115.79 Suman Set

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