Editorial - Indian Academy of Sciences

Editorial

T N C Vidya, Associate Editor

Email:

[email protected]

We are happy to bring to you, an issue that celebrates Niko-laas Tinbergen, who along with Konrad Lorenz and Karl vonFrisch, laid the foundations of the field of ethology, the studyof animal behaviour. In the late 19th and early 20th centuries,animal behaviour was largely approached either through vital-ism and purposive psychology (in England and then America),suggesting that behaviour was the outcome of mystical forceswithin individuals that could, therefore, not be explained throughphysico-chemical processes, or through comparative psychology(in America) that placed an almost exclusive emphasis on learn-ing as the process responsible for behaviour. Comparative psy-chologists at that time often anthropomorphised animal behaviourand relied on laboratory experiments to test animals. EthologistsLorenz, Tinbergen, and von Frisch (in Europe), on the other hand,articulated how animal behaviour itself could be an evolved phe-nomenon. The behaviour showed by an animal could, therefore,be inherited, have survival value, and be acted upon by natu-ral selection. This was in contrast to the view of comparativepsychologists who thought that mental faculties – and not be-haviours – evolved and allowed various species to learn appro-priate behaviours. Therefore, ethologists tended to focus on an-imal behaviour in the natural environment and study instinctivebehaviours – behaviours that animals displayed in response tospecific stimuli even in the absence of prior experience. How-ever, they realized that learning could also be important in somespecies at least. Lorenz, Tinbergen, and von Frisch carried outcareful observations and experiments on insects, fishes, and birds.Their research paved the way for further work on obtaining anevolutionary understanding of behaviours in various animals, in-cluding humans, a proximate understanding of critical periodsfor normal development, and how adverse psychosocial environ-ments can lead to behavioural abnormalities and psychosomatic

RESONANCE | August 2018 829

EDITORIAL

illnesses. The triumvirate was awarded the Nobel Prize in Phys-iology or Medicine in 1973 “for their discoveries concerning or-ganization and elicitation of individual and social behaviour pat-terns”, a departure from the norm of awarding the prize to re-search more directly related to human physiology or disease.

Tinbergen was interested in the specific stimuli eliciting certainbehavioural responses of animals and in the adaptive value ofbehaviour. His life and his work are described in the Article-in-a-Box (Study Nature, Not Just Books) and the General Arti-cle (Nikolaas Tinbergen: The Careful Scientist), respectively, bySindhu Radhakrishna in this issue. Regarding the former, Rad-hakrishna points out to us that Tinbergen, the man, was even moreremarkable than Tinbergen, the ethologist; all of us in academiawould do well to strive towards such personal qualities.

Tinbergen is well-known for persistently fine-tuning and carry-ing out simple, but carefully designed, elegant experiments in theanimal’s natural habitat to test hypotheses about a behaviour. Itis a pleasure, therefore, to have the first of a series of articles onHow to Design Experiments in Animal Behaviour by Raghaven-dra Gadagkar featuring Tinbergen’s experiments on digger waspsin this issue. This series encourages logical thinking and creativ-ity in setting up experiments to study animal behaviour and de-scribes experiments that can be performed (with some modifica-tion if required) by the readers of Resonance. I encourage you towrite to the Resonance Facebook page (@Resonance.IASc.Bng)with your experiences of trying these experiments.

Tinbergen discovered that exaggerated versions of certain stimulievoked exaggerated responses from animals compared to whatnormal stimuli achieved. These supernormal stimuli seem to hi-jack the normal adaptive responses and are seen in a range of taxa– from birds to humans to butterflies. An article on Supernor-mal Stimuli and Responses appears in this issue. Some aspects ofTinbergen’s work are also illustrated in Science Smiles.

It is far too easy to get lost in the details of one’s work, hardlypausing to step back and examine one’s field of work. However,

830 RESONANCE | August 2018

EDITORIAL

Tinbergen did what few do, emphasising the lines of thought andmethods used by ethologists rather than emphasising only factualinformation in his 1963 classic paper ‘On Aims and Methods ofEthology’ and in his 1965 book Animal Behaviour (LIFE NatureLibrary Series). The former was the Classics chosen for this issueand, in lieu of the original paper being reprinted here, we have itsessence brilliantly captured in an essay (See Article-in-a-Box) byR Gadagkar that I hope will make you all read the original paper.

Although Tinbergen primarily focussed on instinctive behaviourthat was inherited, he attributed his success to his environment –his family, peers, teachers, and the widespread interest in natu-ral history that was part of the social milieu in the Netherlandsat the time. Unfortunately, we do not have a widespread interestin natural history, behaviour, organismal or evolutionary biologyin India, despite the abundance of biodiversity that can be veryrewarding to study. Although ethology and other disciplines inorganismal/supra-organismal biology became a ‘testable science’many decades to about a century ago, most of our school andcollege syllabi in organismal biology are hopelessly outdated andrarely extend beyond ‘stamp collecting’. An understanding of thetheory in various subjects, especially evolutionary biology, is cru-cial to progressing beyond descriptions and addressing meaning-ful questions in organismal biology. There is, unfortunately, nota single masters programme on evolutionary biology in the coun-try while there should logically be multiple institutes dedicatedto the subject, given its scope of research and ramifications forunderstanding human society and health (evolutionary medicine,for example) amongst other issues. In this context, it is excitingthat the formation of the first society of evolutionary biologyin India, the Indian Society of Evolutionary Biologists (ISEB),(https://www.facebook.com/Indian-Society-of-Evolutionary-Biologists-510429992749285/) has just been announced. The soci-ety has amongst its aims, promoting evolutionary biology in Indiathrough outreach in schools and colleges, which might be of in-terest to readers of Resonance. Of course, this is just a beginningand a lot more needs to be done to improve the state of organismal


EDITORIAL

biology in the country.

This issue also carries the review of a very interesting book, Howto Tame a Fox (and Build a Dog). The book describes a long-term experiment, conceived of and initiated by the Russian ge-neticist, Dmitri Belyaev, in the early 1950s (and continuing topresent times) to understand the evolution of animal domestica-tion. Selecting and breeding the tamest silver foxes on fox farmsin remote Siberia, Lyudmila Trut, one of the authors of the book,and Belyaev unravelled possible processes that might have en-abled the transformation of wolves into domestic dogs. I hopethe inviting review by Sujata Deshpande will encourage you toread the book.

Apart from articles relating to ethology and evolution, we havein this issue, another General Article – The Easiest Proof of Fer-mat’s Principle by H Ray (Late) and S Roy, and a ClassroomArticle intriguingly titled Card Games and Chemistry by A GSamuelson. This issue also carries the second of a three-part lu-cid and informative series on Breakthroughs in Information andCommunication Technologies by V Rajaraman and the last in along Classroom Series of beautifully demonstrated Experimentsin Fluid Dynamics by Chirag Kalelkar. I hope you enjoy the col-lection of articles.


Science SmilesAyan Guha

Email for Correspondence: [email protected]


834 RESONANCE August 2018

Resonance journal of science education

August 2018 Volume 23 Number 8

GENERAL ARTICLES

845 Nikolaas Tinbergen

The Careful Scientist

Sindhu Radhakrishna

853 Supernormal Stimuli and Responses

T N C Vidya

861 The Easiest Proof of Fermat’s Principle

Hasi Ray and Sudipto Roy

SERIES ARTICLES

871 How to Design Experiments in Animal Behaviour

1. How Wasps Find Their Nests

Raghavendra Gadagkar

885 Breakthroughs in Information and Communication

Technologies – II

V Rajaraman

925

905

853

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Science Education

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835RESONANCE August 2018

Nikolass Tinbergen (1907–1988)

Illustration: Subhankar Biswas

Front Cover

Back Cover

Science Smiles

Ayan Guha

833

Editorial

T N C Vidya829

Classroom

905The Inveterate Tinkerer

Flow Visualisation

Chirag Kalelkar

Card Games and Chemistry

Teaching Organometallic Reactions

Through Card Games

A G Samuelson

Beewolf (Philanthus triangulum) carrying a bee to its tunnel

nest. Nikolaas Tinbergen studied how these wasps found

the way back to their own unfinished nest (read How to

Design Experiments in Animal Behaviour in this issue).

Photo from https://en.wikipedia.org/wiki/Beewolf#/media/

File:Bee_wolf.jpg licensed under the Creative Commons

Attribution-ShareAlike 2.5 License.

Article-in-a-Box

Study Nature, Not

Just Books:

Nikolaas Tinbergen

and His Naturalistic Life

Sindhu Radhakrishna

What Do

Ethologists

Wish to Know?


915

837

841

Book Review

Magic of

Transforming a Fox

Into a Dog!

Sujata Deshpande

925

Information & Announcements

India Flourishes at International

Olympiads

Science Academies’ Refresher Course

in Experimental Physics

Science Academies’ Refresher Course

in Statistical Physics

929

934

Inside Back Cover

Night Life

Malabar Gliding FrogCredit: Sindhu Radhakrishna

935

DEPARTMENTSDEPARTMENTSDEPARTMENTSDEPARTMENTSDEPARTMENTSDEPARTMENTS

ARTICLE-IN-A-BOX

Study Nature, Not Just BooksNikolaas Tinbergen and His Naturalistic Life

Nikolaas Tinbergen, co-winner of the 1973 Nobel Prize in Medicine/Physiology and one ofthe founding fathers of ethology, is a poster child for the best that can happen when natureand nurture work in harmony. Many have argued that Tinbergen was always destined forgreatness; after all, his family has produced not one, but two Nobel Laureates (himself and hiselder brother Jan Tinbergen), a potentially distinguished scientist, and a Director of Energy inThe Hague (South Holland). Tinbergen, however, always attributed his success to the supportof his warm and loving family and the great interest in nature that was a significant part ofsocial and cultural life in the Netherlands when he was growing up. At various stages in hislife, Tinbergen received encouragement and support from his peers and teachers to pursue hisscientific interests the way he wished to, and one wonders how his life may have unfolded hadhe not been blessed with the many opportunities provided by his well-wishers.

Nikolaas Tinbergen was born in 1907 in The Hague. His parents were schoolteachers andhe had four siblings – three brothers Jan, Dik and Luuk, and a sister Jacomiena. Tinbergen’sparents and his siblings were academically inclined and were formidable scholars in the artsand the sciences. Tinbergen once confessed that in his youth, he was considered “the dim onein the family”. Holland in the early twentieth century was deeply influenced by the writingsof naturalists – E Heimans and J P Thijsse. This not only boosted an interest in nature amongthe general populace but also led to natural history lessons becoming an important part ofschool curriculums. Little surprise then that young Nikolaas was allowed by his family to dowhat he liked best, i.e., nature walks, camping out, observing and photographing animals andbirds. Despite his interest in nature, Nikolaas was an indifferent student; traditional botany andzoology that emphasized taxonomy and anatomy bored him, and at the end of his school yearsin 1925, he did not consider biology as a career option. However, fate intervened in the form ofPaul Ehrenfest – theoretical physicist and a family friend – who arranged for Nikolaas to spenda few months at the Rossitten Bird Observatory on the Baltic Sea Coast (then in East Prussia,now in Russia). Tinbergen often admitted that his experiences at Rossitten and watching theautumn bird migration were responsible for his decision to pursue biology and academia.

In 1926, Tinbergen joined the University of Leiden as a zoology student. Again, his luck withfinding ‘kindred souls’ stood him in good stead. The concept of studying animal behaviour inthe field was unusual back then, but Tinbergen was supported in his explorations by Jan Verwey,a biologist and later, Hildebrand Boschma, his PhD advisor. For his PhD thesis, Tinbergen


ARTICLE-IN-A-BOX

extended his field studies on the ecology of the beewolf, Philanthus triangulum, to understandits homing abilities and how it oriented itself during the bee hunt. In 1931, Tinbergen acceptedan invitation to join a Dutch expedition to Greenland. In 1932, after receiving his doctorate(largely due to Boschma accepting a very short dissertation of 32 pages), Tinbergen marriedElizabeth Rutten, and the duo left on the expedition to Greenland. In Greenland, they livedwith a group of Inuits and studied the snow bunting’s territorial behaviour. On his return toHolland in 1933, Tinbergen continued with his assistant position at the Zoological Laboratoryin Leiden. Two years later, he was hired as lecturer in general zoology by the University, andhe established a teaching program in animal behaviour that included practical sessions in thefield and laboratory.

In 1936, Tinbergen met Konrad Lorenz at a conference in Leiden. This marked the beginningof a deep friendship between the two men that had a lasting impact on Tinbergen’s life, bothpersonally and professionally. Later that year, Tinbergen visited Lorenz at his home in Austriaand stayed with him for over three months, discussing and conducting experiments to investi-gate mutually exciting aspects of animal behaviour patterns. This period of active collaborationled, among other ideas, to the now famous study of the egg-rolling behaviour of the graylaggoose. However, the Second World War brought about a rupture in their association as theyfound themselves on the opposite sides of the global political divide. In 1942, Tinbergen wastaken as a prisoner by the Nazi authorities after he protested the removal of Jewish professorsfrom Leiden University. His experiences in the war camp left Tinbergen wary of Germany andGermans. Although he resumed his association with Lorenz after the war ended, they neverregained the initial warmth of their relationship.

After the war, Tinbergen returned to his position in Leiden University and was made Professorin 1947. In 1949, Tinbergen gave up his position in Leiden to move to a less prestigiousposition in the University of Oxford, angering his Dutch colleagues in the process. However,Tinbergen made Oxford his new home, personally and professionally, and became a Britishcitizen in 1955. At the University, he built a strong program of ethology, both through hisown research work as well as that of his students and collaborators. Towards the end of hisresearch career, Tinbergen withdrew from animal field studies and developed an interest inunderstanding human problems. He promoted the application of ethological methodologiesto studying human behaviour and collaborated with his wife Elizabeth to carry out his lastresearch project on the behaviour of autistic children.

Tinbergen received many honours for his work; these include the Swammerdam Medal, God-man Salvin Medal, honorary degrees from Edinburgh and Leicester, the Distinguished Scien-tific Contribution Award from the American Psychological Association, the Diploma of Honourof the Sociedad Argentina Protectora de Animales, and of course, the Nobel Prize. Apart from


ARTICLE-IN-A-BOX

his writings and lectures on ethology, Tinbergen also popularized science through his docu-mentaries. In 1969, he was recognized for his achievements as a filmmaker, when he and HughFalkus were awarded the Italia Prize and the Blue Ribbon of the New York Film Festival fortheir film, Signals for Survival. Tinbergen died in his home in Oxford in 1988, after sufferinga stroke.

Tinbergen, the scientist, is a remarkable figure who left behind an awe-inspiring scientificlegacy. His work played a critical role in introducing a new approach to understanding animalbehaviour and human evolution. His carefully thought-out field experiments (see articles by SRadhakrishna and R Gadagkar in this issue) ushered in a new era of research design for animalstudies in the wild, his ideas inspired multiple generations of thinkers and scholars, and he men-tored many students who went on to become highly influential animal and human behaviourscholars. But, it is Tinbergen the man, who should draw more attention from an aspiring ethol-ogist. Tinbergen’s personal qualities and the way he conducted himself embodied the values ofgenerosity, patience, courtesy and humility. Always ready to acknowledge the contributions ofother scholars and collaborators, Tinbergen was unfailingly generous when he spoke or wroteabout how his peers influenced his thoughts and ideas. His students remember the spirit ofteamwork that existed in the group at Oxford, and how Tinbergen always offered them thegift of his attention whenever they wanted to discuss an idea. Modest about his achievements,Tinbergen rarely spoke about the many honours he received or even his standing as a world-renowned scientist. Instead, he described his work as “no more than tentative groping attemptsat seeing some sense in the variety of animal behaviour systems that fascinated, yet bewildered,us”.

A little-known fact about Tinbergen is that he suffered from depression for most of his adultlife. Unfortunately, during his lifetime, physicians were unable to diagnose the cause behindhis depressive bouts, though later accounts speculate that a fatty-acid deficiency and/or proteinintolerance may possibly have been responsible for his condition. In view of his illness, hissuccess as a scientist appears even more commendable.

Tinbergen encouraged his students to go out into the natural world, to observe animal behaviourfor themselves, and think about what the behaviour may mean. In Leiden and in Oxford, it waswell-known that he far preferred the classroom of the wild to the study rooms within the univer-sities. It is said that when Tinbergen first set up his animal behaviour teaching program in theUniversity of Leiden, he wrote above the departmental library “Study Nature and Not Books”.Tinbergen lived by the advice he promoted all his life.


ARTICLE-IN-A-BOX

Suggested Reading

[1] H Kruuk, Niko’s Nature: The Life of Niko Tinbergen and His Science of Animal Behaviour, OUP Oxford, 2003.

[2] R A Hinde, Nikolaas Tinbergen, 15 April 1907 – 21 December 1988. Biographical Memoirs of Fellows of the Royal

Society, Vol.36, pp.548–565, 1990.

[3] S Radhakrishna, Resonance – Journal of Science Education, Vol.23, No.8, pp.845–851, 2018.

[4] R Gadagkar, How to Design Experiments in Animal Behaviour: 1. How Wasps Find Their Nests, Resonance – Journal

of Science Education, Vol.23, No.8, pp.871–884, 2018.

Sindhu RadhakrishnaNational Institute of Advanced Studies Indian Institute of Science Campus, Bengaluru

Email: [email protected]


ARTICLE-IN-A-BOX

What Do Ethologists Wish to Know?

This issue celebrates the life and work of one of the founders of ethology and Nobel Laureate,Niko Tinbergen. Readers of Resonance will be aware that we celebrate the contributions ofone scientist in every issue and in doing so, we reprint for the benefit of our young readers,one of the more important papers of the scientist being celebrated. In this issue, we wishedto do the same and reprint what is perhaps Tinbergen’s most important paper and certainlyhis most enduring legacy. However, the publishers of the original paper decided to charge usan unreasonably high amount of money which this not-for-profit educational journal cannotafford. It is a tragedy of our times that intellectual material, even when very old, is hiddeninside vaults of commercial publishers and unavailable to young students who were not bornwhen they were first published. I will, therefore, whet your appetite by providing a glimpseinto the main theme of the paper in question and give a reference so that some of you may beable to find some way to read the original paper.

On the occasion of the 60th birthday of another founder of ethology and also Nobel Laureate,Konrad Lorenz, Tinbergen wrote a paper entitled, ‘On the Aims and Methods of Ethology’ [1].In this paper, Tinbergen did what scientists do not do as often as they should, namely to sit back,reflect and re-examine the foundations of his discipline of study. Tinbergen evocatively calledthis process ‘soul-searching’. Thus, Tinbergen searched his soul and asked what were the aimsand methods of ethology. In doing so, Tinbergen created a map of the conceptual space ofethology and asked what ethologists really wish to know and how they go about it? Based onprevious work and his own reflection, Tinbergen created an ethologist’s wish list in the form offour fundamental questions namely, 1) What makes a behaviour happen (causation), 2) whatis the survival value of the behaviour (function), 3) how does a behaviour develop within thelifetime of an individual organism (ontogeny), and 4) how has the behaviour changed overevolutionary time, across species (evolution)? This framework has endured and has come to beknown as ‘Tinbergen’s Four Questions’.

I will illustrate Tinbergen’s four questions using the example of birdsong. Many species ofbirds, especially the males (also females in some species), produce remarkably melodioussongs which are not only fascinating to biologists but have long captured the imagination ofwriters, poets and lovers. The song of our own koel (Eudynamys scolopaceus) is a familiarexample [2].

(1) What Causes Birds to Sing?

In answering this question, we study the anatomy of the sound producing organ of birds –


ARTICLE-IN-A-BOX

the syrinx – analogous to our larynx. But the syrinx by itself cannot do much without theorchestration of several membranes and muscles that help channel air in unique ways. Themembranes and muscles are controlled by elaborate neural structures and circuits in the brain.But the birds do not sing all the time. What are, therefore, the environmental and hormonalstimuli that motivate birds to sing? As you can imagine this is in itself a major field of study,aimed at understanding the mechanism of song production [3].

(2) What is the Survival Value of Birdsong?

Birds generally sing during courtship and the song helps attract mates. Where the females alsosing, there is generally a duet between the male and the female. Understanding the survivalvalue of behaviours has blossomed into a major sub-field of ethology namely, ‘behaviouralecology’. There is a vast literature on the behavioural ecology of birdsong and about howfemales may be choosing males that sing songs of their liking, a process which Darwin referredto as ‘sexual selection’ [4].

(3) How Does Birdsong Develop in the Lifetime of a Bird?

This is an especially fascinating area of study because in most cases, birds are known to learntheir species-specific song by a process of trial and error; they match their songs with the songsthey have heard, usually their father’s, songs. The brain mechanisms that permit the bird toaccomplish this feat are being unravelled at a rapid pace [5].

(4) How Have Birdsongs Changed Across Species?

Such questions are usually answered by constructing phylogenetic trees of related species andnoting the branches in the trees in which traits of interest (in this case, song) arise, or are lost.This question has not received adequate attention with reference to birdsong, perhaps becausesong is not a simple, clear trait that can be easily scored as present or absent. Nevertheless,there is an interesting study of the evolution of songs in orioles [6].

Tinbergen’s four questions are sometimes divided into two groups and called proximate ques-tions (causation and ontogeny) and ultimate questions (function and evolution) [7]. You can seehow anything we want to understand about birdsong can be mapped onto one or the other ofTinbergen’s four questions. Such a taxonomy of questions allows us to clarify our thoughts andmake sure that we learn everything possible about any particular behaviour. Not surprisingly,this legacy of Tinbergen has endured and is being put to use not only in different branches ofethology but in other areas of biology as well. As we do with famous people, we have alsobegun to celebrate the birthdays of this paper! On the 50th anniversary of the publication ofTinbergen’s original paper, Bateson and Laland celebrated its anniversary by revisiting Tinber-gen’s four questions, pointing out why they have endured and, more importantly, showing how


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modern developments in the study of ethology have made it necessary to treat Tinbergen’s fourquestions now in a much more nuanced manner [8]. Both Tinbergen’s original paper [1] andBateson and Laland’s update [8] are well worth reading.

Suggested Reading

[1] N Tinbergen, On the Aims and Methods of Ethology, Zeitschrift fur Tierpsychologie, Vol.20, pp.410–433. (This journal

was renamed Ethology in 1986), 1963.

[2] A A Khan, I Z Qureshi, Vocalizations of Adult Male Asian Koels (Eudynamys scolopacea) in the Breeding Season,

PLoS ONE, Vol.12, No.10, p.e0186604, https://doi.org/10.1371/journal.pone.0186604, 2017.

[3] H P Zeigler and P Marler, Eds. Neuroscience of Birdsong, Cambridge University Press, 2008.

[4] C K Catchpole and P J B Slater, Bird Song: Biological Themes and Variations, Cambridge University Press, 2008.

[5] V Gadagkar, P A Puzerey, R Chen, E Baird-Daniel, A R Farhang, J H Goldberg, Dopamine Neurons Encode Perfor-

mance Error in Singing Birds,Science, Vol.354, pp.1278–1282, 2016.

[6] J Price, et al., Song and Plumage Evolution in the New World Orioles (Icterus) Show Similar Lability and Convergence

in Patterns, Evolution, Vol.61, pp.850–863, 2007.

[7] R Gadagkar, Survival Strategies: Cooperation and Conflict in Animal Societies, Harvard University Press, USA and

Universities Press, Hyderabad, India, 1997.

[8] P Bateson and K Laland, Tinbergen’s Four Questions: An Appreciation and An Update, Trends in Ecology & Evolu-

tion, Vol.28, pp.712–718, 2013.

Raghavendra GadagkarCentre for Ecological Sciences and Centre

for Contemporary StudiesIndian Institute of ScienceBangalore 560 012, India.

Email: [email protected]://ces.iisc.ac.in/hpg/ragh

https://www.researchgate.net/profileRaghavendra Gadagkar


GENERAL ARTICLE

Nikolaas TinbergenThe Careful Scientist

Sindhu Radhakrishna

Sindhu Radhakrishna holds a

master’s degree in psychology

and a doctorate in animal

behaviour. She is presently

Professor and Dean at the

Animal Behaviour and

Cognition Programme,

National Institute of

Advanced Studies,

Bengaluru. Her research

interests are in the fields of

primatology, behavioral

ecology and conservation

biology, and her work is

focused on gaining a better

understanding of social

behaviour and

communication in nocturnal

primates.

What is it about the work of some great scientists that setsthem apart from the admirable work done by many good sci-entists? Is it because some, if not all, of their contributionsstand the test of time? Or is it because their work paved theway for other great ideas to develop? Nikolaas Tinbergen’slife and work suggests that it is a combination of both thesefactors that characterise a truly great scientist.

Nikolaas Tinbergen (1907–1988) was a Dutch scientist who stud-ied animal behaviour. Tinbergen began his academic career atthe University of Leiden in the Netherlands and later moved toOxford, where he set up a school for animal behaviour stud-ies. Tinbergen pioneered and popularised the science of ethol-ogy through his research and teaching. He lectured widely onthe subject and wrote extensively; some of his more well-knownbooks include The Study of Instinct (1951), The Herring Gull’sWorld (1953), Curious Naturalists (1958), and the Time-life vol-ume, Animal Behavior (1965). Tinbergen was an influential bi-ologist within his lifetime and received many honours for hiswork, most notably, the Nobel Prize, the Swammerdam Medal,the Distinguished Scientific Contribution Award from the Ameri-can Psychological Association and the Diploma of Honour of theSociedad Argentina Protectora de Animales. Apart from beingan excellent communicator who mentored a new generation ofrenowned biologists, Tinbergen was also an exceptional photog-rapher and filmmaker who was celebrated for his films on animalbehaviour.

Tinbergen is often described as one of the founding fathers of Keywords

Animal behaviour, ethology, stick-

leback fish, gull, stimuli, experi-

ment.

ethology, or animal behaviour. This simplistic description, how-ever, does not provide a holistic understanding of the importance


GENERAL ARTICLE

of Tinbergen’s achievements, and some historicalUnlike early animalbehavioural researchers

who relied on acomparative psychology

approach and viewedbehaviour as a learning

process, Tinbergenbelieved that the answerto animal behaviour was

in the hereditaryinfluences occurring

inside the animal.

context is nec-essary to appreciate this. Animal behavioural science existedlong before Tinbergen began his work on animal behaviour; thecrucial difference being that the predominant approach then wasone of comparative psychology, and psychologists largely viewedbehaviour as a learning process. Tinbergen, on the other hand,was more interested in understanding why “animals behave asthey do?” and believed that the answer lay in the “hereditaryinfluences occurring inside the animal”. In other words, Tinber-gen saw behaviour as an evolutionarily adaptive trait and empha-sised a more objective, biological approach to understanding be-haviour.

To understand why animals behave the way they do, Tinbergenobserved animal behaviour in the natural environment of the speciesand conducted painstakingly designed, simple field experimentsto test out his hypotheses about how animals reacted to exter-nal stimuli. He studied a variety of species ranging from waspsand stickleback fish to gulls, blackbirds and kittiwake and showedhow natural observation techniques can be married successfullyto experiments within laboratories. Tinbergen’s field experimentswere elegantly designed simple setups that carefully teased apartfunctional explanations for particular behaviours exhibited by an-imals and the nature of external stimuli that may elicit certain be-havioural responses from animals. The design of his earliest ex-periments on the orientation behaviour of the beewolf, Philanthustriangulum, highlighted what was to be the hallmark of his re-search – a careful, dogged approach that incrementally addressedthe effect of one variable at a time, so that it was absolutely clearwhat kind of cues were being used by the beewolf females to ori-ent themselves (for a better idea about the design of Tinbergen’sbeewolf experiments, please see Prof. Gadagkar’s article on ani-mal behaviour experiments in this issue).

Tinbergen refined this research approach throughout his career.For example, when Tinbergen started studying the reproductivebehaviour of the stickleback fish in the laboratory he set up atLeiden University, he was initially interested in observing the


GENERAL ARTICLE

courtship behaviour To prove that it was thecolour red that acted asthe ‘sign stimulus’ or‘releaser’, Tinbergendesigned a set ofexperiments wherein hecreated some roughmodels of sticklebacks,painted them in variouscolours, including red,and presented them tothe male sticklebacks inthe tank. Red colouredmodels always elicitedmore reaction fromcourting males,demonstrating that it wasthe colour red (ratherthan the shape/identity ofthe fish) that acted as the‘releaser’ for a specificaction from the male.

of male sticklebacks and carefully docu-mented the many steps in their complex mating ritual. He noticedthat courting males turned red on their underside and attackedother coloured individuals that approached their territories. Thecolour red appeared to be a stimulus that set off aggressive reac-tions in the males, for male sticklebacks attacked the sides of theaquarium even when a red mail van passed beside the window ofthe aquarium. To prove that it was the colour red that acted as the‘sign stimulus’ or ‘releaser’, Tinbergen designed a set of exper-iments wherein he created some rough models of sticklebacks,painted them in various colours, including red, and presentedthem to the male sticklebacks in the tank. Red coloured modelsalways elicited more reaction from courting males, demonstrat-ing that it was the colour red (rather than the shape/identity ofthe fish) that acted as the ‘releaser’ for a specific action from themale. Tinbergen then continued with his experiments to show thatparticular shape, size or type of body movement can elicit certainreactions from males and females in the breeding period. For in-stance, females will follow a red dummy fish and even try to moveinto a nest in the sand (where none exists), when the dummy fishis poked into the sand. Again, females will begin to lay eggs,when they are tapped repeatedly on the base of the tail (in a par-ody of the male prodding her tail base) although they observedthe removal of the red fish that led them into the nest. These find-ings led Tinbergen to conclude that sticklebacks (and many otherspecies) respond “simply to ‘sign stimuli’, i.e., to a few charac-teristics of an object rather than to the object as a whole....it is thesignal, not the object, that counts. It seems to be typical of innatebehaviour, and many social relationships in animals apparentlyare based on a system of signs.”

Tinbergen’s careful experimentation (in natural conditions and inthe laboratory) shows that he was an exceptional scientist, but itwas his constant ability to learn that marks him as a truly out-standing biologist. Tinbergen’s thinking about animal behaviourconstantly evolved during the course of his research career and hebuilt on the findings of his earlier studies to ask newer and more


GENERAL ARTICLE

exciting questions. For example, his earlier studies such as hiswork on Philanthus homing behaviour, and stickleback matingbehaviour were built around the central question: What stimulielicit innate and fixed behaviour patterns in animals? In his laterstudies, he moved on to ask: What is the function of behaviour?His work on eggshell removal by the black-headed gull typifiesthis approach.

Black-headedIn a very curiousbehaviour, black-headedgulls remove eggshells

from the vicinity of theirnests almost

immediately afterhatching. Except for the

top end, shells do notmarkedly differ from

eggs. Yet, eggs are neverremoved from the nest.

gulls remove eggshells from the vicinity of theirnests almost immediately after hatching. Except for the top end,shells do not markedly differ from eggs. Yet, eggs are never re-moved from the nest. Tinbergen asked the question: What isthe function of the eggshell removal behaviour? He hypothesisedthat it was to increase the survival chances of the chicks and pro-ceeded to conduct a series of experiments to test out this hypoth-esis. Tinbergen observed that the insides of the eggshells werewhite which could attract the attention of predators. To build ev-idence for this point, he and his collaborators first conducted aset of three experiments wherein they investigated if the naturalcolour of the black-headed gulls’ eggs acted as camouflage andthereby protected them from the attention of predators. To do this,they painted some gull eggs white and left them alongside someunpainted eggs in shallow depressions in the ground that weresimilar to black-headed gulls’ nests. Comparative rates of preda-tion on the experimental eggs showed that the natural colour ofthe gulls’ eggs made them less vulnerable to predation than thosepainted white. Tinbergen then went on to test if the presence ofthe eggshells in the vicinity of nests increased chances of preda-tion. He did this by comparing the rates of predation on gull eggsthat were placed near eggshells and those that were not. He alsoconducted another experiment wherein eggshells were placed atincreasing distances from eggs to investigate the effect of prox-imity of eggshells on egg/chick predation. The results of his ex-periments conclusively proved that the presence of eggshells neareggs/chicks made them more vulnerable to predation and that thechances of predation decreased with increasing distance betweeneggs and eggshells.


GENERAL ARTICLE

The black-headed gull study demonstrates how Tinbergen couldeffectively deconstruct a simple animal behavior to show that ev-ery behavioral response has adaptive and evolutionary signifi-cance. In his discussion of this study, Tinbergen wrote: “Re-moval of an eggshell lasts a few seconds. It is normally donethree times a year. Nothing would seem to be more trivial thanthis response, which at first glance might seem to be no more thanfussy ‘tidying-up’ by a ‘house proud’ bird. Yet we have seen thatit has considerable survival value and that the behavioural organ-isation is complicated and well adapted to the needs.”

Through Through his fieldexperiments andemphasis on naturalobservations, Tinbergennot only revealed severalunexpected (and hithertounknown) aspects ofanimal behaviour, healso revolutionised thestudy of animalbehaviour through thisunusual approach.

his field experiments and emphasis on natural observa-tions, Tinbergen not only revealed several unexpected (and hith-erto unknown) aspects of animal behaviour, he also revolutionisedthe study of animal behaviour through this unusual approach. AsDesmond Morris described it, biologists “wear a white coat orWellington boots, one or the other.....Tinbergen does both. In mybook, that makes him the most important person in his field thiscentury.”

Tinbergen is best remembered for his formulation of the ‘FourQuestions of Ethology’. In his most famous paper ‘On Aims andMethods of Ethology’, published in 1963, he systematically laidout what he saw as the defining characteristics of ethology. Thispaper encapsulates his thinking (and changes in his views) aboutethology over 30 years of his ethological career. To understandbehaviour, he wrote, one must ask four main questions, namely:“(1) What is its physiological causation? (2) What is its func-tion or survival value? (3) How has it evolved over time?, and(4) How has it developed in the individual?” By “dividing be-haviour studies into physiology, development, natural selection,and evolutionary history”, Tinbergen provided biologists with aclear and holistic framework for studying behaviour that wouldin later years be expanded to connect genes to behavioural phe-notypes. For this reason, Tinbergen’s four questions continue toremain as central to our understating of behaviour as they werewhen they were first published (see Prof. Gadagkar’s Article-in-a-Box on this classic paper in this issue). Although many early


GENERAL ARTICLE

theories of ethology suchTinbergen’s fourquestions about

behavioural causation,development, function,

and evolution still formsthe cornerstone of

teachings in ethology.

as Lorenz’s psycho-hydraulic modeland Tinbergen’s hierarchical model of instinctive action have cometo be critiqued over the years, Tinbergen’s four questions aboutbehavioural causation, development, function, and evolution stillforms the cornerstone of teachings in ethology.

The hallmark of Tinbergen’s research contributions was his care-ful, patient observations and it was in this regard that he differedmost significantly from his peer, collaborator and friend KonradLorenz, one of the other founding fathers of ethology. Lorenz wasa flamboyant personality, whose pronouncements on imprintingand aggression took the biological world by storm, yet it is Tin-bergen’s methodology of careful experimentation and conceptualframeworks to study behaviour that has become the textbook ma-terial for all aspiring students of behaviour. Robert Hinde, in hisbiographical sketch of Tinbergen, relates an incident that encap-sulates the differences in temperament and work between the twomen. Post-World War II, Tinbergen and Lorenz met at a confer-ence in Cambridge in 1949. During one of their discussions, theytalked about “how often you had to see an animal do somethingbefore you could say that the species did it. Konrad said he hadnever made such a claim unless he had seen the behaviour at leastfive times. Niko laughed and clapped him on the back and said“Don’t be silly, Konrad, you know you have often said it whenyou have only seen it once!” Konrad laughed even louder, ac-knowledging the point and enjoying the joke at his own expense.”

Tinbergen’s contributions to biology are manifold. He advocatedthe biological approach to understanding behaviour that is takenfor granted today, highlighted the importance of detailed, natu-ralistic observations in understanding behaviour, showed the pos-sibilities of designing simple field experiments that can answerquestions related to the function and cause of a behaviour, andconsistently stressed the need for careful studies that would buildup evidence through careful observations and experiments to jus-tify any conclusions they made. Looking back, more than 50years after the event, it is difficult to appreciate the differencethat Tinbergen’s ideas have made to our understanding of animal


GENERAL ARTICLE

and human behaviour. Today behavioural ecology and evolution-ary developmental biology are integral subdisciplines of biologyand it is hard to imagine that Tinbergen’s work helped stimu-late the development of these fields. Tinbergen’s (and his col-leagues’) greatest accomplishment was that they made behaviouran integral part of biology, a ‘testable science’, and this particularachievement was due more to Tinbergen’s careful construction ofhow we can study behaviour than anything else. It is telling thatin its history, the Nobel Prize has been given only once for animalbehaviour. In his speech, granting the Prize to the trio of Karl vonFrisch, Konrad Lorenz and Nikolaas Tinbergen, Borje Cronholmtalked about how the triumvirate had succeeded in transformingthe study of behaviour to an analytical science, by treating be-haviour as a biological trait within an evolutionary framework.While von Frisch was awarded the prize for his work on honeybeecommunication and Lorenz for discovering fixed action patternsand imprinting, Tinbergen was cited for his ‘experimentation andthe discovery of extra-normal stimuli that released cascades ofactions’.

Tinbergen passed away in 1988 in his home in Oxford after a longand fulfilling career in research and academics. Yet, every timebiology students are introduced to the four questions of ethologyor are taught about designing behavioural experiments, Tinbergenis reborn. And this, more than anything else, is why NikolaasTinbergen was a great scientist.

Address for Correspondence

Sindhu Radhakrishna

School of Natural Sciences

and Engineering

Room No: S 23

National Institute of Advanced

Studies

IISc Campus

Bengaluru 560 012

India

Email:

sindhu.radhakrishna@

gmail.com

Suggested Reading

[1] Roberts (ed), Special Issue on Tinbergen, Human Ethology Bulletin, 28, No 4,

2013.

[2] Joan E Strassmann, Tribute to Tinbergen: The Place of Animal Behav-

ior in Biology, Biology Faculty Publications and Presentations, Paper 43,

http://openscholarship.wustl.edu/bio_facpubs/43, 2014.

[3] N Tinbergen, On Aims and Methods of Ethology, Animal Biology, 55.4, pp.297–

321, 2005. Originally published in 1963.

[4] N Tinbergen, The Curious Behavior of the Stickleback, Scientific American,

187(6), pp.22–27, 1952.

[5] N Tinbergen, G J Broekhuysen, F Feekes, J C W Houghton, H Kruuk and

E Szulc, Eggshell Removal by the Black-headed Gull, Larus ridibundus L., A

Behaviour Component of Camouflage, Behaviour, 19(1), pp.74–116, 1962.


http://openscholarship.wustl.edu/bio_facpubs/43

GENERAL ARTICLE

Supernormal Stimuli and Responses

T N C Vidya

T N C Vidya is interested in

animal behaviour and

phylogeography, and teaches

these at JNCASR. Her

primary research is on the

social organization and

behaviour of Asian elephants.

In this article, I describe the curious phenomenon of exagger-ated responses to supernormal stimuli in animals. These havebeen observed across various taxa and include preferences forlarger egg size, darker or more contrasting colours or, in thecase of humans, preferences for processed foods and televi-sion among others. I describe mechanisms that have beenproposed to explain supernormal responses and possible con-sequences of such responses.

Experiments with Oystercatchers and Other Birds

The Eurasian oystercatcher (Haematopus ostralegus) is a wadingbird that feeds on earthworms and mussels. During a study ofthis oystercatcher, ethologist Nikolaas Tinbergen (see articles bySindhu Radhakrishna and Raghavendra Gadagkar in this issue)noticed that female oystercatchers laid a few eggs and then beganto incubate the entire clutch. Tinbergen and his colleagues pre-sented female oystercatchers with a clutch of five eggs rather thantheir normal three eggs and found that they preferred to incubatethe larger clutch that was not their own! The scientists proceededto offer the females a choice of eggs of varying sizes. In mostcases, the females clambered on to the largest egg, which wasmany times the size of their normal egg, making it extremely dif-ficult for them to even sit down upon [1] (see Figure 1)! Similarexperiments were carried out in herring gulls and black-headedgulls by removing the gull’s eggs when the bird was away fromthe nest and placing two eggs at the rim of the nest. Gulls have a Keywords

Supernormal stimuli, sign stimuli,

exaggerated response, Nikolaas

Tinbergen, oystercatcher egg

size, food-begging in gulls,

grayling butterflies, generalization

and peak shift, brood parasite.

tendency to retrieve eggs that have rolled away accidentally andwould, therefore, choose one of them first to roll back to the nest,exhibiting their preference. Using different combinations of arti-ficial eggs, Tinbergen and his colleagues showed that gulls alsopreferred larger eggs to smaller ones. You can, perhaps, try this


GENERAL ARTICLE

Figure 1. (a) Eurasian

oystercatcher at the nest.

Photo by John Haslam.

Source:

https://en.wikipedia.org/wiki/

Eurasian oystercatcher#/media

/File:Haematopus ostralegus

-Scotland -nesting-8.jpg

under Creative Commons

license CC BY 2.0. (b) Oys-

tercatcher preferring giant

egg to its own (smallest)

egg. Source: Artwork by T

N C Vidya based on Figure

43 from Tinbergen [1].

(a) (b)

experiment with pigeons, ducks or hens! Reactions to stimulifrom artificial eggs in the context of colour, not size, had first beendescribed by Koehler and Zagarus in an article (unfortunately, forus, in German) on the ringed plover in 1937. Koehler and Zagarusfound that the plovers preferred eggs with clear white backgroundand black spots to their own light brown eggs with darker brownspots.

Why did these birds prefer artificial eggs to their own eggs, espe-cially when the artificial eggs were of a size that they could nothave possibly laid themselves? The large egg size and markedcolour contrast above are examples of what are referred to as‘supernormal stimuli’. As the termAs the term suggests,

supernormal stimuli areexaggerated versions of

stimuli to which animalsrespond more intenselythan to normal stimuli.

While the preference fora slightly exaggerated

version of the stimulusmay be adaptive – for

instance, preference for alarger egg over a smaller

egg within a normalrange may be beneficial

as larger eggs may bemore viable – the

supernormal stimulushijacks the normal,possibly adaptive,

response.

suggests, supernormal stim-uli are exaggerated versions of stimuli to which animals respondmore intensely than to normal stimuli. While the preference for aslightly exaggerated version of the stimulus may be adaptive – forinstance, preference for a larger egg over a smaller egg within anormal range may be beneficial as larger eggs may be more viable– the supernormal stimulus hijacks the normal, possibly adaptive,response and leads to an exaggerated or supernormal response.

Apart from his work on the organisation of instinctive behaviouror ‘fixed action patterns’ – behaviour that is largely influenced bygenetic rather than environmental components and is, therefore,shown by animals in response to a specific stimulus without anyprior experience – Tinbergen is famous for his work on supernor-mal stimuli. The stimuli that evoked instinctive behaviours werecalled ‘sign stimuli’ or ‘releasers’ (as behaviours were thoughtto be released by an ‘innate releasing mechanism’ by KonradLorenz, who first suggested this idea). Tinbergen observed var-


GENERAL ARTICLE

ious animal behaviours to identify releasers of those behaviours(see Sindhu Radhakrishna’s article in this issue for a descriptionof Tinbergen’s work on sticklebacks). One such behaviour was‘food-begging’ by chicks of herring gulls. Using models of her-ring gull heads with various combinations of head, bill, and billpatch colour, head shape, bill length, and movement, Tinbergenand Perdeck [2] found that herring gull chicks pecked most atmoving cardboard cutouts with long bills, whose bill patch colourcontrasted with that of the bill. Herring gulls have a white head,yellow bill, and a red bill patch. Tinbergen and Perdeck then pre-sented chicks with a choice of a thin, red rod with three whitebands at one end, and a three-dimensional head, and found thatthe former seemed to be perceived as a ‘supernormal bill’ and waspreferred to the latter.

Supernormal Stimuli in Other Taxa

Tinbergen showed that the grayling butterfly also reacts to su-pernormal stimuli, in the context of finding a mate [3]. Malegrayling butterflies are seen resting camouflaged on the groundor tree barks and flying up towards passing females. Femalesrespond by alighting upon the ground if they are ready to mate,or by flying away if they are not, upon which the male wouldabandon the chase and settle down to wait for another female. In-terestingly, males were sometimes seen flying up towards fallingleaves, other butterflies and insects, birds, and even shadows! Us-ing paper dummies tied to a stick and various combinations ofcharacteristics such as colour, size, and shape, Tinbergen and hiscolleagues carried out about 50,000 tests on male graylings in thewild and found that black dummies elicited a greater responsefrom males although females were naturally brown. Larger dum-mies were also important, as was fluttering Tinbergen showed that

the grayling butterflyalso reacts tosupernormal stimuli, inthe context of finding amate.

movement, althoughthe shape was not. Simple circles or rectangles could elicit thesame response as a butterfly-shaped dummy! Thus, larger, darker,flying dummies seemed to provide supernormal stimulation. Whywould males waste their energy flying up towards objects that arenot conspecific females? If females were rare and/or competi-


GENERAL ARTICLE

tion amongst males for access to females important, the cost ofreacting to other objects (energetically and/or through possibleexposure to predators) might be outweighed by the benefit of notmissing flying females, and therefore, increasing the male’s re-productive success. Similarly, Australian jewel beetles have beenfound attempting to copulate with shiny, brown beer bottles thatseem to be perceived as supernormal females [4], a finding thatearned Gwynne and Rentz the Ig Nobel Prize in 2011!

AreAre humans sensitive toany supernormal

stimulus? A quick lookaround leads to a

resounding YES. Aneveryday example is the

craving for variousprocessed foods,

optimised to provide ourtaste buds with

irresistible combinationsof sugar, salt, and fat that

natural foods seldompossess.

humans sensitive to any supernormal stimulus? A quicklook around leads to a resounding YES. An everyday exampleis the craving for various processed foods, optimised to provideour taste buds with irresistible combinations of sugar, salt, andfat that natural foods seldom possess. Supernormal stimuli arealso evident in depictions of the human body in paintings andsculpture to appear more sexually attractive. Movie superheroes,certain video games, television shows, and social media are alsothought to provide supernormal stimuli, exaggerating social stim-uli that are normally beneficial. Hyperbole in language presum-ably serves the same function.

Mechanisms for Supernormal Response Generation

How do supernormal responses arise? Research during the 20thcentury showed that certain principles seem to be followed in gen-erating learned responses to stimuli. The first, called ‘generaliza-tion’, is that novel stimuli evoke the same response as establishedbehaviour towards known stimuli if the two stimuli are similar.There is a gradient of generalization such that the response tothe novel stimulus decreases with decreasing similarity of stim-uli. The second, called the ‘peak shift’, is that modified stim-uli can sometimes elicit a more intense response than expected,in a specific direction. For example, if an animal is trained todiscriminate between the colours red and orange by providing areward when it chooses red and no reward when it chooses or-ange, red is a positive stimulus (S+) and orange is an inhibitory(S-) stimulus. Each has a gradient of generalization around it,


GENERAL ARTICLE

Figure 2. Gradient of gen-

eralization and peak-shift il-

lustrated. S+ (red colour)

and S- (orange colour) are

two stimuli that an animal

is trained to discriminate be-

tween by providing a reward

when it chooses red and no

reward when it chooses or-

ange. Each stimulus has

a gradient of generalization

around it, represented by the

two curves. The excita-

tory generalization gradient

(around S+) is larger than

the inhibitory generalization

gradient (around S-) because

of reward-associated learn-

ing. S’ (dark red) is a

new stimulus presented to

the animal. The difference

between the two gradients,

shown as filled set brackets,

results in the tendency to ap-

proach one stimulus versus

another. The animal prefers

S’ instead of S+ that it had

earlier been rewarded for be-

cause the magnitude of dif-

ference between the gradi-

ents is greater at S’ than at

S+. Drawn after Pearce [5].

Stimulus

Res

pons

est

reng

th

S' S+ S-

the responses around S+ being more frequent than that around S-because of reward-associated learning. Now, if a new stimulus(S’) is presented to the animal in the form of dark red colour, theanimal prefers dark red (S’) instead of red (S+) that it had earlierbeen rewarded for because the magnitude of difference betweenthe excitatory (S+) and inhibitory (S-) generalization gradients isgreater at the dark red stimulus (S’) rather than at red (S+) it-self (Figure 2, see [5]). This, then, could result in exaggeratedresponses such as to supernormal stimuli. Peak shifts occur dur-ing discriminant learning and should not themselves be confusedwith supernormal responses, but it is possible that there is a sim-ilar mechanism in the latter, with an underlying bias (such as a‘bigger is better’ rule) having been shaped adaptively over evo-lutionary time. This underlying bias is possibly shaped by asym-metric selection pressure, corresponding to differential reward inthe learning paradigm above. It has been suggested that just asthere is a reward (‘selection’) for a specific preference but no pun-ishment for the other in the learning experiments, there might beselection for, say, large eggs as opposed to small eggs, but noselection against supersized eggs, leading to the underlying bias[6]. This is, obviously, not always the case, as there might beother costs such as predation.

In 1993, Enquist and Arak used a simple neural network model totry to explain the evolution of exaggerated signals and suggested


GENERAL ARTICLE

that the evolution of hidden biasesSupernormal stimuli inhumans are thought to

act as addiction-formingsubstances, making the

individual seek out moreof the stimuli. This can

eventually lead todopamine

desensitization, withmore and more stimuli

required to elicit aresponse.

was inevitable in recognitionsystems. This study was criticised as the simple neural networkmodel used probably did not represent animal recognition sys-tems, and a subsequent study to address a similar problem did notfind evolved networks to be responsive to supernormal stimuli.In more recent times, while neural network models have becomemore complex, how well they can predict supernormal responsesremains to be seen. In terms of a mechanistic neurobiologicalunderstanding, studies in humans have suggested that dopamineplays an important role in learning and in reward pathways, thusmotivating (adaptive) responses towards stimuli. Supernormalstimuli in humans are thought to act as addiction-forming sub-stances, making the individual seek out more of the stimuli. Thiscan eventually lead to dopamine desensitization, with more andmore stimuli required to elicit a response.

Evolutionary Significance

What are the evolutionary outcomes of exhibiting supernormalresponses? As mentioned above, supernormal responses usuallyoccur in cases when more intense responses towards slightly ex-aggerated stimuli are adaptive: preference for larger eggs, quickerresponse towards a potential mate, greater intake of calories. There-fore, the costs of overreacting to supernormal stimuli may be out-weighed by the benefits, allowing for such responses to persist oreven increase over evolutionary time. However, responses to suchstimuli can also be exploited. For example, supernormal stimulimay enable brood parasites (species that use other species to raisetheir young ones) to take advantage of their hosts. If egg size orgape11The interior of the mouth that

is often brightly coloured in

young birds.

size or colour are stimuli to which birds show parental re-sponses (as described above), small host bird species might incu-bate eggs and rear chicks of brood parasites that are much largerthan themselves (Figure 3). As Tinbergen wrote in 1965 [3], “....itis possible that many songbirds are not merely willing to feed ayoung cuckoo but simply love to feed it, just because the cuckoooffers such an enormous and inviting gape.” It must be said herethat the study of brood parasitism is a vast field and there are sev-


GENERAL ARTICLE

Figure 3. A Eurasian

reed warbler feeding a

common cuckoo (brood

parasite) chick. Note the

size difference between

the foster parent and chick

and the large, red gape of

the chick. Photo by Per

Harald Olsen. Source:

https://commons.wikimedia.

org/w/index.php?curid=

1887345 under Creative

Commons Attribution-

Share Alike 3.0 Unported

license (CC BY-SA 3.0),

http://creativecommons.org/

licenses/by-sa/3.0/deed.en.

eral hypotheses about why brood parasites exist. These includethe ‘mafia hypothesis’, according to which, hosts that reject thebrood parasite’s eggs are punished by their nests being destroyedby the brood parasite [see 7], and the cost to the host of wronglyrejecting its own offspring when brood parasite eggs and chicksclosely mimic those of its own. In the case of humans, positiveresponses to calorie-rich food, crucial in pre-agricultural societiesfaced with unpredictable access to food, is currently manipulatedby the food industry through the marketing of supernormal (or‘hyperpalatable’) foods. A wide range of other products are alsomarketed by the advertising industry tapping into supernormal re-sponses.


GENERAL ARTICLE

WhileWhile supernormalstimuli may not be

frequently present in ananimal’s environmentordinarily, a change inthe environment may

result in an ‘evolutionarymismatch’ with

responses that evolvedunder previous

circumstances being outof sync with and

possibly beingmaladaptive under thechanged environment.

supernormal stimuli may not be frequently present in ananimal’s environment ordinarily, a change in the environment mayresult in an ‘evolutionary mismatch’ [8] with responses that evolvedunder previous circumstances being out of sync with and possiblybeing maladaptive under the changed environment. For example,the evolutionary mismatch that humans face today, resulting invarious supernormal responses being shown, possibly arise fromthe transition between the hunting-gathering lifestyle that we hadfor most of our lineage’s existence and the relatively recent adventof agriculture. Responses do not have to be necessarily maladap-tive in a new environment. If there are costs (say, in the form ofpredation) to displaying an exaggerated response to a supernor-mal stimulus, and if the environment changes such that the cost isremoved, there may be selection for the supernormal stimulus (inthe form of, say, brighter eggs or specific mate characteristics),thus allowing for divergence between populations and/or evolu-tion of new forms.

Suggested Reading

[1] N Tinbergen, The Study of Instinct, Clarendon Press, Oxford, UK, 1989.

[2] N Tinbergen, A C Perdeck, On the Stimulus Situation Releasing the Begging

Response in the Newly Hatched Herring Gull Chick (Larus argentatus argen-

tatus Pont.), Behaviour, Vol.3, No.1, pp.1–39, 1950.

[3] N Tinbergen, Editors of Life, Animal Behaviour, Time Incorporated, New

York, USA, 1965.


T N C Vidya

Jawaharlal Nehru Centre for

Advanced Scientific Research

(JNCASR)

Jakkur

Bengaluru 560 064, India.

Email:

[email protected]

[email protected]

[4] D T Gwynne, D C F Rentz, Beetles on the Bottle: Male Buprestids Mistake

Stubbies for Females (Coleoptera), Journal of the Australian Entomological So-

ciety, Vol.22, pp.79–80, 1983.

[5] J Pearce, Discrimination and Categorization, In N J Mackintosh (Ed.), Animal

Learning and Cognition, pp.109–134, Academic Press, New York, USA, 1994.

[6] J E R Staddon, A Note on the Evolutionary Significance of ‘Supernormal’

Stimuli, The American Naturalist, Vol.109, No.969, pp.541–545, 1975.

[7] R Gadagkar, M Kolatkar, Evidence for Bird Mafia! Threat Pays, Resonance-

Journal of Science Education, Vol.1, No.5, pp.82–84, 1996.

[8] N P Li, M van Vugt, S M Colarelli, The Evolutionary Mismatch Hypothesis:

Implications for Psychological Science, Current Directions in Psychological Sci-

ence, Vol.27, No.1, pp.38–44.


GENERAL ARTICLE

The Easiest Proof of Fermat’s Principle

Hasi Ray and Sudipto Roy

This article is a contribution

by Late Professor Hasi Ray,

Study Center JnaganSiksha,

Kolkata and Sudipto Roy,

David Hare School, Kolkata.

This article presents the easiest direct proof of Fermat’s prin-ciple with the help of differential calculus for all types of sur-faces.

1. Introduction

Teaching and learning Fermat’s principle in optics often suffersfrom lack of satisfactory proof [1–5]. Students generally have theknowledge of the laws of reflection and refraction of light raysin geometrical optics, and they are also familiar with differen-tial calculus at the undergraduate level when they learn Fermat’sprinciple. However, the difficulties in teaching and grasping theconcept motivated us to find the present logical proofs of Fermat’sprinciple of stationary optical paths.

Fermat’s principle states that when a light ray moves from onefixed point to another fixed point, through any number of reflec-tions or refractions, the total optical path followed by the light rayshould be stationary; it will either be minimum or maximum. Forreflection and refraction at plane surfaces, the total optical pathfollowed by the light ray should be a minimum, while for reflec-tion and refraction at curved surfaces, the total optical path fol-lowed by the light ray should be a maximum. It is also describedas the ‘principle of least time’ in many books. The optical pathis defined as the actual path followed by the light ray in vacuumor in air medium; so it is the product of the path length in themedium with the refractive index of the medium.

The methodology we discuss in this article in the context of themost logical proof of Fermat’s principle, might be a convincing Keywords

Optical path, stationary, reflection,

refraction, curved surface.teaching and learning method. It might help in proper under-standing of the concept and instill confidence in students to learnphysics. It will also enhance their inventing power by following


GENERAL ARTICLE

Figure 1. Reflection at a

plane surface.

easy tricks to overcome many difficult steps and the approxima-tions used to extract proper knowledge. The new method wasapplied by one of the authors (HR) in a BSc first year class, andreceived encouraging results.

2. Methodology

I. Reflection and Refraction at Plane Surfaces

Figures 1 and 2 are pictorially presents the concepts of reflectionand refraction at plane surfaces respectively.

In Figure 1, the lines AN and NB with arrow signs indicate theincident and the reflected rays and OO‘ is the plane of reflectionwith normal NC at the point of incidence N. The angle ∠ANC=∠i(say) is the angle of incidence and the angle ∠ BNC= ∠r (say)is the angle of reflection. Say μ1 is the refractive index of themedium. The optical path followed by light ray to reach from thefixed point A to the fixed point B through the point of incidenceN is y = μ1.AN + μ1.NB. Perpendiculars are drawn on the lineOO‘ from the fixed points A and B as lines AE and BF. Thenwe get two right triangles ΔANE and ΔBNF where ∠ AEN and ∠BFN are the right angles in first and second triangles respectively.The height of the perpendiculars AE and BF (say h1 and h2) areconstants since the points A and B are fixed. Again the distancebetween the feet of the perpendiculars EF = d is a constant.


GENERAL ARTICLE

Figure 2. Refraction at a

plane surface.

Similarly, in Figure 2, the lines AN and NB with arrow signsindicate the incident and the refracted rays and OO‘ is the planeof refraction with normal CNM at the point of incidence N. Theangle ∠ ANC= ∠i (say) is the angle of incidence and the angle ∠BNM = ∠r′ (say) is the angle of refraction. Say μ1 and μ2 are therefractive indices of the first and the second media respectively –these are constant quantities. The optical path followed by lightray to reach from the fixed point A to the fixed point B throughthe point of incidence N is y= μ1. Perpendiculars are drawn onOO‘ from the fixed points A and B as lines AE and BF. Thenwe get two right triangles ΔANE and ΔBNF with ∠ AEN and ∠BFN as the right angles in first and second triangles respectively.The height of the perpendiculars AE and BF (say h1 and h2) areconstants since the points A and B are fixed. Again, the distancebetween the feet of the perpendiculars EF = d is a constant.

In both the cases and in both the figures, the total optical pathlength will vary if the point of incidence N changes. Let us saythe distance EN = x, so that FN = d − x. Accordingly, followingthe Pythagorean theorem for right triangles, the total optical pathin case of reflection can be written as:


GENERAL ARTICLE

y = μ1.AN+μ1.NB = μ1√

(h21 + x2)+μ1

√{h2

2 + (d − x)2} = f1(x)(1)

Similarly, in case of refraction the total optical path can be ex-pressed as:

y = μ1.AN+μ2.NB = μ1√

(h21 + x2)+μ2

√{h2

2 + (d − x)2} = f2(x)(2)

So in both the cases, we are able to write the total optical path yas a function of a variable x and it is differentiable with respectto the variable x. In case of reflection, after differentiation, (1)becomes:

dydx

= μ1x√

(h21 + x2)

− μ1 (d − x)√{h2

2 + (d − x)2}

= μ1ENAN− μ1 FN

BN= μ1 cos ∠ANE − μ1 cos ∠BNF)

= μ1 cos(π

2− ∠i)− μ1 cos

(π

2− ∠r)

= μ1 sin ∠i − μ1 sin ∠r (3)

We know from the law of reflection that the angles ∠i = ∠r. Ap-plying it in (3) gives dy

dx = 0⇒ y = f1(x) = stationary.

Hence, Fermat’s principle is proved for reflection on a plane sur-face.

In a reverse manner, if we consider that the Fermat’s principle istrue, then we can derive the laws of reflection from (3) applyingthe derivative equal to zero.

In case of refraction, after differentiation (2) becomes :


GENERAL ARTICLE

dydx = μ1

x√(h2

1 = x2)− μ2 (d − x)√

{h22 + (d − x)2}

= μ1ENAN− μ2 FN

BN= μ1 cos ∠ANE − μ2 cos ∠BNF)

= μ1 cos(π

2− ∠i)− μ2 cos

(π

2− ∠r′

)

= sin ∠i − μ2 sin ∠r′ (4)

According to the law of refraction we know that μ1 sin ∠i = μ2 sin ∠r′.Applying it in (4) gives dy

dx = 0⇒ y = f2(x) = stationary.

Hence, Fermat’s principle is proved for refraction on a plane sur-face.

In reverse manner, if we consider that the Fermat’s principle istrue, then we can derive the laws of refraction from (4) applyingthe derivative equal to zero.

II. Reflection at Curved Surfaces – Convex and Concave Sur-faces.

The reflections at the curved surfaces are pictorially presentedin Figure 3a and in Figure 3b for convex and concave surfacesrespectively. Let OO′ is the curved surface, and C is the center ofcurvature with R as the radius of curvature in both the figures.

Let A and B be two fixed points situated in a medium of refractiveindex μ1 and B in a medium of refractive index μ2. The lines ANand NB with arrow signs indicate the incident and the reflectedrays with N as the point of incidence or the point of reflection.Draw the normal CN at the point of incidence N on the curvedsurface by joining C with N so that CN = R. The total opticalpath followed by the light ray to reach from the fixed point Ato the fixed point B through the point of incidence at N is y =μ1.AN+μ1.NB. The total path will vary if the point of incidence Nchanges. Perpendiculars are drawn on CN from the fixed points Aand B as lines AE and BF; then we get two right triangles ΔANEand ΔBNF where ∠AEN and ∠BFN are the right angles in firstand second triangles respectively in both the figures. The angle


GENERAL ARTICLE

Figure 3. (a) Reflection at

a convex surface. (b) Reflec-

tion at a concave surface.(a) (b)

∠ANE = ∠i (say) is the angle of incidence and the angle ∠BNF =∠r (say) is the angle of reflection. Join A and B with C, then weget another two right triangles ΔAEC and ΔBFC when AC=h1

and BC=h2 are fixed distances i.e., constants. The angle ∠ACB =Θ is a constant angle. But the angle ∠ACN = θ varies if the pointof incidence N changes.

Applying the laws of triangles inΔANC andΔBNC, we can write:

y = μ1.AN + μ1.NB

= μ1

√(h2

1 + R2 − 2h1R cos θ) + μ1√{h2

2 + R2 − 2h2R cos (Θ − θ}+ f1(θ) (5)

Differentiating with respect to θ, one can express the above ex-pression as:

dydθ= μ1

h1R sin θ√(h2

1 + R2 − 2h1R cos θ− μ1 h2R sin (Θ − θ)√

{h22 + R2 − 2h2R cos(Θ − θ)}

= μ1RAEAN− μ1R BF

BN= μ1R sin ∠ANE − μ1R sin ∠BNF

= μ1R sin ∠i − μ1R sin ∠r

= μ1R(sin ∠i − sin ∠r) (6)


GENERAL ARTICLE

Figure 4. (a) Refraction at

a convex surface. (b) Re-

fraction at a concave sur-

face.

(a) (b)

We know from the law of reflection that the angles ∠i = ∠r. Ap-plying it in (6) gives dy

dθ = 0⇒ y = f1(θ) = stationary.

Hence, Fermat’s principle is proved for reflection on a curvedsurface.

In a reverse manner, if we consider that the Fermat’s principle istrue, then we can derive the laws of reflection from (6) insertingthe derivative equal to zero.

III. Refraction at Curved Surfaces – Convex and ConcaveSurfaces

The refractions at the curved surfaces are pictorially presentedin Figure 4a and in Figure 4b for convex and concave surfacesrespectively. Let OO′ is the curved surface separating two media,and C is the center of curvature with R as the radius of curvaturein both the figures.

Let A and B be two fixed points with A situated in a mediumof refractive index μ1 and B in a medium of refractive index μ2.The lines AN and NB with arrow signs indicate the incident andthe refracted rays with N as the point of incidence or refraction.Draw the normal CN at the point of incidence N on the curvedsurface by joining C with N so that CN = R. The total optical pathfollowed by light ray to reach from the fixed point A to the fixedpoint B through the point of incidence at N is y = μ1.AN+μ2.NB.The path will vary if the point of incidence N changes. Perpendic-


GENERAL ARTICLE

ulars are drawn on CN from the fixed points A and B as lines AEand BF; then we get two right triangles ΔANE and ΔBNF where∠ AEN and ∠ BFN are the right angles in first and second trian-gles respectively in both the figures. The angle ∠ ANE= ∠i (say)is the angle of incidence and the angle ∠ BNF = ∠r′ (say) is theangle of refraction. Join A and B with C, then we get another tworight triangles ΔAEC and ΔBFC when AC=h1 and BC=h2 arefixed distances i.e. contants. The angle ACB = Θ is a constantangle. But the angle ∠ ACN= θ varies if the point of incidence Nchanges.

Applying the laws of triangles inΔANC andΔBNC, we can write:

y = μ1.AN + μ2.NB

= m1

√(h2

1 + R2 − 2h1R cos θ)

+ μ2

√{h2

2 + R2 − 2h2R cos (Θ − θ)}= f2 (θ) (7)

Differentiating with respect to θ, one can express the above ex-pression as:

dydθ= μ1

h1R sin θ√(h2

1 + R2 − 2h1R cos θ− μ2 h2R sin (Θ − θ)√

{h22 + R2 − 2h2R cos (Θ − θ)}

= μ1 RAEAN− μ2 R

BFBN= μ1 R sin ∠ANE − μ2 R sin ∠BNF

= μ1 R sin ∠i − μ2 R sin ∠r′

= R(μ1 sin ∠i − μ2 sin ∠r′) (8)

According to the law of refraction we know that μ1 sin ∠i = μ2 sin ∠r′;applying it in (8) gives dy

dθ = 0 ⇒ y = f2(θ) = stationary. So theFermat’s principle is proved for refraction on a curved surface.

In a reverse manner, if we consider that the Fermat’s principle istrue, then we can derive the laws of refraction from (8) insertingthe derivative equal to zero.


GENERAL ARTICLE

3. Conclusion

In conclusion, we have successfully developed some efficient sci-entific ways to prove Fermat’s principle e.g., the principle of sta-tionary optical path, using a completely new method. It would bemuch easier and convincing to the students and comfortable forteachers to teach in classrooms. It would also boost the interestand confidence of students in learning and their reasoning ability.

4. Acknowledgements

Hasi Ray had acknowledged DST, Government of India for theProject Grant No.SR/WOSA/PS-13/2009 for using the computerfacilities.

Suggested Reading

[1] B Ghosh and K G Mazumdar, A Text Book on Light, New Joykali Press, 5th

Edition, 2003.


Sudipto Roy

Science Division

David Hare School

College Street

Kolkata 700 073, India.

[2] B K Mathur and T P Pandya, Principles of Optics, New Gopal Printing Press,

3rd Edition, 1972.

[3] A K Ghatak, Optics, Tata McGraw Hill, 2015.

[4] F A Jenkins and H E White, Fundamentals of Optics, McGraw Hill Kogakusla,

1957.


SERIES ARTICLE

How to Design Experiments in Animal Behaviour1. How Wasps Find Their Nests


Raghavendra Gadagkar is

Year of Science Chair

Professor at the Centre for

Ecological Sciences and

Chairman, Centre for

Contemporary Studies, IISc,

Honorary Professor at

JNCASR and Non-Resident

Permanent Fellow of the

Wissenschaftskolleg (Institute

for Advanced Study), Berlin.

During the past 35 years he

has established an active

school of research in the area

of animal behaviour, ecology

and evolution. The origin and

evolution of cooperation in

animals, especially in social

insects, such as ants, bees and

wasps, is a major goal of his

research.

In this series of articles, I will introduce the reader to the sci-ence of ethology, somewhat indirectly by describing simpleexperiments, both old and new, designed to understand howand why animals behave the way they do. My emphasis willbe on the design of the experiments and my goal will be tomotivate readers not only to think about the design but alsoto come up with alternatives and improvements. Motivatedreaders can indeed replicate some of these experiments evenif they end up replacing the study animal or the behaviours ofinterest with their own favourite choices. In the first part ofthe series, I describe how Niko Tinbergen – Nobel Laureateand one of the founding fathers of ethology (the science of an-imal behaviour) – designed remarkably simple experimentsto successfully understand how digger wasps find their ownnests in a complex habitat also consisting nests built by otherwasps.

1. Ethology

I study animal behaviour and I am technically called an ‘etholo-gist’. Ethology, literally the study of ‘ethos’ or character, is nota very old discipline. Charles Darwin’s The Expression of Emo-tions in Man and Animals (1872) [1] may be considered as thefirst modern treatment of the subject. Notwithstanding the awardof the Nobel Prize to three of the founders of modern ethology,Niko Tinbergen, Konrad Lorenz and Karl von Frisch in 1973, andthe popular appeal of its subject matter, ethology does not always Keywords

Ethology, beewolf, digger wasps,

visual cues, olfactory cues, nest-

ing, orientation, experiment de-

sign.

enjoy the prestige it deserves in the academia. For an aspiringethologist, and one desirous of elevating its prestige, it is inspiringto read Peter and Jeanne Medawar, in a remarkable book entitled


SERIES ARTICLE

A Philosophical Dictionary of Biology [2], describes“The word ‘ethology’ isnot merely an alternate

designation for thescience of behaviour: it

is a term that stands for agenuine revolution in

biological thought.Ethology is rooted inobservation of animalbehaviour, an activitythat only simpletons

think simple.”

– Peter and JeanneMedawar

ethology inthe following words:

“The word ‘ethology’ is not merely an alternate designation forthe science of behaviour: it is a term that stands for a genuine rev-olution in biological thought. Ethology is rooted in observationof animal behaviour, an activity that only simpletons think sim-ple....observation is a difficult and sophisticated process callingupon all the intellectual virtues: attention, patience, heightenedawareness, caution in coming to conclusions, courage in framingexpectations.”

2. Experiments

These words can, of course, be taken as praise, but budding ethol-ogists would be better advised to rather take them as a challenge– to measure up to Medawars’ expectations. Let us focus on theprocess of observation, so elegantly described by them. I believethat we often need to perform ‘experiments’ prior to observation,to match the rigour that is being demanded. In this series, I willdescribe several experiments in ethology, both new and old. Myfocus will be on the ‘design’ of the experiments while the ethol-ogy learned in the process will be a collateral benefit. I will delib-erately pick simple experiments that almost anyone can performwithout requiring much instrumentation or other research infras-tructure. The goal will be to use reasoning and logic rather thantechnology and automation and will require a passion for animalsrather than for machines. I encourage readers to attempt to repeatthese experiments, modifying them in any way you wish, guidedby necessity and creativity, swapping the animals used and eventhe questions asked, with your own personal favourites [3]. Asa general introduction to performing simple and elegant exper-iments, I encourage readers to study Darwin’s Backyard: HowSmall Experiments Led to a Big Theory by James Costa [4].


SERIES ARTICLE

3. Wasps and Their Nests

Wasps are a diverse group belonging to the insect orderHymenoptera, along with ants and bees. Most wasps are soli-tary while a small number of them are social. All social waspsbuild nests to lay eggs and raise their offspring and are carnivo-rous, preying on other insects or spiders (or any other meat if theycan get hold of – they are known to steal meat from butchers’shops), to feed their growing larvae. They themselves persist onthe nectar and juices imbibed while masticating their prey, as theycannot ingest solid food on account of their characteristically nar-row waists. Among the solitary wasps, many are egg parasitoidslaying their own eggs in or on the eggs of other insects. Otherslay their eggs on the larvae or adults of other insects (or spiders).Let us consider the life cycle of one such solitary wasp using theexample of Philanthus triangulum, that was used in the experi-ments I will discuss in this article. The genus Philanthus consistsof about 135 species that are often called the ‘beewolf’ becausethey usually hunt adult honeybees. Along with other wasps withsimilar habits, they are more generally called the ‘digger wasps’.Philanthus triangulum, male and female, emerge from their un-derground nests to begin a new life cycle. Males mate and diewhile the females have to do more to pass on their genes to fu-ture generations. When it is warm enough, Spending what might

seem like idle timeoutdoors, being a keenobserver curious abouthow and why the naturalworld is what it is, is thefirst part of being anethologist. The secondpart requires the abilityto ask questions, framehypothetical answers,make predictions arisingout of those answers anddesign simpleexperiments to test thepredictions.

the female waspspainstakingly and with much trial and error, locate suitably softpatches of ground and dig tunnels at angles of about 30o followedby several lateral branches that serve as brood chambers. Thenthey fly out to hunt adult honeybees and sting them, carefully ma-neuvering their posture so as not to be stung by the bees instead.They paralyze the bees with a neurotoxic venom and fill up thebrood chambers with up to six honeybees per chamber, as food fortheir as yet unborn larvae, laying one egg per brood chamber. Thebrood chambers are built, stocked with prey, and supplied with anegg, sequentially so that a mother may be at work on a nest forseveral days. At the same time, other female Philanthus triangu-lum wasps are doing the same nearby and herein lies a problem.How does a wasp find her own unfinished nest among the many


SERIES ARTICLE

that do not belong to her? Watching many wasps rapidly fly inand out of their respective nest entrances made Tinbergen won-der. Spending what might seem like idle time outdoors and beinga keen observer curious about how and why the natural world iswhat it is, forms the first part of being an ethologist. The secondpart requires the ability to ask questions, frame hypothetical an-swers, make predictions arising out of those answers and designsimple experiments to test the predictions.

4. Niko Tinbergen

Niko Tinbergen, one of the founders of modern ethology and oneof the recipients of the Nobel Prize in 1973 (as mentioned above),possessed all these traits. But how did he come to possess themand how did he come to put them to good use? You can read aboutTinbergen’s life and work in the accompanying article by SindhuRadhakrishna. Here, I will quote a few passages from an essayby Tinbergen’s first PhD student Gerard Baerends [5], indicatingthe environment that Tinbergen was born in:

“In the Netherlands, between 1930 and 1940, ethology grew fromwhat was originally seen as a pleasant and harmless hobby, to anew biological discipline, recognized by the academic world....Inthe 1880s, coinciding with a growing awareness of the need for amore socially just society, cultural attitudes towards nature changed.Literature and the fine arts became increasingly interested in arealistic representation of nature. Writers and poets....and sculp-tors....began to deal with landscapes, plants and animals in a stylethat took as much care with the correctness of naturalistic detailsas with the emotional impressions felt by the observer. Entirelynew methods were developed for the teaching of children in pri-mary schools, aimed at making them aware of the life and workof people in different communities and professions, and with par-ticular emphasis on informing urban children about rural life. In-spired by this atmosphere two schoolmasters....began writing aseries of six popular books, each dealing with the life of plantsand animals in a characteristic Dutch habitat and a field guide


SERIES ARTICLE

for identifying the more common animals and plants....As a con-sequence Tinbergen devised six

simple outdoorexperiments tounderstand how thewasps located their nests.

of the increasing interest in natural history, naturalistsocieties were formed all over the country....A unique feature ofthe Netherlands – and one that in my opinion was very importantfor the development of ethology in our own country – was thatyoung naturalists, from 11 to 23 years old, formed societies oftheir own, quite separate from those of adults.”

5. Tinbergen’s Experiments

Now, I will briefly describe six simple outdoor experiments per-formed by Tinbergen for his PhD thesis, in order to understandhow the wasps located their nests [6].

Experiment 1

In the first experiment, Tinbergen tested the hypothesis that thewasps learned and remembered the visual landmarks around theirnests to distinguish them from other nests. Between 8 and 10a.m., he placed about 20 pine cones that were lying around in thegeneral area around a wasp’s nest. In the afternoon, by whichtime the wasp might have learned the new landmarks around itsnest, he waited for the wasp to fly out on one of its hunting tripsand moved the circle of cones about 30 cm away from the originalnest and around a sham nest made by “imitating fairly accuratelythe sandy spot and the slight depression indicating the (covered)entrance”, to use his own words (Figure 1).

The If visual cues of thelandmarks around thenest were guiding thehoming behavior of thewasp, then she shouldreturn to the sham nestwith the pine cones but ifsome other cues werebeing used, then sheshould return to her ownnest in spite of themissing pine cones.

idea was to see whether the returning wasp would go to thereal nest, now without the pine cones, or to the displaced circleof pine cones around the sham nest. If visual cues of the land-marks around the nest were guiding the homing behavior of thewasp, then she should return to the sham nest with the pine cones.But if some other cues were being used, then she should return toher own nest in spite of the missing pine cones. Since the return-ing wasps would make her choice only once and Tinbergen didnot want to test any wasp more than once, he used a clever trickto increase his sample size. After the wasp had unambiguously


SERIES ARTICLE

Figure 1. Cartoon depict-

ing the arrangements in Tin-

bergen’s first experiment.

(a) Depicts the training sit-

uation during which Tinber-

gen had placed a circle of

about 20 pine cones around

the original nest in the morn-

ing. This allowed the wasp

to learn these new land-

marks for a few hours, dur-

ing the course of its natu-

ral flights in and out of the

nest. (b) Shows the test

situation during which Tin-

bergen had moved the cir-

cle of pine cones from the

original nest to a sham nest

he had made about 30 cm

away, leaving the original

nest intact but without pine

cones. Redrawn from Tin-

bergen (1932) (see [6]).

demonstrated her preference for the real or the sham nest but be-fore she actually landed and dropped the bee she was carrying,he shooed her away gently, making her fly away some distanceand try again. In this manner, he made the wasp demonstrate herpreference at least five times. After shooing her away once more,he quickly relocated the circle of pine cones around the originalnest and retested her preference, again several times. If visualcues were indeed involved, she should now switch her preferenceand go to her original nest, now with the pine cones returned.Tinbergen repeated the experiment with 17 different wasps, test-ing them five to twelve times each with pine cones around thesham nest (he called this the ‘experiment’), and five to six timeswith the pine cones returned to the original nest (he called this the‘control’). His results (Table 1) could not have been more clear-cut. In 105 out of 105 trials, the wasps chose the sham nest whenit had pine cones around it (experiment), and 86 out of 86 times,they chose the original nest when the pine cones were returned toit (control). This experiment showed clearly that the pine conesoverwhelmingly decided the choice of the wasps. Tinbergen waswell aware that this did not necessarily prove that the wasps hadused visual cues, but only that they had used the pine cones.


SERIES ARTICLE

Table 1. The results of Tin-

bergen’s study showing the

importance of pine cones in

the choice of the wasps. The

original data was published

by Tinbergen in his 1932

publication [6].

Results of Results ofTinbergen’s Tinbergen’s

Control ExperimentTraining situation Training situationwith the pine cones with the pine conesarranged around arranged aroundthe original nest. the sham nest.See Figure 1(a) See Figure 1(b)

Wasp No. of No. of No. of No. ofNumber times times times times

the wasp the wasp the wasp the waspreturned returned returned returnedto the to the to the to the

original sham original shamnest nest nest nest

1 5 0 0 9

2 5 0 0 6

3 5 0 0 7

4 5 0 0 5

5 6 0 0 5

6 5 0 0 5

7 5 0 0 7

8 5 0 0 5

9 5 0 0 6

10 5 0 0 8

11 5 0 0 12

12 5 0 0 5

13 5 0 0 5

14 5 0 0 5

15 5 0 0 5

16 5 0 0 5

17 5 0 0 5

Total 86 0 0 105


SERIES ARTICLE

Figure 2. Cartoon de-

picting the arrangements in

Tinbergen’s second experi-

ment. (a) Shows the train-

ing situation during which

Tinbergen placed a circle of

about 20 pine cones as well

as a pair of scented plates

around the original nest in

the morning and allowed the

wasp to learn these new

landmarks (visual and olfac-

tory), for a few hours, dur-

ing the course of its natural

flights in and out of the nest.

(b) Shows the test situa-

tion during which Tinbergen

had moved the circle of pine

cones (visual landmarks) but

not the scented plates (ol-

factory landmarks), from the

original nest to a sham

nest. To make the vi-

sual landmarks around the

sham nest similar to those

around the original nest dur-

ing the training situation, he

placed an identical pair of

unscented plates around the

sham nest. Redrawn from

Tinbergen (1932) (see [6]).

Experiment 2

To rule out the possibility that the wasps had relied on the smellrather than the sight of the pine cones, Tinbergen did a second ex-periment. Now, during the training period, he placed along withthe pine cones, two cardboard plates scented with pine-needle oil(Oleum pini sylvestris) that gives off smell characteristic of pinecones. The wasps could thus get accustomed to the sight of pinecones or the smell of pine cones around their nests, or both. Dur-ing the test phase, he retained the scented plates around the orig-inal nest and moved only the pine cones to the sham nest. Tomimic the visual cues of the scented cardboard plates he placedtwo identical cardboard plates but without scenting them, aroundthe sham nest. Thus, the sham nest had all the visual cues andthe original nest had the olfactory cues present during the train-ing phase. After recording the choices of the returning wasps asin experiment 1, he created a control situation by interchangingthe cues, i.e., he moved the pine cones and the unscented platesto the original nest and the scented plates to the sham nest andtested the wasps again (Figure 2). This time he used five differentwasps and found that in 29 out of 29 trials, the wasps chose thesham nest when it had pine cones and unscented plates aroundit (experiment) and chose the original nest when it had the pinecones and unscented plates moved back to it (control) (Table 2).


SERIES ARTICLE

Clearly, the pine cones won over the scented plates. However,Tinbergen was quite aware of a potential design flaw in the ex-periment. The scent from the scented plates may have been toostrong leading to their rejection because the wasps might havebeen more accustomed to the smell of the real pine cones. Thus,the wasps may have been sensing the real pine cones by theirsmell after all. The real problem with this design was that Tinber-gen had set up a competition between visual and olfactory stimulirather than eliminate one of them altogether. In the third experi-ment, he set out to do the latter.

Experiment 3

Tinbergen soaked the cones overnight in alcohol and dried themin the sun. Now he repeated experiment 1 taking care to trainthe wasps with fresh cones and test them with dried, presumablyodourless cones. In 37 experimental trials and 30 control trials,the wasps never made a mistake – they always chose the cones.The operative phrase here is ‘presumably odourless’ which meanshe needed an even better experiment.

Experiment 4

With fine scissors and forceps, Tinbergen amputated both anten-nae of four wasps but of course only after the training period. Tohis delight, these antenna-less wasps flew about and performedtheir usual homing behaviour. In 20 experimental trials and 20control trials, not one mistake! Wasps that had learned the pres-ence of the cones when they possessed their antennae chose thecones even after they had lost their antennae. It was clear that vi-sual stimuli were enabling correct orientation of the wasps. Neverthrowing caution and modesty to the winds even as a PhD stu-dent, Tinbergen imposed on himself two caveats. First, these ex-periments may have shown that visual stimuli were adequate andeven dominant, but they did not prove that the wasps were en-tirely incapable of using olfactory stimuli. Second, visual cuesmay have worked in his experiments, but he had only studied the


SERIES ARTICLE

Table 2. The results of Tin-

bergen’s study after train-

ing and testing the wasps

with pine cones and scented

plates. The original data was

published by Tinbergen in

his 1932 publication [6].

Results of Results ofTinbergen’s Tinbergen’s

Control ExperimentTraining situation Test situation

with pine cones and with pine cones andscented plates around unscented plates aroundthe original nest and the sham nest

unscented plates around scented plates around andthe sham nest. the original nest.See Figure 2(a) See Figure 2(b)

Wasp No. of No. of No. of No. ofNumer times times times times

the wasp the wasp the wasp the waspreturned returned returned returnedto the to the to the to the

original sham nest original sham nestnest instead of nest instead of

original originalnest nest

1 5 0 0 5

2 5 0 0 5

3 5 0 0 6

4 5 0 0 8

5 5 0 0 5

Total 25 0 0 29

role of visual stimuli in close proximity to the nests. How did thewasps get close enough to see the pine cones in the first place?Tirelessly, he set out to explore these caveats.

Experiment 5

To test whether the wasps could be trained to recognize theirnest by odor alone, he first confirmed that the wasps could in-deed smell the oil he was using. He did this by putting someoil near the nest entrance. He observed that the wasps reacted


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quite strikingly to the presence of oil, twitching their body andflying away for some time. Then he repeated his experiment 2only with the scented and unscented plates and without the pinecones. During the training, he placed two scented odor platesat the original nest, and this time he trained the wasps for 2 to3 days instead of 2 hours as before. During the experimentalphase of the test he placed the scented plates around the sham nestand the unscented plates around the original nest. For the controlphase, he interchanged the scented and unscented plates betweenthe sham and original nests. He found that the wasps which ap-peared quite confident while landing on their nest of choice withthe pine cones – be it sham or original – in all the previous experi-ments, now seemed a bit confused. In this experiment, the wasps,in spite of being trained with the scented plates, chose the origi-nal nest with the unscented plates and ignored the sham nest withscented plates 21 out of 24 times. In the control, they once againchose the original nest with the scented plates 19 out of 20 times.In other words, they chose their original nests, with or withoutthe scented plates and were not distracted by the presence of thescented plates around the sham nest. Thus, it appeared that thewasps could not be trained to use odor for nest recognition.

Experiment 6

Tinbergen Tinbergen realized thathis success in trainingthe wasps to find theirnest using visual cues isrelevant only when thewasp is already close tothe nest (proximateorientation) but itdoesn’t explain how thewasps find the generalareas where their nest islocated (distantorientation).

realized that his success in training the wasps to findtheir nest using visual cues is relevant only when the wasp is al-ready close to the nest (proximate orientation) but it doesn’t ex-plain how the wasps find the general areas where their nest islocated (distant orientation). Admitting that distant orientationwas very difficult to study experimentally in the field, he tried todetermine the point where the distant orientation ended, and theproximate orientation began. To do this, he trained wasps withpine cones around their original nests at 30 cm as before. But inthe test, he placed the cones at increasing distances around thesham nests, making bigger circles of pine cones, varying the di-ameter of the circle of pine cones around the sham nest from adiameter of 50 cm to up to a diameter of 200 cm (he had already


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tried 30 cm with success). The idea wasTinbergen concludedthat proximate

orientation operated upto about 100 to 200 cm

only, cautioning ofcourse that this value

will vary depending onthe physical features of

the environment.

that if the circle of pinecones was too big for proximate orientation then the wasp willnot be able to find the sham nest (let us say, will not be distractedby it) and should search harder for their real nests. Although hewas able to test fewer and fewer wasps at longer distances (dueto bad weather), he found that the wasps always chose the shamnest with pine cones when the diameter was 50, 70 or 100 cm.But a single wasp that he was able to test at a diameter of 200cm could not find the sham nest and went to the original nest af-ter a long search. Tinbergen concluded that proximate orientationoperated up to about 100 to 200 cm only, cautioning of coursethat this value will vary depending on the physical features of theenvironment.

Here, I will not describe the 4 other (rather inconclusive) experi-ments Tinbergen performed to test if the wasps used colour visionto find their nests.

In summary, Tinbergen concluded that “females of Philanthus tri-angulum are able to orient by means of visual landmarks once,through a yet unknown method of ‘distant orientation’, they havefound the ‘nest surroundings’. These occupy a roughly circulararea of 1–2 m diameter, within which they can be misled by dis-placement of the landmarks in the immediate vicinity of the nestentrance.”

6. Reflections

Let us now reflect on the set of six experiments as a whole. Thefirst thing that comes to my mind is that Tinbergen vindicatedMedawars’ of any charge of exaggeration when they claimed that“observation is a difficult and sophisticated process calling uponall the intellectual virtues: attention, patience, heightened aware-ness, caution in coming to conclusions, courage in framing ex-pectations.” There are several useful lessons to be learned fromthese set of experiments. Where we can emulate Tinbergen, wemust do so, and where we cannot, we must at least reflect on whywe cannot. Scientists, especially during the early stages of their


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careers, are unsure about how to choose a problem to work on.Today, science has become such an ‘industrial’ and expensive ac-tivity that PhD students are not encouraged to and cannot affordto decide by themselves; their research problem is nearly alwaysassigned by their thesis supervisors and research is almost alwaysa collaboration between the student and the supervisor. But thiswas not how it always was and need not always be.

Tinbergen Tinbergen strolledaround the woods andhis curiosity about howthe wasps managed tofind their nest holeamong so many others,was aroused. He framedhypotheses andproceeded to test them,designing the simplestpossible experimentsusing what was readilyavailable – a method thatis sometimesaffectionately called‘quick and dirty’.

strolled around the woods and his curiosity about howthe wasps managed to find their nest hole among so many others,was aroused. He framed hypotheses and proceeded to test them,designing the simplest possible experiments using what was read-ily available – a method that is sometimes affectionately called‘quick and dirty’. Tinbergen did not take detailed photographsof the nest surroundings and he tried to reproduce the exact fea-tures of the nests around the sham nests. He did not apply fora big research grant nor did he try to make his research appearsophisticated. His experiments were not more sophisticated thanabsolutely necessary. They were literally playful. And yet, hisexperiments were designed very thoughtfully, with precision andimagination, yielding clear-cut results.

Tinbergen’s six experiments illustrate how we learn from our fail-ures. When the wasps could not be trained with scented plates,he tried with de-scented cones, and when that failed he tried withantenna-less wasps. Even when he was successful with the circleof pine cones, he kept on increasing the diameter of the cone cir-cles until he failed to train the wasps. Unfortunately, today it hasbecome fashionable to discard negative results.

Tinbergen’s modesty and caution come through clearly and arein stark contrast to the prevailing standards today. In his paper,he constantly refers to previous researchers, not just by way ofintroducing the subject but with a clear intention of giving creditwhere it is due. In his concluding remarks, he says less aboutwhat he has discovered and more about what he has not – “ayet unknown method of distant orientation”, “did not succeed indemonstrating colour vision”, “this in no way implies that Phi-lanthus is unable to perceive colour”, “wasps orient themselves


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to.....a complex of stimuli, which I have so far not analysed”, “at-tempt to train the wasps to use olfactory stimuli was not success-ful” (rather than that the wasps cannot learn olfactory stimuli),“these results may not apply to other digging wasps”, “my obser-vations cannot decide whether Philanthus is able to register andremember the number of turns made on the way out”.

II would like torecommend that readersreflect on the design of

Tinbergen’s sixexperiments, attempt to

find flaws, come up withalternative designs

which are just as good orperhaps better.

would like to recommend that readers reflect on the design ofTinbergen’s six experiments, attempt to find flaws, come up withalternative designs which are just as good or perhaps better. Inaddition to reflection, I encourage my young readers to try theirhands at designing and carrying out simple experiments of theirown, using animals and questions, driven by their own imagina-tion and curiosity. In this article, wasps were the protagonists andthey hunted and paralysed honeybees. In the next article in thisseries, I will restore the glory of the honeybees by making themthe protagonists!

Suggested Reading

[1] C Darwin, The Expression of Emotions in Man and Animals, The University of

Chicago Press, Chicago and London, 1965, 1872.

[2] P B Medawar and J S Medawar, Aristotle to Zoos – A Philosophical Dictionary

of Biology, Harvard University Press, Cambridge, Massachusetts, USA, 1983.

[3] R Gadagkar, Survival Strategies: Cooperation and Conflict in Animal Societies,

Harvard University Press, Cambridge, Massachusetts, USA and Universities

Press, Hyderabad, India, 1997.



Centre for Ecological Sciences

and Centre for Contemporary

Studies

Indian Institute of Science

Bangalore 560 012, India.


[4] J T Costa, Darwin’s Backyard - How Small Experiments Led to a Big Theory, W

W Norton & Company, Inc., New York, London, 2017.

[5] G P Baerends, Early Ethology: Growing From Dutch Roots. In: The Tinbergen

Legacy, Eds, M S Dawkins, T R Halliday and R Dawkins, Chapman and Hall,

London, pp.1–17, 1991.

[6] N Tinbergen, On the Orientation of the Digger Wasp Philanthus triangulum,

Fabr. Zs. Uber die vergl. Physiol., 16, pp.305–334, 1932. [Translated from the

original German into English and published in: N Tinbergen, The Animal in Its

World: Explorations of an Ethologist 1932–1972. Vol.1, Field Studies, Harvard

University Press, Cambridge, Massachusetts, USA. pp.103–127].


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Breakthroughs in Information and CommunicationTechnologies

Part II

V Rajaraman

V Rajaraman is at the Indian

Institute of Science,

Bengaluru. Several

generations of scientists and

engineers in India have learnt

computer science using his

lucidly written textbooks on

programming and computer

fundamentals. His current

research interests are parallel

computing and history of

computing.

In Part 1 of this series of articles, I defined what is meantby a breakthrough in ICT, listed fourteen breakthroughs inchronological order, and described five breakthroughs. Inthis second part of the three-part series of articles on Break-throughs in Information and Communication Technologies, Idescribe four more breakthroughs: Computer Graphics, In-ternet, Global Positioning Systems, and the World Wide Web.As in the last part, I will justify why I consider them as break-throughs and briefly describe each of them.

6. Computer Graphics

Computer graphics is concerned with the generation and displayof digital data as pictures on a computer monitor. It includes sim-ple two-dimensional (2D) illustrations such as engineering draw-ings, sophisticated realistically shaded three-dimensional (3D) ob-jects such as automobiles, and videos such as animated movies.One of the most popular applications of computer graphics is inthe design and development of interactive computer games. An-other everyday use of computer graphics is as an aid for human-computer interaction (called a Graphical User Interface – GUI).GUI displays graphical icons on the screen of a monitor repre-senting applications such as a browser, search engine, and wordprocessor. The application is invoked by pointing to its icon usinga device such as a mouse or a finger/stylus. Keywords

Computer graphics, internet,

global positioning systems, World

Wide Web.

Even though it was realised early in the development of com-puters that giving the output of computation in a graphical formenhances human understanding of the result, no cost-effective


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graphical output device thatThe first majorbreakthrough in

computer graphics wasthe doctoral work of Ivan

Sutherland at MIT in1963. He wrote a 2D

drawing program called‘Sketchpad’. It had

graphical objects such aslines, rectangles,

ellipses, and circles.They could be

manipulated using adevice called a light pen

that had a sensor todetect the light beam on

a CRT screen.Sutherland wrote

algorithms for geometricoperations such as clip,

zoom, and coalescegraphical objects for

drawing useful 2Dfigures.

could be connected to a computerwas available in the 1950s and 60s. Another constraining factorwas that graphical output is useful only if it can be interactivelyused with a computer. For drawing pictures using a computer, it isnecessary to have one-to-one interaction with the computer. Dig-ital computers were too expensive in the 1950s and 60s to permitusers this luxury. Computers were primarily used in a batch modewith many users sharing them. Research in computer graphicswas hence restricted to well-funded institutions.

The first major breakthrough in computer graphics was the doc-toral work of Ivan Sutherland at MIT in 1963. He wrote a pro-gram called ‘Sketchpad’ for the Lincoln TX-2 computer – a singleuser interactive computer – that had a Cathode Ray Tube (CRT)display. Sketchpad was a 2D drawing program. It had graphicalobjects such as lines, rectangles, ellipses, and circles. They couldbe manipulated using a device called a light pen that had a sen-sor to detect the light beam on a CRT screen. Sutherland wrotealgorithms for geometric operations such as clip, zoom, and co-alesce graphical objects for drawing useful 2D figures. Interest-ingly around the same time (1964) Douglas Engelbart, workingat the Stanford Research Institute in the west coast of the USA,invented the ‘mouse’ that is widely used even today to move thecursor on a display unit of a computer. We have described somerelated work of Engelbart in Section 9 on the World Wide Web.

PDP-1 computerPDP-1 computer had alarge CRT screen as an

output device andbecame famous for

history’s first computergame called ‘Space War’

developed by SteveRussell in 1962 at MIT.This kindled interest ingraphics for interactive

game playing.

was manufactured by the Digital Equipment Cor-poration in 1959 and was one of the first commercial transis-torised computers with an architecture similar to Lincoln TX-2.It had a large CRT screen as an output device and became famousfor history’s first computer game called ‘Space War’ developedby Steve Russell in 1962 at MIT. This kindled interest in graph-ics for interactive game playing. IBM sold interactive computergraphics terminals for around USD 100,000 in 1965 which onlymajor corporations could afford. These companies used the IBMgraphics terminals for writing computer-aided design software todesign complex structures (bridges, aircrafts, etc.) and for dis-playing the results of simulation of dynamic systems. The major


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problem in the 60s was the high In 1969, the Associationfor ComputingMachinery (ACM),USA, established theSpecial Interests Groupin Graphics (ACMSIGGRAPH) indicatingthe emergence ofcomputer graphics as animportant discipline incomputer science.Among the academicinstitutions, the groupestablished by DavidEvans at the Universityof Utah in 1966contributed manyimportant algorithms incomputer graphics.

cost of computers and graphicsoutput devices. Progress was slow.

Academic research picked up when time-shared computers thatallowed many users to simultaneously use a computer were in-troduced in early the 1970s. Even then graphics terminals wereexpensive. A significant development was the introduction ofDirect-View Storage oscilloscope by Tektronix for USD 1500 thatcould be used as a graphics terminal with time-shared computers.This development enabled researchers in many academic institu-tions and research laboratories to develop graphics algorithms. In1969, the Association for Computing Machinery (ACM), USA,established the Special Interests Group in Graphics (ACM SIG-GRAPH) indicating the emergence of computer graphics as animportant discipline in computer science. Among the academicinstitutions, the group established by David Evans at the Univer-sity of Utah in 1966 contributed many important algorithms incomputer graphics. In 1967 he invited Ivan Sutherland to jointhe department. They were frustrated by the non-availability ofcomputer systems for graphics and started their own company –Evans and Sutherland – in 1968 to design and manufacture graph-ics workstations that were used in developing many innovativegraphics programs. Several research students at the Universityof Utah designed important algorithms in computer graphics. In1974 Edwin Catmull contributed to texture mapping in 3D mod-elling of objects. The group also developed algorithms for hiddensurface removal in 3D modelling. In 1977 a group of 25 expertsof the ACM SIGGRAPH developed the first standard for graph-ics called ‘3D core graphics system’ that became the foundationfor further developments in In 1977 a group of 25

experts of the ACMSIGGRAPH developedthe first standard forgraphics called ‘3D coregraphics system’ thatbecame the foundationfor further developmentsin graphics.

graphics. (This is the reason I picked1977 as the breakthrough year for computer graphics).

Incidentally, several students who graduated from the computergraphics group of the University of Utah started some of the best-known companies that did pioneering work in computer graph-ics. Pixar, which specialised in realistic computer animation,was started by Catmull. Silicon Graphics that made workstationswith excellent graphics programming features was started by Jim


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Clark. AdobeResearchers who hadearlier worked at the

Stanford ResearchInstitute in Douglas

Engelbart’s group movedto Xerox PARC. Thisgroup developed a PCnamed ‘Alto’ in 1973.Alto had the first GUI

consisting of windows,icons, menus, and a

mouse developed by agroup headed by Alan

Kay. By 1975 the groupalso developed

What-You-See-is-What-You-Get (WYSIWYG)software that allowed a

user to cut and pastepictures in typed

documents.

Systems, famous for PostScript, Photoshop, andPortable Document Format (PDF), was started by John Warnock.Alan Kay working at Xerox Palo Alto Research Center (PARC)invented the GUI and object-oriented programming.

Graphical User Interface (GUI)

As I pointed out, in the 1960s and 70s computers were not in-teractive. Even when time-shared computers were introduced,graphics terminals were expensive and the input devices weretele-typewriters. The entire scenario changed with the adventof Personal Computers (PCs) in 1975. PCs were inexpensive,single user machines and had fairly large, 15" diagonal, rasterscan display. Researchers who had earlier worked at the Stan-ford Research Institute in Douglas Engelbart’s group moved toXerox PARC. This group developed a PC named ‘Alto’ in 1973.Alto had the first GUI consisting of windows, icons, menus, anda mouse developed by a group headed by Alan Kay. By 1975 thegroup also developed What-You-See-is-What-You-Get (WYSI-WYG) software that allowed a user to cut and paste pictures intyped documents. Alto was not introduced as a commercial prod-uct but was widely used in many Xerox laboratories and someuniversities. It greatly influenced the design of PCs in the decadesto follow. Apple’s Macintosh computer adopted Alto’s GUI in1984. By mid-1980s, PCs were widely used and MicrosoftApple’s Macintosh

computer adopted Alto’sGUI in 1984. By

mid-1980s, PCs werewidely used and

Microsoft introduced theWindows Operating

System (OS) in 1985that had a good GUI.

GUI provides easyhuman-computer

interaction and is nowstandard in all PCs,

greatly enhancing userproductivity.

in-troduced the Windows Operating System (OS) in 1985 that hada good GUI. GUI provides easy human-computer interaction andis now standard in all PCs, greatly enhancing user productivity.

Desktop Graphics Workstations

With the reduction of the cost of integrated circuits and the ad-vent of fast microprocessors and co-processors for performingfast graphics oriented operations, computers that were much fasterthan PCs, called ‘graphics workstations’ appeared in the early1980s. The typical workstations had to satisfy the so-called 3Mcriterion – a Megabyte memory, a Megapixel screen, and a Megaflop


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(million floating point operations per second) speed. Worksta-tions made by companies such as Sun, Apollo, DEC, HewlettPackard, and Silicon Graphics had 19" to 21" monitors and usedUnix OS. They were the workhorses of researchers as well as de-signers developing graphics and computer-aided design softwarein the 1980s. Many of the advances in graphics software occurredduring this period. They catalysed the development of sophisti-cated interactive games that became a hit with the general public.Computer animation got an impetus.

Coming of Age of Computer Graphics

Starting early 90s, there was significant progress in 3D computergraphics. In 1992, a standard for generating 3D graphics, calledopenGL (Graphics Language), was released. OpenGL has a li-brary of primitives that is machine and OS independent. It wasquickly adopted by designers of diverse graphics programs suchas computer-aided design, creators of realistic graphical scenes,and animation designers. Even game developers who used themost powerful computers (for quick interaction) used OpenGL.

Computer graphics were used routinely by movie production housesto enhance movies such as Jurassic Park. A landmark was the re-lease of Toy Story, a full-length movie in 1995, by Pixar Anima-tion Studios under the leadership of Ed Catmull. The movie Computer graphics were

used routinely by movieproduction houses toenhance movies. Alandmark was the releaseof Toy Story, afull-length movie in1995, by PixarAnimation Studios underthe leadership of EdCatmull. The movie wasentirely computergenerated with nocamera used. It was a hitand had many successorsToy Story 2, 3, etc.

wasentirely computer generated with no camera used. It was a hit andhad many successors Toy Story 2, 3, etc. Hundreds of full-lengthmovies are now being produced entirely using computer graphicswithout cameras and human actors.

Computer Games

Computer graphics also ushered in the computer games market[2]. A company named Atari was a pioneer in this area in theearly days of PCs. Real progress began in 1985 when Nintendo– a Japanese company – released a handheld device with mul-tiple buttons (called a ‘gaming console’) that improved human-computer interaction for games. Sony PlayStation was very so-


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phisticated and sold over 100 million units in 1995. Microsoftalso entered the field of gaming hardware with a device called‘Xbox’ in 1998. By 2010, more than 40% of homes in the USAhad gaming consoles. Playing games required fast interactionand highly realistic graphics. As the number of people playinggames increased to hundreds of millions, the market expanded.This influenced integrated circuit (IC) chip makers to design spe-cialised graphics processing chips. Nvidia Corporation becamea specialised graphics chip maker and manufactured a Graph-ics Processing Unit (GPU) used in real-time high-resolution 3Dcompute-intensive tasks. The internal architecture was fast enoughto be used as general-purpose co-processors in current supercom-puters.

Computer graphics and games have now moved to small hand-held mobile devices such as smartphones. Other developmentsare head-mounted displays that project 3D images in space giv-ing an immersive experience called virtual reality.

Computer graphics is a breakthrough in ICT due to the followingreasons:

• The idea that both 2D and 3D images can be generated by com-

puter programs and displayed on a graphics output device is novel.

• The idea that the movement of a hand-held device (namely a

mouse) on a desk can be translated to the movement of a pointer

on the display screen is novel. This has immensely aided human-

computer interaction.

• ResultsNew fields such ascomputer-aided design,

computer animation,computer games, andspecialised hardwaredesign for computer

graphics have becomemulti-billion-dollarindustries and have

provided employment tomillions of professionals.

of computation displayed as 2D and 3D images aids our

understanding of results of computation as opposed to reams of

numbers printed on paper. Graphics has now become an essential

aid for engineers, architects, and designers.

• Graphical User Interfaces greatly enhances our productivity in

using computers. Windows, icons, menu, and pointing device

are now standard on all computers. The importance of human-

computer interaction has been realised and many new devices are

appearing to improve our interaction with computers not only in

computation but also in playing games with computers.


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• New fields such as computer-aided design, computer animation,

computer games, and specialised hardware design for computer

graphics have become multi-billion-dollar industries and have

provided employment to millions of professionals.

• Computer games, besides spawning a new industry, has indi-

rectly led to the development of fast computer chips that are now

used in high-performance computers.

• Computer games have changed our society with millions of per-

sons playing games with computers. Youngsters are not only

innovating new games but also being glued to their computers

for hours on end playing games. Games have now moved to

smartphones with some game apps selling millions of copies.

• 3D graphics has led to the development of 3D printers that are

now used in the computer-assisted manufacturing of objects. This

has reduced the cost of many objects and has benefited our soci-

ety.

Internet today hasbecome an essentialinfrastructure in theworld much likeelectricity. We dependon it for communicatingwith our friends,relatives, andorganizations usingemail, disseminate andsearch for information,collaborate withcolleagues anywhere inthe world, listen tomusic, see videos, play agame with a remoteopponent, hail a cab, andshop – to mention a fewof our daily activities. Ithas been universallyrecognized as one of thegreatest breakthroughsof the twentieth century.

7. Internet

Internet today has become an essential infrastructure in the worldmuch like electricity. We depend on it for communicating withour friends, relatives, and organizations using email, disseminateand search for information, collaborate with colleagues anywherein the world, listen to music, see videos, play a game with a re-mote opponent, hail a cab, and shop – to mention a few of ourdaily activities. It has been universally recognized as one of thegreatest breakthroughs of the twentieth century.

As with many of the breakthroughs we have discussed in thisarticle, it did not appear suddenly. The idea of such an infras-tructure for social interactions using a network of computers wasenvisaged by JCR Licklider of MIT, in the early 1960s, whenhe wrote a paper proposing this idea. Subsequently, the Ad-vanced Research Projects Agency (ARPA) of the US Departmentof Defence (DoD) appointed him to head the new InformationProcessing Technology Office (IPTO) with a mandate to furtherthe research related to the Semi-Automatic Ground Environment


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(SAGE) program for protecting the USA against a space-basednuclear attack. Within IPTO Licklider evangelized the potentialbenefits of a country-wide computer communications network,influencing his successors to hire Lawrence Roberts, who wasearlier at MIT, to implement his vision. Worldwide telephonenetworks existedIn 1961 Leonard

Kleinrock proposed thatmany independentmessages could be

transmitted betweencomputers by breakingthem into packets, each

labelled with anidentifier and

interspersed and sentover a single

communication pathconnecting them. The

same idea was proposedindependently by bothPaul Baran at RAND

Corporation, USAbetween 1961 and 1964,and by Donald Davies at

the UK NationalPhysical Laboratory in

1965.

in the 1960s. However, these networks were de-signed to carry conversations between two subscribers by estab-lishing a circuit exclusively between them for the entire durationof the conversation. This method called circuit switching waswasteful and not suitable for carrying digital data between com-puters that is generated intermittently in bursts. This was pointedout by Leonard Kleinrock as a part of his doctoral work at MITin 1961. He proposed that many independent messages could betransmitted between computers by breaking them into packets,each labelled with an identifier and interspersed and sent over asingle communication path connecting them. The same idea wasproposed independently by both Paul Baran at RAND Corpora-tion, USA between 1961 and 1964, and by Donald Davies at theUK National Physical Laboratory in 1965.

Roberts led the development of a computer network, based onthis new idea of packet switching. A special computer calledan Interface Message Processor was developed by a company,Bolt, Beranek, and Newman (BBN), in 1969 to provide a system-independent interface that could be used by any computer sys-tem to architecture a network using packet switching. This workwas sponsored by ARPA and laid the foundation for designing a‘Wide Area Computer Network’ (WAN) called the ARPANET.ARPANET went live in early October 1969. The first communi-cation of packetized messages using the existing telephone net-work was between a computer in Kleinrock’s laboratory at theUniversity of California, Los Angeles, and a computer at theStanford Research Institute at Palo Alto, near San Francisco. Itwas later expanded to connect computers at the University of Cal-ifornia at Santa Barbara and the University of Utah. Gradually,many computers were connected using the existing telephone in-frastructure. In 1972 the first email messaging system for com-


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municating among researchers of the ARPANET was designedby Ray Tomlinson of BBN1 1Shiva Ayyadurai wrote an

email software in 1978 when he

was a 14-year-old student in the

USA and registered a copyright

in 1982 for the name EMAIL

for his program.

. A file transfer protocol (FTP) totransfer files between computers connected to the ARPANET wasdesigned by Abhay Bhushan of MIT in 1971 [3].

Meanwhile, research in computer networking was also initiatedin the UK by the National Physical Laboratory and in France byIRIA (now called INRIA). The French network was called the‘Cyclades’.

The first networking protocol used on the ARPANET was calledthe ‘Network Control Program’ (NCP). This was used to architec-ture larger national computer networks with mainframes as nodes.In the late 1970s, PCs began to proliferate and Ethernet for con-necting them to a LAN was invented by Robert Metcalfe. LANsgrew rapidly and an interconnection system was required to con-nect them. It required a new protocol to succeed the NetworkControl Program. This protocol was designed to satisfy the fol-lowing four criteria.

(i) Each network should be considered as an independent entity.

(ii) The communication was to be “best effort”. In other words, if

a packet was lost in transit, it should be detected by the receiver

and the sender requested to resend it.

(iii) Routers were designed to control the transmission of packets be-

tween networks. The protocol tointerconnect computernetworks was called the‘Transmission ControlProtocol/InternetProtocol’ (TCP/IP). Itwas invented by RobertKahn of BBN andVinton Cerf of StanfordUniversity in 1983,borrowing ideas from theCyclades networkdesigned by LouisPouzin in France.

(iv) There was no global control of communication.

These four principles made it possible to create the Internet asa network of networks spread throughout the USA and acrossthe Atlantic. The protocol to interconnect computer networkswas called the ‘Transmission Control Protocol/Internet Protocol’(TCP/IP). It was invented by Robert Kahn of BBN and VintonCerf of Stanford University in 1983, borrowing ideas from theCyclades network designed by Louis Pouzin in France. Thisquickly became the most widely used network protocol in theworld and led to the development of many networks supported


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by ARPA as well as those in other parts of the world. TCP/IPis a two-layered protocol. Given a message to be sent to a com-puter B from computer A, TCP disassembles the message fromA into small ‘data packets’ called datagrams that are then trans-mitted over the network to be reassembled by B’s TCP into themessage’s original form. TCP also ensures the recovery of lostpackets and the reordering of packets received out of order. IP isa unique address assigned to each computer (or device) connectedto the Internet. As a datagram travels from one device to the next,IP address of the destination is checked by every device in thenetwork which ensures that the datagram reaches the correct des-tination address. TCP/IP protocol ensures error-free transmissionof messages between computers connected to the Internet. Eachrequest for transmitting a message is new and unrelated to all pre-vious requests. This allows the paths in the network to be usedcontinuously [4].

InIn 1990, the ARPANETwas transferred to the

National ScienceFoundation of the USA

and named the NSFNET.A Computer Science

Network (CSNET)connecting universitiesin North America hadalso been formed. The

NSFNET was connectedto the CSNET. A

network called EUnetconnected research

facilities in Europe. TheNorth American net was

connected to EUnetmaking it a large

international networkallowing collaboration

among scientists acrossthe Atlantic.

1990, the ARPANET was transferred to the National ScienceFoundation of the USA and named the NSFNET. A ComputerScience Network (CSNET) connecting universities in North Amer-ica had also been formed. The NSFNET was connected to theCSNET. A network called EUnet connected research facilities inEurope. The North American net was connected to EUnet mak-ing it a large international network allowing collaboration amongscientists across the Atlantic [5].

The groundwork was thus completed to create the Internet as aworldwide communication infrastructure for computers to com-municate with one another. In due course, all the computer net-works in countries all over the world were connected using theTCP/IP protocol. Once the infrastructure was in place many ap-plications could be built over this infrastructure.

The major issues of management of such a worldwide infrastruc-ture and commercial use of the infrastructure that was primarilybuilt for academic use remained. Those have been resolved to areasonable extent and now the Internet is a stable, well managed,infrastructure.


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Internet is a breakthrough in ICT due to the following reasons:

• The idea of transforming a worldwide telephone network that

carried continuous audio signals between people using circuit

switching, to one that carries digital signals between computers

using packet switching, is novel.

• The idea of the TCP/IP protocol that allows orderly communi-

cation among computers using different operating systems con-

nected to diverse networks is novel.

• This Internet spawned many other breakthroughs including the

World Wide Web, search engines, and cloud computing that we

will discuss in what follows.

• The Internet is an infrastructure that has completely changed the

way computers are used. In addition to data processing, it is now

used as a communication system to send and receive mail, make

video calls, search for information, buy items from e-shops, and

a myriad of other applications. It has now become as vital to our

daily life as electricity and tapped water.

• Applications built on the Internet infrastructure have brought in

societal changes in the form of social networks.Politicians A number of newindustries have emergeddue to the availability ofthe Internet.E-commerce platformssuch as Flipkart, searchengine companies suchas Google, cloudcomputing companiessuch as Amazon WebServices, software as aservice companies suchas Salesforce, socialnetworking companiessuch as Facebook, andcompanies such asDropbox providingcloud storage owe theirexistence to the Internet.

and

celebrities, among many, use tweets to communicate their ideas.

Facebook has enriched the nature of social interactions. Blogs

allow people to disseminate their ideas quickly and widely.

• The Internet has tremendously increased our efficiency by en-

abling quick communication, searching for information, and get-

ting advice from experts on various issues.

• A number of new industries have emerged due to the availability

of the Internet. E-commerce platforms such as Flipkart, search

engine companies such as Google, cloud computing companies

such as Amazon Web Services, software as a service companies

such as Salesforce, social networking companies such as Face-

book, and companies such as Dropbox providing cloud storage

owe their existence to the Internet.

• Internet of Things (IoT) is an emerging technology that would

connect, using the Internet infrastructure, all the gadgets we use


SERIES ARTICLE

and enable us to control them from anywhere at any time. This

will be a big new industry.

8. Global Positioning Systen (GPS)

Throughout human history, navigation has been an important ac-tivity. In the early days, the position of the stars was used toapproximately detect one’s location and this was used by sailors.The emergence of a compass that depended on the Earth’s mag-netic field was an important breakthrough in navigation. The nexttechnology that was used for navigation emerged with the in-vention of wireless transmission over long distances by Marconi1901 22Sir J C Bose invented the

mercury coherer (together with

the telephone receiver) used by

Marconi.

Low-frequency radio beacons transmitted by fixed land-based stations were used by ships during the 1970s and 80s tonavigate employing a system called Loran-C. The biggest break-through that occurred in the twentieth century was the launch ofthe first artificial satellite, Sputnik, by the Soviet Union in 1957.It was soon realised that time signals sent from satellites couldbe used to determine the position of an object anywhere in theworld accurately within a few metres. This was of great strategicimportance to defence during the cold war between the USA andthe Soviet Union.

AOriginally GPS wasintended only for the useof the defence forces of

the USA. When acivilian Korean Airlines

plane strayed into theSoviet airspace in 1983,due to poor navigationinstruments, and was

shot down by the SovietUnion leading to the

death of 269 innocentpeople, President

Reagan of the USAdecided to allow GPS tobe used by anyone in the

world free of charge.

meeting of the heads of the armed forces of the USA washeld in 1973 when the first concrete steps were taken to cre-ate a satellite-based global navigation system. The system tobe developed was called NAVSTAR (Navigation Satellite Tim-ing and Ranging) Global Positioning System (GPS). The systemwas planned to have a constellation of 24 satellites of which thefirst was launched in 1974. As in all breakthroughs we describe inthis article, the fruition of the idea of using satellites to detect theposition of an object anywhere on the earth’s surface, that wasconceptualised in 1973, became operational with the launch ofall 24 satellites (and 3 spare satellites to substitute if one or moresatellite failed) in 1995 [6].

Originally GPS was intended only for the use of the defenceforces of the USA. When a civilian Korean Airlines plane strayedinto the Soviet airspace in 1983, due to poor navigation instru-


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ments, and was shot down by the Soviet Union leading to thedeath of 269 innocent people, President Reagan of the USA de-cided to allow GPS to be used by anyone in the world free ofcharge. The positional accuracy for civilian use was reduced toabout 100 metres initially. This restriction was removed by Pres-ident Clinton in 2000, and a positional accuracy of around 5 me-tres was made available to the public. Even though GPS is freelyavailable now for all to use, it is controlled by the U.S. Depart-ment of Defence [7].

Many countries are not comfortable with this situation as theUS government can unilaterally blackout GPS in any part of theworld if it desires, and it has done so in the past. Many coun-tries have therefore developed their own systems for use in theircountries and the surrounding regions. Russia has a global nav-igation system called GLONASS that has 24 satellites in orbit

Indian Space ResearchOrganization (ISRO) hasdeveloped its ownsystem IRNSS (IndianRegional NavigationSatellite System) thathas 7 satellites ingeosynchronous orbit.IRNSS can providepositional informationfor the whole of Indiaand the surroundingareas to an accuracy of20 metres for the public.

with 3 spares and covers the whole world. The European Unionhas a system called Galileo. Indian Space Research Organiza-tion (ISRO) has developed its own system IRNSS (Indian Re-gional Navigation Satellite System) that has 7 satellites in geosyn-chronous orbit. IRNSS can provide positional information for thewhole of India and the surrounding areas to an accuracy of 20metres for the public. China has a system called BeiDou. Japanand France are also developing their own systems. GPS develop-ment cost is extremely high and no private institution would havetaken up the project. It was undertaken by the USA mainly for itsdefence. Fortunately, the cold war ended and it has now becomea boon for all.

The main idea behind GPS is to use the signals transmitted bysatellites. These signals specify the time and position of the satel-lite when it transmitted a signal. When a receiver on Earth detectsthis signal, it knows how far it is from the satellite, as electro-magnetic signals from the satellite travel at the speed of light.Signals from at least four different satellites are required to de-tect the position, namely latitude, longitude, and altitude of thereceiver using triangulation. Altitude data is required by aircraft.In order that at least four satellites are visible from anywhere on


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Earth, a constellationA GPS receiver fitted toa car or a truck to find its

position costs aroundrupees 5000. Apps are

available on mobilephones at no cost or a

few hundred rupeesdepending on the

features of the app todetect the position of the

mobile phone usingGPS.

of 24 satellites is required. These satellitesare placed in six different orbits that are tightly controlled. Theseorbits are in planes inclined at around 55 degrees to the equa-torial plane. Each orbit has four satellites. This disposition ofsatellites ensures that a receiver at any place in the globe will beable to receive signals from between 5–8 of these satellites. Threemore satellites were launched to ensure that in case one or moresatellites fail, at least 24 operational satellites are available. GPSreceivers on the ground are inexpensive. A GPS receiver fitted toa car or a truck to find its position costs around rupees 5000. Appsare available on mobile phones at no cost or a few hundred rupeesdepending on the features of the app to detect the position of themobile phone using GPS. This position information is shown onmaps provided by companies such as Google to find out the streetaddress of the location of a mobile phone or that of a car fittedwith a receiver. In fact, some of the recent apps in mobile phoneshave a voice guidance system that tells the driver the route froma location A to a location B while he/she drives the car.

GPS is a breakthrough in ICT due to the following reasons:

• The idea of using timing signals from satellites to accurately find

the position and altitude of objects anywhere on Earth is novel.

• Even though GPS was developed at very high costs for defence

purposes by various governments, its release for civilian use has

led to many useful applications and innovations.

• NavigationGPS is of greatassistance to navigate

ships, sailing boats, andaircraft. Coupled with

weather maps,ships/sailing

boats/aircraft can avoidareas where there are

storms brewing. Fishingboats can avoid strayinginto the territorial waters

of other countries.

that is vital for travel by road, sea or air, has become

very simple after the advent of GPS as accurate location and al-

titude information is given by the system. Nowadays when one

travels by road, a smartphone is used to find the location of the

vehicle using the signals emanating from GPS satellites. Apps

are available in smartphones to guide a person to travel to any

given destination.

• GPS is of great assistance to navigate ships, sailing boats, and

aircraft. Coupled with weather maps, ships/sailing boats/aircraft

can avoid areas where there are storms brewing. Fishing boats

can avoid straying into the territorial waters of other countries.


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• A new industry that designs, manufactures, and markets inexpen-

sive computer-based devices that could be mounted on a motor

vehicle that assist the driver with oral commands to travel to a

specified destination has emerged due to the availability of GPS.

• The low cost of GPS-based systems has enabled local transport

companies to track buses/trains and give accurate information to

commuters about the current schedules real-time status allowing

them to plan their trips. Large truck-operating companies track

their trucks using GPS and optimise their movement.

• New cab hailing mobile apps that depend on GPS have disrupted

the old local taxi services. The emergence of companies such

as Uber, Lyft, and Ola has made commuting in cities convenient

and cost-effective. A despatching program that uses GPS has the

location of taxis and customers at all times. It allows optimal

despatch of taxis, saving fuel for the taxis and the waiting time

of customers.

• The new emerging industry of driverless cars depends on GPS

besides light imaging, detection, and ranging (LIDAR) system.

9. World Wide Web

Vannevar Bush conceptualised in 1945 the idea that the informa-tion stored in the repositories of individuals and organizations,usually as typewritten, handwritten or printed documents, if made

Doug Engelbart gave apresentation in 1968,now legendary (availableon YouTube), in whichhe demonstrated the useof a mouse to navigatedocuments displayed ona video screen. He alsodemonstrated in thatpresentation,teleconferencing, wordprocessing, file creation,file maintenance,hypertext, hypermedia,and collaborativereal-time editing ofdocuments.

available to everyone in an easily accessible form, will enhancethe knowledge base of all. He wrote an article titled ‘As We MayThink’ in the Atlantic Monthly expressing this idea. Digital tech-nology was not available then. He proposed an electromechanicaldevice called MEMEX that would use documents photographedin microfilms, indexed, connected via a network of ‘links’ and‘associative trails’. This article foresaw the idea of hypertext tolink documents and using the links to search and retrieve relevantdocuments.

The next big step was taken by Doug Engelbart in 1960 by in-venting the computer mouse as a tool to point at a desired objectdisplayed on a video screen. He showed how it could be used toedit documents. Soon it became an indispensable part of desktop


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computers. He gave a presentation in 1968, now legendary (avail-able on YouTube), in which he demonstrated the use of a mouse tonavigate documents displayed on a video screen. He also demon-strated in that presentation, teleconferencing, word processing,file creation, file maintenance, hypertext, hypermedia, and col-laborative real-time editing of documents. Most of these ideaswere his but the implementation was done by a large team ofprogrammers guided by him at the Stanford Research Instituteat Menlo Park, California. Meanwhile, computer technology pro-gressed with the invention of the PC, LAN, and the creation ofthe Internet infrastructure. The time was ripe to implement theidea of linking documents stored in computers of individuals andorganizations.

Tim Berners-Lee, a graduateBerners-Lee noticed thateven though CERN was

an internationallaboratory with a large

number of scientists whowere expected tocollaborate, their

research reports werestored in their own

computers and it was noteasy for other scientists

to access these reports inspite of their computers

being networked. He gotthe idea that he couldenable the sharing of

files among scientists atCERN and also with

other scientists workingelsewhere in the world asthe Internet connected all

computers and allowedeasy communication

between them.

from Oxford University joined CERN,the large particle physics laboratory near Geneva, Switzerland, in1980 for a few months as a contract employee during which hebuilt a prototype system named ENQUIRE to share and updatethe reports written by scientists in CERN. He came back to CERNas a programmer in 1989. By this time, networking and Inter-net were ripe for implementing novel applications. Berners-Leenoticed that even though CERN was an international laboratorywith a large number of scientists who were expected to collab-orate, their research reports were stored in their own computersand it was not easy for other scientists to access these reports inspite of their computers being networked. He got the idea thathe could enable the sharing of files among scientists at CERNand also with other scientists working elsewhere in the world asthe Internet connected all computers and allowed easy commu-nication between them. He wrote a proposal titled ‘InformationManagement: A Proposal’ that outlined his idea of structuringdocuments with embedded links that would point to other relateddocuments that may be located in any connected computer. Theproposal was not initially accepted by his manager Mike Sendallbut he changed his mind in October 1990 and allowed Berners-Lee to proceed with the project using a desktop computer NeXTthat had been recently bought and networked with other comput-


SERIES ARTICLE

ers. NeXT had many good features to aid in the developmentof the software. In order to link the documents stored in dif-ferent computers, Berners-Lee realised that the documents musthave symbols added to them which assign special meanings tothe documents. These symbols These innovations that

describe what adocument contains, howit is related to otherdocuments, where thesedocuments are stored,and how to access them,laid the groundwork forthe World Wide Web.

are called ‘markups’. He sug-gested that documents be written using a special language calledthe ‘Hypertext Markup Language’, abbreviated HTML. HTMLdescribes the structure and contents of a document and how itis to be linked to other documents. The links are important asthey allow traversing from a document to all related documents.HTML has gradually become the basis for the creation of a webof documents.

The next important innovation was to design a protocol that wouldallow a computer to retrieve related documents from another com-puter connected to it. This was called the ‘Hypertext TransferProtocol (HTTP). This protocol is used to access HTML pages.The third important step was to assign a unique address speci-fying the computer where the required document resides. Thiswas originally called Universal Resource Indicator by Berners-Lee and is now called ‘Universal Resource Locator’ (URL). (TheInternet already had a ‘Domain Name System’ (DNS) that re-sponded A crucial step was

needed to easily navigatethe web of documents. Asoftware called‘Hypertext Browser’ wasdeveloped by MarcAndreessen and his teamof programmers at theNational Centre forSupercomputingApplications at theUniversity of IllinoisUSA. It was called the‘Mosaic browser’ andwas launched in 1993. Itallowed easy navigationof the web.

with the IP address of the server that hosted the websitewhich facilitated assigning a URL). These innovations that de-scribe what a document contains, how it is related to other doc-uments, where these documents are stored, and how to accessthem, laid the groundwork for the World Wide Web. This basicidea and the relevant software were essential but not sufficient toallow easy retrieval of documents scattered in computers all overthe world connected by the Internet. A crucial step was neededto easily navigate the web of documents. Even though a rudi-mentary navigation software to explore the web was developedby the team at CERN in 1991, it was not easy to use. A softwarecalled ‘Hypertext Browser’ was developed by Marc Andreessenand his team of programmers at the National Centre for Super-computing Applications at the University of Illinois USA. It wascalled the ‘Mosaic browser’ and was launched in 1993. Using


SERIES ARTICLE

this browser one can retrieve, for example, a document by typingin the address bar, the URL of the document that has the format:http://www.xcollege.ac.in/admission-rules.html, wherehttp stands for hypertext transfer protocol, :// link, www.xcollege.ac.in,the address of the server of the collegeThe World Wide Web

became usable with theavailability of Mosaic

browser as it had anintuitive user interface

and could displaygraphics. Since then

many browsers, such asNetscape, Internet

Explorer, Firefox, Opera,Safari, and Chrome were

developed.

where the document isstored, followed by the path to the desired document, namely,admission-rules, which is in HTML format. The World WideWeb became usable with the availability of Mosaic browser as ithad an intuitive user interface and could display graphics. Sincethen many browsers, such as Netscape, Internet Explorer, Fire-fox, Opera, Safari, and Chrome were developed. Nowadays, abrowser is an essential software in any computer, and many free,feature-rich, browsers are available [8, 9].

Tim Berners-Lee was far-sighted and wanted the World WideWeb technology to spread widely and be used extensively. Inorder to achieve this, certain principles were enunciated by himand his team.

(i) The web technology was made non-exclusive and available to

anyone.

(ii) No central authority controlled it.

(iii) The web was designedA World Wide WebConsortium (abbreviatedW3C) was formed as the

main internationalstandards organization

for the World Wide Webunder the leadership of

Tim Berners-Lee.Besides standardisation,W3C conducts trainingprogrammes, develops

software, andcoordinates an open

forum for discussionsabout the web and its

future.

to be non-discriminatory, that is, no one

was given preference and better quality of service on payment.

These principles pioneered the philosophy of ‘open source’ and‘open access’ to allow many interested and qualified people tocontribute towards the improvement of the World Wide Web. AWorld Wide Web Consortium (abbreviated W3C) was formed asthe main international standards organization for the World WideWeb under the leadership of Tim Berners-Lee. Besides standard-isation, W3C conducts training programmes, develops software,and coordinates an open forum for discussions about the web andits future.

The World Wide Web technology is a breakthrough in ICT due tothe following reasons:


SERIES ARTICLE

• The idea of organizing documents using a hypertext markup lan-

guage that enables the linking of these documents stored in in-

terconnected computers across the world is novel.

• The World Website designing andmaintenance hasemerged as a newprofession. Today anumber of companies allover the world employmillions of persons todesign websites for largecorporations as well asindividuals.

Wide Web enabled the underlying Internet infrastruc-

ture to be useful to the public by allowing anyone to easily ac-

cess billions of documents stored in computers spread all over

the world.

• It made it essential for every organization and even individual to

have a ‘web presence’ in order to be noticed. Every organization

now creates a website giving details about it and places it in a

publicly available web server, and updates it frequently.

• Many useful documents such as government rules and regula-

tions, judgements delivered by courts, telephone directories, and

stock prices are now available on the web.

• Website designing and maintenance has emerged as a new pro-

fession. Today a number of companies all over the world employ

millions of persons to design websites for large corporations as

well as individuals.

• Entirely new mode of commerce (e-commerce) has developed by

allowing companies to create websites with a catalogue of items

with prices that customers can search and order from anywhere

in the world.

In the next concluding part of this series, I describe search en-gines, digitization and compression, mobile computers, cloud com-puting, and deep learning.

Suggested Reading

[1] Brief History of Computer Graphics, www.technotif.com/brief-history-of-

computer-graphics

[2] Riad Chikhani,The History of gaming: an evolving community.

https://techcrunch.com/2015/10/31/the-history-of-gaming-an-evolving-

community/

[3] Robert Hobbes Zakon, Hobbes’ Internet Timeline 25,

www.zakon.org/robert/internet/timeline/

[4] V Rajaraman, Introduction to Information Technology, 3rd Edition, PHI

Learning, Delhi, pp.152–157, 2015.


SERIES ARTICLE

[5] Kim Ann Zimmermann, Jesse Emspak, Internet History Timeline: ARPANET

to the World Wide Web, June 17, 2017, www.livescience.com

[6] GPS history, chronology, and budgets, https://www.cs.cmu.edu/readings/GPS

[7] John W Betz, Engineering Satellite-based Navigation and Timing: Global Nav-

igation Satellite Systems, Signals, and Receivers, IEEE and John Wiley, New

York, 2015.


V Rajaraman

Supercomputer Education &

Research Centre


Bengaluru 560 012, India.


[8] History of the World Wide Web, World Wide Web Foundation,

https://webfoundation.org/about/vision/

[9] Lenny Zelster, Early History of the World Wide Web: Origin and beyond,

2015, https://www.zelster.com/web-history/


Classroom

In this section of Resonance, we invite readers to pose questions likely to be raised in aclassroom situation. We may suggest strategies for dealing with them, or invite responses,or both. “Classroom” is equally a forum for raising broader issues and sharing personalexperiences and viewpoints on matters related to teaching and learning science.

Chirag Kalelkar

Department of Mechanical

Engineering,

IIT Kharagpur, Kharagpur

West Bengal 721 302, India.

[email protected]

The Inveterate Tinkerer16. Flow Visualisation

We conclude our series of articles on experiments in fluid dy-namics by listing the materials and methods employed, aswell as discuss a few experimental techniques which were notconsidered in earlier articles. Several books on flow visuali-sation [1, 2] are available which the reader may wish to refer.

1. Materials

1.1 Powders/Beads/Flakes

(a) Powdered pepper.

(b) Dairy whitener (Britannia), Coffee-Mate (Nestle).

(c) Lycopodium (Accolent Dried Herbs, Australia).

(d) Potassium permanganate.

(e) Hollow glass spheres (10090, TSI Instruments, United States):

55 µm diameter, neutrally buoyant (density=1.016 g/cc), Polyamide

particles (50 µm diameter).

(f) Kalliroscope AQ-1000 (Kalliroscope Corp., United States). Keywords

Flow visualisation, shadowgraph,

contact lines, bubble-ring, vortex

ring.

(g) Food dye (red).

(h) Copper sulphate.

(i) Mica Pearl White.


CLASSROOM

(j) Rhodamine–B.

(k) Fluorescein.

(l) Photochromic pigment.

(m) Poster color (turquoise blue, Camel).

(n) Acrylic metallic powder (silver, Camel Fabrica).

(o) Talcum powder.

1.2 Inks/Dyes/Emulsions

(a) Parker Quink ink (blue).

(b) Camlin fountain pen ink (Royal blue, scarlet red, permanent black).

(c) Methylene blue.

(d) Candle dye.

(e) Fabrica acrylic color (black, Camel).

(f) Glass colours (Camlin).

(g) Stamp ink (black, Shiny).

(h) Hi-tecpoint ink (black, Luxor)

(i) Printer ink (cyan, ASR Resin & Chemicals Co.)

(j) Permanent marker ink (black, Camlin).

(k) UV ink.

(l) Taral Alta dye (Ranga Java Soap and Chemical Works, India).

(m) Royale Emulsion (silver, Asian Paints).

(n) Congo Red, Phenolphthalein 1% indicator solution.

(o) Sudan III, Oil Red.

1.3 Oil Droplets [3]

1.4 Smoke

We used extruded incense (dhoop) sticks (Rocket Agarbatty Com-pany, India) for generating smoke. An advantage of using incensesticks vis-a-vis agarbattis (which possess a wooden core) is thatthey are malleable and can be shaped as per requirement.


CLASSROOM

Figure 1. Visualisation of

the wake behind an obstacle

using smoke.

An alternate method utilised smoke from the vaporisation of oildroplets. A coating of silicone oil was applied on a fine platinumwire using a paintbrush, which forms periodically-spaced pendantdroplets of oil due to the Rayleigh–Plateau instability [4]. If thewire is heated by passing a current (∼2 A), the oil droplets vapor-ise releasing smoke. An obstacle (such as a pencil) placed in thepath of the smoke may be used to visualise the wake as shown inFigure 1. See the video: youtube.com/watch?v=5-7fgLHVmBk

2. Methods

2.1 Photography with a DSLR and High-speed Camera

We used a DSLR camera (D3200, Nikon) and a high-speed cam-era (Phantom Miro 110, Vision Research) for our experiments.On one occasion, we used a CCD camera (DCU223M, Thorlabs)mounted on an inverted microscope (Ti–S, Nikon) to image themicroscopic structure of shaving foam (Gillette Foamy) betweentwo glass slides. See the video:youtube.com/watch?v=g4_BtnYD25s


youtube.com/watch?v=5-7fgLHVmBk

youtube.com/watch?v=g4_BtnYD25s

CLASSROOM

a) Backdrop and Supports: We used a wooden board of dimen-sions 64 × 38 × 1 cm3 with one side painted black and the otherside painted white. Both sides were useful in different experi-ments, as per the requirement of a dark or light contrast. Threewooden blocks of size 20 × 9.5 × 7 cm3 were fabricated, whichacted as supports for the backdrop. We used a tripod stand (Sim-pex 2400) for mounting the camera.

b) Light Sources: For experiments which required bottom light-ing, we used a lightbox (A930, Artograph Lightpad). For experi-ments which utilised the high-speed camera we used an LED lightsource (YN-600L, Yongnuo). Occasionally, we used a halogenlamp (500 W, Halonix) or UV lamp (11 W, Philips) for illumina-tion while using the DSLR camera.

c) Lenses and Accessories: For nearly all our experiments weused a macro lens (AF-S DX Micro 40 mm f2.8, Nikon) for imag-ing. The sole exception being the shadowgraph experiment dis-cussed below which required use of a zoom lens (AF 70–300 mmf4–5.6, Nikon). A circular polariser (52 mm, Osaka) was screwedonto the lens to reduce glare.Shadowgraph is a

technique for visualisingdifferences in

temperature intransparent media.

2.2 Shadowgraph

Shadowgraph [5] is a technique for visualising differences in tem-perature in transparent media (usually air). Differences in light in-tensity are proportional to spatial gradients in the refractive index(which varies with temperature). The shadows cast by a heatedobject placed in front of a concave mirror are imaged using a cam-era. The focal plane of the camera is positioned at the focal pointof the concave mirror (which is illuminated with a point sourceof light).

A photograph of the setup is shown in Figure 2. We used a con-cave mirror (diameter = 8 inches, Dolphy) for imaging. A whiteLED was converted into an (approximate) point source of lightby coating the surface with black acrylic paint leaving a smallpatch exposed. The LED was powered via an Arduino micro-controller which was duct-taped onto an optical post placed on a


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Figure 2. Setup for the

shadowgraph technique.

Figure 3. (a) Shadowgraph

of jet of air from a heat gun.

(b) Shadowgraph of buoy-

ant plumes above a burn-

ing cigarette lighter (note the

double image.

(a) (b)

laboratory jack. A DSLR camera with zoom lens was mountedon a tripod stand, and used for imaging. The position of the fo-cal plane of the camera was adjusted to coincide with the focalpoint of the mirror. It is important to increase the f-stop numberof the lens, to prevent overexposure. A heated object placed infront of the mirror shows quite clearly the shadow of buoyant tur-bulent plumes rising above the object, see Figure 3 and the video:youtube.com/watch?v=MyOLkHR5prw


youtube.com/watch?v=MyOLkHR5prw

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Figure 4. Visualisation of a

liquid front flowing through

glass beads between plexi-

glas plates.

2.3 Chemical Reaction

Chemical reactions may be used as a means of flow visualisation.Phenolphthalein 1% indicator solution turns pink on mixing withaqueous sodium hydroxide solution. A monolayer of glass beads(diameter = 3 mm) was sandwiched between two plexiglas platesand coated with the indicator solution using a paintbrush. Sodiumhydroxide solution was pumped into the gap between the platesusing a peristaltic pump. The moving fluid front may be readilyvisualised via this technique, as seen in Figure 4 and the video:youtube.com/watch?v=fc1inkTXOMI

The saponification reaction between aqueous sodium hydroxidesolution and oleic acid may be used to image flow near an inter-face, as discussed in an earlier article [3].

2.4 Miscellaneous Methods

Chemical reactions maybe used as a means of

flow visualisation.Phenolphthalein 1%

indicator solution turnspink on mixing with

aqueous sodiumhydroxide solution.

(a) Pinning of Contact Lines Under Floating Bodies: A grid com-prising of squares of length 2 mm was printed onto a sheet ofpaper, which was stuck to the bottom of a (square cross-section)glass aquarium. The aquarium was filled with water. Small piecesof plastic film were made to float on the water by gently placingthem on the surface using a tweezer. The pinning of contact linesat the interface may readily be visualised, as seen in Figure 5 and


youtube.com/watch?v=fc1inkTXOMI

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Figure 5. Pinning of con-

tact lines under floating bod-

ies.

the video: youtube.com/watch?v=8TmYjgOR0Xg

(b) Half-ring Vortex: A plastic tray of dimension 44 × 32 × 8cm3 was filled with water to the brim and illuminated using a500 W halogen lamp. If a tablespoon is dipped into the wa-ter and lifted off, the shadow of a submerged half-ring vortex isobserved to traverse the length of the tray, as seen in the video:youtube.com/watch?v=Gv2u1sa_zHY

(c) Bubble-ring Vortex: A plexiglas tank of dimension 20.5 ×20.5 × 36.5 cm3 was fabricated, with a plastic elbow connectorsticking out of the bottom (see Figure 6). The tank was filledwith 10 litres of aqueous glycerol solution. The elbow connec-tor was attached via flexible plastic piping to a solenoid valve(2W-025-08, Senya Solenoid Valve Co., China). The valve wasattached via tubing to an air compressor (100 psi, Aihui Co. Ltd.,China). To regulate the flow of air from the compressor, a T-joint assembly was created using two saline drip valves and aplastic T-joint. One of the saline drip valves served as the out-let (into the solenoid valve) and the other was used for exhaust.The solenoid valve was switched via a 5 V relay which was con-trolled using an Arduino microcontroller. It is important to ensurea sufficient head by placing the compressor-valve assembly at acertain height above the top of the tank. The compressor wasturned on and the relay was switched periodically with a delay


youtube.com/watch?v=8TmYjgOR0Xg

youtube.com/watch?v=Gv2u1sa_zHY

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Figure 6. Side-view of the

setup for producing bubble

rings.

of ∼15 ms which permits a bubble of turbulent air to enter theelbow joint and the solution. The bubble rises due to buoyancyand undergoes an instability, leading to the formation of a turbu-lent bubble ring which rises to the surface of the solution. See thevideo taken with a high-speed camera and LED light source asbackdrop: youtube.com/watch?v=e0h17S11LGY

3. Acknowledgment

The author acknowledges help from students who participatedin over 200 experiments during the period 2013–2018: AbhijeetKant Sinha, Aditi Kambli, Abhilash Velalam, Amal Narayanan,Akshita Sahni, Arun Kumar Singh, Ashok Kumar, Bigyansu Be-hera, Debajyoti Das, Kratika Shrivastava, Kabita Naik, Kiran Raj,Lokesh Attarade, Naresh Kumar, Nayeeni Manoj, Ojas Satbhai,P. Hemanth, Patruni Kiran, Sanat Singha, Sanket Mandal, SukrutPhansalkar, Sagnik Paul, Santosh Gavhane, Saurav Sen, Shub-ham Kant and Tarique Anwar. The author also acknowledgesthe partial funding support from the Science and Engineering Re-


youtube.com/watch?v=e0h17S11LGY

CLASSROOM

search Board (SB/S3/CE/071/2013).

Suggested Reading

[1] Flow Visualisation: Techniques and Examples, Ed. A Smits and T Lim, Imperial

College Press, 2012.

[2] W Merzkirch, Flow Visualisation, Academic Press, 1987.

[3] C Kalelkar, Experiments With Liquid Drops, Resonance, Vol.23, No.6, pp.693–

701, 2018.

[4] C Kalelkar, Miscellaneous Fluid Instabilities, Resonance-Journal of Science

Education, Vol.23, No.7, pp.809–819, 2018.

[5] G Settles, Schlieren and Shadowgraph Techniques: Visualizing Phenomena in

Transparent Media, Springer, 2001.


Classroom

In this section of Resonance, we invite readers to pose questions likely to be raised in aclassroom situation. We may suggest strategies for dealing with them, or invite responses,or both. “Classroom” is equally a forum for raising broader issues and sharing personalexperiences and viewpoints on matters related to teaching and learning science.

A G Samuelson

Department of Inorganic and

Physical Chemistry


Bangalore 560 012, India.


Card Games and ChemistryTeaching Organometallic Reactions Through Card Games

We present a card game suitable for classroom use to pro-vide an interactive and lively experience while studyingorganometallic reactions, synthesis and catalysis. It is basedon a deck of playing cards, and we call it CARS (Catalysisand Reaction Sequences). The object is to arrange a set ofrandom cards served to the player in a correct sequence. Thecorrect sequence is based on the sequence of steps found inthe catalytic cycle of a set of reactions. The game is similarto the popular multiplayer card game rummy. We illustratethe game with a set of cards based on the C–C bond formingreactions, but it can be modified by the teacher to suit the top-ics being taught and could even be converted to a web-basedversion or a stand-alone study tool operating on a computer.

Introduction

Systematization and teaching of inorganic and organometallicchemistry reactions are daunting tasks. Teachers and studentsare bogged down by the prospect of studying literally hundredsof ‘seemingly’ unrelated reactions. Keywords

Catalysis, organometallic

chemistry, card games, fun in

chemistry.

Anything that facilitates thisprocess and helps in visualizing relationships is welcome. If oneunderstands for example, how several organometallic reactions


CLASSROOM

follow a common pattern in catalytic and stoichiometric reac-tions, it would be a great help to the student and teacher alike. BywritingBy writing the catalytic

cycles presented inorganometallic

chemistry as a set ofsequential reactions, it ispossible to see that manyreactions indeed follow a

pattern.

the catalytic cycles presented in organometallic chemistryas a set of sequential reactions, it is possible to see that many reac-tions indeed follow a pattern. It becomes easier for the student toconnect a large number of reactions and attempt the constructionof new catalytic cycles, given the reactants and products.

Games have been used effectively for enhancing student involve-ment and making the student-teacher interaction more enjoyablethan lecture-based classes [1]. In the past, games have aidedchemical education especially in the nomenclature of compounds,study of elements in the periodic table and reactions [2]. Some ofthem are indeed card games to aid the study of nomenclature [3],formulas [4] and even improve the understanding of stereochem-istry [5]. Recently, there have been some excellent descriptionsof card games for teaching functional groups in organic chemistry[6], synthetic organic chemistry [7, 8], and one to teach retrosyn-thetic analysis [9].

We believe an extremely simple and general version of the popu-lar card game – rummy – can be devised to learn organometallicchemistry and catalysis. We will illustrate the idea using a set ofcards based on organometallic catalytic cycles using organic/organo-metallic synthesis. They are only illustrative and the game isdesigned in such a way that it can be used in different learn-ing/teaching situations wherever a sequence of events is part ofthe learning objective.

The deck of cards is patterned after the familiar 54 cards in com-mon card games. The cards are divided into four groups or suits,each one representing a catalytic cycle (as in spades, clubs orclovers, diamonds and hearts). The name of each reaction isprinted on a color-coded card and the substrates, products andreagents, if any, in that reaction are printed in the same color.The transformations or steps in the reaction can also be made intocards indicative of the reaction type such as oxidative addition,insertion or transmetallation, reductive elimination, ligand disso-ciation, etc. Each reaction cycle is thus mapped into a set of 12


CLASSROOM

cards. In order to increase the element of fun, one card, desig-nated as a wild or special card, is included in each suit, and thismay be used to fill in any part of the sequence. Two additionalcards are generic multicolored ‘wild’ cards that can be used forany reaction (across suits), reagent or sequence, making a totalof 54 cards. Although the popular game of rummy is suggested,other games could be devised as well as the cards map to a regularpack of 54 cards in a deck.

We will illustrate how this game can be used to teach/learn severalC–C bond forming reactions where the catalytic cycles bear someresemblance. When the catalytic cycles are grouped togetherin this fashion, the similarities and differences are brought out,and student understanding is significantly enhanced during theplay. We have chosen four named reactions: HECK, NEGISHI,SUZUKI and SONOGHASHIRA. Each of these named reactionshas a well-established catalytic cycle. Apart from the fact that thecommon catalyst of choice is a palladium complex, three of thesereactions proceed through steps that are similar in the beginningand in the end. The Heck reaction has significant differences. Thegame allows the students to recognize the similarities and appre-ciate the differences. If the game is played in class after thesereactions are taught, or right after the lecture in a tutorial class,it is easy for students to recollect these steps. It also allows thestudent to construct new cycles for reactions they encounter in theliterature with ease.

Figure 1 shows the catalytic cycle for the Heck reaction and Fig-ure 2 shows the representative cards one can generate from thiscycle. A similar exercise with the other three reactions wouldyield the requisite number of cards. A complete set of 54 cardsis given in the supplementary section for the four reactions men-tioned above. These card sets are only illustrative. Any four reac-tions could be substituted for these C–C bond-forming reactions.One only needs to simplify the steps so that the reaction is com-pletely represented by 12 to 13 cards.

In order to play the game with two to four people, one pack ofcards is thoroughly shuffled to generate a random set and each


CLASSROOM

player is dealt a set of 10 cards. The remaining cards are keptaside face down as the stockpile. Each player tries to arrange theten cards (s)he has according to a reaction sequence. The objectof the game is to be the first one to arrange all the cards in validsequences. Valid sequences could be formed as a sequence of 10cards from one complete catalytic cycle (same color cards). Wildor special cards are permitted. If they are two different sequencesthey could be from two different catalytic cycles of say, a set of7 in one cycle and a set of 3 from another, or even three differentsequences of 3, 3 and 4. Players get to draw from the stockpileand discard unwanted cards until they can form sequences. In ourexperience, sequences are generated by at least one player within15–20 minutes. After the winner is confirmed, every player showstheir sequences to other players and then a lively discussion fol-lows. In one group, the students helped one another form all foursequences further reinforcing the learning experience.

Although we emphasize the similarity with numbered cards, acaveat must be added. Sequences in CARS could have some dif-ferences from the classic card sequences. For example, in a reac-tion of A + B transformed by a substitution reaction ‘R’ to giveC + D; the sequence could be cards corresponding to ‘A, B, R’ or‘B, A, R’ or ‘R, C, D’ or ‘R, D, C’. All of them are chemicallymeaningful. However, the sequence ‘B, R, and C’ is not consid-ered a valid ‘reaction sequence’ although based on numbers it isa valid sequence. Rules regarding this must be announced beforestarting the game.

AA player can choose toput down a run orsequence of three

(minimum), four orseven cards in the centreof the playing area. This

might allow anotherplayer to continue thecatalytic sequence by

adding a set.

player can choose to put down a run or sequence of three (min-imum), four or seven cards in the centre of the playing area. Thismight allow another player to continue the catalytic sequence byadding a set. The object of the game is to help the students buildthe catalytic cycle or parts of it using the cards. So putting downthe sequences as and when they form could help them recognizethe catalytic cycles, the reactions and the substrates. This mayincrease the educational value. When played in this fashion, theperson who puts down all the cards first wins. However, as amatter of strategy, many players choose not to put it down!


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Figure 1. The catalytic

cycle of the Heck reaction:

(LD = ligand dissociation;

OA = oxidative addition; LS

= ligand substituttion; MI =

migratory insertion; HE = β-

hydride elimination; RE =

reductive elimination.

The student learns different aspects of a catalytic cycle such as therequirement for a vacant site, a suitable oxidation state, matchingsubstrates and catalysts in a lively environment. In the first fewrounds of the game, students may be permitted to use their classnotes or even have access to complete catalytic cycles. If needed,an easier card set could be printed with suitable hints on the cardssuggesting what reactions are possible for the substrate or whatsubstrates are suitable for the reaction. In an electronic version ofthe game, this could be made easier through the use of help filesor simpler card sets.

In order to play this game to aid self-study, one can play the equiv-alent of a ‘Single Suit Spider’. Multiple copies, usually eight, ofthe same (reaction) colored cards are needed to play this game.Both Rummy and Spider are readily played with these cards, andhence the games should be transferable to soft versions. Simi-larly, with some modifications, a board game like ‘Snakes andLadders’ could be constructed using the sequence. Board games


CLASSROOM

Figure 2. Representa-

tive cards generated from

the Heck reaction cycle pre-

sented in Figure 1.

have the advantage that they could even be elaborated into socialgames such as ‘Farmville’. The framework described here is alsosuitable for further elaboration by increasing the difficulty level,and adding gaming elements so that a full-fledged gaming expe-rience can be incorporated in the future. Converting the gameinto an app suitable for the mobile, or a web-based program in-dependent of device architecture should also help more studentsto participate. If a gaming environment is provided, additionalmotivational aspects can set in, such as the desire to role play,gaining social recognition, a sense of accomplishment, handlingchallenges, mystery and fun that can lead to interactive and en-joyable learning. An excellent opportunity for ‘gamification’ of


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Figure 3. Set of 54

cards suitable for printing

on a plastic sheet. To

download a set of print-

able cards please visit:

https://is.gd/ZwUdVh

learning exists [10]. We believe the incorporation of such gameseither through physical cards/boards or even through computergames or apps will improve the motivation and engagement ofstudents.

Conclusions

Teaching organometallic reaction mechanisms and catalytic cy-cles using card games, in a fun-filled interactive setting is moreeffective than a slide presentation or even a chalk and board lec-ture. Since the game is tunable, it is likely to be of great valuein teaching other topics where sequences are involved: such as intotal synthesis. We have described here a general framework forconverting any complex reaction with multiple steps into a cardgame very similar to rummy, the popular game of cards. Manyopportunities open up once the teacher converts the learning ob-jective into a game [11].

Supporting Information

This section illustrates the set of 54 cards (Figure 3) suitable forprinting on a plastic sheet. The sequence number is printed belowthe cards for the teacher’s reference. Detailed instructions forplaying the game is as follows.


CLASSROOM

Instructions for Playing the Card Game – CARS

In order to play the game with four people, the cards are thor-oughly shuffled to generate a random set and each player is dealta set of 10 cards. The remaining cards are kept aside face downas the stockpile. The first player, takes a card from the stock andattempts to improve on the number of sequences (s)he has in hand(10 cards), and then discards any unwanted card with its face up.The next player in a similar fashion can take one card (DRAW)from the top of the stock or the card that was discarded by the pre-vious player. However, each player must put back (DISCARD)the most unwanted card from her/his cards, or the card that wastaken from the stock. So, at any stage of the game except duringthe player’s turn, one has only 10 cards on hand. When one playerfinally forms three sequences, (s)he is declared the winner. If thestock is exhausted, the set of open cards are shuffled and replacedface down to form a fresh stock to continue the game.

Acknowledgments

The author thanks the students of the organometallic course whohave participated in the game and several faculty members of IITswho have given valuable feedback.

Suggested Reading

[1] M J Samide, A M Wilson, Games, Games, Games; Playing to Engage with

Chemistry Concepts, Chem. Educ., Vol.19, pp.167–170, 2014.

[2] J V Russell, Using Games to Teach Chemistry: An Annotated Bibliography. J.

Chem. Educ., Vol.76, pp.481–484, 1999.

[3] R S Sevcik, L D Schultz, S V Alexander, Elements – A Card Game of Chemical

Names and Symbols, J. Chem. Educ., Vol.85, pp.514–515, 2008.

[4] T A Morris, Go Chemistry: A Card Game to Help Students to Learn Chemical

Formulas, J. Chem. Educ., Vol.88, pp.1397–99, 2011.

[5] M J Costa, Carbohydeck: A Card Game To Teach the Stereochemistry of Car-

bohydrates, J. Chem. Educ., Vol.84, pp.977–978, 2007.

[6] M J Welsh, Organic functional Group Playing Card Deck, J. Chem. Educ.,

Vol.80, pp.426–427, 2003.


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[7] C A Knudtson, ChemKarta: A Card Game for Teaching Functional Groups

in Undergraduate Organic Chemistry, J. Chem. Educ., Vol.92, pp.1514–1517,

2015.

[8] S C Farmer, M K Schuman, A Simple Card Game to Teach Synthesis in Or-

ganic Chemistry Courses, J. Chem. Educ., Vol.93, pp.695–698, 2016.

[9] J M Carney, Retrosynthetic Rummy: A Synthetic Organic Chemistry Card

Game, J. Chem. Educ., Vol.92, pp.328–331, 2015.

[10] Y-k Chou, Actionable Gamification: Beyond Points Badges and Leaderboards,

Octalysis Media, Freemont, 2014.

[11] M Antunes, M A R Pacheco, M Giovanela, Design and Implementation of

an Educational Game for Teaching Chemistry in Higher Education, J. Chem.

Educ., Vol.89, pp.517–521, 2012.


BOOK REVIEW

Magic of Transforming aFox Into a Dog!

Sujata Deshpande

How to Tame a Fox (and Build a Dog)Visionary Scientists and a Siberian Taleof Jump-Started EvolutionAuthors: Lee Alan Dugatkin and LyudmilaTrutPublished by: University of Chicago Press,2017Pages: 240 (clothbound)Price: USD 26 (clothbound)Other formats: E-book USD 18.00(The book will be available in paperback forUSD 18 in October 2018)

This book tells the story of the Russian geneti-cist Dmitri Belyaev’s idea. In his own words,the idea was ‘to make a dog out a fox’. Myvery first question upon getting the book inmy hands was – why would anyone want todo this? The two animals are perceived tobe opposites. The fox is labeled as the mostcunning animal while the dog is a human’s

most loyal friend. The fox is solitary whilethe dog is social. The fox is a wild animal thatstays away from humans as much as possiblewhile the dog is a domesticated, beloved petwho sits in your living room resting its headon your knees. But the domesticated dog wasonce a wild animal, known to have descendedfrom wolf ancestors. Our ancestors domesti-cated those wolves into dogs over a period ofthousands of years. Dmitri Belyaev wantedto mimic this process, with the silver fox, inorder to understand the process of domestica-tion. He was especially interested in the ini-tial part of the process – how domesticationof a wild animal began. He chose the silverfox – a close genetic cousin of the wolf – forthis experiment. Dmitri Belyaev’s experimentstarted in the early 1950s and it continues tilltoday, even after his death in 1985, havinggone through fifty-seven generations of do-mesticated, tamed silver foxes to date. Someof these foxes have become household pets!This is one of the longest run experiments inbiology, but perhaps a short one for evolution.

The book is written by Lee Alan Dugatkinwho is an evolutionary biologist and historianof science in the Department of Biology at theUniversity of Louisville, along with LyudmilaTrut, Professor of Genetics at the Institute ofCytology and Genetics in Siberia who hasbeen associated with the fox-taming projectsince 1959. Together, the author duo describesthe evolution of this experiment right from itsinception. They delve into the science behindit – evolution, animal behaviour, animal do-mestication and biology of the fox. They also


BOOK REVIEW

outline the history and politics of the USSR(Union of Soviet Socialist Republics) and howit affected the science and the scientists of thattime. The picture of the effect of history andpolitics appears black. However, silver rayspenetrate this dark cloud in the form of bravescientists who strove to do their science, tostand up against political hindrance, and to en-sure that their country would not lose the richscientific heritage it once had. They risked ev-erything, sometimes lost their careers, werelocked behind bars, lost their loved ones, oreven lost their own lives. Dmitri Belyaevemerges as a charismatic person, a visionaryscientist, a skilled administrator, and a bravesoldier. He suffered many personal losses butremained a warm-hearted individual, alwaysthoughtful of the people associated with him.He wanted to learn from the experts all overthe world and went out of his way to contactthem.

The story of the fox domestication experimentcan easily fit into a thrilling science fiction.Belyaev wanted to select foxes for their tame-ness and breed them over generations hopingto get glimpses of the early stages of domes-tication. He was a trained geneticist, how-ever, when he began his career he was pro-hibited from doing research in genetics. Hisjob as a lead scientist in Russia’s state-ownedfur industry was to help mass breeders offoxes and minks to produce more beautifulfurs. He accepted the job so that he couldcarry out his studies under the cover of thejob. Even then, he could not start his ownfox domestication experiment under the op-

pressive political conditions imposed by JosefStalin and Trofim Lysenko (who vehementlyopposed Mendelian genetics and geneticistspractising it). Therefore, Belyaev asked an Es-tonian colleague, Nina Sorokina, to start theexperiment under a different pretext in 1952.Over the next few years, political conditionsstarted becoming less unfavourable. Belyaevbecame the Head of the Institute of Cytologyand Genetics. By then, the foxes with hisEstonian colleague were also showing subtlebehavioural and morphological changes. En-couraged by these events, Belyaev decided toexpand the experiment and looked for a personhighly trained in animal behaviour. Now, thisis quite interesting and I would like to draw theattention of undergraduate students. LyudmilaTrut (yes!the co-author of the book) was thathighly trained person and she was just aboutto finish her undergraduate studies! The bookdescribes in detail how Lyudmila Trut got thejob and I do not want to break the suspense. Iurge undergraduate students and their teachersto read the book!

Lyudmila Trut decided to work on the fox-domestication project by going to the institutethat was being newly formed. The institutewas being set up in a city called Novosibirsk inSiberia, more than three thousand kilometersaway from Moscow where Lyudmila and herfamily were located. Lyudmila had just mar-ried and had a baby girl. However, when shedecided to go, her husband whole-heartedlysupported her by agreeing to go along withher and finding a job in the new location. Hermother too joined them soon afterwards to


BOOK REVIEW

look after the baby. This was happening in thelate 1950s and this is the kind of family sup-port many women scientists even today dreamabout; luckily, the number of those who getthis support is slowly increasing.

This is a slim book of about two hundredpages with a photograph of a cute fox onthe cover. It is written lucidly and it car-ries the reader with the flow of events whichget more and more interesting, and some veryheart-warming. Even before I realized it, thebook was over and I wished it just went on!The experiment started with behavioural ob-servations of the foxes but went on to inves-tigate changes in fur colouration, facial fea-tures, hormones, reproductive cycle and dif-ferential gene expression. These changes wereall associated with domestication. The book

describes this extended experiment in detailand provides a good number of references.The book is not for undergraduate studentsalone. It demands attention of the experts inthe fields like evolutionary biology, genetics,developmental biology, history of science, an-thropology and perhaps animal ethics. Andthis book is for you if you are an animal lover!

Sujata DeshpandeAssistant Professor

Department of Zoology,St. Xavier’s College (Autonomous),

5 - Mahapalika Marg,Mumbai 400 001, India.



Information and Announcements

India Flourishes at International Olympiads

As in previous years, Indian teams performed well at the International Olympiads in Biol-ogy, Chemistry, Mathematics, and Physics in 2018. Of the 19 students who participatedin four Olympiads held so far this year, 7 secured gold medals, 9 silver medals, 2 bronzemedals, and 1 certificate of honorable mention. The most remarkable performance was inthe International Physics Olympiad (IPhO) where all the five Indian students received goldmedals, lifting the country to the top position in the medals tally along with China, a first in21 years of Indian participation in IPhO.

The Olympiad programme in India is fully supported by the government through variousdepartments and ministries: DAE, DST, MHRD, and DOS. The Homi Bhabha Centre forScience Education (HBCSE–TIFR) is the nodal center for all the science and mathematicalOlympiads in the country. The teams for the International Olympiads are selected througha three-stage selection process, and trained by HBCSE(http://olympiads.hbcse.tifr.res.in).

The winning delegations to the different Olympiads are given below.


INF. & ANN.

29th International Biology Olympiad (IBO) held at Tehran, Iran (July 15–22, 2018)

Left to Right: Kunjal Parnami, Vishwesh Bharadiya, Shaswat Jain and Stuti Khand-wala.

Kunjal Parnami SilverBGS National Public School, Bengaluru

Shaswat Jain SilverNalanda Academy Sr. Sec.School, Kota

Stuti Khandwala SilverDisha Delphi Public School, Kota

Vishwesh Bharadiya SilverH.P.T. Arts & R.Y.K. ScienceCollege, Nasik

Leaders: Dr Sasikumar Menon (TDM Lab, Mumbai), Prof. Kauresh Vachrajani (M.S.University, Baroda)

Sc. Observers: Prof. Pradeep Burma (Delhi University), Mr. Vikrant Ghanekar (HBCSE,Mumbai)


INF. & ANN.

50th International Chemistry Olympiad (IChO) held at Slovakia & Czech Republic(July 19–28, 2018)

Left to Right: Aayush Kadam, Dhyey Gandhi, Jishnu Basavaraju and Sanchit Agrawal.

Dhyey Gandhi GoldDisha Delphi Public School, Kota

Jishnu Basavaraju GoldSri Chaitanya Narayana JrCollege, Vijayawada

Aayush Kadam SilverPragati School, Kota

Sanchit Agrawal SilverSardar Patel Vidyalaya, Delhi

Mentors: Dr Savita Ladage (HBCSE, Mumbai), Dr Lakshmy Ravishankar (V.G. Vaze Col-lege of Arts, Science and Commerce, Mumbai)

Sc. Observers: Dr. Dimple Dutta (BARC, Mumbai), Ms. Swapna Narvekar (HBCSE,Mumbai)


INF. & ANN.

59th International Mathematical Olympiad (IMO) held at Cluj Napoca, Romania(July 4–14, 2018)

Left to Right: Spandan Ghosh, Amit Kumar Mallik, Anant Mudgal, Pranjal Srivastava,Pulkit Sinha and Sutanay Bhattacharya

Anant Mudgal SilverDelhi Public School, Faridabad

Pranjal Srivastava SilverNational Public SchoolKoramangala, Bengaluru

Pulkit Sinha SilverSt. Francis SchoolIndirapuram, Ghaziabad

Spandan Ghosh BronzeSouth Point High School, KolkataSutanay Bhattacharya BronzeBishnupur High School,Bishnupur

Amit Kumar Mallik Honourable MentionSri Chaitanya Jr College, Vijayawada

Leaders: Prof. Venkatachala Belur Jana (Retc. HBCSE, Mumbai), Mr Prashant Sohani(Bhaskaracharya Pratishthan, Pune)

Sc. Observers: Prof. Vinod Kumar Grover (Punjab University, Chandigarh), Mr PranavNuti (IISc, Bangalore)


INF. & ANN.

49th International Physics Olympiad (IPhO) held at Lisbon, Portugal (July 21–28, 2018)

Left to Right: Lay Jain, Siddharth Tiwary, Nishant Abhangi, Pawan Goyal and BhaskarGupta

Lay Jain GoldDisha Delphi Public School, Kota

Siddharth Tiwary GoldLakshmipat Singhania Academy,Kolkata

Nishant Abhangi GoldDisha Delphi Public School, Kota

Pawan Goyal GoldAklank Public School, Kota

Bhaskar Gupta GoldShiv Jyoti Sr Sec School, Kota

Leaders: Dr. Praveen Pathak (HBCSE, Mumbai), Prof. K. G. M. Nair (Chennai Mathemat-ical Institute)

Sc. Observers: Prof. Surajit Chakrabarti (Retd. M. M. Chandra College, Kolkata), Dr.Manish Kapoor (Christ Church College, Kanpur)


INF. & ANN.

Science Academies’ Refresher Course in Experimental Physics

atOsmania University College for Women (OUCW)

Koti, Osmania University, Hyderabad25 September to 10 October 2018

Sponsored byIndian Academy of Sciences, Bengaluru

Indian National Science Academy, New DelhiThe National Academy of Sciences, India, Allahabad

A Science Academies’ Refresher Course in “Experimental Physics” will be held in the OsmaiaUniversity College for Women (OUCW), Koti, Osmania University, Hyderabad, Telengana State,from 25th September 2018 to 10th October 2018 for the benefit of faculty involved in teachingundergraduate and postgraduate courses in Physics. Participants in this course will gain hands onexperience with about 25 experiments designed by Professor R. Srinivasan, the Course Director,Indian Academy of Sciences.

One of the mandated objectives of Osmania University College for Women (OUCW), Koti, Osma-nia University, Hyderabad, is to develop scientific skills and capacity building in various areas ofscience, with a special focus on women and their scietific empowerment. The OUCW has beenconducting various capacity building programs for University teachers and research scholars.

Professor R. Srinivasan has conducted such Refresher Course in Experimental Physics in manyinstitutions so far including universities, autonomous colleges, and advanced scientific institutionsinvolved in education. The Course will enable the participants, through lectures and laboratorysessions, to enhance their skills in experimental physics and facilitate them to introduce the ex-periments in their respective curricula. UGC has approved two weeks Refresher Courses of goodstanding for promotion, vide notification: F31/2009 dated 30 June 2010.

Applications are invited from teachers with experience in teaching undergraduate and postgraduatecourses in Physics. III year B.Sc., I year M.Sc. Physics students and research scholars with keeninterest in Experimental Physics may also apply. The number of seats will not exceed 34. Selectedparticipants will be provided with roundtrip bus/train (III AC) fare by the shortest route and localhospitality during the course in addition to course material. Interested applicants must submit theirapplication ONLINE by clicking on the following link:

http://web-japps.ias.ac.in:8080/Refreshcourse/ORRP.jsp

A copy of the application form signed by the applicant should also be sent by post to The CourseCoordinator. In case of teachers, the form must also be signed and stamped by the Head of theapplicant’s institution stating that leave will be sanctioned, if the applicant is selected for the Course.A recommendation letter from a teacher is essential for student applicants. Scanned copies of theduly signed documents sent by email will also be accepted.

Applications may be sent to: Dr Madhuri Dumpala, Course Coordinator, Refresher Course in Ex-perimental Physics, Osmania University College for Women (OUCW), Koti, Hyderabad 500 095.Email: [email protected] Phone: 8919245804

Last date for the receipt of applications: 31st August 2018. Selected participants will beinformed by: 10th September 2018.


http://web-japps.ias.ac.in:8080/Refreshcourse/ORRP.jsp

INF. & ANN.

Science Academies’ Refresher Course in Statistical Physics

atRamakrishna Mission Vivekananda University

Belur Math, Kolkata09 to 23 December 2018

Sponsored byIndian Academy of Sciences, Bengaluru

Indian National Science Academy, New DelhiThe National Academy of Sciences, India, Allahabad

A Refresher Course in Statistical Physics will be held at the Department of Physics, RamakrishnaMission Vivekananda University (RKMVU), Belur Math, Kolkata, from 9 to 23 December 2018 forthe benefit of faculty involved in teaching undergraduate and postgraduate courses. This course willaddress the transition from a one-particle description (as in classical mechanics) to a many-particlestatistical description (as in statistical mechanics). An intermediate step involves dynamical systemtheory, which describes the evolution of a set of initial conditions under dynamics. Often, with theincrease in the number of degrees of freedom, these lead to statistically similar behaviour, allowinga description through equilibrium statistical mechanics. In addition to lectures on these topics,there will be lectures on stochastic dynamics, nonequilibrium statistical mechanics and quantumstatistical mechanics.

The course is sponsored by Indian Academy of Sciences, Bengaluru, Indian National ScienceAcademy, New Delhi and The National Academy of Sciences, India, Allahabad. It will be directedby Prof. Mustansir Barma, TIFR Hyderabad, F.A.Sc., F.N.A.Sc., F.N.A., and coordinated by DrShamik Gupta, Department of Physics, Ramakrishna Mission Vivekananda University. The topicsand lecturers: Classical Mechanics: Prof. N Mukunda (IISc, Bengaluru); Dynamical Systems: Prof.Soumitro Banerjee (IISER Kolkata) and Dr Shamik Gupta (RKMVU, Belur Math); Stochastic Dy-namics: Prof. Mustansir Barma (TIFR, Hyderabad); Classical Equilibrium Statistical Mechanics: DrShamik Gupta (RKMVU, Belur Math); Quantum Equilibrium Statistical Mechanics: Dr Arnab Sen(IACS, Kolkata); Nonequilibrium Statistical Mechanics: Prof. P K Mohanty (SINP, Kolkata).

Since 1999, more than 270 successful Refresher Courses have been organized throughout thecountry. It may be noted that UGC regulations include Refresher Courses in API scores for careeradvancement. Applications are invited from teachers with experience in teaching undergraduateand postgraduate courses in Engineering and Physics. Motivated BSc and MSc Physics studentsmay also apply. There will be 25 outstation and 10 local participants. Selected outstation partici-pants will be provided with travel assistance (limited to three-tier A/C train fare), while all participantswill be provided accommodation and local hospitality during the Course, in addition to the coursematerial.

Interested applicants must submit their application ONLINE by clicking on the following link:

http://web-japps.ias.ac.in:8080/Refreshcourse/SSSR.jsp

A copy of the application form signed by the applicant should also be sent by post to the CourseCoordinator, at the address given below. In case of teachers, the form must also be signed andstamped by the Head of the applicant’s institution stating that leave will be sanctioned if the appli-cant is selected for the Course. A recommendation letter from a teacher is essential for studentapplicants. Scanned copies of the duly signed documents sent by email will also be accepted.Address for communication: Dr Shamik Gupta, Department of Physics, Ramakrishna MissionVivekananda University, Belur Math, Howrah 711202, West Bengal. Email: [email protected]: +91 33 2654 9999.Last date for the receipt of applications: 15 September 2018. Selected participants will beinformed by: 5 October 2018.


http://web-japps.ias.ac.in:8080/Refreshcourse/SSSR.jsp

Editorial - Indian Academy of Sciences

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