Nature's Third Cycle: A Story of Sunspots

The cycle of day and night and the cycle of seasons are two familiar natural cycles around which many human activities are organized. But is there a third natural cycle of importance for us humans? On 13 March 1989, six million people in Canada went without electricity for many hours: a large explosion on the sun was discovered as the cause of this blackout. Such explosions occur above sunspots, dark features on the surface of the Sun that have been observed through telescopes since the time of Galileo. The number of sunspots has been found to wax and wane over a period of 11 years. Although this cycle was discovered less than two centuries ago, it is becoming increasingly important for us as human society becomes more dependent on technology. For nearly a century after its discovery, the cause of the sunspot cycle remained completely shrouded in mystery. The 1908 discovery of strong magnetic fields in sunspots made it clear that the 11-year cycle is the magnetic cycle of the sun. It is only during the last few decades that major developments in plasma physics have at last given us the clue to the origins of the cycle and how the large explosions affecting the earth arise. Nature's Third Cycle discusses the fascinating science behind the sunspot cycle, and gives an insider's perspective of this cutting-edge scientific research from one of the leaders of the field.

Table of Contents:
Nigel Weiss: Foreword Preface 1: Explosions, blackouts and cycles 2: The mysterious sunspots 3: Here comes the sun 4: The fourth state of matter 5: Floating magnetic buoys 6: Dynamos in the sky 7: The conveyor belt inside the sun 8: A journey from the sun to the earth 9: Gazing into the crystal ball 10: Epilogue: Dynamos are forever Appendix: Technical details of some important topics

About the Author :
Arnab Rai Choudhuri is a Professor of Physics at the Indian Institute of Science. He received his PhD in 1985 from the University of Chicago under the supervision of Eugene Parker, usually regarded as the most influential solar physicist of our time. Choudhuri has carried on theoretical research on the formation of sunspots and the 11-year sunspot cycle. He was one of the originators of the flux transport dynamo model, the currently favoured theoretical model of the 11-year sunspot cycle. He is the author of two advanced textbooks, The Physics of Fluids and Plasmas (CUP, 1998) and Astrophysics for Physicists (CUP, 2010), used in many universities around the world.

Review :
Choudhuri gives us a condensed history of the study of the sun and of sunspots over the past few centuries back to Galileo Gailiei, whose discovery of the Sun's 27-day rotation marked the serious start of solar physics... The remarkable tale includes skilled amateurs as well as professional academics, the rivalries between the main players, and a probable husband-wife murder-suicide thrown into the mix. Yes, there is a lot in the story of studying the sun, and the author does a masterful job of making it a fascinating read. A fascinating, engaging and enjoyable book. I strongly recommend Nature's Third Cycle to readers who are interested in learning about solar activity, its effects on Earth, and the history of the field. It includes technical details and references for delving deeper into a fascinating topic, yet it is easy and enjoyable to read. Choudhuri (Indian Institute of Science, Bangalore) provides a very readable mixture of the physics of sunspots and the history of understanding them. ... Undergraduates and general readers interested in the human understanding of the sun and how that understanding came about will find this book worthwhile and enjoyable reading. Recommended. The book [is] an excellent account - historical, scientific and autobiographical all at the same time - an account that is not only illuminating about the Third Cycle but also makes an extremely well-told story. And it gives young students, at the threshold of their scientific careers, a feel for the nature of the human enterprise called science. Easy to read but difficult to put away ... interesting to a broad range of readers - from high-school students and curious amateurs to serious scholars and top-level professionals. The author's account of the historical development of sunspots science and solar-dynamo theory is first rate in terms of accuracy as well as the precision of the language used to describe difficult concepts verbally. ... Choudhuri is strong in his explanations of the basic physics behind the observed phenomena. The scientific detective work investigating the structure and activity of the Sun is a mystery story that should not be missed. 'Nature's Third Cycle' is an outstanding account of the case, carrying the reader from the first discoveries through the numerous stages of the puzzle to the latest results on the magnetic cycle of activity. This is a highly engaging and informative account of the fascinating discoveries that have been made about the nature of the Sun and its spots, enlivened by the often colourful characters who have striven to understand it, and woven together with the author's personal story which is honestly told and frequently moving. No astrophysical process other than the solar cycle has left massive footprints on our living environment. Arnab tells many stories about eminent astrophysicists, their personal lives and their ceaseless striving for new understanding and scientific truth. The tales about his supervisor, the giant Eugene Parker and his own scientific career are so vivid and engaging with his own style - frank, honest, enthusiastic and ready for scientific debate. Our Sun influences the climate and space environment of the Earth in profound ways. In his wonderful popular book on science, Choudhuri describes the history and current understanding of the sunspot cycle, and skilfully weaves in the tale of his own career with its hopes and fears, difficulties and joys. ... makes compulsive reading. Arnab Rai Choudhuri has succeeded in producing an interesting and instructive book. He writes in an engaging style and his own personal tale will carry readers through the scientific details. This delightful, most unusual book on the solar magnetic cycle, provides more than a glimpse behind the professional curtains of leading scientific research, as it is also a scientific autobiography, sharing the excitement of discovery, the dismay of not being understood and believed at first, scientific debate and rivalry among leading teams, and the joy of triumph having been proven right in forecasting the behaviour of the solar cycle. It is a most enjoyable book, which I wholeheartedly recommend. This captivating book immerses the readers in the development of solar physics as though they were participating in a theatre play. Many personal memories provide fascinating links to the historical development of solar science. It is a book hard to put down once started! Going through Nature's Third Cycle - A Story of Sunspots by Arnab Rai Choudhuri is equivalent to having a ringside view of the gradual unveiling of one of the abiding mysteries associated with the Sun ... 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. This [book] establishes new (unprecedentedly high) standards of scientific writing ... Already in the beginning, the reviewer has to tell that this book is among the best he has ever taken in his hands ... It should be stressed that reading this book will be easy for geoscientists ... [and] will attract more young people to science. I recommend this book to anyone who wishes to gain an insight into the physics behind the solar cycle. . .This is the best book I have read on this topic.