Monday, 1 February 2016

An unusual book..

From  the time  of the  ancient Indian  'gurukul' to  the present  day academia, the 'guru-shishya'  (teacher-student) relation is inherently asymmetric. The teacher teaches, the  student learns. The teacher assesses,  the teacher  judges and  the student  stays forever  at the receiving end of such evaluations.  And then, once  in an interesting while comes a student's chance of chairing the judge's seat.

Arnab  Rai Choudhuri,  Arnab-da ('elder  brother Arnab') to most of his  Bengali speaking  colleagues and students, is one of my  dear old professors.  In  the physics department of  the Indian Institute of Science (IISc, Bangalore) he  is known as one of the best teachers around and  for people like me he belongs  to that remarkable group  of foreign  returnees who  helped shape  the Indian scientific scene the way we see  it today. But  for these people, many in our generation would not  have had the luxury  of finding world class  researchers as PhD supervisors without leaving the Indian shores.

I have had the privilege of taking a course offered by him in my first year of graduate studies and later working with him as  a scientific collaborator. I have to say that  the pleasure and the privilege has been entirely mine. Inevitably, over  the years we forged a friendship that  is  characteristically typical  of  academia. It's a valued friendship between a teacher and a former  student,  between  two research  associates bridging  the generation gap which  allows, even obliges one  to be impartial while  judging the work of the other and yet remain close to each other.

During my job hunting days, a  couple of decades ago, Arnab-da had the unenviable  task of  writing  scores of  recommendation  letters -  an almost mandatory  duty for  being a teacher/senior  collaborator.  And suddenly, a few months ago, I find myself with the task of writing a review for one of his books for a science magazine. The onus is now definitely on me to be as fair and as impartial!

I have to  admit upfront that I am totally  impressed by the frankness shown by  Arnab-da in exposing the reality  of front-line  research in this book. Instead of the  standard de-humanised  style of the popular science  genre, this  book  has truly  become  Arnab-da's  'scientific autobiography'. He  has lived through  interesting times and  the book takes us along this roller-coaster ride of frustration and joy that is the hallmark of every scientists' working life.

Of  course,  there  have  been   difference  of  opinions  about  this particular style of writing even  amongst his closest friends.  We all know  that  there exists  a  gulf between  the  style  and  sense of presenting   a   narrative (from  serious   technical   reports   to spy-thrillers) between the  two shores of the  Atlantic.  Most of  us, given our  personal trajectories,  tend to  subscribe to one  style or  the other. I suppose the debate  arises mainly from this perception.  But, after  all  is said  and  done,  people  belonging to  the  scientific community  would immediately  realise  that the  book  has managed  to capture the true essence of the scientific environment around him.

In defense  of his style, Arnab-da  himself says - "I  have found that most scientists are reticent  in making their  life stories  public - perhaps due to the general perception that an average scientist's life is rather  drab and colourless  compared to an average  artist's life. Through my  story, I  have tried  to give  an idea  of how science is actually done in our field. I  have tried to write about a scientist's hopes and  fears, friendships, competitors, jealousies,  and the utter joy of  occasionally discovering  a clue  to understanding  some deep mysteries  of  nature."   In  my humble opinion  his  attempt  is  an unqualified success.

This review has appeared in Resonance - Journal of Science Education. Given the academy (Indian Academy of Sciences, publisher of Resonance) website's not too commendable connection speed, I include it below.

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A Scientific Autobiography 


Going through  "Nature's Third Cycle -  A Story of Sunspots" by Arnab Rai Choudhuri is  akin to having a  ringside  view of the  gradual unveiling of one of the abiding mysteries associated with our friendly neighbourhood star, the Sun.

In  the emergent  era  of gigantic  telescopes,  expected to straddle continents and sometimes  place another foot far beyond mother Earth, Big-data (with a definitive capital B) is inevitably giving rise to humongous collaborative groups in Astronomy & Astrophysics, the sizes of which can sometimes even  shame an  army division. The  old world scientists, working  with  a  handful  of  associates and students, building numerical codes from scratch  on their puny desktop computers are  but a vanishing breed. Arnab  Rai Choudhuri, of the Indian Institute  of Science (IISc,  Bangalore), is one of  those last Mohicans, belonging to a small minority of theoretical astrophysicists (since,  astrophysics by  its  very nature is  an  applied branch  of physics).  He has  even displayed the audacity of devoting his entire scientific career to stellar physics, wondering about the mysteries of our friendly neighbourhood Sun, an  area which  happens to be  at the bottom  of  the pecking order  as  far  as the  current Astrophysics snobbery goes.

Sun, the ultimate arbiter of human civilisation's fate, has fascinated mankind from the beginning of history.   And yet the attraction of Sun in popular  psyche has waned  over the years  to be replaced  by newer frontiers of science like cosmology. The author correctly notes that - 'the unwritten assumption (about solar physics) is that the underlying science is  a kind  of dry  boring science best  left to  the experts, unlike  the science  behind  cosmology or  particle  physics that  can excite general readers.'  So the author wishes to go against this bias by  trying his  hand  at a  popular  account of  the  physics and  the sociological effects of  the solar cycle after  writing two completely pedagogic textbooks  very well received by  practicing astrophysicists and graduate level  students (The physics of fluids  and plasma, 1998, CUP; Astrophysics for Physicists, 2010, CUP).

Our  lives  literally  revolve  around Sun,  a  rather  ordinary  main sequence star, through the  diurnal and the  annual cycles.   Both of these cycles are imposed upon us by the motion of the Earth - the spin around its own  axis, and the rotation in an elliptic path around the Sun. The  other natural cycle  is provided by  the Sun itself, in the form of the eleven year sunspot cycle which is at the heart of all the unusual solar  activities. It is  this third cycle that  Rai Choudhuri  talks about  in  his 'Nature's Third Cycle  :  A story  of sunspots' (2015,  OUP).  He accepts  the challenge of explaining  this behaviour  to  people  not  involved in solar  science  research  and intertwines this account with the tale of his own career.

Interestingly, we  have witnessed a  recent revival of an  interest in the Sun primarily because of two  reasons.  The more dramatic of these is the arrival of space weather upon us.  Solar flares launching bolts of  hot, electrified  gas stir  up magnetic  storms around  the Earth. Earlier the effects  of such space storms were hardly  noticed. But in today's electrically powered, space-based technology dependent society the impact  of the  space storm  induced by  such solar  activities is quite significant.   The other story  is related to long  term climate changes. Accumulation  of large timescale  data on climate  change and its correlation with  solar cycles has finally  brought the connection clear.  As a result, popular  accounts of the solar activity affecting climate  change, its  history and  its  effect on  space weather  have recently made  their appearance  on bookshelves  (for example,  Hoyt & Schatten 1997; Carlowicz & Lopez 2002; Brody 2002 etc.).

In contrast, `Nature's Third Cycle' in unique in its subject matter as it  explains the physics  behind  the  solar  cycle itself.   And  it certainly is not a popular science book intended for lay readers.  The author expects the readers to, at least, have worked through Resnick & Halliday (1966) (the absolute last word in high school physics) and in some  places  the  expectation  is even  higher.   The  real intended readership is the aspiring  physicists at undergraduate level upwards, the physics teachers and, of course, the practising physicists.

Sunspots are dark areas of irregular  shape on the Sun's surface, some as large as 50,000 miles (80,000 km) in diameter,i.e.,  they can even be seen  by naked eye. Their  incidence varies cyclically and  has an average  period  of  eleven  years. They  move  across  the  surface, contracting  and  expanding as  they  go  and actually  correspond  to regions of higher magnetic field that inhibit convection and result in reduced    surface   temperature    compared   to    the   surrounding photo-sphere. This is the reason they appear as dark spots compared to surrounding regions.   Because it is  rather difficult to  observe the Sun directly, records  of sunspots are almost  non-existent before the seventeenth  century but have only  been observed  through telescopes since the time of Galileo.   'Nature's Third Cycle' traces the history of sunspot  science from  the first  discoveries through  the numerous stages of  the puzzle to the  latest results on the  magnetic cycle of activity.

Magnetohydrodynamics (MHD),  governing the  behaviour of  plasma under magnetic field,  is a difficult  subject. The author manages  to bring the  basics of MHD  and dynamo  theory,  underlying the  physics  of sunspots, to a  level accessible to a  large non-technical readership. In the academic community Rai Choudhuri is known as a wonderful teacher and a brilliant scientist. He  uses his expertise as a teacher to take  the readers  effortlessly through  the complexities of solar physics.   One of the interesting  plus points  of this  book is  the section entitled "Notes" in the end. Apart from a list of popular and technical books as suggestion for further reading, the author provides a compilation  of chapter-wise appropriate research articles and his own clarifications  on various  issues. This would be  invaluable for experts and aspiring students alike.

As far as the style goes, it  is an unusual offering from a practicing scientist though  not  entirely  unexpected.  Arnab  Rai Choudhuri is known for his brutally honest opinion about everyone and everything;  sometimes  even  to the discomfiture  of  the  listeners themselves.  It is no wonder then that  he bares his soul in this book and gives the reader a glimpse of the real world of research, contrary to the  sanitary and impersonal fares  that we have typically come to expect.  I myself have seen part  of the story, narrated in this book, unfold in front of  my own eyes while I was a  graduate student in the physics  department of IISc.   And  we  all  know that  such  stories inevitably abound the corridors of every department of every research institution. On  the one hand, there  exist an unwritten code  to keep scientific writing objective  and impersonal.  On the  other hand, the practice of science  is a very human enterprise,  and personal clashes and disagreements are very much a part of this process.

To be sure, the maximal impact  of the book comes from this particular aspect as it makes the  book a compulsive reading. While this may inevitably  attract controversy, in my  view  this also  would be  of immeasurable value to those young readers  who are aspiring to take up research as their future career. Quite aptly, Nigel Weiss terms this book  as  the  'scientific  autobiography' of  Rai  Choudhuri, written  at a  time when the author  was undergoing treatment for  a life-threatening illness.

Also,  Rai  Choudhuri's  personal commentary  on the  struggling phase  of Indian academia is  quite valuable.   After completing  his graduate studies in  Chicago he made the decision to  return to India. At that time research facilities in India were limited and funding was minimal.  Yet, like many of his  peers, he and his students persevered and developed  a theoretical model  of Sun's magnetic cycle  which has been quite successful  in predicting the nature of  the upcoming solar cycle.   Over the  years Indian  research infrastructure  has improved significantly. But it needs to be remembered that the bunch of foreign returnees  like   Rai   Choudhuri  have made   an  invaluable contribution in shaping the Indian scientific  scene the way we see it today.  This historical  element,  touching upon  the  early phase  of Indian scientific research, is another invaluable aspect of this book.

There exist  some other minor points  which many people may  not agree with.  For his doctoral thesis  Rai Choudhuri worked with Eugene Parker, regarded as the most influential solar physicists of our time. He is one  of the originators of the flux  transport dynamo model, the currently favoured theoretical model of  the 11-year sunspot cycle. My personal feeling is that a  somewhat more impersonal depiction of this giant would  have been  more appropriate. Since  there does  exist the possibility of  a reader automatically assuming  a not-quite-objective view of  the author  precisely because of  his close  association with Parker.

I also  have some  reservations about the  author's faith  in citation index. It is, at best, a rather faulty indicator. We are forced to use it for  want of  something better.  But  readers outside  the research community  may not  be aware  of the pinch (or  the sackful,  that is needed in some cases)  of salt that should go with it. Moreover, for the general reader the  author order may not make much  sense. In fact in many branches  of physics the  author order is  strictly alphabetical. The Physical  Review Letters (PRL)  may not  be a very  good indicator either to illustrate the import  of a research article.  Because while PRL is arguably the last word  for areas like condensed matter physics it  certainly does  not  enjoy  the same  status in  the Astronomy  & Astrophysics community.

One  of my  minor  complaints about  this  book is  the  absence of  a photograph of  the physics department  of IISc.  Since the  author has included  a  picture  of  his  PhD institution,  it  would  have  been appropriate  to also  include a  picture of  his workplace  from where significant contribution of India to solar physics has emerged.

Physics Department (old building), IISc, Bangalore
 In summary, this  delightful, most unusual book on  the solar magnetic cycle, explains  the complex  science behind sunspots in  a wonderful manner and  goes far beyond being  a simple popular science  book.  It provides  more than  a glimpse behind  the  professional curtains  of leading scientific  research,  and  would  probably  end  up  greatly influencing many  a young minds  preparing to be the  practitioners of science in not-too-distant a future.

This review has been prepared with valuable inputs from Biman Nath and Niruj Mohan Ramanujan. The reviewer would like to thank both of them.
   

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