Nikolaas Tinbergen: the Careful Scientist), Respectively, by Sindhu Radhakrishna in This Issue

Home , Nikolaas Tinbergen, Supernormal stimulus

Editorial

T N C Vidya, Associate Editor

We are happy to bring to you, an issue that celebrates Niko- laas Tinbergen, who along with Konrad Lorenz and Karl von Frisch, laid the foundations of the field of ethology, the study of 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 forces Email: within individuals that could, therefore, not be explained through [email protected] physico-chemical processes, or through comparative psychology (in America) that placed an almost exclusive emphasis on learning as the process responsible for behaviour. Comparative psychologists at that time often anthropomorphised animal behaviour and relied on laboratory experiments to test animals. Ethologists Lorenz, Tinbergen, and von Frisch (in Europe), on the other hand, articulated how animal behaviour itself could be an evolved phenomenon. The behaviour showed by an animal could, therefore, be inherited, have survival value, and be acted upon by natural selection. This was in contrast to the view of comparative psychologists who thought that mental faculties – and not behaviours – evolved and allowed various species to learn appro- priate behaviours. Therefore, ethologists tended to focus on animal behaviour in the natural environment and study instinctive behaviours – behaviours that animals displayed in response to specific stimuli even in the absence of prior experience. How- ever, they realized that learning could also be important in some species at least. Lorenz, Tinbergen, and von Frisch carried out careful observations and experiments on insects, fishes, and birds. Their research paved the way for further work on obtaining an evolutionary understanding of behaviours in various animals, including humans, a proximate understanding of critical periods for normal development, and how adverse psychosocial environ- ments can lead to behavioural abnormalities and psychosomatic

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illnesses. The triumvirate was awarded the Nobel Prize in Phys- iology or Medicine in 1973 “for their discoveries concerning organization and elicitation of individual and social behaviour patterns”, a departure from the norm of awarding the prize to research more directly related to human physiology or disease. Tinbergen was interested in the specific stimuli eliciting certain behavioural responses of animals and in the adaptive value of behaviour. 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, by Sindhu Radhakrishna in this issue. Regarding the former, Rad- hakrishna points out to us that Tinbergen, the man, was even more remarkable than Tinbergen, the ethologist; all of us in academia would do well to strive towards such personal qualities. Tinbergen is well-known for persistently fine-tuning and carrying out simple, but carefully designed, elegant experiments in the animal’s natural habitat to test hypotheses about a behaviour. It is a pleasure, therefore, to have the first of a series of articles on How to Design Experiments in Animal Behaviour by Raghaven- dra Gadagkar featuring Tinbergen’s experiments on digger wasps in this issue. This series encourages logical thinking and creativity in setting up experiments to study animal behaviour and describes experiments that can be performed (with some modifica- tion if required) by the readers of Resonance. I encourage you to write to the Resonance Facebook page (@Resonance.IASc.Bng) with your experiences of trying these experiments. Tinbergen discovered that exaggerated versions of certain stimuli evoked exaggerated responses from animals compared to what normal 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 of Tinbergen’s work are also illustrated in Science Smiles. It is far too easy to get lost in the details of one’s work, hardly pausing 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 and methods used by ethologists rather than emphasising only factual information in his 1963 classic paper ‘On Aims and Methods of Ethology’ and in his 1965 book Animal Behaviour (LIFE Nature Library Series). The former was the Classics chosen for this issue and, in lieu of the original paper being reprinted here, we have its essence brilliantly captured in an essay (See Article-in-a-Box) by R Gadagkar that I hope will make you all read the original paper. Although Tinbergen primarily focussed on instinctive behaviour that was inherited, he attributed his success to his environment – his family, peers, teachers, and the widespread interest in natural history that was part of the social milieu in the Netherlands at the time. Unfortunately, we do not have a widespread interest in natural history, behaviour, organismal or evolutionary biology in India, despite the abundance of biodiversity that can be very rewarding to study. Although ethology and other disciplines in organismal/supra-organismal biology became a ‘testable science’ many decades to about a century ago, most of our school and college syllabi in organismal biology are hopelessly outdated and rarely extend beyond ‘stamp collecting’. An understanding of the theory in various subjects, especially evolutionary biology, is crucial to progressing beyond descriptions and addressing meaningful questions in organismal biology. There is, unfortunately, not a single masters programme on evolutionary biology in the country while there should logically be multiple institutes dedicated to the subject, given its scope of research and ramiﬁcations for understanding human society and health (evolutionary medicine, for example) amongst other issues. In this context, it is exciting that the formation of the ﬁrst society of evolutionary biology in India, the Indian Society of Evolutionary Biologists (ISEB), (https://www.facebook.com/Indian-Society-of-Evolutionary-Bio logists-510429992749285/) has just been announced. The society has amongst its aims, promoting evolutionary biology in India through outreach in schools and colleges, which might be of interest to readers of Resonance. Of course, this is just a beginning and a lot more needs to be done to improve the state of organismal

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biology in the country. This issue also carries the review of a very interesting book, How to Tame a Fox (and Build a Dog). The book describes a long- term experiment, conceived of and initiated by the Russian geneticist, Dmitri Belyaev, in the early 1950s (and continuing to present times) to understand the evolution of animal domestication. Selecting and breeding the tamest silver foxes on fox farms in remote Siberia, Lyudmila Trut, one of the authors of the book, and Belyaev unravelled possible processes that might have enabled the transformation of wolves into domestic dogs. I hope the inviting review by Sujata Deshpande will encourage you to read the book. Apart from articles relating to ethology and evolution, we have in this issue, another General Article – The Easiest Proof of Fer- mat’s Principle by H Ray (Late) and S Roy, and a Classroom Article intriguingly titled Card Games and Chemistry by A G Samuelson. This issue also carries the second of a three-part lu- cid and informative series on Breakthroughs in Information and Communication Technologies by V Rajaraman and the last in a long Classroom Series of beautifully demonstrated Experiments in Fluid Dynamics by Chirag Kalelkar. I hope you enjoy the col- lection of articles.

832 RESONANCE | August 2018 Science Smiles Ayan Guha

Email for Correspondence: [email protected]

RESONANCE | August 2018 833 Resonance journal of science education

August 2018 Volume 23 Number 8

GENERAL ARTICLES 925

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

853 871 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

905

834 RESONANCE August 2018 Classroom DEPARTMENTSDEPARTMENTS

The Inveterate Tinkerer 905 Flow Visualisation Chirag Kalelkar Editorial 829 T N C Vidya Card Games and Chemistry 915 Teaching Organometallic Reactions Through Card Games A G Samuelson

Science Smiles 833 Information & Announcements Ayan Guha

India Flourishes at International 929 Article-in-a-Box Olympiads Study Nature, Not Science Academies’ Refresher Course 934 837 in Experimental Physics Just Books: Nikolaas Tinbergen Science Academies’ Refresher Course 935 and His Naturalistic Life in Statistical Physics Sindhu Radhakrishna

What Do 841 Ethologists

Front Cover Wish to Know? Beewolf (Philanthus triangulum) carrying a bee to its tunnel Raghavendra Gadagkar nest. Nikolaas Tinbergen studied how these wasps found Book Review the way back to their own unfinished nest (read How to Design Experiments in Animal Behaviour in this issue). Magic of 925 Photo from https://en.wikipedia.org/wiki/Beewolf#/media/ Transforming a Fox File:Bee_wolf.jpg licensed under the Creative Commons Attribution-ShareAlike 2.5 License. Into a Dog! Back Cover Sujata Deshpande

Inside Back Cover

Night Life

Nikolass Tinbergen (1907–1988) Malabar Gliding Frog Credit: Sindhu Radhakrishna Illustration: Subhankar Biswas

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ARTICLE-IN-A-BOX Study Nature, Not Just Books Nikolaas Tinbergen and His Naturalistic Life

Nikolaas Tinbergen, co-winner of the 1973 Nobel Prize in Medicine/Physiology and one of the founding fathers of ethology, is a poster child for the best that can happen when nature and nurture work in harmony. Many have argued that Tinbergen was always destined for greatness; after all, his family has produced not one, but two Nobel Laureates (himself and his elder brother Jan Tinbergen), a potentially distinguished scientist, and a Director of Energy in The Hague (South Holland). Tinbergen, however, always attributed his success to the support of his warm and loving family and the great interest in nature that was a significant part of social and cultural life in the Netherlands when he was growing up. At various stages in his life, Tinbergen received encouragement and support from his peers and teachers to pursue his scientific interests the way he wished to, and one wonders how his life may have unfolded had he 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 and he had four siblings – three brothers Jan, Dik and Luuk, and a sister Jacomiena. Tinbergen’s parents and his siblings were academically inclined and were formidable scholars in the arts and the sciences. Tinbergen once confessed that in his youth, he was considered “the dim one in the family”. Holland in the early twentieth century was deeply influenced by the writings of naturalists – E Heimans and J P Thijsse. This not only boosted an interest in nature among the general populace but also led to natural history lessons becoming an important part of school curriculums. Little surprise then that young Nikolaas was allowed by his family to do what he liked best, i.e., nature walks, camping out, observing and photographing animals and birds. Despite his interest in nature, Nikolaas was an indifferent student; traditional botany and zoology that emphasized taxonomy and anatomy bored him, and at the end of his school years in 1925, he did not consider biology as a career option. However, fate intervened in the form of Paul Ehrenfest – theoretical physicist and a family friend – who arranged for Nikolaas to spend a 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 the autumn 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 with finding ‘kindred souls’ stood him in good stead. The concept of studying animal behaviour in the 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

RESONANCE | August 2018 837 ARTICLE-IN-A-BOX extended his field studies on the ecology of the beewolf, Philanthus triangulum, to understand its homing abilities and how it oriented itself during the bee hunt. In 1931, Tinbergen accepted an 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 married Elizabeth Rutten, and the duo left on the expedition to Greenland. In Greenland, they lived with a group of Inuits and studied the snow bunting’s territorial behaviour. On his return to Holland in 1933, Tinbergen continued with his assistant position at the Zoological Laboratory in Leiden. Two years later, he was hired as lecturer in general zoology by the University, and he established a teaching program in animal behaviour that included practical sessions in the field and laboratory. In 1936, Tinbergen met Konrad Lorenz at a conference in Leiden. This marked the beginning of a deep friendship between the two men that had a lasting impact on Tinbergen’s life, both personally and professionally. Later that year, Tinbergen visited Lorenz at his home in Austria and stayed with him for over three months, discussing and conducting experiments to investigate mutually exciting aspects of animal behaviour patterns. This period of active collaboration led, among other ideas, to the now famous study of the egg-rolling behaviour of the graylag goose. However, the Second World War brought about a rupture in their association as they found themselves on the opposite sides of the global political divide. In 1942, Tinbergen was taken as a prisoner by the Nazi authorities after he protested the removal of Jewish professors from Leiden University. His experiences in the war camp left Tinbergen wary of Germany and Germans. Although he resumed his association with Lorenz after the war ended, they never regained the initial warmth of their relationship. After the war, Tinbergen returned to his position in Leiden University and was made Professor in 1947. In 1949, Tinbergen gave up his position in Leiden to move to a less prestigious position 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 British citizen in 1955. At the University, he built a strong program of ethology, both through his own research work as well as that of his students and collaborators. Towards the end of his research career, Tinbergen withdrew from animal field studies and developed an interest in understanding human problems. He promoted the application of ethological methodologies to studying human behaviour and collaborated with his wife Elizabeth to carry out his last research 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 Honour of the Sociedad Argentina Protectora de Animales, and of course, the Nobel Prize. Apart from

838 RESONANCE | August 2018 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 Hugh Falkus were awarded the Italia Prize and the Blue Ribbon of the New York Film Festival for their film, Signals for Survival. Tinbergen died in his home in Oxford in 1988, after suffering a stroke. Tinbergen, the scientist, is a remarkable figure who left behind an awe-inspiring scientific legacy. His work played a critical role in introducing a new approach to understanding animal behaviour and human evolution. His carefully thought-out field experiments (see articles by S Radhakrishna and R Gadagkar in this issue) ushered in a new era of research design for animal studies in the wild, his ideas inspired multiple generations of thinkers and scholars, and he mentored many students who went on to become highly influential animal and human behaviour scholars. But, it is Tinbergen the man, who should draw more attention from an aspiring ethologist. Tinbergen’s personal qualities and the way he conducted himself embodied the values of generosity, patience, courtesy and humility. Always ready to acknowledge the contributions of other scholars and collaborators, Tinbergen was unfailingly generous when he spoke or wrote about how his peers influenced his thoughts and ideas. His students remember the spirit of teamwork that existed in the group at Oxford, and how Tinbergen always offered them the gift 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 attempts at 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 adult life. Unfortunately, during his lifetime, physicians were unable to diagnose the cause behind his depressive bouts, though later accounts speculate that a fatty-acid deficiency and/or protein intolerance may possibly have been responsible for his condition. In view of his illness, his success as a scientist appears even more commendable. Tinbergen encouraged his students to go out into the natural world, to observe animal behaviour for themselves, and think about what the behaviour may mean. In Leiden and in Oxford, it was well-known that he far preferred the classroom of the wild to the study rooms within the universities. It is said that when Tinbergen first set up his animal behaviour teaching program in the University of Leiden, he wrote above the departmental library “Study Nature and Not Books”. Tinbergen lived by the advice he promoted all his life.

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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 Radhakrishna National Institute of Advanced Studies Indian Institute of Science Campus, Bengaluru Email: [email protected]

840 RESONANCE | August 2018 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 of one 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 wished to do the same and reprint what is perhaps Tinbergen’s most important paper and certainly his most enduring legacy. However, the publishers of the original paper decided to charge us an unreasonably high amount of money which this not-for-profit educational journal cannot afford. It is a tragedy of our times that intellectual material, even when very old, is hidden inside vaults of commercial publishers and unavailable to young students who were not born when they were first published. I will, therefore, whet your appetite by providing a glimpse into the main theme of the paper in question and give a reference so that some of you may be able 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 called this process ‘soul-searching’. Thus, Tinbergen searched his soul and asked what were the aims and methods of ethology. In doing so, Tinbergen created a map of the conceptual space of ethology and asked what ethologists really wish to know and how they go about it? Based on previous work and his own reflection, Tinbergen created an ethologist’s wish list in the form of four fundamental questions namely, 1) What makes a behaviour happen (causation), 2) what is the survival value of the behaviour (function), 3) how does a behaviour develop within the lifetime of an individual organism (ontogeny), and 4) how has the behaviour changed over evolutionary time, across species (evolution)? This framework has endured and has come to be known as ‘Tinbergen’s Four Questions’. I will illustrate Tinbergen’s four questions using the example of birdsong. Many species of birds, especially the males (also females in some species), produce remarkably melodious songs which are not only fascinating to biologists but have long captured the imagination of writers, poets and lovers. The song of our own koel (Eudynamys scolopaceus) is a familiar example [2]. (1) What Causes Birds to Sing? In answering this question, we study the anatomy of the sound producing organ of birds –

RESONANCE | August 2018 841 ARTICLE-IN-A-BOX the syrinx – analogous to our larynx. But the syrinx by itself cannot do much without the orchestration of several membranes and muscles that help channel air in unique ways. The membranes 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 hormonal stimuli 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 also sing, there is generally a duet between the male and the female. Understanding the survival value of behaviours has blossomed into a major sub-field of ethology namely, ‘behavioural ecology’. There is a vast literature on the behavioural ecology of birdsong and about how females may be choosing males that sing songs of their liking, a process which Darwin referred to 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 learn their species-specific song by a process of trial and error; they match their songs with the songs they have heard, usually their father’s, songs. The brain mechanisms that permit the bird to accomplish 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 and noting 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 because song 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 questions (causation and ontogeny) and ultimate questions (function and evolution) [7]. You can see how anything we want to understand about birdsong can be mapped onto one or the other of Tinbergen’s four questions. Such a taxonomy of questions allows us to clarify our thoughts and make 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 of ethology but in other areas of biology as well. As we do with famous people, we have also begun to celebrate the birthdays of this paper! On the 50th anniversary of the publication of Tinbergen’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

842 RESONANCE | August 2018 ARTICLE-IN-A-BOX modern developments in the study of ethology have made it necessary to treat Tinbergen’s four questions now in a much more nuanced manner [8]. Both Tinbergen’s original paper [1] and Bateson 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 Gadagkar Centre for Ecological Sciences and Centre for Contemporary Studies Indian Institute of Science Bangalore 560 012, India. Email: [email protected] http://ces.iisc.ac.in/hpg/ragh https://www.researchgate.net/profileRaghavendra Gadagkar

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GENERAL ARTICLE Nikolaas Tinbergen The Careful Scientist

Sindhu Radhakrishna

What is it about the work of some great scientists that sets them apart from the admirable work done by many good scientists? Is it because some, if not all, of their contributions stand the test of time? Or is it because their work paved the way for other great ideas to develop? Nikolaas Tinbergen’s life and work suggests that it is a combination of both these factors that characterise a truly great scientist. Nikolaas Tinbergen (1907–1988) was a Dutch scientist who studied animal behaviour. Tinbergen began his academic career at Sindhu Radhakrishna holds a master’s degree in psychology the University of Leiden in the Netherlands and later moved to and a doctorate in animal Oxford, where he set up a school for animal behaviour stud- behaviour. She is presently ies. Tinbergen pioneered and popularised the science of ethol- Professor and Dean at the ogy through his research and teaching. He lectured widely on Animal Behaviour and Cognition Programme, the subject and wrote extensively; some of his more well-known National Institute of books include The Study of Instinct (1951), The Herring Gull’s Advanced Studies, World (1953), Curious Naturalists (1958), and the Time-life vol- Bengaluru. Her research ume, Animal Behavior (1965). Tinbergen was an influential bi- interests are in the fields of primatology, behavioral ologist within his lifetime and received many honours for his ecology and conservation work, most notably, the Nobel Prize, the Swammerdam Medal, biology, and her work is the Distinguished Scientific Contribution Award from the Ameri- focused on gaining a better can Psychological Association and the Diploma of Honour of the understanding of social behaviour and Sociedad Argentina Protectora de Animales. Apart from being communication in nocturnal an excellent communicator who mentored a new generation of primates. renowned biologists, Tinbergen was also an exceptional photog- rapher and filmmaker who was celebrated for his films on animal behaviour.

Tinbergen is often described as one of the founding fathers of Keywords ethology, or animal behaviour. This simplistic description, how- Animal behaviour, ethology, stick- ever, does not provide a holistic understanding of the importance leback ﬁsh, gull, stimuli, experiment.

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Unlike early animal of Tinbergen’s achievements, and some historical context is nec- behavioural researchers essary to appreciate this. Animal behavioural science existed who relied on a long before Tinbergen began his work on animal behaviour; the comparative psychology ff approach and viewed crucial di erence being that the predominant approach then was behaviour as a learning one of comparative psychology, and psychologists largely viewed process, Tinbergen behaviour as a learning process. Tinbergen, on the other hand, believed that the answer was more interested in understanding why “animals behave as to animal behaviour was in the hereditary they do?” and believed that the answer lay in the “hereditary influences occurring influences occurring inside the animal”. In other words, Tinber- inside the animal. gen saw behaviour as an evolutionarily adaptive trait and empha- sised a more objective, biological approach to understanding behaviour. To understand why animals behave the way they do, Tinbergen observed animal behaviour in the natural environment of the species and conducted painstakingly designed, simple field experiments to test out his hypotheses about how animals reacted to external stimuli. He studied a variety of species ranging from wasps and stickleback fish to gulls, blackbirds and kittiwake and showed how natural observation techniques can be married successfully to experiments within laboratories. Tinbergen’s field experiments were elegantly designed simple setups that carefully teased apart functional explanations for particular behaviours exhibited by animals and the nature of external stimuli that may elicit certain behavioural responses from animals. The design of his earliest experiments on the orientation behaviour of the beewolf, Philanthus triangulum, highlighted what was to be the hallmark of his research – a careful, dogged approach that incrementally addressed the effect of one variable at a time, so that it was absolutely clear what kind of cues were being used by the beewolf females to orient themselves (for a better idea about the design of Tinbergen’s beewolf experiments, please see Prof. Gadagkar’s article on animal behaviour experiments in this issue). Tinbergen refined this research approach throughout his career. For example, when Tinbergen started studying the reproductive behaviour of the stickleback fish in the laboratory he set up at Leiden University, he was initially interested in observing the

846 RESONANCE | August 2018 GENERAL ARTICLE courtship behaviour of male sticklebacks and carefully docu- To prove that it was the mented the many steps in their complex mating ritual. He noticed colour red that acted as that courting males turned red on their underside and attacked the ‘sign stimulus’ or ‘releaser’, Tinbergen other coloured individuals that approached their territories. The designed a set of colour red appeared to be a stimulus that set off aggressive reac- experiments wherein he tions in the males, for male sticklebacks attacked the sides of the created some rough aquarium even when a red mail van passed beside the window of models of sticklebacks, painted them in various the aquarium. To prove that it was the colour red that acted as the colours, including red, ‘sign stimulus’ or ‘releaser’, Tinbergen designed a set of exper- and presented them to iments wherein he created some rough models of sticklebacks, the male sticklebacks in painted them in various colours, including red, and presented the tank. Red coloured models always elicited them to the male sticklebacks in the tank. Red coloured models more reaction from always elicited more reaction from courting males, demonstrat- courting males, ing that it was the colour red (rather than the shape/identity of demonstrating that it was the fish) that acted as the ‘releaser’ for a specific action from the the colour red (rather than the shape/identity of male. Tinbergen then continued with his experiments to show that the fish) that acted as the particular shape, size or type of body movement can elicit certain ‘releaser’ for a specific reactions from males and females in the breeding period. For in- action from the male. stance, females will follow a red dummy fish and even try to move into a nest in the sand (where none exists), when the dummy fish is 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 observed the removal of the red fish that led them into the nest. These findings led Tinbergen to conclude that sticklebacks (and many other species) respond “simply to ‘sign stimuli’, i.e., to a few characteristics of an object rather than to the object as a whole....it is the signal, not the object, that counts. It seems to be typical of innate behaviour, and many social relationships in animals apparently are based on a system of signs.” Tinbergen’s careful experimentation (in natural conditions and in the laboratory) shows that he was an exceptional scientist, but it was his constant ability to learn that marks him as a truly out- standing biologist. Tinbergen’s thinking about animal behaviour constantly evolved during the course of his research career and he built on the findings of his earlier studies to ask newer and more

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

In a very curious Black-headed gulls remove eggshells from the vicinity of their behaviour, black-headed nests almost immediately after hatching. Except for the top end, gulls remove eggshells shells do not markedly differ from eggs. Yet, eggs are never re- from the vicinity of their nests almost moved from the nest. Tinbergen asked the question: What is immediately after the function of the eggshell removal behaviour? He hypothesised hatching. Except for the that it was to increase the survival chances of the chicks and pro- top end, shells do not ceeded to conduct a series of experiments to test out this hypoth- markedly differ from eggs. Yet, eggs are never esis. Tinbergen observed that the insides of the eggshells were removed from the nest. white which could attract the attention of predators. To build evidence for this point, he and his collaborators first conducted a set of three experiments wherein they investigated if the natural colour of the black-headed gulls’ eggs acted as camouflage and thereby protected them from the attention of predators. To do this, they painted some gull eggs white and left them alongside some unpainted eggs in shallow depressions in the ground that were similar to black-headed gulls’ nests. Comparative rates of predation on the experimental eggs showed that the natural colour of the gulls’ eggs made them less vulnerable to predation than those painted white. Tinbergen then went on to test if the presence of the eggshells in the vicinity of nests increased chances of predation. He did this by comparing the rates of predation on gull eggs that were placed near eggshells and those that were not. He also conducted another experiment wherein eggshells were placed at increasing distances from eggs to investigate the effect of proximity of eggshells on egg/chick predation. The results of his experiments conclusively proved that the presence of eggshells near eggs/chicks made them more vulnerable to predation and that the chances of predation decreased with increasing distance between eggs and eggshells.

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The black-headed gull study demonstrates how Tinbergen could effectively deconstruct a simple animal behavior to show that every behavioral response has adaptive and evolutionary significance. In his discussion of this study, Tinbergen wrote: “Re- moval of an eggshell lasts a few seconds. It is normally done three times a year. Nothing would seem to be more trivial than this response, which at first glance might seem to be no more than fussy ‘tidying-up’ by a ‘house proud’ bird. Yet we have seen that it has considerable survival value and that the behavioural organisation is complicated and well adapted to the needs.”

Through his field experiments and emphasis on natural observa- Through his field tions, Tinbergen not only revealed several unexpected (and hith- experiments and erto unknown) aspects of animal behaviour, he also revolutionised emphasis on natural observations, Tinbergen the study of animal behaviour through this unusual approach. As not only revealed several Desmond Morris described it, biologists “wear a white coat or unexpected (and hitherto Wellington boots, one or the other.....Tinbergen does both. In my unknown) aspects of book, that makes him the most important person in his field this animal behaviour, he also revolutionised the century.” study of animal Tinbergen is best remembered for his formulation of the ‘Four behaviour through this unusual approach. Questions of Ethology’. In his most famous paper ‘On Aims and Methods of Ethology’, published in 1963, he systematically laid out what he saw as the defining characteristics of ethology. This paper encapsulates his thinking (and changes in his views) about ethology over 30 years of his ethological career. To understand behaviour, he wrote, one must ask four main questions, namely: “(1) What is its physiological causation? (2) What is its function or survival value? (3) How has it evolved over time?, and (4) How has it developed in the individual?” By “dividing behaviour studies into physiology, development, natural selection, and evolutionary history”, Tinbergen provided biologists with a clear and holistic framework for studying behaviour that would in later years be expanded to connect genes to behavioural phe- notypes. For this reason, Tinbergen’s four questions continue to remain as central to our understating of behaviour as they were when they were first published (see Prof. Gadagkar’s Article-in- a-Box on this classic paper in this issue). Although many early

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Tinbergen’s four theories of ethology such as Lorenz’s psycho-hydraulic model questions about and Tinbergen’s hierarchical model of instinctive action have come behavioural causation, to be critiqued over the years, Tinbergen’s four questions about development, function, and evolution still forms behavioural causation, development, function, and evolution still the cornerstone of forms the cornerstone of teachings in ethology. teachings in ethology. The hallmark of Tinbergen’s research contributions was his careful, patient observations and it was in this regard that he differed most significantly from his peer, collaborator and friend Konrad Lorenz, one of the other founding fathers of ethology. Lorenz was a flamboyant personality, whose pronouncements on imprinting and aggression took the biological world by storm, yet it is Tin- bergen’s methodology of careful experimentation and conceptual frameworks to study behaviour that has become the textbook material for all aspiring students of behaviour. Robert Hinde, in his biographical sketch of Tinbergen, relates an incident that encapsulates the differences in temperament and work between the two men. Post-World War II, Tinbergen and Lorenz met at a conference in Cambridge in 1949. During one of their discussions, they talked about “how often you had to see an animal do something before you could say that the species did it. Konrad said he had never made such a claim unless he had seen the behaviour at least five times. Niko laughed and clapped him on the back and said “Don’t be silly, Konrad, you know you have often said it when you 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 advocated the biological approach to understanding behaviour that is taken for granted today, highlighted the importance of detailed, naturalistic observations in understanding behaviour, showed the pos- sibilities of designing simple field experiments that can answer questions related to the function and cause of a behaviour, and consistently stressed the need for careful studies that would build up evidence through careful observations and experiments to justify any conclusions they made. Looking back, more than 50 years after the event, it is difficult to appreciate the difference that Tinbergen’s ideas have made to our understanding of animal

850 RESONANCE | August 2018 GENERAL ARTICLE and human behaviour. Today behavioural ecology and evolutionary developmental biology are integral subdisciplines of biology and it is hard to imagine that Tinbergen’s work helped stimu- late the development of these fields. Tinbergen’s (and his colleagues’) greatest accomplishment was that they made behaviour an integral part of biology, a ‘testable science’, and this particular achievement was due more to Tinbergen’s careful construction of how we can study behaviour than anything else. It is telling that in its history, the Nobel Prize has been given only once for animal behaviour. In his speech, granting the Prize to the trio of Karl von Frisch, Konrad Lorenz and Nikolaas Tinbergen, Borje¨ Cronholm talked about how the triumvirate had succeeded in transforming the study of behaviour to an analytical science, by treating behaviour as a biological trait within an evolutionary framework. While von Frisch was awarded the prize for his work on honeybee communication and Lorenz for discovering fixed action patterns and imprinting, Tinbergen was cited for his ‘experimentation and the discovery of extra-normal stimuli that released cascades of actions’. Tinbergen passed away in 1988 in his home in Oxford after a long and fulfilling career in research and academics. Yet, every time biology students are introduced to the four questions of ethology or are taught about designing behavioural experiments, Tinbergen is reborn. And this, more than anything else, is why Nikolaas Tinbergen was a great scientist.

Suggested Reading Address for Correspondence Sindhu Radhakrishna [1] Roberts (ed), Special Issue on Tinbergen, Human Ethology Bulletin, 28, No 4, School of Natural Sciences 2013. and Engineering [2] Joan E Strassmann, Tribute to Tinbergen: The Place of Animal Behav- Room No: S 23 ior in Biology, Biology Faculty Publications and Presentations, Paper 43, National Institute of Advanced http://openscholarship.wustl.edu/bio_facpubs/43, 2014. Studies [3] N Tinbergen, On Aims and Methods of Ethology, Animal Biology, 55.4, pp.297– IISc Campus 321, 2005. Originally published in 1963. Bengaluru 560 012 [4] N Tinbergen, The Curious Behavior of the Stickleback, ScientiﬁcAmerican, India 187(6), pp.22–27, 1952. Email: [5] N Tinbergen, G J Broekhuysen, F Feekes, J C W Houghton, H Kruuk and sindhu.radhakrishna@ E Szulc, Eggshell Removal by the Black-headed Gull, Larus ridibundus L.,A gmail.com Behaviour Component of Camouﬂage, Behaviour, 19(1), pp.74–116, 1962.

RESONANCE | August 2018 851

GENERAL ARTICLE Supernormal Stimuli and Responses

TNCVidya

In this article, I describe the curious phenomenon of exaggerated responses to supernormal stimuli in animals. These have been observed across various taxa and include preferences for larger egg size, darker or more contrasting colours or, in the case of humans, preferences for processed foods and television among others. I describe mechanisms that have been proposed to explain supernormal responses and possible con- sequences of such responses. T N C Vidya is interested in animal behaviour and Experiments with Oystercatchers and Other Birds phylogeography, and teaches these at JNCASR. Her The Eurasian oystercatcher (Haematopus ostralegus) is a wading primary research is on the bird that feeds on earthworms and mussels. During a study of social organization and behaviour of Asian elephants. this oystercatcher, ethologist Nikolaas Tinbergen (see articles by Sindhu Radhakrishna and Raghavendra Gadagkar in this issue) noticed that female oystercatchers laid a few eggs and then began to incubate the entire clutch. Tinbergen and his colleagues presented female oystercatchers with a clutch of five eggs rather than their normal three eggs and found that they preferred to incubate the larger clutch that was not their own! The scientists proceeded to offer the females a choice of eggs of varying sizes. In most cases, the females clambered on to the largest egg, which was many times the size of their normal egg, making it extremely difficult for them to even sit down upon [1] (see Figure 1)! Similar experiments were carried out in herring gulls and black-headed gulls by removing the gull’s eggs when the bird was away from the nest and placing two eggs at the rim of the nest. Gulls have a Keywords tendency to retrieve eggs that have rolled away accidentally and Supernormal stimuli, sign stimuli, would, therefore, choose one of them first to roll back to the nest, exaggerated response, Nikolaas Tinbergen, oystercatcher egg ff exhibiting their preference. Using di erent combinations of arti- size, food-begging in gulls, ficial eggs, Tinbergen and his colleagues showed that gulls also grayling butterflies, generalization preferred larger eggs to smaller ones. You can, perhaps, try this and peak shift, brood parasite.

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Figure 1. (a) Eurasian oystercatcher at the nest. (a) (b) Photo by John Haslam. Source: https://en.wikipedia.org/wiki/ Eurasian oystercatcher#/media /File:Haematopus ostralegus -Scotland -nesting-8.jpg experiment with pigeons, ducks or hens! Reactions to stimuli under Creative Commons from artificial eggs in the context of colour, not size, had first been license CC BY 2.0. (b) Oys- tercatcher preferring giant described by Koehler and Zagarus in an article (unfortunately, for egg to its own (smallest) us, in German) on the ringed plover in 1937. Koehler and Zagarus egg. Source: Artwork by T found that the plovers preferred eggs with clear white background N C Vidya based on Figure and black spots to their own light brown eggs with darker brown 43 from Tinbergen [1]. spots. Why did these birds prefer artificial eggs to their own eggs, especially when the artificial eggs were of a size that they could not have possibly laid themselves? The large egg size and marked colour contrast above are examples of what are referred to as As the term suggests, ‘supernormal stimuli’. As the term suggests, supernormal stim- supernormal stimuli are uli are exaggerated versions of stimuli to which animals respond exaggerated versions of more intensely than to normal stimuli. While the preference for a stimuli to which animals respond more intensely slightly exaggerated version of the stimulus may be adaptive – for than to normal stimuli. instance, preference for a larger egg over a smaller egg within a While the preference for normal range may be beneficial as larger eggs may be more viable a slightly exaggerated – the supernormal stimulus hijacks the normal, possibly adaptive, version of the stimulus may be adaptive – for response and leads to an exaggerated or supernormal response. instance, preference for a Apart from his work on the organisation of instinctive behaviour larger egg over a smaller egg within a normal or ‘fixed action patterns’ – behaviour that is largely influenced by range may be beneficial genetic rather than environmental components and is, therefore, as larger eggs may be shown by animals in response to a specific stimulus without any more viable – the prior experience – Tinbergen is famous for his work on supernor- supernormal stimulus hijacks the normal, mal stimuli. The stimuli that evoked instinctive behaviours were possibly adaptive, called ‘sign stimuli’ or ‘releasers’ (as behaviours were thought response. to be released by an ‘innate releasing mechanism’ by Konrad Lorenz, who first suggested this idea). Tinbergen observed var-

854 RESONANCE | August 2018 GENERAL ARTICLE ious animal behaviours to identify releasers of those behaviours (see Sindhu Radhakrishna’s article in this issue for a description of Tinbergen’s work on sticklebacks). One such behaviour was ‘food-begging’ by chicks of herring gulls. Using models of herring gull heads with various combinations of head, bill, and bill patch colour, head shape, bill length, and movement, Tinbergen and Perdeck [2] found that herring gull chicks pecked most at moving cardboard cutouts with long bills, whose bill patch colour contrasted with that of the bill. Herring gulls have a white head, yellow bill, and a red bill patch. Tinbergen and Perdeck then presented chicks with a choice of a thin, red rod with three white bands at one end, and a three-dimensional head, and found that the former seemed to be perceived as a ‘supernormal bill’ and was preferred to the latter.

Supernormal Stimuli in Other Taxa

Tinbergen showed that the grayling butterfly also reacts to supernormal stimuli, in the context of finding a mate [3]. Male grayling butterflies are seen resting camouflaged on the ground or tree barks and flying up towards passing females. Females respond by alighting upon the ground if they are ready to mate, or by flying away if they are not, upon which the male would abandon the chase and settle down to wait for another female. In- terestingly, males were sometimes seen flying up towards falling leaves, other butterflies and insects, birds, and even shadows! Us- ing paper dummies tied to a stick and various combinations of characteristics such as colour, size, and shape, Tinbergen and his colleagues carried out about 50,000 tests on male graylings in the wild and found that black dummies elicited a greater response from males although females were naturally brown. Larger dummies were also important, as was fluttering movement, although Tinbergen showed that the shape was not. Simple circles or rectangles could elicit the the grayling butterfly same response as a butterfly-shaped dummy! Thus, larger, darker, also reacts to supernormal stimuli, in flying dummies seemed to provide supernormal stimulation. Why the context of finding a would males waste their energy flying up towards objects that are mate. not conspecific females? If females were rare and/or competi-

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tion amongst males for access to females important, the cost of reacting to other objects (energetically and/or through possible exposure to predators) might be outweighed by the benefit of not missing flying females, and therefore, increasing the male’s reproductive success. Similarly, Australian jewel beetles have been found attempting to copulate with shiny, brown beer bottles that seem to be perceived as supernormal females [4], a finding that earned Gwynne and Rentz the Ig Nobel Prize in 2011!

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

Mechanisms for Supernormal Response Generation

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

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Figure 2. Gradient of generalization and peak-shift illustrated. S+ (red colour) and S- (orange colour) are two stimuli that an animal is trained to discriminate between by providing a reward when it chooses red and no

Response strength reward when it chooses orange. Each stimulus has S' S+ S- a gradient of generalization Stimulus around it, represented by the two curves. The excitatory generalization gradient + the responses around S being more frequent than that around S- (around S+)islargerthan because of reward-associated learning. Now, if a new stimulus the inhibitory generalization (S’) is presented to the animal in the form of dark red colour, the gradient (around S-) because animal prefers dark red (S’) instead of red (S+) that it had earlier of reward-associated learn- been rewarded for because the magnitude of difference between ing. S’ (dark red) is a the excitatory (S+) and inhibitory (S-) generalization gradients is new stimulus presented to greater at the dark red stimulus (S’) rather than at red (S+) it- the animal. The difference self (Figure 2, see [5]). This, then, could result in exaggerated between the two gradients, responses such as to supernormal stimuli. Peak shifts occur dur- shown as filled set brackets, ing discriminant learning and should not themselves be confused results in the tendency to ap- with supernormal responses, but it is possible that there is a sim- proach one stimulus versus another. The animal prefers ilar mechanism in the latter, with an underlying bias (such as a S’ instead of S+ that it had ‘bigger is better’ rule) having been shaped adaptively over evo- earlier been rewarded for be- lutionary time. This underlying bias is possibly shaped by asym- cause the magnitude of dif- ff metric selection pressure, corresponding to di erential reward in ference between the gradi- the learning paradigm above. It has been suggested that just as ents is greater at S’ than at there is a reward (‘selection’) for a specific preference but no pun- S+. Drawn after Pearce [5]. ishment for the other in the learning experiments, there might be selection for, say, large eggs as opposed to small eggs, but no selection against supersized eggs, leading to the underlying bias [6]. This is, obviously, not always the case, as there might be other costs such as predation. In 1993, Enquist and Arak used a simple neural network model to try to explain the evolution of exaggerated signals and suggested

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Supernormal stimuli in that the evolution of hidden biases was inevitable in recognition humans are thought to systems. This study was criticised as the simple neural network act as addiction-forming model used probably did not represent animal recognition sys- substances, making the individual seek out more tems, and a subsequent study to address a similar problem did not of the stimuli. This can ﬁnd evolved networks to be responsive to supernormal stimuli. eventually lead to In more recent times, while neural network models have become dopamine more complex, how well they can predict supernormal responses desensitization, with more and more stimuli remains to be seen. In terms of a mechanistic neurobiological required to elicit a understanding, studies in humans have suggested that dopamine response. plays an important role in learning and in reward pathways, thus motivating (adaptive) responses towards stimuli. Supernormal stimuli in humans are thought to act as addiction-forming substances, making the individual seek out more of the stimuli. This can eventually lead to dopamine desensitization, with more and more stimuli required to elicit a response.

Evolutionary Signiﬁcance

What are the evolutionary outcomes of exhibiting supernormal responses? As mentioned above, supernormal responses usually occur in cases when more intense responses towards slightly exaggerated stimuli are adaptive: preference for larger eggs, quicker response towards a potential mate, greater intake of calories. There- fore, the costs of overreacting to supernormal stimuli may be outweighed by the benefits, allowing for such responses to persist or even increase over evolutionary time. However, responses to such stimuli can also be exploited. For example, supernormal stimuli may enable brood parasites (species that use other species to raise their young ones) to take advantage of their hosts. If egg size or 1The interior of the mouth that gape1 size or colour are stimuli to which birds show parental re- is often brightly coloured in sponses (as described above), small host bird species might incu- young birds. bate eggs and rear chicks of brood parasites that are much larger than themselves (Figure 3). As Tinbergen wrote in 1965 [3], “....it is possible that many songbirds are not merely willing to feed a young cuckoo but simply love to feed it, just because the cuckoo offers such an enormous and inviting gape.” It must be said here that the study of brood parasitism is a vast field and there are sev-

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Figure 3. AEurasian 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 include the ‘maﬁa hypothesis’, according to which, hosts that reject the brood parasite’s eggs are punished by their nests being destroyed by the brood parasite [see 7], and the cost to the host of wrongly rejecting its own oﬀspring when brood parasite eggs and chicks closely mimic those of its own. In the case of humans, positive responses to calorie-rich food, crucial in pre-agricultural societies faced with unpredictable access to food, is currently manipulated by the food industry through the marketing of supernormal (or ‘hyperpalatable’) foods. A wide range of other products are also marketed by the advertising industry tapping into supernormal responses.

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While supernormal While supernormal stimuli may not be frequently present in an stimuli may not be animal’s environment ordinarily, a change in the environment may frequently present in an result in an ‘evolutionary mismatch’ [8] with responses that evolved animal’s environment ordinarily, a change in under previous circumstances being out of sync with and possibly the environment may being maladaptive under the changed environment. For example, result in an ‘evolutionary the evolutionary mismatch that humans face today, resulting in mismatch’ with various supernormal responses being shown, possibly arise from responses that evolved under previous the transition between the hunting-gathering lifestyle that we had circumstances being out for most of our lineage’s existence and the relatively recent advent of sync with and of agriculture. Responses do not have to be necessarily maladap- possibly being tive in a new environment. If there are costs (say, in the form of maladaptive under the changed environment. predation) to displaying an exaggerated response to a supernormal stimulus, and if the environment changes such that the cost is removed, there may be selection for the supernormal stimulus (in the form of, say, brighter eggs or speciﬁc mate characteristics), thus allowing for divergence between populations and/or evolution 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 argentatus Pont.), Behaviour, Vol.3, No.1, pp.1–39, 1950. [3] N Tinbergen, Editors of Life, Animal Behaviour, Time Incorporated, New York, USA, 1965. Address for Correspondence [4] D T Gwynne, D C F Rentz, Beetles on the Bottle: Male Buprestids Mistake T N C Vidya Stubbies for Females (Coleoptera), Journal of the Australian Entomological So- Jawaharlal Nehru Centre for ciety, Vol.22, pp.79–80, 1983. Advanced Scientific Research [5] J Pearce, Discrimination and Categorization, In N J Mackintosh (Ed.), Animal (JNCASR) Learning and Cognition, pp.109–134, Academic Press, New York, USA, 1994. Jakkur [6] J E R Staddon, A Note on the Evolutionary Significance of ‘Supernormal’ Bengaluru 560 064, India. Stimuli, The American Naturalist, Vol.109, No.969, pp.541–545, 1975. Email: [7] R Gadagkar, M Kolatkar, Evidence for Bird Mafia! Threat Pays, Resonance- [email protected] Journal of Science Education, Vol.1, No.5, pp.82–84, 1996. [email protected] [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.

860 RESONANCE | August 2018 GENERAL ARTICLE The Easiest Proof of Fermat’s Principle

Hasi Ray and Sudipto Roy

This article presents the easiest direct proof of Fermat’s principle with the help of differential calculus for all types of surfaces. This article is a contribution by Late Professor Hasi Ray, Study Center JnaganSiksha, 1. Introduction Kolkata and Sudipto Roy, David Hare School, Kolkata. Teaching and learning Fermat’s principle in optics often suffers from lack of satisfactory proof [1–5]. Students generally have the knowledge of the laws of reflection and refraction of light rays in geometrical optics, and they are also familiar with differential calculus at the undergraduate level when they learn Fermat’s principle. However, the difficulties in teaching and grasping the concept motivated us to find the present logical proofs of Fermat’s principle of stationary optical paths. Fermat’s principle states that when a light ray moves from one fixed point to another fixed point, through any number of reflections or refractions, the total optical path followed by the light ray should be stationary; it will either be minimum or maximum. For reflection and refraction at plane surfaces, the total optical path followed by the light ray should be a minimum, while for reflection and refraction at curved surfaces, the total optical path followed by the light ray should be a maximum. It is also described as the ‘principle of least time’ in many books. The optical path is defined as the actual path followed by the light ray in vacuum or in air medium; so it is the product of the path length in the medium with the refractive index of the medium. The methodology we discuss in this article in the context of the most logical proof of Fermat’s principle, might be a convincing Keywords teaching and learning method. It might help in proper under- Optical path, stationary, reflection, standing of the concept and instill confidence in students to learn refraction, curved surface. physics. It will also enhance their inventing power by following

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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 was applied by one of the authors (HR) in a BSc ﬁrst year class, and received encouraging results.

2. Methodology

I. Reflection and Refraction at Plane Surfaces Figures 1 and 2 are pictorially presents the concepts of reflection and refraction at plane surfaces respectively. In Figure 1, the lines AN and NB with arrow signs indicate the incident and the reflected rays and OO‘ is the plane of reflection with 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 the medium. The optical path followed by light ray to reach from the fixed point A to the fixed point B through the point of incidence Nisy = μ1.AN + μ1.NB. Perpendiculars are drawn on the line OO‘ from the fixed points A and B as lines AE and BF. Then we 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)are constants since the points A and B are fixed. Again the distance between the feet of the perpendiculars EF = d is a constant.

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Figure 2. Refraction at a plane surface.

Similarly, in Figure 2, the lines AN and NB with arrow signs indicate the incident and the refracted rays and OO‘ is the plane of refraction with normal CNM at the point of incidence N. The angle ∠ ANC= ∠i (say) is the angle of incidence and the angle ∠ BNM = ∠r (say) is the angle of refraction. Say μ1 and μ2 are the refractive indices of the first and the second media respectively – these are constant quantities. The optical path followed by light ray to reach from the fixed point A to the fixed point B through the point of incidence N is y = μ1. Perpendiculars are drawn on OO‘ from the fixed points A and B as lines AE and BF. Then we 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)are constants since the points A and B are fixed. Again, the distance between the feet of the perpendiculars EF = d is a constant. In both the cases and in both the figures, the total optical path length will vary if the point of incidence N changes. Let us say the distance EN = x, so that FN = d − x. Accordingly, following the Pythagorean theorem for right triangles, the total optical path in case of reflection can be written as:

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= μ . +μ . = μ 2 + 2 +μ { 2 + − 2} = y 1 AN 1 NB 1 (h1 x ) 1 h2 (d x) f1(x) (1) Similarly, in case of refraction the total optical path can be ex- pressed as:

= μ . +μ . = μ 2 + 2 +μ { 2 + − 2} = y 1 AN 2 NB 1 (h1 x ) 2 h2 (d x) f2(x) (2) So in both the cases, we are able to write the total optical path y as a function of a variable x and it is differentiable with respect to the variable x. In case of reflection, after differentiation, (1) becomes:

dy x (d − x) = μ1 − μ1 dx 2 + 2 { 2 + − 2} (h1 x ) h2 (d x) EN FN = μ − μ = μ cos ∠ANE − μ cos ∠BNF) 1 AN 1 BN 1 1 π π = μ cos − ∠i − μ cos − ∠r 1 2 1 2 = μ1 sin ∠i − μ1 sin ∠r (3)

We know from the law of reflection that the angles ∠i = ∠r.Ap- dy = ⇒ = = plying it in (3) gives dx 0 y f1(x) stationary. Hence, Fermat’s principle is proved for reflection on a plane surface. In a reverse manner, if we consider that the Fermat’s principle is true, then we can derive the laws of reflection from (3) applying the derivative equal to zero. In case of refraction, after differentiation (2) becomes :

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d x (d − x) dx = μ1 − μ2 y 2 = 2 { 2 + − 2} (h1 x ) h2 (d x) EN FN = μ1 − μ2 = μ1 cos ∠ANE − μ2 cos ∠BNF) AN BN π π = μ cos − ∠i − μ cos − ∠r 1 2 2 2 = sin ∠i − μ2 sin ∠r (4)

According to the law of refraction we know that μ1 sin ∠i = μ2 sin ∠r . dy = ⇒ = = Applying it in (4) gives dx 0 y f2(x) stationary. Hence, Fermat’s principle is proved for refraction on a plane surface. In reverse manner, if we consider that the Fermat’s principle is true, then we can derive the laws of refraction from (4) applying the derivative equal to zero. II. Reflection at Curved Surfaces – Convex and Concave Sur- faces. The reflections at the curved surfaces are pictorially presented in Figure 3a and in Figure 3b for convex and concave surfaces respectively. Let OO is the curved surface, and C is the center of curvature with R as the radius of curvature in both the figures. Let A and B be two fixed points situated in a medium of refractive index μ1 and B in a medium of refractive index μ2. The lines AN and NB with arrow signs indicate the incident and the reflected rays with N as the point of incidence or the point of reflection. Draw the normal CN at the point of incidence N on the curved surface by joining C with N so that CN = R. The total optical path followed by the light ray to reach from the fixed point A to 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 N changes. Perpendiculars are drawn on CN from the fixed points A and B as lines AE and BF; then we get two right triangles ΔANE and ΔBNF where ∠AEN and ∠BFN are the right angles in first and second triangles respectively in both the figures. The angle

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Figure 3. (a) Reﬂection at a convex surface. (b) Reﬂec- (a) (b) tion at a concave surface.

∠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 we get 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 point of incidence N changes. Applying the laws of triangles in ΔANC and ΔBNC, we can write:

= μ . + μ . y 1 AN 1 NB = μ 2 + 2 − θ + μ { 2 + 2 − Θ − θ} 1 (h1 R 2h1R cos ) 1 h2 R 2h2R cos ( + f1(θ)(5)

Diﬀerentiating with respect to θ, one can express the above expression as:

dy h R sin θ h R sin (Θ − θ) = μ 1 − μ 2 θ 1 1 d 2 + 2 − θ { 2 + 2 − Θ − θ } (h1 R 2h1R cos h2 R 2h2R cos( ) AE BF = μ R − μ R = μ R sin ∠ANE − μ R sin ∠BNF 1 AN 1 BN 1 1 = μ1R sin ∠i − μ1R sin ∠r

= μ1R(sin ∠i − sin ∠r)(6)

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Figure 4. (a) Refraction at a convex surface. (b) Re- (a) (b) fraction at a concave surface.

We know from the law of reflection that the angles ∠i = ∠r.Ap- dy = ⇒ = θ = plying it in (6) gives dθ 0 y f1( ) stationary. Hence, Fermat’s principle is proved for reflection on a curved surface. In a reverse manner, if we consider that the Fermat’s principle is true, then we can derive the laws of reflection from (6) inserting the derivative equal to zero. III. Refraction at Curved Surfaces – Convex and Concave Surfaces The refractions at the curved surfaces are pictorially presented in Figure 4a and in Figure 4b for convex and concave surfaces respectively. Let OO is the curved surface separating two media, and C is the center of curvature with R as the radius of curvature in both the figures. Let A and B be two fixed points with A situated in a medium of refractive index μ1 and B in a medium of refractive index μ2. The lines AN and NB with arrow signs indicate the incident and the refracted rays with N as the point of incidence or refraction. Draw the normal CN at the point of incidence N on the curved surface by joining C with N so that CN = R. The total optical path followed by light ray to reach from the fixed point A to the fixed point 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-

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ulars are drawn on CN from the fixed points A and B as lines AE and BF; then we get two right triangles ΔANE and ΔBNF where ∠ AEN and ∠ BFN are the right angles in first and second triangles respectively in both the figures. The angle ∠ ANE= ∠i (say) is the angle of incidence and the angle ∠ BNF = ∠r (say) is the angle of refraction. Join A and B with C, then we get another two right triangles ΔAEC and ΔBFC when AC=h1 and BC=h2 are fixed distances i.e. contants. The angle ACB =Θis a constant angle. But the angle ∠ ACN= θ varies if the point of incidence N changes. Applying the laws of triangles in ΔANC and ΔBNC, we can write:

= μ . + μ . y 1 AN 2 NB 2 2 = m1 (h + R − 2h1R cos θ) 1 + μ { 2 + 2 − Θ − θ } 2 h2 R 2h2R cos ( ) = f2 (θ)(7)

Diﬀerentiating with respect to θ, one can express the above expression as:

dy h R sin θ h R sin (Θ − θ) = μ 1 − μ 2 θ 1 2 d 2 + 2 − θ { 2 + 2 − Θ − θ } (h1 R 2h1R cos h2 R 2h2R cos ( ) AE BF = μ R − μ R = μ R sin ∠ANE − μ R sin ∠BNF 1 AN 2 BN 1 2 = 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 ; dy = ⇒ = θ = applying it in (8) gives dθ 0 y f2( ) stationary.Sothe Fermat’s principle is proved for refraction on a curved surface. In a reverse manner, if we consider that the Fermat’s principle is true, then we can derive the laws of refraction from (8) inserting the derivative equal to zero.

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3. Conclusion

In conclusion, we have successfully developed some efficient scientific ways to prove Fermat’s principle e.g., the principle of stationary optical path, using a completely new method. It would be much easier and convincing to the students and comfortable for teachers to teach in classrooms. It would also boost the interest and confidence of students in learning and their reasoning ability.

4. Acknowledgements

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

Suggested Reading

[1] B Ghosh and K G Mazumdar, A Text Book on Light, New Joykali Press, 5th Edition, 2003. [2] B K Mathur and T P Pandya, Principles of Optics, New Gopal Printing Press, Address for Correspondence 3rd Edition, 1972. Sudipto Roy [3] A K Ghatak, Optics, Tata McGraw Hill, 2015. Science Division [4] F A Jenkins and H E White, Fundamentals of Optics, McGraw Hill Kogakusla, David Hare School 1957. College Street Kolkata 700 073, India.

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SERIES ARTICLE How to Design Experiments in Animal Behaviour 1. How Wasps Find Their Nests

Raghavendra Gadagkar

In this series of articles, I will introduce the reader to the science of ethology, somewhat indirectly by describing simple experiments, both old and new, designed to understand how and why animals behave the way they do. My emphasis will be on the design of the experiments and my goal will be to motivate readers not only to think about the design but also to come up with alternatives and improvements. Motivated readers can indeed replicate some of these experiments even Raghavendra Gadagkar is if they end up replacing the study animal or the behaviours of Year of Science Chair Professor at the Centre for interest with their own favourite choices. In the firstpartof Ecological Sciences and the series, I describe how Niko Tinbergen – Nobel Laureate Chairman, Centre for and one of the founding fathers of ethology (the science of an- Contemporary Studies, IISc, imal behaviour) – designed remarkably simple experiments Honorary Professor at JNCASR and Non-Resident to successfully understand how digger wasps find their own Permanent Fellow of the nests in a complex habitat also consisting nests built by other Wissenschaftskolleg (Institute wasps. for Advanced Study), Berlin. During the past 35 years he has established an active 1. Ethology school of research in the area of animal behaviour, ecology I study animal behaviour and I am technically called an ‘etholo- and evolution. The origin and gist’. Ethology, literally the study of ‘ethos’ or character, is not evolution of cooperation in animals, especially in social a very old discipline. Charles Darwin’s The Expression of Emo- insects, such as ants, bees and tions in Man and Animals (1872) [1] may be considered as the wasps, is a major goal of his first modern treatment of the subject. Notwithstanding the award research. of the Nobel Prize to three of the founders of modern ethology, Niko Tinbergen, Konrad Lorenz and Karl von Frisch in 1973, and the popular appeal of its subject matter, ethology does not always Keywords enjoy the prestige it deserves in the academia. For an aspiring Ethology, beewolf, digger wasps, ethologist, and one desirous of elevating its prestige, it is inspiring visual cues, olfactory cues, nesting, orientation, experiment de- to read Peter and Jeanne Medawar, in a remarkable book entitled sign.

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“The word ‘ethology’ is A Philosophical Dictionary of Biology [2], describes ethology in not merely an alternate the following words: designation for the science of behaviour: it “The word ‘ethology’ is not merely an alternate designation for is a term that stands for a the science of behaviour: it is a term that stands for a genuine rev- genuine revolution in olution in biological thought. Ethology is rooted in observation biological thought. Ethology is rooted in of animal behaviour, an activity that only simpletons think sim- observation of animal ple....observation is a diﬃcult and sophisticated process calling behaviour, an activity upon all the intellectual virtues: attention, patience, heightened that only simpletons awareness, caution in coming to conclusions, courage in framing think simple.” expectations.” – Peter and Jeanne Medawar 2. Experiments

These words can, of course, be taken as praise, but budding ethologists would be better advised to rather take them as a challenge – to measure up to Medawars’ expectations. Let us focus on the process of observation, so elegantly described by them. I believe that we often need to perform ‘experiments’ prior to observation, to match the rigour that is being demanded. In this series, I will describe several experiments in ethology, both new and old. My focus will be on the ‘design’ of the experiments while the ethology learned in the process will be a collateral beneﬁt. I will delib- erately pick simple experiments that almost anyone can perform without requiring much instrumentation or other research infrastructure. The goal will be to use reasoning and logic rather than technology and automation and will require a passion for animals rather than for machines. I encourage readers to attempt to repeat these experiments, modifying them in any way you wish, guided by necessity and creativity, swapping the animals used and even the questions asked, with your own personal favourites [3]. As a general introduction to performing simple and elegant experiments, I encourage readers to study Darwin’s Backyard: How Small Experiments Led to a Big Theory by James Costa [4].

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3. Wasps and Their Nests

Wasps are a diverse group belonging to the insect order Hymenoptera, along with ants and bees. Most wasps are solitary while a small number of them are social. All social wasps build nests to lay eggs and raise their offspring and are carnivo- rous, preying on other insects or spiders (or any other meat if they can get hold of – they are known to steal meat from butchers’ shops), to feed their growing larvae. They themselves persist on the nectar and juices imbibed while masticating their prey, as they cannot ingest solid food on account of their characteristically nar- row waists. Among the solitary wasps, many are egg parasitoids laying their own eggs in or on the eggs of other insects. Others lay their eggs on the larvae or adults of other insects (or spiders). Let us consider the life cycle of one such solitary wasp using the example of Philanthus triangulum, that was used in the experiments I will discuss in this article. The genus Philanthus consists of about 135 species that are often called the ‘beewolf’ because they usually hunt adult honeybees. Along with other wasps with similar 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 die while the females have to do more to pass on their genes to future generations. When it is warm enough, the female wasps Spending what might painstakingly and with much trial and error, locate suitably soft seem like idle time patches of ground and dig tunnels at angles of about 30o followed outdoors, being a keen observer curious about by several lateral branches that serve as brood chambers. Then how and why the natural they fly out to hunt adult honeybees and sting them, carefully ma- world is what it is, is the neuvering their posture so as not to be stung by the bees instead. first part of being an They paralyze the bees with a neurotoxic venom and fill up the ethologist. The second part requires the ability brood chambers with up to six honeybees per chamber, as food for to ask questions, frame their as yet unborn larvae, laying one egg per brood chamber. The hypothetical answers, brood chambers are built, stocked with prey, and supplied with an make predictions arising egg, sequentially so that a mother may be at work on a nest for out of those answers and design simple several days. At the same time, other female Philanthus triangu- experiments to test the lum wasps are doing the same nearby and herein lies a problem. predictions. How does a wasp find her own unfinished nest among the many

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

4. Niko Tinbergen

Niko Tinbergen, one of the founders of modern ethology and one of the recipients of the Nobel Prize in 1973 (as mentioned above), possessed all these traits. But how did he come to possess them and how did he come to put them to good use? You can read about Tinbergen’s life and work in the accompanying article by Sindhu Radhakrishna. Here, I will quote a few passages from an essay by Tinbergen’s first PhD student Gerard Baerends [5], indicating the environment that Tinbergen was born in: “In the Netherlands, between 1930 and 1940, ethology grew from what was originally seen as a pleasant and harmless hobby, to a new biological discipline, recognized by the academic world....In the 1880s, coinciding with a growing awareness of the need for a more socially just society, cultural attitudes towards nature changed. Literature and the fine arts became increasingly interested in a realistic representation of nature. Writers and poets....and sculp- tors....began to deal with landscapes, plants and animals in a style that took as much care with the correctness of naturalistic details as with the emotional impressions felt by the observer. Entirely new methods were developed for the teaching of children in primary schools, aimed at making them aware of the life and work of people in different communities and professions, and with particular emphasis on informing urban children about rural life. In- spired by this atmosphere two schoolmasters....began writing a series of six popular books, each dealing with the life of plants and animals in a characteristic Dutch habitat and a field guide

874 RESONANCE | August 2018 SERIES ARTICLE for identifying the more common animals and plants....As a con- sequence of the increasing interest in natural history, naturalist Tinbergen devised six societies were formed all over the country....A unique feature of simple outdoor the Netherlands – and one that in my opinion was very important experiments to understand how the for the development of ethology in our own country – was that wasps located their nests. young naturalists, from 11 to 23 years old, formed societies of their own, quite separate from those of adults.”

5. Tinbergen’s Experiments

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

Experiment 1

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

The idea was to see whether the returning wasp would go to the If visual cues of the real nest, now without the pine cones, or to the displaced circle landmarks around the of pine cones around the sham nest. If visual cues of the land- nest were guiding the homing behavior of the marks around the nest were guiding the homing behavior of the wasp, then she should wasp, then she should return to the sham nest with the pine cones. return to the sham nest But if some other cues were being used, then she should return to with the pine cones but if her own nest in spite of the missing pine cones. Since the return- some other cues were being used, then she ing wasps would make her choice only once and Tinbergen did should return to her own not want to test any wasp more than once, he used a clever trick nest in spite of the to increase his sample size. After the wasp had unambiguously missing pine cones.

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Figure 1. Cartoon depict- ing the arrangements in Tin- bergen’s first experiment. (a) Depicts the training situation during which Tinber- gen had placed a circle of about 20 pine cones around the original nest in the morning. This allowed the wasp to learn these new landmarks for a few hours, during the course of its natural flights in and out of the nest. (b) Shows the test demonstrated her preference for the real or the sham nest but be- situation during which Tin- fore she actually landed and dropped the bee she was carrying, bergen had moved the circle of pine cones from the he shooed her away gently, making her fly away some distance original nest to a sham nest and try again. In this manner, he made the wasp demonstrate her he had made about 30 cm preference at least five times. After shooing her away once more, away, leaving the original he quickly relocated the circle of pine cones around the original nest intact but without pine nest and retested her preference, again several times. If visual cones. Redrawn from Tin- cues were indeed involved, she should now switch her preference bergen (1932) (see [6]). and go to her original nest, now with the pine cones returned. Tinbergen repeated the experiment with 17 different wasps, testing them five to twelve times each with pine cones around the sham nest (he called this the ‘experiment’), and five to six times with 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 when it had pine cones around it (experiment), and 86 out of 86 times, they chose the original nest when the pine cones were returned to it (control). This experiment showed clearly that the pine cones overwhelmingly decided the choice of the wasps. Tinbergen was well aware that this did not necessarily prove that the wasps had used visual cues, but only that they had used the pine cones.

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Table 1. The results of Tin- Results of Results of bergen’s study showing the Tinbergen’s Tinbergen’s importance of pine cones in Control Experiment the choice of the wasps. The Training situation Training situation original data was published with the pine cones with the pine cones by Tinbergen in his 1932 arranged around arranged around publication [6]. the original nest. the sham nest. See Figure 1(a) See Figure 1(b) Wasp No. of No. of No. of No. of Number times times times times the wasp the wasp the wasp the wasp returned returned returned returned to the to the to the to the original sham original sham nest 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

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Figure 2. Cartoon de- picting the arrangements in Tinbergen’s second experiment. (a) Shows the training 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 olfactory), for a few hours, during the course of its natural flights in and out of the nest. Experiment 2 (b) Shows the test situa- To rule out the possibility that the wasps had relied on the smell tion during which Tinbergen rather than the sight of the pine cones, Tinbergen did a second ex- had moved the circle of pine periment. Now, during the training period, he placed along with cones (visual landmarks) but the pine cones, two cardboard plates scented with pine-needle oil not the scented plates (ol- (Oleum pini sylvestris) that gives off smell characteristic of pine factory landmarks), from the original nest to a sham cones. The wasps could thus get accustomed to the sight of pine nest. To make the vi- cones or the smell of pine cones around their nests, or both. Dur- sual landmarks around the ing the test phase, he retained the scented plates around the orig- sham nest similar to those inal nest and moved only the pine cones to the sham nest. To around the original nest dur- mimic the visual cues of the scented cardboard plates he placed ing the training situation, he two identical cardboard plates but without scenting them, around placed an identical pair of the sham nest. Thus, the sham nest had all the visual cues and unscented plates around the the original nest had the olfactory cues present during the train- sham nest. Redrawn from ing phase. After recording the choices of the returning wasps as Tinbergen (1932) (see [6]). in experiment 1, he created a control situation by interchanging the cues, i.e., he moved the pine cones and the unscented plates to the original nest and the scented plates to the sham nest and tested the wasps again (Figure 2). This time he used five different wasps and found that in 29 out of 29 trials, the wasps chose the sham nest when it had pine cones and unscented plates around it (experiment) and chose the original nest when it had the pine cones and unscented plates moved back to it (control) (Table 2).

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

Experiment 3

Tinbergen soaked the cones overnight in alcohol and dried them in the sun. Now he repeated experiment 1 taking care to train the wasps with fresh cones and test them with dried, presumably odourless 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 means he needed an even better experiment.

Experiment 4

With ﬁne scissors and forceps, Tinbergen amputated both antennae of four wasps but of course only after the training period. To his delight, these antenna-less wasps ﬂew about and performed their usual homing behaviour. In 20 experimental trials and 20 control trials, not one mistake! Wasps that had learned the presence of the cones when they possessed their antennae chose the cones even after they had lost their antennae. It was clear that visual stimuli were enabling correct orientation of the wasps. Never throwing caution and modesty to the winds even as a PhD student, Tinbergen imposed on himself two caveats. First, these experiments may have shown that visual stimuli were adequate and even dominant, but they did not prove that the wasps were entirely incapable of using olfactory stimuli. Second, visual cues may have worked in his experiments, but he had only studied the

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Table 2. The results of Tin- bergen’s study after train- Results of Results of ing and testing the wasps Tinbergen’s Tinbergen’s with pine cones and scented Control Experiment plates. The original data was Training situation Test situation published by Tinbergen in his 1932 publication [6]. with pine cones and with pine cones and scented plates around unscented plates around the original nest and the sham nest unscented plates around scented plates around and the sham nest. the original nest. See Figure 2(a) See Figure 2(b) Wasp No. of No. of No. of No. of Numer times times times times the wasp the wasp the wasp the wasp returned returned returned returned to the to the to the to the original sham nest original sham nest nest instead of nest instead of original original nest 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 the wasps 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 their nest by odor alone, he ﬁrst conﬁrmed that the wasps could indeed smell the oil he was using. He did this by putting some oil near the nest entrance. He observed that the wasps reacted

880 RESONANCE | August 2018 SERIES ARTICLE quite strikingly to the presence of oil, twitching their body and ﬂying away for some time. Then he repeated his experiment 2 only with the scented and unscented plates and without the pine cones. During the training, he placed two scented odor plates at the original nest, and this time he trained the wasps for 2 to 3 days instead of 2 hours as before. During the experimental phase of the test he placed the scented plates around the sham nest and the unscented plates around the original nest. For the control phase, he interchanged the scented and unscented plates between the sham and original nests. He found that the wasps which appeared quite conﬁdent while landing on their nest of choice with the pine cones – be it sham or original – in all the previous experiments, now seemed a bit confused. In this experiment, the wasps, in spite of being trained with the scented plates, chose the original nest with the unscented plates and ignored the sham nest with scented plates 21 out of 24 times. In the control, they once again chose the original nest with the scented plates 19 out of 20 times. In other words, they chose their original nests, with or without the scented plates and were not distracted by the presence of the scented plates around the sham nest. Thus, it appeared that the wasps could not be trained to use odor for nest recognition.

Experiment 6

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

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Tinbergen concluded tried 30 cm with success). The idea was that if the circle of pine that proximate cones was too big for proximate orientation then the wasp will orientation operated up not be able to find the sham nest (let us say, will not be distracted to about 100 to 200 cm only, cautioning of by it) and should search harder for their real nests. Although he course that this value was able to test fewer and fewer wasps at longer distances (due will vary depending on to bad weather), he found that the wasps always chose the sham the physical features of nest with pine cones when the diameter was 50, 70 or 100 cm. the environment. But a single wasp that he was able to test at a diameter of 200 cm could not find the sham nest and went to the original nest after a long search. Tinbergen concluded that proximate orientation operated up to about 100 to 200 cm only, cautioning of course that this value will vary depending on the physical features of the environment. Here, I will not describe the 4 other (rather inconclusive) experiments Tinbergen performed to test if the wasps used colour vision to find their nests. In summary, Tinbergen concluded that “females of Philanthus triangulum are able to orient by means of visual landmarks once, through a yet unknown method of ‘distant orientation’, they have found the ‘nest surroundings’. These occupy a roughly circular area of 1–2 m diameter, within which they can be misled by dis- placement of the landmarks in the immediate vicinity of the nest entrance.”

6. Reﬂections

Let us now reflect on the set of six experiments as a whole. The first thing that comes to my mind is that Tinbergen vindicated Medawars’ of any charge of exaggeration when they claimed that “observation is a difficult and sophisticated process calling upon all the intellectual virtues: attention, patience, heightened awareness, caution in coming to conclusions, courage in framing expectations.” There are several useful lessons to be learned from these set of experiments. Where we can emulate Tinbergen, we must do so, and where we cannot, we must at least reflect on why we cannot. Scientists, especially during the early stages of their

882 RESONANCE | August 2018 SERIES ARTICLE careers, are unsure about how to choose a problem to work on. Today, science has become such an ‘industrial’ and expensive activity that PhD students are not encouraged to and cannot aﬀord to decide by themselves; their research problem is nearly always assigned by their thesis supervisors and research is almost always a collaboration between the student and the supervisor. But this was not how it always was and need not always be.

Tinbergen strolled around the woods and his curiosity about how Tinbergen strolled the wasps managed to find their nest hole among so many others, around the woods and was aroused. He framed hypotheses and proceeded to test them, his curiosity about how the wasps managed to designing the simplest possible experiments using what was read- find their nest hole ilyavailable–amethodthatissometimesaffectionately called among so many others, ‘quick and dirty’. Tinbergen did not take detailed photographs was aroused. He framed of the nest surroundings and he tried to reproduce the exact fea- hypotheses and proceeded to test them, tures of the nests around the sham nests. He did not apply for designing the simplest a big research grant nor did he try to make his research appear possible experiments sophisticated. His experiments were not more sophisticated than using what was readily absolutely necessary. They were literally playful. And yet, his available – a method that is sometimes experiments were designed very thoughtfully, with precision and affectionately called imagination, yielding clear-cut results. ‘quick and dirty’. 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 with antenna-less wasps. Even when he was successful with the circle of pine cones, he kept on increasing the diameter of the cone circles until he failed to train the wasps. Unfortunately, today it has become fashionable to discard negative results. Tinbergen’s modesty and caution come through clearly and are in stark contrast to the prevailing standards today. In his paper, he constantly refers to previous researchers, not just by way of introducing the subject but with a clear intention of giving credit where it is due. In his concluding remarks, he says less about what he has discovered and more about what he has not – “a yet unknown method of distant orientation”, “did not succeed in demonstrating 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”, “attempt to train the wasps to use olfactory stimuli was not successful” (rather than that the wasps cannot learn olfactory stimuli), “these results may not apply to other digging wasps”, “my observations cannot decide whether Philanthus is able to register and remember the number of turns made on the way out”.

I would like to I would like to recommend that readers reflect on the design of recommend that readers Tinbergen’s six experiments, attempt to find flaws, come up with reflect on the design of alternative designs which are just as good or perhaps better. In Tinbergen’s six experiments, attempt to addition to reflection, I encourage my young readers to try their find flaws, come up with hands at designing and carrying out simple experiments of their alternative designs own, using animals and questions, driven by their own imagina- which are just as good or tion and curiosity. In this article, wasps were the protagonists and perhaps better. they hunted and paralysed honeybees. In the next article in this series, I will restore the glory of the honeybees by making them the 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. Address for Correspondence [4] J T Costa, Darwin’s Backyard - How Small Experiments Led to a Big Theory,W Raghavendra Gadagkar W Norton & Company, Inc., New York, London, 2017. Centre for Ecological Sciences [5] G P Baerends, Early Ethology: Growing From Dutch Roots. In: The Tinbergen and Centre for Contemporary Legacy, Eds, M S Dawkins, T R Halliday and R Dawkins, Chapman and Hall, Studies London, pp.1–17, 1991. Indian Institute of Science [6] N Tinbergen, On the Orientation of the Digger Wasp Philanthus triangulum, Bangalore 560 012, India. Fabr. Zs. Uber die vergl. Physiol., 16, pp.305–334, 1932. [Translated from the Email: [email protected] 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].

884 RESONANCE | August 2018 SERIES ARTICLE Breakthroughs in Information and Communication Technologies Part II

V Rajaraman

In Part 1 of this series of articles, I defined what is meant by a breakthrough in ICT, listed fourteen breakthroughs in chronological order, and described five breakthroughs. In this second part of the three-part series of articles on Break- throughs in Information and Communication Technologies, I describe four more breakthroughs: Computer Graphics, In- ternet, Global Positioning Systems, and the World Wide Web. V Rajaraman is at the Indian As in the last part, I will justify why I consider them as break- Institute of Science, throughs and briefly describe each of them. Bengaluru. Several generations of scientists and engineers in India have learnt 6. Computer Graphics computer science using his lucidly written textbooks on Computer graphics is concerned with the generation and display programming and computer fundamentals. His current of digital data as pictures on a computer monitor. It includes sim- research interests are parallel ple two-dimensional (2D) illustrations such as engineering draw- computing and history of ings, sophisticated realistically shaded three-dimensional (3D) ob- computing. jects such as automobiles, and videos such as animated movies. One of the most popular applications of computer graphics is in the 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 representing applications such as a browser, search engine, and word processor. The application is invoked by pointing to its icon using a device such as a mouse or a finger/stylus. Keywords Computer graphics, internet, Even though it was realised early in the development of com- global positioning systems, World puters that giving the output of computation in a graphical form Wide Web. enhances human understanding of the result, no cost-effective

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The first major graphical output device that could be connected to a computer breakthrough in was available in the 1950s and 60s. Another constraining factor computer graphics was was that graphical output is useful only if it can be interactively the doctoral work of Ivan Sutherland at MIT in used with a computer. For drawing pictures using a computer, it is 1963. He wrote a 2D necessary to have one-to-one interaction with the computer. Dig- drawing program called ital computers were too expensive in the 1950s and 60s to permit ‘Sketchpad’. It had users this luxury. Computers were primarily used in a batch mode graphical objects such as lines, rectangles, with many users sharing them. Research in computer graphics ellipses, and circles. was hence restricted to well-funded institutions. They could be manipulated using a The first major breakthrough in computer graphics was the doc- device called a light pen toral work of Ivan Sutherland at MIT in 1963. He wrote a pro- that had a sensor to gram called ‘Sketchpad’ for the Lincoln TX-2 computer – a single detect the light beam on user interactive computer – that had a Cathode Ray Tube (CRT) a CRT screen. Sutherland wrote display. Sketchpad was a 2D drawing program. It had graphical algorithms for geometric objects such as lines, rectangles, ellipses, and circles. They could operations such as clip, be manipulated using a device called a light pen that had a sen- zoom, and coalesce sor to detect the light beam on a CRT screen. Sutherland wrote graphical objects for drawing useful 2D algorithms for geometric operations such as clip, zoom, and co- figures. alesce graphical objects for drawing useful 2D figures. Interest- ingly around the same time (1964) Douglas Engelbart, working at the Stanford Research Institute in the west coast of the USA, invented the ‘mouse’ that is widely used even today to move the cursor on a display unit of a computer. We have described some related work of Engelbart in Section 9 on the World Wide Web.

PDP-1 computer had a PDP-1 computer was manufactured by the Digital Equipment Cor- large CRT screen as an poration in 1959 and was one of the first commercial transis- output device and torised computers with an architecture similar to Lincoln TX-2. became famous for history’s first computer It had a large CRT screen as an output device and became famous game called ‘Space War’ for history’s first computer game called ‘Space War’ developed developed by Steve by Steve Russell in 1962 at MIT. This kindled interest in graph- Russell in 1962 at MIT. ics for interactive game playing. IBM sold interactive computer This kindled interest in graphics for interactive graphics terminals for around USD 100,000 in 1965 which only game playing. major corporations could afford. These companies used the IBM graphics terminals for writing computer-aided design software to design complex structures (bridges, aircrafts, etc.) and for displaying the results of simulation of dynamic systems. The major

886 RESONANCE | August 2018 SERIES ARTICLE problem in the 60s was the high cost of computers and graphics In 1969, the Association output devices. Progress was slow. for Computing Machinery (ACM), Academic research picked up when time-shared computers that USA, established the allowed many users to simultaneously use a computer were in- Special Interests Group troduced in early the 1970s. Even then graphics terminals were in Graphics (ACM SIGGRAPH) indicating expensive. A significant development was the introduction of the emergence of Direct-View Storage oscilloscope by Tektronix for USD 1500 that computer graphics as an could be used as a graphics terminal with time-shared computers. important discipline in This development enabled researchers in many academic institu- computer science. Among the academic tions and research laboratories to develop graphics algorithms. In institutions, the group 1969, the Association for Computing Machinery (ACM), USA, established by David established the Special Interests Group in Graphics (ACM SIG- Evans at the University GRAPH) indicating the emergence of computer graphics as an of Utah in 1966 contributed many important discipline in computer science. Among the academic important algorithms in institutions, the group established by David Evans at the Univer- computer graphics. sity of Utah in 1966 contributed many important algorithms in computer graphics. In 1967 he invited Ivan Sutherland to join the department. They were frustrated by the non-availability of computer systems for graphics and started their own company – Evans and Sutherland – in 1968 to design and manufacture graphics workstations that were used in developing many innovative graphics programs. Several research students at the University of Utah designed important algorithms in computer graphics. In 1974 Edwin Catmull contributed to texture mapping in 3D modelling of objects. The group also developed algorithms for hidden surface removal in 3D modelling. In 1977 a group of 25 experts of the ACM SIGGRAPH developed the first standard for graphics called ‘3D core graphics system’ that became the foundation for further developments in graphics. (This is the reason I picked In 1977 a group of 25 1977 as the breakthrough year for computer graphics). experts of the ACM SIGGRAPH developed Incidentally, several students who graduated from the computer the first standard for graphics group of the University of Utah started some of the best- graphics called ‘3D core known companies that did pioneering work in computer graph- graphics system’ that became the foundation ics. Pixar, which specialised in realistic computer animation, for further developments was started by Catmull. Silicon Graphics that made workstations in graphics. with excellent graphics programming features was started by Jim

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Researchers who had Clark. Adobe Systems, famous for PostScript, Photoshop, and earlierworkedatthe Portable Document Format (PDF), was started by John Warnock. Stanford Research Alan Kay working at Xerox Palo Alto Research Center (PARC) Institute in Douglas Engelbart’s group moved invented the GUI and object-oriented programming. to Xerox PARC. This group developed a PC Graphical User Interface (GUI) named ‘Alto’ in 1973. Alto had the first GUI As I pointed out, in the 1960s and 70s computers were not in- consisting of windows, icons, menus, and a teractive. Even when time-shared computers were introduced, mouse developed by a graphics terminals were expensive and the input devices were group headed by Alan tele-typewriters. The entire scenario changed with the advent Kay. By 1975 the group of Personal Computers (PCs) in 1975. PCs were inexpensive, also developed What-You-See-is-What- single user machines and had fairly large, 15" diagonal, raster You-Get (WYSIWYG) scan display. Researchers who had earlier worked at the Stan- software that allowed a ford Research Institute in Douglas Engelbart’s group moved to user to cut and paste Xerox PARC. This group developed a PC named ‘Alto’ in 1973. pictures in typed documents. Alto had the first GUI consisting of windows, icons, menus, and a mouse developed by a group headed by Alan Kay. By 1975 the group also developed What-You-See-is-What-You-Get (WYSI- WYG) software that allowed a user to cut and paste pictures in typed documents. Alto was not introduced as a commercial product but was widely used in many Xerox laboratories and some universities. It greatly influenced the design of PCs in the decades to follow. Apple’s Macintosh computer adopted Alto’s GUI in Apple’s Macintosh 1984. By mid-1980s, PCs were widely used and Microsoft in- computer adopted Alto’s troduced the Windows Operating System (OS) in 1985 that had GUI in 1984. By a good GUI. GUI provides easy human-computer interaction and mid-1980s, PCs were widely used and is now standard in all PCs, greatly enhancing user productivity. Microsoft introduced the Windows Operating Desktop Graphics Workstations System (OS) in 1985 that had a good GUI. With the reduction of the cost of integrated circuits and the ad- GUI provides easy human-computer vent of fast microprocessors and co-processors for performing interaction and is now fast graphics oriented operations, computers that were much faster standard in all PCs, than PCs, called ‘graphics workstations’ appeared in the early greatly enhancing user 1980s. The typical workstations had to satisfy the so-called 3M productivity. criterion – 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, Hewlett Packard, and Silicon Graphics had 19" to 21" monitors and used Unix OS. They were the workhorses of researchers as well as designers developing graphics and computer-aided design software in the 1980s. Many of the advances in graphics software occurred during this period. They catalysed the development of sophisticated 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 computer graphics. In 1992, a standard for generating 3D graphics, called openGL (Graphics Language), was released. OpenGL has a library of primitives that is machine and OS independent. It was quickly adopted by designers of diverse graphics programs such as computer-aided design, creators of realistic graphical scenes, and animation designers. Even game developers who used the most powerful computers (for quick interaction) used OpenGL. Computer graphics were used routinely by movie production houses to enhance movies such as Jurassic Park. A landmark was the release of Toy Story, a full-length movie in 1995, by Pixar Anima- tion Studios under the leadership of Ed Catmull. The movie was Computer graphics were entirely computer generated with no camera used. It was a hit and used routinely by movie had many successors Toy Story 2, 3, etc. Hundreds of full-length production houses to enhance movies. A movies are now being produced entirely using computer graphics landmark was the release without cameras and human actors. of Toy Story, a full-length movie in 1995, by Pixar Computer Games Animation Studios under the leadership of Ed Computer graphics also ushered in the computer games market Catmull. The movie was [2]. A company named Atari was a pioneer in this area in the entirely computer early days of PCs. Real progress began in 1985 when Nintendo generated with no – a Japanese company – released a handheld device with mul- camera used. It was a hit and had many successors tiple buttons (called a ‘gaming console’) that improved human- Toy Story 2, 3, etc. computer interaction for games. Sony PlayStation was very so-

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phisticated and sold over 100 million units in 1995. Microsoft also entered the ﬁeld of gaming hardware with a device called ‘Xbox’ in 1998. By 2010, more than 40% of homes in the USA had gaming consoles. Playing games required fast interaction and highly realistic graphics. As the number of people playing games increased to hundreds of millions, the market expanded. This inﬂuenced integrated circuit (IC) chip makers to design specialised graphics processing chips. Nvidia Corporation became a specialised graphics chip maker and manufactured a Graph- ics Processing Unit (GPU) used in real-time high-resolution 3D compute-intensive tasks. The internal architecture was fast enough to be used as general-purpose co-processors in current supercom- puters. Computer graphics and games have now moved to small handheld mobile devices such as smartphones. Other developments are head-mounted displays that project 3D images in space giving an immersive experience called virtual reality. Computer graphics is a breakthrough in ICT due to the following reasons:

• The idea that both 2D and 3D images can be generated by computer 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.

New ﬁelds such as • Results of computation displayed as 2D and 3D images aids our computer-aided design, understanding of results of computation as opposed to reams of computer animation, numbers printed on paper. Graphics has now become an essential computer games, and aid for engineers, architects, and designers. specialised hardware design for computer • Graphical User Interfaces greatly enhances our productivity in graphics have become using computers. Windows, icons, menu, and pointing device multi-billion-dollar industries and have are now standard on all computers. The importance of human- provided employment to computer interaction has been realised and many new devices are millions of professionals. 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 indirectly 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 persons 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 society.

7. Internet Internet today has become an essential Internet today has become an essential infrastructure in the world infrastructure in the much like electricity. We depend on it for communicating with worldmuchlike electricity. We depend our friends, relatives, and organizations using email, disseminate on it for communicating and search for information, collaborate with colleagues anywhere with our friends, in the world, listen to music, see videos, play a game with a re- relatives, and mote opponent, hail a cab, and shop – to mention a few of our organizations using email, disseminate and daily activities. It has been universally recognized as one of the search for information, greatest breakthroughs of the twentieth century. collaborate with colleagues anywhere in As with many of the breakthroughs we have discussed in this the world, listen to article, it did not appear suddenly. The idea of such an infras- music, see videos, play a tructure for social interactions using a network of computers was game with a remote envisaged by JCR Licklider of MIT, in the early 1960s, when opponent, hail a cab, and shop–tomentionafew he wrote a paper proposing this idea. Subsequently, the Ad- of our daily activities. It vanced Research Projects Agency (ARPA) of the US Department has been universally of Defence (DoD) appointed him to head the new Information recognized as one of the Processing Technology Oﬃce (IPTO) with a mandate to further greatest breakthroughs of the twentieth century. the research related to the Semi-Automatic Ground Environment

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(SAGE) program for protecting the USA against a space-based nuclear attack. Within IPTO Licklider evangelized the potential benefits of a country-wide computer communications network, influencing his successors to hire Lawrence Roberts, who was earlier at MIT, to implement his vision. Worldwide telephone In 1961 Leonard networks existed in the 1960s. However, these networks were de- Kleinrock proposed that signed to carry conversations between two subscribers by estab- many independent lishing a circuit exclusively between them for the entire duration messages could be transmitted between of the conversation. This method called circuit switching was computers by breaking wasteful and not suitable for carrying digital data between com- them into packets, each puters that is generated intermittently in bursts. This was pointed labelled with an out by Leonard Kleinrock as a part of his doctoral work at MIT identifier and interspersed and sent in 1961. He proposed that many independent messages could be over a single transmitted between computers by breaking them into packets, communication path each labelled with an identifier and interspersed and sent over a connecting them. The single communication path connecting them. The same idea was same idea was proposed independently by both proposed independently by both Paul Baran at RAND Corpora- Paul Baran at RAND tion, USA between 1961 and 1964, and by Donald Davies at the Corporation, USA UK National Physical Laboratory in 1965. between 1961 and 1964, and by Donald Davies at Roberts led the development of a computer network, based on the UK National this new idea of packet switching. A special computer called Physical Laboratory in an Interface Message Processor was developed by a company, 1965. Bolt, Beranek, and Newman (BBN), in 1969 to provide a system- independent interface that could be used by any computer system to architecture a network using packet switching. This work was 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 communication of packetized messages using the existing telephone network was between a computer in Kleinrock’s laboratory at the University of California, Los Angeles, and a computer at the Stanford Research Institute at Palo Alto, near San Francisco. It was 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 infrastructure. In 1972 the first email messaging system for com-

892 RESONANCE | August 2018 SERIES ARTICLE municating among researchers of the ARPANET was designed by Ray Tomlinson of BBN11.Afile transfer protocol (FTP) to Shiva Ayyadurai wrote an transfer files between computers connected to the ARPANET was email software in 1978 when he designed by Abhay Bhushan of MIT in 1971 [3]. was a 14-year-old student in the USA and registered a copyright Meanwhile, research in computer networking was also initiated in 1982 for the name EMAIL in the UK by the National Physical Laboratory and in France by for his program. IRIA (now called INRIA). The French network was called the ‘Cyclades’. The first networking protocol used on the ARPANET was called the ‘Network Control Program’ (NCP). This was used to architecture larger national computer networks with mainframes as nodes. In the late 1970s, PCs began to proliferate and Ethernet for connecting them to a LAN was invented by Robert Metcalfe. LANs grew rapidly and an interconnection system was required to connect them. It required a new protocol to succeed the Network Control Program. This protocol was designed to satisfy the following 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 between networks. The protocol to interconnect computer (iv) There was no global control of communication. networks was called the ‘Transmission Control Protocol/Internet These four principles made it possible to create the Internet as Protocol’ (TCP/IP). It a network of networks spread throughout the USA and across was invented by Robert the Atlantic. The protocol to interconnect computer networks Kahn of BBN and was called the ‘Transmission Control Protocol/Internet Protocol’ Vinton Cerf of Stanford University in 1983, (TCP/IP). It was invented by Robert Kahn of BBN and Vinton borrowing ideas from the Cerf of Stanford University in 1983, borrowing ideas from the Cyclades network Cyclades network designed by Louis Pouzin in France. This designed by Louis quickly became the most widely used network protocol in the Pouzin in France. world 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/IP is a two-layered protocol. Given a message to be sent to a computer B from computer A, TCP disassembles the message from A into small ‘data packets’ called datagrams that are then transmitted over the network to be reassembled by B’s TCP into the message’s original form. TCP also ensures the recovery of lost packets and the reordering of packets received out of order. IP is a unique address assigned to each computer (or device) connected to the Internet. As a datagram travels from one device to the next, IP address of the destination is checked by every device in the network which ensures that the datagram reaches the correct destination address. TCP/IP protocol ensures error-free transmission of messages between computers connected to the Internet. Each request for transmitting a message is new and unrelated to all previous requests. This allows the paths in the network to be used continuously [4].

In 1990, the ARPANET In 1990, the ARPANET was transferred to the National Science was transferred to the Foundation of the USA and named the NSFNET. A Computer National Science Science Network (CSNET) connecting universities in North Amer- Foundation of the USA and named the NSFNET. ica had also been formed. The NSFNET was connected to the A Computer Science CSNET. A network called EUnet connected research facilities in Network (CSNET) Europe. The North American net was connected to EUnet mak- connecting universities ing it a large international network allowing collaboration among in North America had also been formed. The scientists across the Atlantic [5]. NSFNET was connected The groundwork was thus completed to create the Internet as a to the CSNET. A network called EUnet worldwide communication infrastructure for computers to com- connected research municate with one another. In due course, all the computer net- facilities in Europe. The works in countries all over the world were connected using the North American net was TCP/IP protocol. Once the infrastructure was in place many ap- connected to EUnet making it a large plications could be built over this infrastructure. international network The major issues of management of such a worldwide infrastruc- allowing collaboration among scientists across ture and commercial use of the infrastructure that was primarily the Atlantic. built for academic use remained. Those have been resolved to a reasonable 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.

• TheideaoftheTCP/IP protocol that allows orderly communication among computers using diﬀerent operating systems connected 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 and A number of new celebrities, among many, use tweets to communicate their ideas. industries have emerged Facebook has enriched the nature of social interactions. Blogs due to the availability of the Internet. allow people to disseminate their ideas quickly and widely. E-commerce platforms such as Flipkart, search • The Internet has tremendously increased our eﬃciency by en- engine companies such abling quick communication, searching for information, and get- as Google, cloud ting advice from experts on various issues. computing companies such as Amazon Web • A number of new industries have emerged due to the availability Services, software as a of the Internet. E-commerce platforms such as Flipkart, search service companies such engine companies such as Google, cloud computing companies as Salesforce, social such as Amazon Web Services, software as a service companies networking companies such as Salesforce, social networking companies such as Face- such as Facebook, and companies such as book, and companies such as Dropbox providing cloud storage Dropbox providing owe their existence to the Internet. 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

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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 activity. In the early days, the position of the stars was used to approximately detect one’s location and this was used by sailors. The emergence of a compass that depended on the Earth’s magnetic field was an important breakthrough in navigation. The next technology that was used for navigation emerged with the invention of wireless transmission over long distances by Marconi 2Sir J C Bose invented the 1901 2 Low-frequency radio beacons transmitted by fixed land- mercury coherer (together with based stations were used by ships during the 1970s and 80s to the telephone receiver) used by navigate employing a system called Loran-C. The biggest break- Marconi. through that occurred in the twentieth century was the launch of the first artificial satellite, Sputnik, by the Soviet Union in 1957. It was soon realised that time signals sent from satellites could be used to determine the position of an object anywhere in the world accurately within a few metres. This was of great strategic importance to defence during the cold war between the USA and the Soviet Union.

Originally GPS was A meeting of the heads of the armed forces of the USA was intended only for the use held in 1973 when the ﬁrst concrete steps were taken to cre- of the defence forces of ate a satellite-based global navigation system. The system to the USA. When a civilian Korean Airlines be developed was called NAVSTAR (Navigation Satellite Tim- plane strayed into the ing and Ranging) Global Positioning System (GPS). The system Soviet airspace in 1983, was planned to have a constellation of 24 satellites of which the due to poor navigation ﬁrst was launched in 1974. As in all breakthroughs we describe in instruments, and was shot down by the Soviet this article, the fruition of the idea of using satellites to detect the Union leading to the position of an object anywhere on the earth’s surface, that was death of 269 innocent conceptualised in 1973, became operational with the launch of people, President all 24 satellites (and 3 spare satellites to substitute if one or more Reagan of the USA decided to allow GPS to satellite failed) in 1995 [6]. be used by anyone in the Originally GPS was intended only for the use of the defence world free of charge. forces of the USA. When a civilian Korean Airlines plane strayed into the Soviet airspace in 1983, due to poor navigation instru-

896 RESONANCE | August 2018 SERIES ARTICLE ments, and was shot down by the Soviet Union leading to the death of 269 innocent people, President Reagan of the USA decided to allow GPS to be used by anyone in the world free of charge. The positional accuracy for civilian use was reduced to about 100 metres initially. This restriction was removed by Pres- ident Clinton in 2000, and a positional accuracy of around 5 metres was made available to the public. Even though GPS is freely available 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 the US government can unilaterally blackout GPS in any part of the world if it desires, and it has done so in the past. Many countries have therefore developed their own systems for use in their countries and the surrounding regions. Russia has a global navigation system called GLONASS that has 24 satellites in orbit with 3 spares and covers the whole world. The European Union Indian Space Research has a system called Galileo. Indian Space Research Organiza- Organization (ISRO) has tion (ISRO) has developed its own system IRNSS (Indian Re- developed its own system IRNSS (Indian gional Navigation Satellite System) that has 7 satellites in geosyn- Regional Navigation chronous orbit. IRNSS can provide positional information for the Satellite System) that whole of India and the surrounding areas to an accuracy of 20 has 7 satellites in metres for the public. China has a system called BeiDou. Japan geosynchronous orbit. IRNSS can provide and France are also developing their own systems. GPS develop- positional information ment cost is extremely high and no private institution would have for the whole of India taken up the project. It was undertaken by the USA mainly for its and the surrounding defence. Fortunately, the cold war ended and it has now become areas to an accuracy of 20 metres for the public. a boon for all. The main idea behind GPS is to use the signals transmitted by satellites. These signals specify the time and position of the satellite when it transmitted a signal. When a receiver on Earth detects this 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 detect the position, namely latitude, longitude, and altitude of the receiver using triangulation. Altitude data is required by aircraft. In order that at least four satellites are visible from anywhere on

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A GPS receiver fitted to Earth, a constellation of 24 satellites is required. These satellites a car or a truck to find its are placed in six different orbits that are tightly controlled. These position costs around orbits are in planes inclined at around 55 degrees to the equa- rupees 5000. Apps are available on mobile torial plane. Each orbit has four satellites. This disposition of phones at no cost or a satellites ensures that a receiver at any place in the globe will be few hundred rupees able to receive signals from between 5–8 of these satellites. Three depending on the more satellites were launched to ensure that in case one or more features of the app to detect the position of the satellites fail, at least 24 operational satellites are available. GPS mobile phone using receivers on the ground are inexpensive. A GPS receiver fitted to GPS. a car or a truck to find its position costs around rupees 5000. Apps are available on mobile phones at no cost or a few hundred rupees depending on the features of the app to detect the position of the mobile phone using GPS. This position information is shown on maps provided by companies such as Google to find out the street address of the location of a mobile phone or that of a car fitted with a receiver. In fact, some of the recent apps in mobile phones have a voice guidance system that tells the driver the route from a 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.

GPSisofgreat • Navigation that is vital for travel by road, sea or air, has become assistance to navigate very simple after the advent of GPS as accurate location and al- ships, sailing boats, and titude information is given by the system. Nowadays when one aircraft. Coupled with travels by road, a smartphone is used to ﬁnd the location of the weather maps, ships/sailing vehicle using the signals emanating from GPS satellites. Apps boats/aircraft can avoid are available in smartphones to guide a person to travel to any areas where there are given destination. storms brewing. Fishing boats can avoid straying • GPS is of great assistance to navigate ships, sailing boats, and into the territorial waters aircraft. Coupled with weather maps, ships/sailing boats/aircraft of other countries. 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 inexpensive 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 information stored in the repositories of individuals and organizations, usually as typewritten, handwritten or printed documents, if made available to everyone in an easily accessible form, will enhance Doug Engelbart gave a the knowledge base of all. He wrote an article titled ‘As We May presentation in 1968, Think’ in the Atlantic Monthly expressing this idea. Digital tech- now legendary (available on YouTube), in which nology was not available then. He proposed an electromechanical he demonstrated the use device called MEMEX that would use documents photographed of a mouse to navigate in microfilms, indexed, connected via a network of ‘links’ and documents displayed on ‘associative trails’. This article foresaw the idea of hypertext to a video screen. He also demonstrated in that link documents and using the links to search and retrieve relevant presentation, documents. teleconferencing, word processing, file creation, The next big step was taken by Doug Engelbart in 1960 by in- file maintenance, venting the computer mouse as a tool to point at a desired object hypertext, hypermedia, displayed on a video screen. He showed how it could be used to and collaborative edit documents. Soon it became an indispensable part of desktop real-time editing of documents.

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computers. He gave a presentation in 1968, now legendary (available on YouTube), in which he demonstrated the use of a mouse to navigate documents displayed on a video screen. He also demonstrated in that presentation, teleconferencing, word processing, ﬁle creation, ﬁle maintenance, hypertext, hypermedia, and collaborative real-time editing of documents. Most of these ideas were his but the implementation was done by a large team of programmers guided by him at the Stanford Research Institute at Menlo Park, California. Meanwhile, computer technology pro- gressed with the invention of the PC, LAN, and the creation of the Internet infrastructure. The time was ripe to implement the idea of linking documents stored in computers of individuals and organizations.

Berners-Lee noticed that Tim Berners-Lee, a graduate from Oxford University joined CERN, even though CERN was the large particle physics laboratory near Geneva, Switzerland, in an international 1980 for a few months as a contract employee during which he laboratory with a large number of scientists who built a prototype system named ENQUIRE to share and update were expected to the reports written by scientists in CERN. He came back to CERN collaborate, their as a programmer in 1989. By this time, networking and Inter- research reports were net were ripe for implementing novel applications. Berners-Lee stored in their own computers and it was not noticed that even though CERN was an international laboratory easy for other scientists with a large number of scientists who were expected to collab- to access these reports in orate, their research reports were stored in their own computers spite of their computers and it was not easy for other scientists to access these reports in being networked. He got the idea that he could spite of their computers being networked. He got the idea that enable the sharing of he could enable the sharing of ﬁles among scientists at CERN ﬁles among scientists at and also with other scientists working elsewhere in the world as CERN and also with the Internet connected all computers and allowed easy commu- other scientists working elsewhere in the world as nication between them. He wrote a proposal titled ‘Information the Internet connected all Management: A Proposal’ that outlined his idea of structuring computers and allowed documents with embedded links that would point to other related easy communication documents that may be located in any connected computer. The between them. proposal was not initially accepted by his manager Mike Sendall but he changed his mind in October 1990 and allowed Berners- Lee to proceed with the project using a desktop computer NeXT that had been recently bought and networked with other comput-

900 RESONANCE | August 2018 SERIES ARTICLE ers. NeXT had many good features to aid in the development of the software. In order to link the documents stored in different computers, Berners-Lee realised that the documents must have symbols added to them which assign special meanings to the documents. These symbols are called ‘markups’. He sug- These innovations that gested that documents be written using a special language called describe what a the ‘Hypertext Markup Language’, abbreviated HTML. HTML document contains, how it is related to other describes the structure and contents of a document and how it documents, where these is to be linked to other documents. The links are important as documents are stored, they allow traversing from a document to all related documents. and how to access them, HTML has gradually become the basis for the creation of a web laid the groundwork for the World Wide Web. of documents. The next important innovation was to design a protocol that would allow a computer to retrieve related documents from another computer connected to it. This was called the ‘Hypertext Transfer Protocol (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. This was originally called Universal Resource Indicator by Berners- Lee and is now called ‘Universal Resource Locator’ (URL). (The Internet already had a ‘Domain Name System’ (DNS) that re- sponded with the IP address of the server that hosted the website A crucial step was which facilitated assigning a URL). These innovations that de- needed to easily navigate scribe what a document contains, how it is related to other doc- the web of documents. A software called uments, where these documents are stored, and how to access ‘Hypertext Browser’ was them, laid the groundwork for the World Wide Web. This basic developed by Marc idea and the relevant software were essential but not suﬃcient to Andreessen and his team allow easy retrieval of documents scattered in computers all over of programmers at the National Centre for the world connected by the Internet. A crucial step was needed Supercomputing to easily navigate the web of documents. Even though a rudi- Applications at the mentary navigation software to explore the web was developed University of Illinois by the team at CERN in 1991, it was not easy to use. A software USA. It was called the ‘Mosaic browser’ and called ‘Hypertext Browser’ was developed by Marc Andreessen was launched in 1993. It and his team of programmers at the National Centre for Super- allowed easy navigation computing Applications at the University of Illinois USA. It was of the web. called the ‘Mosaic browser’ and was launched in 1993. Using

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this browser one can retrieve, for example, a document by typing in the address bar, the URL of the document that has the format: http://www.xcollege.ac.in/admission-rules.html, where http stands for hypertext transfer protocol, :// link, www.xcollege.ac.in, The World Wide Web the address of the server of the college where the document is became usable with the stored, followed by the path to the desired document, namely, availability of Mosaic admission-rules, which is in HTML format. The World Wide browser as it had an intuitive user interface Web became usable with the availability of Mosaic browser as it and could display had an intuitive user interface and could display graphics. Since graphics. Since then then many browsers, such as Netscape, Internet Explorer, Fire- many browsers, such as fox, Opera, Safari, and Chrome were developed. Nowadays, a Netscape, Internet Explorer, Firefox, Opera, browser is an essential software in any computer, and many free, Safari, and Chrome were feature-rich, browsers are available [8, 9]. developed. Tim Berners-Lee was far-sighted and wanted the World Wide Web technology to spread widely and be used extensively. In order to achieve this, certain principles were enunciated by him and his team.

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

(ii) No central authority controlled it.

A World Wide Web (iii) The web was designed to be non-discriminatory, that is, no one Consortium (abbreviated was given preference and better quality of service on payment. W3C)wasformedasthe main international standards organization These principles pioneered the philosophy of ‘open source’ and for the World Wide Web ‘open access’ to allow many interested and qualiﬁed people to under the leadership of contribute towards the improvement of the World Wide Web. A Tim Berners-Lee. Besides standardisation, World Wide Web Consortium (abbreviated W3C) was formed as W3C conducts training the main international standards organization for the World Wide programmes, develops Web under the leadership of Tim Berners-Lee. Besides standard- software, and isation, W3C conducts training programmes, develops software, coordinates an open forum for discussions and coordinates an open forum for discussions about the web and about the web and its its future. future. The World Wide Web technology is a breakthrough in ICT due to the following reasons:

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• The idea of organizing documents using a hypertext markup language that enables the linking of these documents stored in in- terconnected computers across the world is novel.

• The World Wide Web enabled the underlying Internet infrastruc- Website designing and ture to be useful to the public by allowing anyone to easily ac- maintenance has cess billions of documents stored in computers spread all over emerged as a new profession. Today a the world. number of companies all • It made it essential for every organization and even individual to over the world employ millions of persons to have a ‘web presence’ in order to be noticed. Every organization design websites for large now creates a website giving details about it and places it in a corporations as well as publicly available web server, and updates it frequently. individuals.

• Many useful documents such as government rules and regulations, judgements delivered by courts, telephone directories, and stock prices are now available on the web.

• Website designing and maintenance has emerged as a new profession. 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 engines, digitization and compression, mobile computers, cloud computing, 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.

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[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. Address for Correspondence [8] History of the World Wide Web, World Wide Web Foundation, V Rajaraman https://webfoundation.org/about/vision/ Supercomputer Education & [9] Lenny Zelster, Early History of the World Wide Web: Origin and beyond, Research Centre 2015, https://www.zelster.com/web-history/ Indian Institute of Science Bengaluru 560 012, India. Email: [email protected]

904 RESONANCE | August 2018 Classroom

In this section of Resonance, we invite readers to pose questions likely to be raised in a classroom 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 personal experiences and viewpoints on matters related to teaching and learning science.

Chirag Kalelkar The Inveterate Tinkerer Department of Mechanical 16. Flow Visualisation Engineering, IIT Kharagpur, Kharagpur West Bengal 721 302, India. We conclude our series of articles on experiments in ﬂuid dy- [email protected] namics by listing the materials and methods employed, as well as discuss a few experimental techniques which were not considered in earlier articles. Several books on ﬂow visualisation [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, (g) Food dye (red). contact lines, bubble-ring, vortex (h) Copper sulphate. ring. (i) Mica Pearl White.

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(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 incense sticks vis-a-vis agarbattis (which possess a wooden core) is that they are malleable and can be shaped as per requirement.

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Figure 1. Visualisation of the wake behind an obstacle using smoke.

An alternate method utilised smoke from the vaporisation of oil droplets. A coating of silicone oil was applied on a ﬁne platinum wire using a paintbrush, which forms periodically-spaced pendant droplets of oil due to the Rayleigh–Plateau instability [4]. If the wire is heated by passing a current (∼2 A), the oil droplets vapor- ise releasing smoke. An obstacle (such as a pencil) placed in the path of the smoke may be used to visualise the wake as shown in Figure 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 camera (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 the microscopic structure of shaving foam (Gillette Foamy) between two glass slides. See the video: youtube.com/watch?v=g4_BtnYD25s

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a) Backdrop and Supports: We used a wooden board of dimen- sions 64 × 38 × 1cm3 with one side painted black and the other side painted white. Both sides were useful in different experiments, as per the requirement of a dark or light contrast. Three wooden blocks of size 20 × 9.5 × 7cm3 were fabricated, which acted 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 experiments which utilised the high-speed camera we used an LED light source (YN-600L, Yongnuo). Occasionally, we used a halogen lamp (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 we used a macro lens (AF-S DX Micro 40 mm f2.8, Nikon) for imaging. The sole exception being the shadowgraph experiment discussed below which required use of a zoom lens (AF 70–300 mm f4–5.6, Nikon). A circular polariser (52 mm, Osaka) was screwed Shadowgraph is a onto the lens to reduce glare. technique for visualising differences in 2.2 Shadowgraph temperature in transparent media. Shadowgraph [5] is a technique for visualising differences in temperature 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 heated object placed in front of a concave mirror are imaged using a camera. The focal plane of the camera is positioned at the focal point of the concave mirror (which is illuminated with a point source of light). A photograph of the setup is shown in Figure 2. We used a concave mirror (diameter = 8 inches, Dolphy) for imaging. A white LED was converted into an (approximate) point source of light by coating the surface with black acrylic paint leaving a small patch exposed. The LED was powered via an Arduino microcontroller 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 (a) (b) of jet of air from a heat gun. (b) Shadowgraph of buoyant plumes above a burn- ing cigarette lighter (note the double image.

laboratory jack. A DSLR camera with zoom lens was mounted on a tripod stand, and used for imaging. The position of the focal plane of the camera was adjusted to coincide with the focal point of the mirror. It is important to increase the f-stop number of the lens, to prevent overexposure. A heated object placed in front of the mirror shows quite clearly the shadow of buoyant turbulent plumes rising above the object, see Figure 3 and the video: youtube.com/watch?v=MyOLkHR5prw

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Figure 4. Visualisation of a liquid front ﬂowing through glass beads between plexiglas plates.

2.3 Chemical Reaction

Chemical reactions may be used as a means of flow visualisation. Phenolphthalein 1% indicator solution turns pink on mixing with aqueous sodium hydroxide solution. A monolayer of glass beads (diameter = 3 mm) was sandwiched between two plexiglas plates and coated with the indicator solution using a paintbrush. Sodium hydroxide solution was pumped into the gap between the plates using a peristaltic pump. The moving fluid front may be readily visualised via this technique, as seen in Figure 4 and the video: youtube.com/watch?v=fc1inkTXOMI The saponification reaction between aqueous sodium hydroxide solution and oleic acid may be used to image flow near an interface, as discussed in an earlier article [3].

2.4 Miscellaneous Methods

Chemical reactions may (a) Pinning of Contact Lines Under Floating Bodies: A grid com- be used as a means of flow visualisation. prising of squares of length 2 mm was printed onto a sheet of Phenolphthalein 1% paper, which was stuck to the bottom of a (square cross-section) indicator solution turns glass aquarium. The aquarium was filled with water. Small pieces pink on mixing with of plastic film were made to float on the water by gently placing aqueous sodium hydroxide solution. them on the surface using a tweezer. The pinning of contact lines at the interface may readily be visualised, as seen in Figure 5 and

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Figure 5. Pinning of contact lines under ﬂoating bodies.

the video: youtube.com/watch?v=8TmYjgOR0Xg (b) Half-ring Vortex: A plastic tray of dimension 44 × 32 × 8 cm3 was filled with water to the brim and illuminated using a 500 W halogen lamp. If a tablespoon is dipped into the water and lifted off, the shadow of a submerged half-ring vortex is observed 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 × 36.5cm3 was fabricated, with a plastic elbow connector sticking out of the bottom (see Figure 6). The tank was filled with 10 litres of aqueous glycerol solution. The elbow connector was attached via flexible plastic piping to a solenoid valve (2W-025-08, Senya Solenoid Valve Co., China). The valve was attached 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 a plastic 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 controlled using an Arduino microcontroller. It is important to ensure asufficient head by placing the compressor-valve assembly at a certain height above the top of the tank. The compressor was turned on and the relay was switched periodically with a delay

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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 the elbow joint and the solution. The bubble rises due to buoyancy and undergoes an instability, leading to the formation of a turbulent bubble ring which rises to the surface of the solution. See the video taken with a high-speed camera and LED light source as backdrop: youtube.com/watch?v=e0h17S11LGY

3. Acknowledgment

The author acknowledges help from students who participated in over 200 experiments during the period 2013–2018: Abhijeet Kant 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, Sukrut Phansalkar, Sagnik Paul, Santosh Gavhane, Saurav Sen, Shub- ham Kant and Tarique Anwar. The author also acknowledges the partial funding support from the Science and Engineering Re-

912 RESONANCE | August 2018 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.

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Classroom

A G Samuelson Card Games and Chemistry Department of Inorganic and Teaching Organometallic Reactions Through Card Games Physical Chemistry Indian Institute of Science Bangalore 560 012, India. [email protected] We present a card game suitable for classroom use to pro- Email: vide an interactive and lively experience while studying organometallic reactions, synthesis and catalysis. It is based on a deck of playing cards, and we call it CARS (Catalysis and Reaction Sequences). The object is to arrange a set of random cards served to the player in a correct sequence. The correct sequence is based on the sequence of steps found in the catalytic cycle of a set of reactions. The game is similar to the popular multiplayer card game rummy. We illustrate the game with a set of cards based on the C–C bond forming reactions, but it can be modiﬁed by the teacher to suit the topics being taught and could even be converted to a web-based version or a stand-alone study tool operating on a computer.

Introduction

Systematization and teaching of inorganic and organometallic chemistry reactions are daunting tasks. Teachers and students are bogged down by the prospect of studying literally hundreds of ‘seemingly’ unrelated reactions. Anything that facilitates this Keywords process and helps in visualizing relationships is welcome. If one Catalysis, organometallic understands for example, how several organometallic reactions chemistry, card games, fun in chemistry.

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follow a common pattern in catalytic and stoichiometric reactions, it would be a great help to the student and teacher alike. By By writing the catalytic writing the catalytic cycles presented in organometallic chemistry cycles presented in as a set of sequential reactions, it is possible to see that many reac- organometallic tions indeed follow a pattern. It becomes easier for the student to chemistry as a set of sequential reactions, it is connect a large number of reactions and attempt the construction possible to see that many of new catalytic cycles, given the reactants and products. reactions indeed follow a ﬀ pattern. Games have been used e ectively for enhancing student involve- ment and making the student-teacher interaction more enjoyable than lecture-based classes [1]. In the past, games have aided chemical education especially in the nomenclature of compounds, study of elements in the periodic table and reactions [2]. Some of them are indeed card games to aid the study of nomenclature [3], formulas [4] and even improve the understanding of stereochemistry [5]. Recently, there have been some excellent descriptions of card games for teaching functional groups in organic chemistry [6], synthetic organic chemistry [7, 8], and one to teach retrosynthetic analysis [9]. We believe an extremely simple and general version of the popular card game – rummy – can be devised to learn organometallic chemistry and catalysis. We will illustrate the idea using a set of cards based on organometallic catalytic cycles using organic/organometallic synthesis. They are only illustrative and the game is designed in such a way that it can be used in diﬀerent learning/teaching situations wherever a sequence of events is part of the learning objective. The deck of cards is patterned after the familiar 54 cards in common card games. The cards are divided into four groups or suits, each one representing a catalytic cycle (as in spades, clubs or clovers, diamonds and hearts). The name of each reaction is printed on a color-coded card and the substrates, products and reagents, if any, in that reaction are printed in the same color. The transformations or steps in the reaction can also be made into cards indicative of the reaction type such as oxidative addition, insertion or transmetallation, reductive elimination, ligand dissociation, etc. Each reaction cycle is thus mapped into a set of 12

916 RESONANCE | August 2018 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 this maybeusedtofill in any part of the sequence. Two additional cards are generic multicolored ‘wild’ cards that can be used for any reaction (across suits), reagent or sequence, making a total of 54 cards. Although the popular game of rummy is suggested, other games could be devised as well as the cards map to a regular pack of 54 cards in a deck. We will illustrate how this game can be used to teach/learn several C–C bond forming reactions where the catalytic cycles bear some resemblance. When the catalytic cycles are grouped together in this fashion, the similarities and differences are brought out, and student understanding is significantly enhanced during the play. We have chosen four named reactions: HECK, NEGISHI, SUZUKI and SONOGHASHIRA. Each of these named reactions has a well-established catalytic cycle. Apart from the fact that the common catalyst of choice is a palladium complex, three of these reactions proceed through steps that are similar in the beginning and in the end. The Heck reaction has significant differences. The game allows the students to recognize the similarities and appreciate the differences. If the game is played in class after these reactions are taught, or right after the lecture in a tutorial class, it is easy for students to recollect these steps. It also allows the student to construct new cycles for reactions they encounter in the literature with ease. Figure 1 shows the catalytic cycle for the Heck reaction and Fig- ure 2 shows the representative cards one can generate from this cycle. A similar exercise with the other three reactions would yield the requisite number of cards. A complete set of 54 cards is given in the supplementary section for the four reactions mentioned above. These card sets are only illustrative. Any four reactions could be substituted for these C–C bond-forming reactions. One only needs to simplify the steps so that the reaction is completely represented by 12 to 13 cards. In order to play the game with two to four people, one pack of cards is thoroughly shuffled to generate a random set and each

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player is dealt a set of 10 cards. The remaining cards are kept aside face down as the stockpile. Each player tries to arrange the ten cards (s)he has according to a reaction sequence. The object of the game is to be the first one to arrange all the cards in valid sequences. Valid sequences could be formed as a sequence of 10 cards from one complete catalytic cycle (same color cards). Wild or special cards are permitted. If they are two different sequences they could be from two different catalytic cycles of say, a set of 7 in one cycle and a set of 3 from another, or even three different sequences of 3, 3 and 4. Players get to draw from the stockpile and discard unwanted cards until they can form sequences. In our experience, sequences are generated by at least one player within 15–20 minutes. After the winner is confirmed, every player shows their sequences to other players and then a lively discussion follows. In one group, the students helped one another form all four sequences further reinforcing the learning experience. Although we emphasize the similarity with numbered cards, a caveat must be added. Sequences in CARS could have some differences from the classic card sequences. For example, in a reaction of A + B transformed by a substitution reaction ‘R’ to give C + 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 chemically meaningful. However, the sequence ‘B, R, and C’ is not considered a valid ‘reaction sequence’ although based on numbers it is a valid sequence. Rules regarding this must be announced before starting the game.

A player can choose to A player can choose to put down a run or sequence of three (min- put down a run or imum), four or seven cards in the centre of the playing area. This sequence of three might allow another player to continue the catalytic sequence by (minimum), four or seven cards in the centre adding a set. The object of the game is to help the students build of the playing area. This the catalytic cycle or parts of it using the cards. So putting down might allow another the sequences as and when they form could help them recognize player to continue the the catalytic cycles, the reactions and the substrates. This may catalytic sequence by adding a set. increase the educational value. When played in this fashion, the person who puts down all the cards ﬁrst wins. However, as a matter 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 the requirement for a vacant site, a suitable oxidation state, matching substrates and catalysts in a lively environment. In the first few rounds of the game, students may be permitted to use their class notes or even have access to complete catalytic cycles. If needed, an easier card set could be printed with suitable hints on the cards suggesting what reactions are possible for the substrate or what substrates are suitable for the reaction. In an electronic version of the game, this could be made easier through the use of help files or 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, of the same (reaction) colored cards are needed to play this game. Both Rummy and Spider are readily played with these cards, and hence the games should be transferable to soft versions. Simi- larly, with some modifications, a board game like ‘Snakes and Ladders’ could be constructed using the sequence. Board games

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Figure 2. Representa- tive cards generated from the Heck reaction cycle presented in Figure 1.

have the advantage that they could even be elaborated into social games such as ‘Farmville’. The framework described here is also suitable for further elaboration by increasing the difficulty level, and adding gaming elements so that a full-fledged gaming experience can be incorporated in the future. Converting the game into an app suitable for the mobile, or a web-based program independent of device architecture should also help more students to participate. If a gaming environment is provided, additional motivational aspects can set in, such as the desire to role play, gaining social recognition, a sense of accomplishment, handling challenges, mystery and fun that can lead to interactive and enjoyable 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 games either through physical cards/boards or even through computer games or apps will improve the motivation and engagement of students.

Conclusions

Teaching organometallic reaction mechanisms and catalytic cycles using card games, in a fun-ﬁlled interactive setting is more eﬀective than a slide presentation or even a chalk and board lecture. Since the game is tunable, it is likely to be of great value in teaching other topics where sequences are involved: such as in total synthesis. We have described here a general framework for converting any complex reaction with multiple steps into a card game very similar to rummy, the popular game of cards. Many opportunities open up once the teacher converts the learning objective into a game [11].

Supporting Information

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

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Instructions for Playing the Card Game – CARS

In order to play the game with four people, the cards are thoroughly shuffled to generate a random set and each player is dealt a set of 10 cards. The remaining cards are kept aside face down as the stockpile. The first player, takes a card from the stock and attempts 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 previous player. However, each player must put back (DISCARD) the most unwanted card from her/his cards, or the card that was taken from the stock. So, at any stage of the game except during the player’s turn, one has only 10 cards on hand. When one player finally forms three sequences, (s)he is declared the winner. If the stock is exhausted, the set of open cards are shuffled and replaced face down to form a fresh stock to continue the game.

Acknowledgments

The author thanks the students of the organometallic course who have participated in the game and several faculty members of IITs who 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.

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BOOK REVIEW

Magic of Transforming a most loyal friend. The fox is solitary while the dog is social. The fox is a wild animal that Fox Into a Dog! stays away from humans as much as possible while the dog is a domesticated, beloved pet Sujata Deshpande who sits in your living room resting its head on your knees. But the domesticated dog was once a wild animal, known to have descended from wolf ancestors. Our ancestors domesticated those wolves into dogs over a period of thousands of years. Dmitri Belyaev wanted to mimic this process, with the silver fox, in order to understand the process of domestication. He was especially interested in the initial part of the process – how domestication of a wild animal began. He chose the silver How to Tame a Fox (and Build a Dog) fox – a close genetic cousin of the wolf – for Visionary Scientists and a Siberian Tale this experiment. Dmitri Belyaev’s experiment of Jump-Started Evolution started in the early 1950s and it continues till Authors: Lee Alan Dugatkin and Lyudmila today, even after his death in 1985, having Trut gone through ﬁfty-seven generations of do- Published by: University of Chicago Press, mesticated, tamed silver foxes to date. Some 2017 of these foxes have become household pets! Pages: 240 (clothbound) This is one of the longest run experiments in Price: USD 26 (clothbound) biology, but perhaps a short one for evolution. Other formats: E-book USD 18.00 The book is written by Lee Alan Dugatkin (The book will be available in paperback for who is an evolutionary biologist and historian USD 18 in October 2018) of science in the Department of Biology at the University of Louisville, along with Lyudmila Trut, Professor of Genetics at the Institute of This book tells the story of the Russian geneti- Cytology and Genetics in Siberia who has cist Dmitri Belyaev’s idea. In his own words, been associated with the fox-taming project the idea was ‘to make a dog out a fox’. My since 1959. Together, the author duo describes very ﬁrst question upon getting the book in the evolution of this experiment right from its my hands was – why would anyone want to inception. They delve into the science behind do this? The two animals are perceived to it – evolution, animal behaviour, animal do- be opposites. The fox is labeled as the most mestication and biology of the fox. They also cunning animal while the dog is a human’s

RESONANCE | August 2018 925 BOOK REVIEW outline the history and politics of the USSR pressive political conditions imposed by Josef (Union of Soviet Socialist Republics) and how Stalin and Trofim Lysenko (who vehemently it affected the science and the scientists of that opposed Mendelian genetics and geneticists time. The picture of the effect of history and practising it). Therefore, Belyaev asked an Es- politics appears black. However, silver rays tonian colleague, Nina Sorokina, to start the penetrate this dark cloud in the form of brave experiment under a different pretext in 1952. scientists who strove to do their science, to Over the next few years, political conditions stand up against political hindrance, and to en- started becoming less unfavourable. Belyaev sure that their country would not lose the rich became the Head of the Institute of Cytology scientific heritage it once had. They risked ev- and Genetics. By then, the foxes with his erything, sometimes lost their careers, were Estonian colleague were also showing subtle locked behind bars, lost their loved ones, or behavioural and morphological changes. En- even lost their own lives. Dmitri Belyaev couraged by these events, Belyaev decided to emerges as a charismatic person, a visionary expand the experiment and looked for a person scientist, a skilled administrator, and a brave highly trained in animal behaviour. Now, this soldier. He suffered many personal losses but is quite interesting and I would like to draw the remained a warm-hearted individual, always attention of undergraduate students. Lyudmila thoughtful of the people associated with him. Trut (yes!the co-author of the book) was that He wanted to learn from the experts all over highly trained person and she was just about the world and went out of his way to contact to finish her undergraduate studies! The book them. describes in detail how Lyudmila Trut got the job and I do not want to break the suspense. I The story of the fox domestication experiment urge undergraduate students and their teachers can easily fit into a thrilling science fiction. to read the book! Belyaev wanted to select foxes for their tame- ness and breed them over generations hoping Lyudmila Trut decided to work on the fox- to get glimpses of the early stages of domes- domestication project by going to the institute tication. He was a trained geneticist, how- that was being newly formed. The institute ever, when he began his career he was pro- was being set up in a city called Novosibirsk in hibited from doing research in genetics. His Siberia, more than three thousand kilometers job as a lead scientist in Russia’s state-owned away from Moscow where Lyudmila and her fur industry was to help mass breeders of family were located. Lyudmila had just mar- foxes and minks to produce more beautiful ried and had a baby girl. However, when she furs. He accepted the job so that he could decided to go, her husband whole-heartedly carry out his studies under the cover of the supported her by agreeing to go along with job. Even then, he could not start his own her and finding a job in the new location. Her fox domestication experiment under the op- mother too joined them soon afterwards to

926 RESONANCE | August 2018 BOOK REVIEW look after the baby. This was happening in the describes this extended experiment in detail late 1950s and this is the kind of family sup- and provides a good number of references. port many women scientists even today dream The book is not for undergraduate students about; luckily, the number of those who get alone. It demands attention of the experts in this support is slowly increasing. the ﬁelds like evolutionary biology, genetics, developmental biology, history of science, an- This is a slim book of about two hundred thropology and perhaps animal ethics. And pages with a photograph of a cute fox on this book is for you if you are an animal lover! the cover. It is written lucidly and it carries the reader with the ﬂow of events which get more and more interesting, and some very heart-warming. Even before I realized it, the book was over and I wished it just went on! Sujata Deshpande The experiment started with behavioural ob- Assistant Professor servations of the foxes but went on to inves- Department of Zoology, tigate changes in fur colouration, facial fea- St. Xavier’s College (Autonomous), tures, hormones, reproductive cycle and dif- 5 - Mahapalika Marg, ferential gene expression. These changes were Mumbai 400 001, India. all associated with domestication. The book Email: [email protected]

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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 participated in four Olympiads held so far this year, 7 secured gold medals, 9 silver medals, 2 bronze medals, and 1 certificate of honorable mention. The most remarkable performance was in the International Physics Olympiad (IPhO) where all the five Indian students received gold medals, lifting the country to the top position in the medals tally along with China, a first in 21 years of Indian participation in IPhO.

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

The winning delegations to the different Olympiads are given below.

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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 Silver BGS National Public School, Bengaluru Shaswat Jain Silver Nalanda Academy Sr. Sec. School, Kota Stuti Khandwala Silver Disha Delphi Public School, Kota Vishwesh Bharadiya Silver H.P.T. Arts & R.Y.K. Science College, 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)

930 RESONANCE | August 2018 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 Gold Disha Delphi Public School, Kota Jishnu Basavaraju Gold Sri Chaitanya Narayana Jr College, Vijayawada Aayush Kadam Silver Pragati School, Kota Sanchit Agrawal Silver Sardar 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)

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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 Silver Delhi Public School, Faridabad Pranjal Srivastava Silver National Public School Koramangala, Bengaluru Pulkit Sinha Silver St. Francis School Indirapuram, Ghaziabad Spandan Ghosh Bronze South Point High School, Kolkata Sutanay Bhattacharya Bronze Bishnupur High School, Bishnupur Amit Kumar Mallik Honourable Mention Sri 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 Pranav Nuti (IISc, Bangalore)

932 RESONANCE | August 2018 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 Bhaskar Gupta

Lay Jain Gold Disha Delphi Public School, Kota Siddharth Tiwary Gold Lakshmipat Singhania Academy, Kolkata Nishant Abhangi Gold Disha Delphi Public School, Kota Pawan Goyal Gold Aklank Public School, Kota Bhaskar Gupta Gold Shiv 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)

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Science Academies’ Refresher Course in Experimental Physics

at Osmania University College for Women (OUCW) Koti, Osmania University, Hyderabad 25 September to 10 October 2018

Sponsored by Indian Academy of Sciences, Bengaluru Indian National Science Academy, New Delhi The National Academy of Sciences, India, Allahabad

A Science Academies’ Refresher Course in “Experimental Physics” will be held in the Osmaia University 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 teaching undergraduate and postgraduate courses in Physics. Participants in this course will gain hands on experience 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 of science, with a special focus on women and their scietific empowerment. The OUCW has been conducting various capacity building programs for University teachers and research scholars. Professor R. Srinivasan has conducted such Refresher Course in Experimental Physics in many institutions so far including universities, autonomous colleges, and advanced scientific institutions involved in education. The Course will enable the participants, through lectures and laboratory sessions, to enhance their skills in experimental physics and facilitate them to introduce the experiments in their respective curricula. UGC has approved two weeks Refresher Courses of good standing for promotion, vide notification: F31/2009 dated 30 June 2010. Applications are invited from teachers with experience in teaching undergraduate and postgraduate courses in Physics. III year B.Sc., I year M.Sc. Physics students and research scholars with keen interest in Experimental Physics may also apply. The number of seats will not exceed 34. Selected participants will be provided with roundtrip bus/train (III AC) fare by the shortest route and local hospitality during the course in addition to course material. Interested applicants must submit their application 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 Course Coordinator. In case of teachers, the form must also be signed and stamped by the Head of the applicant’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 the duly 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 be informed by: 10th September 2018.

934 RESONANCE | August 2018 INF. & ANN.

Science Academies’ Refresher Course in Statistical Physics

at Ramakrishna Mission Vivekananda University Belur Math, Kolkata 09 to 23 December 2018 Sponsored by Indian Academy of Sciences, Bengaluru Indian National Science Academy, New Delhi The National Academy of Sciences, India, Allahabad

A Refresher Course in Statistical Physics will be held at the Department of Physics, Ramakrishna Mission Vivekananda University (RKMVU), Belur Math, Kolkata, from 9 to 23 December 2018 for the beneﬁt of faculty involved in teaching undergraduate and postgraduate courses. This course will address the transition from a one-particle description (as in classical mechanics) to a many-particle statistical description (as in statistical mechanics). An intermediate step involves dynamical system theory, which describes the evolution of a set of initial conditions under dynamics. Often, with the increase in the number of degrees of freedom, these lead to statistically similar behaviour, allowing a description through equilibrium statistical mechanics. In addition to lectures on these topics, there will be lectures on stochastic dynamics, nonequilibrium statistical mechanics and quantum statistical mechanics. The course is sponsored by Indian Academy of Sciences, Bengaluru, Indian National Science Academy, New Delhi and The National Academy of Sciences, India, Allahabad. It will be directed by Prof. Mustansir Barma, TIFR Hyderabad, F.A.Sc., F.N.A.Sc., F.N.A., and coordinated by Dr Shamik Gupta, Department of Physics, Ramakrishna Mission Vivekananda University. The topics and 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: Dr Shamik 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 the country. It may be noted that UGC regulations include Refresher Courses in API scores for career advancement. Applications are invited from teachers with experience in teaching undergraduate and postgraduate courses in Engineering and Physics. Motivated BSc and MSc Physics students may also apply. There will be 25 outstation and 10 local participants. Selected outstation participants will be provided with travel assistance (limited to three-tier A/C train fare), while all participants will be provided accommodation and local hospitality during the Course, in addition to the course material. 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 Course Coordinator, at the address given below. In case of teachers, the form must also be signed and stamped by the Head of the applicant’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 the duly signed documents sent by email will also be accepted. Address for communication: Dr Shamik Gupta, Department of Physics, Ramakrishna Mission Vivekananda University, Belur Math, Howrah 711202, West Bengal. Email: [email protected] Phone: +91 33 2654 9999. Last date for the receipt of applications: 15 September 2018. Selected participants will be informed by: 5 October 2018.

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