RAA 2015 Vol. 15 No. 1, 1–14 doi: 10.1088/1674–4527/15/1/001 Research in http://www.raa-journal.org http://www.iop.org/journals/raa Astronomy and Scientific Reminiscences

Trials and tribulations of playing the devil’s advocate

Jayant V. Narlikar Inter-University Centre for Astronomy and Astrophysics, Pune 411007, India; [email protected]

Received 2014 July 24; accepted 2014 July 30

Abstract Beginning with his student days at school and college, the author describes his training at with special emphasis on his mentor . His early experience of participating in a controversy at Cambridge played a major role in giv- ing him the confidence to defend his scientific ideas. All through his later life he chose areas that were not part of mainstream research. These included the steady state the- ory and later the quasi steady state cosmology, action at a distance, noncosmological redshifts, quantum conformal cosmology, etc. After being a founding member of the Institute of Theoretical Astronomy (IOTA) at Cambridge, the author joined the Tata Institute of Fundamental Research (TIFR) in Mumbai and later moved to Pune to set up the Inter-University Centre for Astronomy and Astrophysics (IUCAA). He briefly reviews his own work and ends by pointing out the difficulties a non-conformist scien- tist faces in his professional life. In the conclusion, he mentions his interests in science popularization and science fiction for which he has won awards and appreciation, in- cluding UNESCO’s Kalinga Prize.

Key words: autobiography — cosmology — sociology of astronomy

1 THE EARLY YEARS

I was born in Kolhapur in 1938. At the time Kolhapur was a princely state abutting the Bombay Presidency, part of the British empire in the Indian subcontinent. Both my parents were born there and had ancestral property dating back to the nineteenth century. My father was educated at Cambridge and as an Isaac Newton student had worked with Eddington, Larmor and Smart. While in Cambridge he was approached by Mahamana Madan Mohan Malaviya, the Founder of the Banaras Hindu University (BHU) with an offer to head the mathematics department after he finished his stud- ies at Cambridge. He accepted the offer and joined BHU in 1932. My mother, unlike most women in the 1930s, had a college education and a master’s degree in Sanskrit. That was how I came to be brought up in the quiet and beautiful BHU campus, receiving school as well as an undergraduate education there. My favourite subject at school was mathematics and while in standard III, I recall all of us children were asked to say what our fathers did. When my turn came, I promptly said that my father was a professor. “Professor of what?”, asked the teacher and I did not know the answer. “You should know that your father teaches mathematics”, the teacher said. While embarrassed at my ignorance I was also pleased that my father taught the subject I liked the most. This liking grew with time and was much aided by the books on extracurricular mathematics that my father introduced me to and further by the arrival in our household of my maternal uncle 2 J. V. Narlikar

Morumama (Professor M. S. Huzurbazar who later retired as Director of the Institute of Science, Mumbai). I was then in standard VIII. Morumama had come to spend two years studying for his M.Sc. degree in maths and he noticed that there were two blackboards on the verandah wall. He promptly used one of them to write what he titled “A Challenge Problem for JVN”. It was a math- ematical puzzle which I had to solve as a test of honour. I did. But soon there appeared another challenge problem and I realized that this was to go on and on. As they say, I won some and lost some. But either way my mathematical horizon expanded well beyond that of a school boy. After my undergraduate years at BHU, my father got me admitted to his old College Fitzwilliam House (later Fitzwilliam College) at Cambridge. The tricky question of finance was solved by the handsome grant (part loan and part gift) from the J. N. Tata Endowment in Mumbai. I recall under- going a tough interview by the Director Mrs P. J. Vesugar. Despite her aggressive questioning she must have formed a good impression of ‘this raw boy from Banaras’. Anyway, throughout my stay as a student in Cambridge, she was friendly and helpful. Thus I sailed for Cambridge on September 5, 1957 on a fateful passage to England. Although I had topped the list at BHU, I found it tough going at Cambridge. A course that would normally take a year at BHU was finished in a fast track of 24 lectures delivered in an eight week term. Morumama’s training that involved facing challenges helped as did the weekly one to one supervision by a faculty member or a senior research student. Thanks to these, I finished the dreaded Mathematical Tripos with the honour of ‘Wrangler’ (First Class) in Part II and distinction in Part III. I was particularly happy to be awarded the Tyson Medal for best performance in astronomy in Part III, a feat my father had achieved thirty years ago with no other Indian following him till I did in 1960. Figure 1 shows me with R.P. Paranjpye who was Senior Wrangler, first from India (in 1899).

2 ENCOUNTER WITH FRED HOYLE

After the Tripos III, one entered the research career. It was clear to me by then that among all branches of maths, pure or applied, I liked astronomy best. This impression may have been formed partly after hearing lectures by Fred Hoyle and to some extent by R. A. Lyttleton and Leon Mestel. In any case as the Tyson Medalist I had the first pick of research guide amongst other astronomy grad- uate students. So, when the Department of Applied Mathematics and Theoretical Physics (DAMTP) sought the student’s choices, I opted for Hoyle as the research guide. And the day after the an- nouncement of the Tripos results, I was told by George Bachelor, the Head of DAMTP, to call on Fred Hoyle at his house at 10 a.m. the following day. I recall that June morning as a brilliant sunny morning of the kind when the English summer is at its best. 1 Clarkson Close was the address and I found it quite different from the typical Cambridge house. The doorbell was answered by Barbara Hoyle, Fred’s wife, whose chatty welcome soon put me at ease. She asked me about my family and where I came from. A few minutes later Fred came with his smiling face and suggested that we sit down outside on the lawn. Indeed when we sat on two deck chairs sipping iced lemonade, I could not help feeling how ‘un-English’ the whole set up was. After a few remarks on the weather and the recent Tripos examination, Fred came to the point. He described a menu of research problems that he considered interesting and worth tackling. These were spinning universes, , gravitational radiation, synchrotron radiation from radio sources, etc. Being a versatile scientist (easily the most versatile of his generation) Fred Hoyle’s range of interests covered almost the whole spectrum of astronomy and astrophysics. However, I noticed that he had not mentioned the steady state theory, of which he was a coauthor with and Tommy Gold. I asked him if I could work on some aspects of that theory. His reply was that he did not feel that a fresh research student should be exposed to a controversial topic. I was naturally disappointed but could see the logic in his reasoning. Ironically, I would recall this statement on a future occasion within a year. Trials and Tribulations of Playing the Devil’s Advocate 3

Fig. 1 Jayant with Senior Wrangler R. P. Paranjpye.

That day I came back with work assigned on spinning universes. In particular, Fred wanted me to look at the spinning universe of Heckmann & Schucking¨ (1958). These authors had argued that a spinning universe would have centrifugal force to counteract gravity. Since in standard Friedmann- Lemaitre models (see Narlikar 2002) the spacetime singularity (i.e., a state of infinite density), is generally believed to be caused by gravity of matter, Heckmann & Schucking¨ were confident that their model would turn out to be nonsingular. Fred wanted to probe this model further. If the universe had no singularity, it might oscillate between finite density states and if so it would be worth investigating how the synthesis of nuclei operated. Would the expanding stage lead to a build up of nuclei from hydrogen to helium and other light nuclei which would break apart during the contracting phase? This approach set Hoyle apart from the typical relativistic cosmologist. The latter would only be interested in the mathematical solutions of Einstein’s relativistic equations, whereas Fred was more concerned with their physical behaviour. The Heckmann-Schucking¨ model had been obtained by the authors from a generalization of the classic Godel¨ model (Godel¨ 1949). Its geometric form was not fully determined but to Fred it was the physical behaviour of the model that mattered. I was planning to visit India for two months starting in early July. I had been away for nearly three years and was looking forward to being with my family. On checking my dates I discovered that on return to Cambridge on September 6, I had just one day of overlap with Fred before he left 4 J. V. Narlikar

for a semester’s visit to Caltech where he had an ongoing interaction with Willy Fowler. This did happen, although when on return to Cambridge in September, I telephoned Fred in the afternoon I was told by Mrs Clarke, his mother in law, that he was busy all through the day and was leaving early morning the next day to catch his flight to the USA. She did have a time slot for me to see him: in his rooms in St John’s College where he was hosting a dinner for the composer Leo Smit. She said that I could see him there at 10 p.m. Although I felt awkward barging in, I had no choice. Fred was happy to see me and carefully planned what I should do during his absence. He arranged with Felix Pirani of King’s College, London for me to make a day visit every week on the day Pirani’s group had seminar activity. This turned out to be very beneficial in enlarging my understanding of symmetries in curved spacetime.

3 A COSMOLOGICAL CONTROVERSY

Thanks to Pirani’s group seminars in which R. K. Sachs, Roger Penrose, Josh Goldberg and others spoke, I was able to appreciate anisotropic spacetimes like the one I was studying and was able to demonstrate that the model in question does not oscillate. In fact it led to a strange topological structure and later to singularity (Narlikar 1962a), so when Fred Hoyle returned in December I was able to tell him that I had carried the problem as far as it could be taken and that it would not be realistic to take it further. Thus the ball was in his court and I was ready for some other Ph.D. problem. At this stage I should say something about Fred’s group of research students. His seniormost student was John Ireland, followed by Sverre Arseth, then Joan Crampin, and the new students like me including Chandra Wickramasinghe from Sri Lanka, John Faulkner, and Ken Griffiths. Two other students, Kumar Chitre and Ian Roxburgh, also interacted with us but were students of Leon Mestel. All of us were accommodated in a hut facing the Cavendish Labs. Later, Batchelor as head of DAMTP grabbed more space when part of the labs near Cavendish burnt down in an accidental fire. Batchelor had it rebuilt and with morbid humour named it ‘Phoenix’. We moved to Phoenix in my second year. Although in our conversation we freely referred to Fred Hoyle by his first name, we were a bit hesitant when he asked us to address him as ‘Fred’. Nevertheless, we did manage it eventually, thanks to his informal attitude. As I was waiting for a suitable research problem, an important controversy broke out. Martin Ryle, the head of the Cambridge radio astronomers announced that his latest survey of radio sources ruled out the steady state theory. What Ryle and his colleagues had done was to count the radio sources brighter than some specified flux levels and plotted them on a log-log scale. Thus if N were the number of sources brighter than flux density S, then for a uniform distribution of equally bright sources in Euclidean geometry the following relation should hold

d log N/d log S = −1.5 . If one supposes there is an expanding universe then the slope would become progressively less steep as one sought fainter (and hence more distant) sources. What Scott et al. (1961) found was a slope starting at −1.8 for nearby sources and becoming less steep at smaller S. Now, in a big bang model there is freedom to choose the number density of sources n such that the above finding is explained. The steady state theory makes a definitive prediction and as seen by the qualification ‘steady state’, the value of n has to be the same at all epochs. This led to a flatter source count curve than found by Ryle. Hence it was argued by Ryle that the model was disproved by his observations. He had arranged to present his findings at the February 10 meeting of the Royal Astronomical Society (RAS). On the second Friday of the month the RAS meeting provided a national forum for the presenta- tion of new works and Ryle’s choice of the meeting was a natural one. The question was, how would Trials and Tribulations of Playing the Devil’s Advocate 5

Fred Hoyle, as a creator of the steady state theory, react? Among the other two authors of the theory, Gold dismissed it as possibly due to observational errors, especially since radio surveys in Australia and Caltech did not report similar findings. Bondi was more cynical, saying that Ryle’s previous surveys had reported even steeper slopes which had progressively come down as errors in earlier surveys that were discovered and corrected: so he would wait until the coming survey’s report of even flatter slopes. Hoyle, in contrast, felt that despite the underestimation of errors, Ryle’s findings needed to be taken seriously, so he asked for and was given a ten minute time slot to present his rejoinder at the RAS meeting. This was in January with barely 3–4 weeks to go when Fred called me to discuss what one could do by way of a rejoinder. After some discussion, we felt that the steep slope was not of any cosmological significance but arose out of local inhomogeneities. Thus we had a possible model with these assumptions:

(1) Radio sources are rare compared to galaxies. (2) The probability of a galaxy becoming a radio source increases with its age. (3) The universe is inhomogeneous on a scale of 50 Mpc, that is, it has superclusters and voids on the scale of this order. (4) The overall cosmological background is that of the steady state theory.

Fred gave me the task of computing the N-S relation under such conditions. Beyond the basic for- mulae, one needed to do numerical computing. I had access to the University computer, the EDSAC and hand operated Facit machines. In order to test how we were doing we needed access to Ryle’s data. Fred arranged to meet him in the Cavendish tea room one afternoon. The meeting, which I also attended along with a couple of Ryle’s colleagues, was a disaster. Ryle had brought a sheet of paper with a hand drawn graph of log N against log S with a few points shown as crosses to indicate observations. There were no error bars and one could not draw any conclusions by looking at the curve drawn as it was! This was all he would reveal: in a way not surprising, since he was known to be very protective of his data. This was our sole database on which to erect our model. Still we managed to have a working hypothesis which supported the steady state theory yet was consistent with Ryle’s data to the extent revealed. As February 10 approached and I was getting ready to plan the London visit, Hoyle dropped a bombshell. He had just found that he had already committed the February 10 afternoon to giving a talk in one of the London colleges and so could not attend the RAS meeting. He asked me to give our rejoinder after Ryle’s presentation. I was terrified at the prospect. How can I, a raw research student argue in a debate against a senior, experienced and hostile opponent? But Hoyle assured me that in a scientific controversy these issues take second place to the fact as to who has the logical argument backed by correct mathematics. In short if I was confident of the mathematical content of our model then I had nothing to fear. The main problem that I had to worry about was how to present the crux of the model in the eight minutes given by the RAS. (Judiciously, Hoyle had allowed two minutes for interruptions!) He warned me that bad time management spoils a good case, so together we rehearsed what I would say and what slides I would show. That afternoon at the RAS everything went according to plan and my presentation was well un- derstood and appreciated. I was particularly happy when a research worker from Ryle’s group came and complimented me on my presentation. As I walked out of Burlington House on to Piccadilly, I enjoyed a sense of relief for having discharged an important responsibility. I felt that after the RAS experience, I could handle any controversy. At the same time I recalled Hoyle’s statement at 1 Clarkson Close on that June morning that he believed that fresh research students should be kept away from controversies. Little did I realize that this was going to be my ‘default pattern of work’ all the way through my research career. 6 J. V. Narlikar

4 MONTE CARLO IN COSMOLOGY

After the RAS meeting was over, we were expected to follow our presentation with a detailed paper dealing with Ryle’s data to start with while also exploring further aspects of the kind of inhomogene- ity we had assumed in our reply. To deal with the first part, Fred Hoyle needed an isolated retreat where he would be away from visitors and telephone calls. Fortunately a friend offered him the use of his cottage near St Austell in Cornwall. Fred invited me to join his family there. Barbara and his daughter Elizabeth were also coming. The week spent in St Austell was a mix of intense work and relaxation in the form of hiking and driving across the Cornish peninsula. Fred and I would get up by 6 a.m. and after a cup of tea would spend the next 5–6 hours writing and calculating with a break for breakfast. The paper that was presented by us at the RAS was later published in the Monthly Notices of the Royal Astronomical Society (MNRAS). It was my first scientific collaboration (Hoyle & Narlikar 1961). The second objective was to study the implication of a universe that was inhomogeneous on a scale of 50 Mpc. While doing the calculation analytically I had been forced to take an average kind of situation and it left unanswered the question: how far would counts in different cases differ from the average count? Thus one had to place random observers in such a universe and study the range of their counts. Such a study called for a fast computer with a large enough capacity. The Cambridge EDSAC was not capable of handling this problem. When I mentioned this difficulty to Fred he immediately found a solution. He had rented time on the IBM 7090 system in London, primarily to study stellar evolution. That work on which my fellow student John Faulkner was engaged had not yet progressed far enough to require the IBM computer. So, Fred encouraged me to take up that problem as it was then a unique experiment of the Monte Carlo technique applied to the universe. Today’s graduate student may have a laptop for doing such a problem without rising from his desk. For me in 1961–1962 it involved going to London once a week with my programme on punched cards, handing over the pile to the IBM programmer by around 11 a.m. and calling for the results at 4 in the afternoon. On a lucky day everything would go well. More typically, some errors would be discovered and I would redo the problem with a modified programme the following week. However, the process converged in a few weeks and a follow up paper by Hoyle and me (Hoyle & Narlikar 1962) duly appeared in MNRAS. By now, Fred had lifted any moratorium he may have had on my working on the steady state theory. I recall having afternoon tea at 1 Clarkson Close where Paul Dirac and Maurice Pryce were present. Maurice Pryce had brought a few sheets of paper in which was given a field theoretical formulation of the creation of matter. A scalar field C with negative energy played the key role. Although Pryce never published this work, we used it many times. In fact my essay on this topic later won me the prestigious Smith’s Prize from Cambridge. At that time, theoretical physicists frowned on scalar fields with negative energy but today the popular phantom fields are exactly a copy of the erstwhile C-field.

5 ACTION AT A DISTANCE

Towards the end of my first year as a research student I had the opportunity to attend a summer school on cosmology and gravitation held at the resort named Varenna on Lake Como. Apart from Fred Hoyle, the speakers included Alfred Schild, C. Moller, Bruno Bertotti, Robert Dicke and Joshua Goldberg. However, a single lecture delivered by Hermann Bondi fired me up to work on a new topic. Bondi spoke on the recent work by a Canadian student of Bill McCrea, named Jack Hogarth (Hogarth 1962). Hogarth had resurrected the 1945–1949 work by John Wheeler and his then student Richard Feynman (Wheeler & Feynman 1945, 1949) on action at a distance electrodynamics. Historically, Coulomb’s law, a topic from electricity and magnetism, had assumed there is instantaneous action at a distance. The question was whether it could be updated in a revised form where the special Trials and Tribulations of Playing the Devil’s Advocate 7

relativistic speed limit of the speed of light was obeyed. In 1845, in a perceptive letter to Weber, Gauss had referred to the problem without offering a solution. Wheeler and Feynman (WF in brief) revived the problem by recalling that independently Schwarzschild (1903), Tetrode (1922) and Fokker (1929a,b, 1932) had written down an effective action for interacting charges in the form X Z X X ZZ 2 i J = mada − eaebδ(sAB)da dbi , a a

2 i i sAB = (a − b )(ai − bi) is the square of invariant distance between A and B. In this expression, the delta is the Dirac delta- function whose vanishing argument is the square of the special relativistic 4-distance s2 meaning that charges interact only when and where they are connectible by a light ray. Thus instantaneous action is replaced by action at the speed of light. While this appears to solve the problem, the reality is otherwise. For an interaction from charge a to charge b travelling in the future, a retarded action must be accompanied by an equal and opposite advanced reaction. This brings the theory into conflict with causality. Clearly a mixture of future and past interaction will bring chaos. Wheeler and Feynman got around this problem by an ingenious device. They argued that any action from a single charge a must trigger an instantaneous reaction from b, no matter how far b is from a. In short we must include the reaction not from a single charge but from all charges in the universe howsoever far they may be. Using a static Euclidean universe, WF demonstrated that the universe responds in such a way that all advanced reactions are cancelled out and all retarded ones are doubled. Thus to start with, one may see that each charge a interacts in a time symmetric way. However, if we denote the retarded and advanced effects of charge a by Ret(a) and Adv(a), it can be shown that the net effect on charge a by other charges is 1 X X 1 {Adv(b) + Ret(b)} ≡ Ret(b) + {Ret(a) − Adv(a)} . 2 2 b6=a b6=a

Here the ≡ denotes the role played by the universe. Notice that for all other charges, b acts on charge a by a retarded action and there is also the radiative reaction which arises not from self-action as in field theory but through the feedback of the universe. WF could arrive at the above relation on the assumption that the universe is a perfect absorber. Thus the radiation emitted by any charge eventually gets absorbed by such a universe. For this important role required of the universe, WF called this theory the absorber theory of radiation. While this seemed to resolve the causality problem, WF were initially puzzled how time- asymmetry emerged in the working of a time-symmetric theory in a time symmetric universe. In fact, as they soon found out, the analysis could be redone with advanced and retarded actions be- ing interchanged. Thus there exists a pair of solutions and one needs to know how the choice of a retarded solution is made. WF resolved the issue by recourse to thermodynamics, arguing that the other solution favouring advanced action would be ruled out by the second law of thermodynamics. Hogarth’s work as described by Bondi consisted of the important step of introducing cosmology into the argument. If one did the WF calculation in an expanding universe, the two solutions obtained by WF would not automatically hold as pointed out by Hogarth. Because to arrive at the retarded solution one needs to deal with the feedback of the universe on the future light cone of charge a whereas for the advanced solution one examines the past light cone. In either case, one needs to know whether the universe is a ‘perfect absorber’. Hogarth’s conclusion was that for the retarded solution to be consistent, one needed the future absorber to be perfect and the past absorber to be 8 J. V. Narlikar imperfect, and vice versa for the advanced solution. He further found that the standard big bang model expanding into the future admits advanced solutions whereas the steady state model admits retarded solutions. As Bondi emphasized, the WF theory resolves the cosmological issue (which model of the uni- verse is correct?) cleanly without any observational uncertainties of the kind we had encountered in the case of radio source counts. Moreover, in the correct model one understood how the electro- magnetic and the cosmological arrows of time were related. Bondi further raised the question that a similar situation may exist for neutrinos. Do they travel forward in time? Fred and I realized that here was an excellent series of problems to be solved. I decided to try the neutrino problem and in a few months solved it in a publishable form (Narlikar 1962b). More serious problems that were to keep us occupied in the coming years included: (1) a cleaner approach to the absorber role of the universe (Hoyle & Narlikar 1964a), (2) action at a distance adapted to curved spacetime (Hoyle & Narlikar 1964c), (3) the adaptation of the C-field to action at a distance (Hoyle & Narlikar 1964b), and (4) a Machian theory of gravitation (Hoyle & Narlikar 1964d). My first ordeal in this context was in 1963 when I presented my work on the WF theory to a select group of some twenty invitees to the Nature of Time meeting at Cornell University. Tommy Gold, who had convened this meeting, had allocated ample discussion time. I recollect that my Ph.D. viva voce examination was conducted here during the lunch interval by the examiners Hermann Bondi and Dennis Sciama. Since I had given a presentation in the morning at the conference, these examiners limited the viva to ten minutes!

6 PAPER PRESENTED AT THE ROYAL SOCIETY

Fred Hoyle was very enthusiastic about the absorber theory, no less because it gave a decisive judge- ment in favour of the steady state theory. As a generalization to the creation field used in the steady state theory, we needed a general method to ‘convert’ any field theory to its action at a distance form. Although I later gave such a prescription (Narlikar 1968), our early work gained considerably from an interaction with Feynman himself. We had this discussion in 1963 when Fred and I had visited Caltech after the Cornell meeting. I recall Feynman getting interested in the creation field concept but unfortunately we did not have another chance to tap his fertile mind. Fred and I were facing a problem on the inertial term in the action principle. If we took our cue from the electromagnetic and the creation field, we were led to an action at a distance theory of inertia. However, we were concerned with how gravity would appear in such a framework. Playing with the physical variables available, we could see that the mass-function m had to satisfy a wave equation and that it had the form ¤m + αRm = N. Here R was the scalar curvature in the underlying Riemannian geometry and N the particle number density. But what was the magnitude of the constant α? Our problem was solved unexpectedly when we heard Roger Penrose mention that if the constant were 1/6, it made the wave equation conformally invariant. Then everything fell into place. Conformal invariance was a symmetry one expected in an action at a distance theory which had null cones as entities of physical invariance: for conformal invariance left intact the null cone structure. We wrote a trilogy of papers for publication in the Proceedings of the Royal Society, London. In view of the importance of the papers it was suggested that they be presented at one of the meet- ings of the Royal Society. Accordingly, June 11 was fixed (the year was 1964). Fred presented the motivational part and I did the technical details. In those days, projection aids were minimal and blackboards were the mainstays. The presentations went off well and we were able to get the main points across. Scientists like Salam, Bondi, Dirac and several others present could appreciate the new theory which sought to relate inertia of a particle to the rest of the universe. Moreover, it linked general relativity to Mach’s principle. Trials and Tribulations of Playing the Devil’s Advocate 9

It is necessary to set the records straight on one incident that has been blown out of all proportion by the media hype following Stephen Hawking. Stephen, then a graduate student at Cambridge, had attended the above meeting and after our presentations raised his hand to ask a question. He said that as per his calculation the particle inertia turns out to be infinite. As his speech was slurred (a consequence of his motor neuron disease), Hoyle could not understand the comment. As I had been aware of Stephen’s work I replied to say that Stephen’s calculation was too simplistic and ignored the localised nonlinearity of the problem. Stephen did not press the argument further and the Chairman passed to the next question. This was all that happened and the media which carried glorified accounts of our presentation, did not, to the best of my knowledge and as per available news clippings, highlight the Hawking intervention. Afterwards Fred asked me: What was Hawking on about? I explained Stephen’s point and the reply I had given and he was satisfied. However, the biographical accounts and films made on Hawking give the impression that he got the better of the argument with Hoyle and that Hoyle was angry with me for letting Stephen have a copy of our paper in advance. The media version is grossly unfair to Fred Hoyle and (as intended) shows Stephen Hawking as the hero.

7 RETURN OF THE NATIVE

The interest taken by the media and the common man in our work was phenomenal and the British media were followed by the Indian media with their own hype! Fred Hoyle was used to being in the public eye, but this was my first experience and I found it difficult to get used to. Shortly after, I re- ceived an invitation from the Government of India to visit educational campuses in India to enthuse the students towards science. I thought it a good opportunity to discuss my work with the aca- demics from university campuses and research institutes. My hosts, the Indian Council for Cultural Relations, planned an itinerary for me that started at Delhi and proceeded to Ahmedabad, Mumbai, Hyderabad, Bangalore, Chennai, Kolkata, Banaras and back to Delhi. I had assumed that I would be talking to graduate level scientists who could understand the maths and physics behind my work. In practice, my lectures attracted huge audiences ranging from graduates down to schoolchildren. The result was that I had to dilute my talk and keep it at a superficial level. My hope of discussing the details of my work was dashed except on two (memorable) occasions. In Ahmedabad, Professor P. C. Vaidya (one of my father’s early students) a senior relativist and in Kolkata, Professor S. N. Bose, arranged discussion sessions with their research students. One important development for me was the meetings with Prime Minister (PM) LaL Bahadur Shastri and Education Minister M. C. Chhagla, both of whom extended an invitation to me to return to India and work at a place of my choice with full support from the Government of India. This open offer was to play a decisive role in my career a few years later. Back in the quiet of Cambridge, I was a witness to the creation of a new and, at the time, unique institution established by Fred Hoyle. Known as the Institute of Theoretical Astronomy (IOTA), it introduced the culture of an autonomous institution within a university with emphasis on visitor programmes. The Institute was funded by the Wolfson Foundation (for building) and the Nuffield Foundation (for running expenses for five years). I decided to stay on in Cambridge as a Founder Staff Member during the initial five years. My work with Fred continued both in Cambridge or hiking in the mountains (as in Fig. 2) with our (ambitious) aim being to quantise the WF theory: ambitious because Feynman himself had tried this problem and given up. Using Feynman’s own technique of path integral and the notion of response of the universe, we were finally able to see the light at the end of the tunnel. For phenomena such as spontaneous transition of an atomic electron, to the full application of quantum electrodynamics including the Lamb shift, the action at a distance approach provided adequate description (Hoyle & Narlikar 1969, 1971). Much later (Hoyle & Narlikar 1993), we also showed how the usual calculations requiring renormalization can be handled without infini- 10 J. V. Narlikar

Fig. 2 On a hike in the Lake District with Fred Hoyle. A lot of our work originated here! ties. In 1995 we published a review of WF theory in Reviews of Modern Physics, to mark 50 years after the original WF article in the same journal (Hoyle & Narlikar 1995). As mentioned earlier, I was now approaching the date which I had set for returning to India. Recalling the PM’s generous invitation, in 1969 I wrote to the then PM, Indira Gandhi, my intention of returning to India in 1972, preferably to work at the Tata Institute of Fundamental Research. Both Mrs Gandhi and the TIFR Dirctor M. G. K. Menon wrote welcoming letters and made my transition as easy as could be under the circumstances. In due course I received an appointment as a Full Professor with the (unwritten) mandate of developing the Theoretical Astrophysics (TAP) Group at TIFR.

8 THE TIFR DAYS

The TAP group in 1972 consisted of Mahendra Singh Vardya, Kumar Chitre, K. S. Krishna Swamy, S. Ramadurai and later S. P. Tarafdar. By the time I left TIFR in 1989, this small group of 5–6 had grown three times and publications-wise also improved in terms of the journals chosen. Kumar Chitre who had been my contemporary at Cambridge as a student had common interests with me to collaborate in relativistic astrophysics and cosmology (Chitre & Narlikar 1976; Narlikar & Chitre 1977). Arising out of our Machian theory of gravity, I could demonstrate that extragalactic objects can show an extra redshift because of variable mass. Thus at creation, a particle (and a composite object made of it) will start with zero mass and the speed of light. As it ages it gets more and more contribution to its inertia (from its growing horizon) so that it slows down while its redshift decreases. This paradigm explains the pairs (or larger groups) of objects with differing redshifts lying in close proximity. Such cases have been found by Chip Arp (Arp 1988, 1998) and others. They are largely ignored because if taken seriously they cast doubts on the Hubble redshift-distance law which is sacrosanct for modern cosmology. I will return to this aspect in the concluding section.

9 QUANTUM COSMOLOGY

While spending a sabbatical term at the University of Texas at Austin at the invitation of John Wheeler, I got interested in what I called quantum cosmology. The basic idea is simple to understand. Suppose we have a solution to Einstein equations with metric gik and we consider non-classical Trials and Tribulations of Playing the Devil’s Advocate 11

2 fluctuations of the form Ω gik. For non-zero and well-behaved Ω, we may call these fluctuations conformal fluctuations. We may consider two spacelike hypersurfaces Σi and Σf on which Ω = Ωi and Ωf respectively. Then using the Feynman sum over histories we set up an action formulated as per the Hilbert approach to relativity and perform the sum. Rather unexpectedly (for me!) the sum over histories could be performed exactly and one could show that the probability of the present universe arising from a singular state has measure zero. In fact one could assert that it is highly likely (probability measure unity) that the universe has emerged from a non-singular state in the past. The details of this work can be found in several references (Narlikar 1981, 1984).

10 THE QSSC

In the 1980s, cosmology took a turn in which it became more and more guided by high energy physics. In a sense this was natural since the desire for big bang theoreticians to probe the universe closer and closer to the big bang led to a mixing of cosmological speculations with those from high energy physics. The ideas resulting from such unification (inflation, nonbaryonic dark matter, dark energy, etc.) have created the false impression that we are close to solving the cosmological problem. In 1989 Fred Hoyle, Geoffrey Burbidge, Chip Arp, Chandra Wickramasinghe and I participated in a week long brain storming session which resulted in our writing a review (Arp et al. 1990) in Nature, criticising the way cosmology was being practised. The article generated a lot of responses including a ‘reply’ by four big bang supporters (Peebles et al. 1991). While conceding some of our criticism, this article expressed the view that standard cosmology may well have defects but in the absence of any other competing model, this was the only one available to work with at present. Taking this as a challenge to provide a satisfactory alternative, Hoyle, Burbidge and I (1993) came up with the so-called Quasi-Steady State Cosmology (QSSC) and followed the paper with several supporting publications including a book published by Cambridge University Press (Hoyle et al. 2000). We believe QSSC provides a viable alternative and deserves a critical appraisal by present day cosmologists.

11 IUCAA: A CHALLENGING ASSIGNMENT

In the mid-eighties I was beginning to feel somewhat bored with the monotony of life at TIFR. Thanks to Founder Homi Bhabha’s foresight, the institute provided excellent conditions for research. But one increasingly had the feeling that life outside is quite different and one is isolated from it. In the year 1932 when my father joined the BHU at the invitation of the Founder Malaviya, conditions in the university were academically attractive. In an environment with dedicated teachers and serious students it was a pleasure to be part of the system. Forty years later, in 1972, the conditions had changed for the worse. Nepotism, a sons of the soil attitude, a lack of spirit in work and an absence of good facilities had made universities far less attractive than in 1932. What was worse was that creation of centres of excellence in the form of autonomous research institutes like TIFR had lured good academics away from the universities. As if to reverse the trend away from universities, the University Grants Commission (UGC) in the mid-eighties decided to have its own centres of excellence in specific subjects for the benefit of universities and colleges. Called an inter-university centre (IUC) because of its interaction with universities, the centre will provide suitable facilities in specific areas to enable improvement of teaching and research. One of the first such IUCs was IUCAA, the IUC for astronomy and astro- physics. The UGC Chairman Yash Pal who was earlier a senior professor at TIFR knew very well that astronomy and astrophysics represent thrust areas in physics and being badly supported in the university sector made a strong case for an IUC. I had helped conduct early brainstorming on the proposed IUCAA and, at the request of UGC, compiled a project report. At that stage, Yash made a categorical statement that he would approve the project report provided I took the responsibility of the Founder Director. After some deliberation, 12 J. V. Narlikar

Fig. 3 With Fred and Barbara Hoyle and Naresh Dadhich on the plot of land where IUCAA was later built.

I agreed to take up full time responsibility for IUCAA from 1989 June 1. Several of my colleagues considered this a rash decision since from a well run institute like TIFR, I was heading for something that did not even exist. But as I explained, like the IOTA set up by Hoyle, this also represented a challenge and its rewards would be very satisfying. Figure 3 shows a photo of Fred Hoyle when he visited the spot where IUCAA came up. A lot has been written on how and why IUCAA was set up and how it functions (see for example Narlikar 2001). Suffice it to say that it has been widely regarded as a successful experiment and it has brought noticeable improvement in the university sector. This is reflected in (1) publications in refereed journals (2) the use of the guest observing programme in international telescopes, (3) improvement in the instrumentation for astronomy and (4) participation by university faculty and research students in important conferences, etc. Another very useful consequence of IUCAA has been its associateship programme which, patterned on the ICTP Abdus Salam Centre in Trieste, brings university faculty and students to IUCAA and has resulted in scientists from different parts of India interacting and collaborating with one another. Figure 4 has Hermann Bondi as one of them.

12 CONCLUDING REMARKS

I now end on a personal note about my scientific contributions. As my mentor Fred Hoyle did, I have preferred working in areas away from the bandwagon route where a large number of bright scholars probe tiny bits and pieces of a large section of scientific enquiry. This has naturally resulted in my sphere of interaction being reduced. The trend started right from my early research career when I stood up to speak against Martin Ryle. My choice of action at a distance (as opposed to the more conventional field theory), my probing alternative theories of gravity (as opposed to working only on general relativity), my championship of nonsingular cosmologies (when the majority believe in the big bang theory), my taking observations of anomalous redshifts seriously (against the general scepticism of the work of Chip Arp) and my work on quantum conformal fluctuations as a route to quantum cosmology have been examples of Rabindranath Tagore’s song Ekla chalo re (go alone your way). Some of my works were subsequently acknowledged although the majority still await Trials and Tribulations of Playing the Devil’s Advocate 13

Fig. 4 Jayant with Hermann Bondi. recognition. To cite some examples: the superclusters and voids in the universe (Hoyle & Narlikar 1961), the anticipation of inflation in which a Friedmann bubble grows in the external de Sitter (steady state) universe (Hoyle & Narlikar 1966b), the prediction of billion solar mass black holes in the nuclei of galaxies (Hoyle & Narlikar 1963, 1966c), the negative energy scalar field (Hoyle & Narlikar 1963, 1966a) that anticipated phantom fields, the quantum cosmological idea of the wavefunction of the universe (Narlikar 1977, 1981, 1984), etc. QSSC is another example of how alternative ideas are treated. In 1994, in an Editorial in Nature John Maddox had paid compliments to the three authors of QSSC in providing a non-singular uni- verse as an alternative, despite having little support from the Establishment. This alternative route is in a sense lined with thorns since one has difficulty publishing one’s ideas in refereed journals. One has to accept delays and (almost) endless arguments with the referees, one has to ignore being excluded from writing invited review or plenary talks in conferences and, of course, one has to take a back seat when being considered for awards and recognitions. On the positive side I can say that despite these problems, some awards and recognitions have come my way and these have brought immense pleasure and satisfaction. A topic I did not touch on in this article relates to my popular science writing and science fiction novels and stories. My main thrust has been for writing in my mother tongue Marathi and I must say that the reader response has been exhilarating. To a lesser extent I have also written in Hindi and English. Reader responses to these modest efforts coupled with the audience response to my public lectures have underscored the need for more scientists to get involved with science popularization. Indeed it was a great honour to be awarded the UNESCO Kalinga award for science popularization: a recognition that had earlier been bestowed on such luminaries as Bertrand Russell, Margaret Mead and Fred Hoyle.

Acknowledgements I thank the journal RAA for the invitation to write this account and Arnab Rai Choudhuri for encouraging me to write it. This paper was completed when I was visiting the Perimeter Institute (PI) in Waterloo, Canada. I thank the PI for their warm hospitality. This work was supported in part by the Perimeter Institute for Theoretical Physics. Research at the Perimeter Institute is supported by the Government of Canada through Industry Canada and by the Province of Ontario through the Ministry of Research and Innovation. 14 J. V. Narlikar

References

Arp, H. C. 1988, Quasars, Redshifts and Controversies (Cambridge: Cambridge Univ. Press) Arp, H. C. 1998, Seeing Red: Redshifts, Cosmology and Academic Science (Halton Arp. Montreal: Apeiron) Arp, H. C., Burbidge, G., Hoyle, F., Narlikar, J. V., & Wickramasinghe, N. C. 1990, Nature, 346, 807 Chitre, S. M., & Narlikar, J. V. 1976, Ap&SS, 44, 101 Fokker, A. D. 1929a, Zeitschrift fur Physik, 58, 386 Fokker, A. D. 1929b, Physica, 9, 33 Fokker, A. 1932, Physica, 12, 145 Godel,¨ K. 1949, Reviews of Modern Physics, 21, 447 Heckmann, O., & Schucking,¨ E. 1958, Report of Solvay Conference (Brussels: Stoops) Hogarth, J. E. 1962, Royal Society of London Proceedings Series A, 267, 365 Hoyle, F., & Narlikar, J. V. 1961, MNRAS, 123, 133 Hoyle, F., & Narlikar, J. V. 1962, MNRAS, 125, 13 Hoyle, F., & Narlikar, J. V. 1963, Royal Society of London Proceedings Series A, 273, 1 Hoyle, F., & Narlikar, J. V. 1964a, Royal Society of London Proceedings Series A, 277, 1 Hoyle, F., & Narlikar, J. V. 1964b, Royal Society of London Proceedings Series A, 282, 178 Hoyle, F., & Narlikar, J. V. 1964c, Royal Society of London Proceedings Series A, 282, 184 Hoyle, F., & Narlikar, J. V. 1964d, Royal Society of London Proceedings Series A, 282, 191 Hoyle, F., & Narlikar, J. V. 1966a, Royal Society of London Proceedings Series A, 290, 143 Hoyle, F., & Narlikar, J. V. 1966b, Royal Society of London Proceedings Series A, 290, 162 Hoyle, F., & Narlikar, J. V. 1966c, Royal Society of London Proceedings Series A, 290, 177 Hoyle, F., & Narlikar, J. V. 1969, Annals of Physics, 54, 207 Hoyle, F., & Narlikar, J. V. 1971, Annals of Physics, 62, 44 Hoyle, F., & Narlikar, J. V. 1993, Royal Society of London Proceedings Series A, 442, 469 Hoyle, F., & Narlikar, J. V. 1995, Reviews of Modern Physics, 67, 113 Hoyle, F., Burbidge, G., & Narlikar, J. V. 1993, ApJ, 410, 437 Hoyle, F., Burbidge, G., & Narlikar, J. V. 2000, A Different Approach to Cosmology: from a Static Universe through the Big Bang towards Reality (Cambridge: Cambridge Univ. Press) Narlikar, J. V. 1962a, Proc. Varenna Summer School on Evidence for Gravitational Theories, ed. C. Miller (Academic Press), 222 Narlikar, J. V. 1962b, Royal Society of London Proceedings Series A, 270, 553 Narlikar, J. V. 1968, Proceedings of the Cambridge Philosophical Society, 64, 1071 Narlikar, J. V. 1977, Nature, 269, 129 Narlikar, J. V. 1981, Foundations of Physics, 11, 473 Narlikar, J. V. 1984, Foundations of Physics, 14, 443 Narlikar, J. V. 2001, IUCAA: A New Experiment for Indian Universities in Organizations and Strategies in Astronomy, in Organizations and Strategies in Astronomy, ed. A. Heck (Kluwer), 29 Narlikar, J. V. 2002, An Introduction to Cosmology (Cambridge: Cambridge Univ. Press) Narlikar, J. V., & Chitre, S. M. 1977, MNRAS, 180, 525 Peebles, P. J. E., Schramm, D. N., Kron, R. G., & Turner, E. L. 1991, Nature, 352, 769 Schwarzschild, K. 1903, Gottinger¨ Nachrichten, 128, 132 Scott, P. F., Ryle, M., & Hewish, A. 1961, MNRAS, 122, 95 Tetrode, H. 1922, Zeitschrift fur¨ Physik, 10, 317 Wheeler, J. A., & Feynman, R. P. 1945, Reviews of Modern Physics, 17, 157 Wheeler, J. A., & Feynman, R. P. 1949, Reviews of Modern Physics, 21, 425