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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 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.
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.
294 pages, Hardcover
First published November 28, 2014
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Displaying 1 - 14 of 14 reviews
May 24, 2019
Science reveals itself, if we only take the time and listen to what it has to say. This book is an extraordinary detective story that reveals itself over 10 or so chapters and gets at how we know what we think we know about the sun and its phenomena and shows science revealing itself in an incredibly exciting way.
One can read a dry book such as ‘Philosophy of Science’ by Curd to understand the nature of science (I actually would highly recommend that book) or one can read this incredibly well told, informative and somewhat exciting detective story on how science actually works in the real world and what it requires in order to create a compelling narrative that is fact based, keeps the story simple, makes predictions about the real world, accurately correlates with what we know, and fits into the broader context of the story that's been told.
Facts about the real world never live by themselves. They have a history and a current background and must ultimately fit into the web of science such that they hold together with coherence. The author gives the reader a history of how we thought about the sun and then empirical facts and heuristic interpretations of what the models say and why they are reasonable and relevant to understanding the sun.
I’ll tell you why this book works. As he teaches the science of the esoteric (MHD, sunspots, solar flares), he is teaching the reader about atoms, EM, Maxwell equations and other interesting things making them relevant to what he is explaining and seamlessly connecting everything into the web of knowledge. Science is messy as it advances. The author shares biographical sketches of himself. They add greatly to the story telling. He tells about his advisor and a student who are in a spat with him. The personnel always matters even when we strive for pure objectivity in the pursuit of scientific certainty.
I want to summarize. This is an extraordinarily good science book. The science of sun spots is great by itself. The philosophy of science that gets revealed is great by itself. The auxiliary science that gets explained is great by itself. The pettiness between competing teams of scientist revealing how real science actually works is fascinating (the author goes out of his way not to cast blame or just tell his side of the story). The detective story that gets revealed over 10 chapters is great by itself. Overall, one of the better pop-science books I’ve read.
One can read a dry book such as ‘Philosophy of Science’ by Curd to understand the nature of science (I actually would highly recommend that book) or one can read this incredibly well told, informative and somewhat exciting detective story on how science actually works in the real world and what it requires in order to create a compelling narrative that is fact based, keeps the story simple, makes predictions about the real world, accurately correlates with what we know, and fits into the broader context of the story that's been told.
Facts about the real world never live by themselves. They have a history and a current background and must ultimately fit into the web of science such that they hold together with coherence. The author gives the reader a history of how we thought about the sun and then empirical facts and heuristic interpretations of what the models say and why they are reasonable and relevant to understanding the sun.
I’ll tell you why this book works. As he teaches the science of the esoteric (MHD, sunspots, solar flares), he is teaching the reader about atoms, EM, Maxwell equations and other interesting things making them relevant to what he is explaining and seamlessly connecting everything into the web of knowledge. Science is messy as it advances. The author shares biographical sketches of himself. They add greatly to the story telling. He tells about his advisor and a student who are in a spat with him. The personnel always matters even when we strive for pure objectivity in the pursuit of scientific certainty.
I want to summarize. This is an extraordinarily good science book. The science of sun spots is great by itself. The philosophy of science that gets revealed is great by itself. The auxiliary science that gets explained is great by itself. The pettiness between competing teams of scientist revealing how real science actually works is fascinating (the author goes out of his way not to cast blame or just tell his side of the story). The detective story that gets revealed over 10 chapters is great by itself. Overall, one of the better pop-science books I’ve read.
May 8, 2019
I would call this book on sunspots, by Arnab Choudhuri an important, seminal work that probably is not on everyone's radar, the way other physics/cosmology books are, but definitely should be. Since I was unfamiliar with so much of his work, I had to read this book twice to really begin to understand what is happening on the surface of the sun.
In Nature's Third Cycle, Choudhuri describes his work on understanding how sunspots form. In doing so, he highlights the career of his mentor, Eugene Parker (who I now adore).
Sunspot cycles are important because they cause lasting changes to Earth's climate. This work, as you can imagine, is being hijacked by global warming denialists, who suggests sunspots are THE reason for global warming. As annoying as that is, the magnetic fields that give rise to sunspots and the temperature changes that result are endlessly fascinating. For example, Choudhuri related a story about Stradivarius violins, which are worth millions. There is no doubt that Stradivarius was an exceptional violin maker. However, it is also true that when Stradivarius made his violins, sunspots had disappeared for an unusually long time period, which cause a climate change on Earth called " the Little Ice Age". During this cold stretch, the chemical properties the Spruce woods was different from when spruce woods grow in average temps. It was this wood that Stradivarius used in making his violins. Some experts suggest that this is a key reason they have provided the world's best violin sound quality, which has never been surpassed. He says that even if this is not true, it's a fun story to talk about at dinner parties. I agree.
Aside from the Little Ice Age, which occurred from about 1650 to 1700, sunspots have an 11 year cycle (which if you read the book, you learn that is actually a 22 year cycle), in which magnetic fields emerge on the sun's surface. These fields are called the toroidal field and poloidal field. Just as Earth's magnetic poles flip, so too do the poles on the sun. The toroidal field gives rise to the poloidal field. In turn the poloidal field gives rise to the toroidal field.
Choudhuri would call the following the central dogma of sunspot research:
"The toroidal magnetic gives rise to poloidal magnetic field. In turn, the poloidal magnetic field comes from toroidal. Sunspots form out of the toroidal magnetic field, whereas the polar magnetic field of the sun is a manifestation of the poloidal field. The sunspot cycle is produced by an oscillation between these two kinds of magnetic fields, by some process. In its turn, the toroidal magnetic field also gives rise to the poloidal magnetic field by some other process, so the cycle goes on. "
These sunspots affect the earth as much as the other 2 cycles, diurnal and annual, because lasting climate changes affect patterns of life. Sunspots also cause geomagnetic storms on Earth, which are going to be more problematic as we depend more on electricity and technology-- because these things are affected by geomagnetic storms. It was long thought that what happens on the sun has no baring on Earth. Even the great Lord Kelvin forcefully argued that sunspots and other sun events could not affect Earth. He assumed there was nothing between the sun and Earth. But, then solar winds were discovered. These solar winds, which take 3 days to reach Earth, are what bring the geostorms we experience (about 3 days after) a solar flare.
Choudhuri reminded his reader how long it took to understand magnetic fields on our planet and then talked about how much more difficult it was to understand the magnetic fields of the sun.
Choudhuri claims to not know much of sunspot history. However he has provided here, in this beautiful book, a fairly complete, entertaining, and informative history of the scientists who worked to understand sunspots. This history is as good or better than any science history I have ever read. I want to summarize the whole history of sunspots because both the discoveries and the personal lives of the scientists were captivating.
As briefly as I can possibly put it, here is the history of sunspot research:
800 BCE, Chinese court astrologers notice sunspots. Began keeping a record! (Impressive)
1128, John of Worcester made the first drawings of sunspots.
1600, William Gilbert proposed that the earth was a magnet. (They thought it was one gigantic loadstone, but at least they were starting to understand).
1610, Galileo began a study of sunspots using the telescope.
In 1630 Christoph Scheiner discovered sunspots and rushed to talk to his local priest/Jesuit. Things did not go well. Scheiner needed permission from the Jesuit priest in order to publish his findings. He was denied this request with the following admonishment from his priest:
"I have read my Aristotle from end to end and I can assure you that I never found in it anything similar to what you mentioned . Go and calm yourself my son and be assured that what you take for spots on the sun our faults on your glasses or your eyes."
All Scheiner could do was anonymously publish a secret pamphlet. (So much animosity between the scientific community and the church who continually tried to suppress any new discovery about our wonderful universe.)
1844, Schwabe discovered sunspots cycle of 11 years.
1859, Richard Carrington observed the first solar flare ever observed. this story was shocking in every detail. His personal and professional life is something about which I feel as if I must now read an entire book.
Carrington's history was a definitely highlight of this book
1890, Lord Kelvin "proved" that solar disturbances could not affect the earth..... but he was wrong.
1908 Hale discovered that sunspots have strong magnetic fields, which really fast forwarded research into sunspots because magnetism is key.
Hale also realized what looked like an 11 yr cycle was really a 22 yr cycle. The key to this finding was understanding magnetism on the sun and understanding that poles can flip.
Hale's personal story was almost as interesting as Richard Carrington's. His rise to fame and his construction of the Mount Wilson Observatory was told so beautifully, I welled up tears of joy while reading. He, along with Hubble, started the Astrophysical Journal. His career was tragically cut short. I was devastated by the time Choudhuri was finished with Hale's story.
1933 Cowling announced famous antidynamo theorem
1955 Parker developed the dynamo equations and proposed the first theoretical model of the sunspot cycle.
1958 Parker developed The theory of the solar wind which was discovered in a few years later.
Lord Kelvin and Herman Helmholtz, who realized that if energy is conserved, then some other type of energy must be driving the song. Some other energy from the interior of the sun must be converted . Into heat and light. Helmholtz and Lord Kelvin were both studying the new field of thermodynamics at the time. They identified this energy as gravitational energy.
In addition to adding details about the personal lives in sunspot researchers throughout history, Choudhuri also wrote about his own personal experiences. That alone was worth reading. He talked about the awe he felt when working certain researchers, the conflicts (shocking) he had with colleagues, the excitement of breakthroughs, the angst he felt over trying to decide if he wanted to make his life easy and work on sunspots here in America (having access to the right scientific tools, grants, fully funded labs, etc) or going back to India to try to help the country participate in important science.
One thing I had not thought much about were the H and K absorption lines in the spectra of stars, like our sun. Choudhuri mentioned this at the end of the book, but didn't pay it nearly as much attention as I would have liked. Learning about these, in great detail, has become an absolute obsession for me in the past month since I finished reading this book. I think a whole book could be written about this process. I thank Choudhuri for piquing my interest.
In Nature's Third Cycle, Choudhuri describes his work on understanding how sunspots form. In doing so, he highlights the career of his mentor, Eugene Parker (who I now adore).
Sunspot cycles are important because they cause lasting changes to Earth's climate. This work, as you can imagine, is being hijacked by global warming denialists, who suggests sunspots are THE reason for global warming. As annoying as that is, the magnetic fields that give rise to sunspots and the temperature changes that result are endlessly fascinating. For example, Choudhuri related a story about Stradivarius violins, which are worth millions. There is no doubt that Stradivarius was an exceptional violin maker. However, it is also true that when Stradivarius made his violins, sunspots had disappeared for an unusually long time period, which cause a climate change on Earth called " the Little Ice Age". During this cold stretch, the chemical properties the Spruce woods was different from when spruce woods grow in average temps. It was this wood that Stradivarius used in making his violins. Some experts suggest that this is a key reason they have provided the world's best violin sound quality, which has never been surpassed. He says that even if this is not true, it's a fun story to talk about at dinner parties. I agree.
Aside from the Little Ice Age, which occurred from about 1650 to 1700, sunspots have an 11 year cycle (which if you read the book, you learn that is actually a 22 year cycle), in which magnetic fields emerge on the sun's surface. These fields are called the toroidal field and poloidal field. Just as Earth's magnetic poles flip, so too do the poles on the sun. The toroidal field gives rise to the poloidal field. In turn the poloidal field gives rise to the toroidal field.
Choudhuri would call the following the central dogma of sunspot research:
"The toroidal magnetic gives rise to poloidal magnetic field. In turn, the poloidal magnetic field comes from toroidal. Sunspots form out of the toroidal magnetic field, whereas the polar magnetic field of the sun is a manifestation of the poloidal field. The sunspot cycle is produced by an oscillation between these two kinds of magnetic fields, by some process. In its turn, the toroidal magnetic field also gives rise to the poloidal magnetic field by some other process, so the cycle goes on. "
These sunspots affect the earth as much as the other 2 cycles, diurnal and annual, because lasting climate changes affect patterns of life. Sunspots also cause geomagnetic storms on Earth, which are going to be more problematic as we depend more on electricity and technology-- because these things are affected by geomagnetic storms. It was long thought that what happens on the sun has no baring on Earth. Even the great Lord Kelvin forcefully argued that sunspots and other sun events could not affect Earth. He assumed there was nothing between the sun and Earth. But, then solar winds were discovered. These solar winds, which take 3 days to reach Earth, are what bring the geostorms we experience (about 3 days after) a solar flare.
Choudhuri reminded his reader how long it took to understand magnetic fields on our planet and then talked about how much more difficult it was to understand the magnetic fields of the sun.
Choudhuri claims to not know much of sunspot history. However he has provided here, in this beautiful book, a fairly complete, entertaining, and informative history of the scientists who worked to understand sunspots. This history is as good or better than any science history I have ever read. I want to summarize the whole history of sunspots because both the discoveries and the personal lives of the scientists were captivating.
As briefly as I can possibly put it, here is the history of sunspot research:
800 BCE, Chinese court astrologers notice sunspots. Began keeping a record! (Impressive)
1128, John of Worcester made the first drawings of sunspots.
1600, William Gilbert proposed that the earth was a magnet. (They thought it was one gigantic loadstone, but at least they were starting to understand).
1610, Galileo began a study of sunspots using the telescope.
In 1630 Christoph Scheiner discovered sunspots and rushed to talk to his local priest/Jesuit. Things did not go well. Scheiner needed permission from the Jesuit priest in order to publish his findings. He was denied this request with the following admonishment from his priest:
"I have read my Aristotle from end to end and I can assure you that I never found in it anything similar to what you mentioned . Go and calm yourself my son and be assured that what you take for spots on the sun our faults on your glasses or your eyes."
All Scheiner could do was anonymously publish a secret pamphlet. (So much animosity between the scientific community and the church who continually tried to suppress any new discovery about our wonderful universe.)
1844, Schwabe discovered sunspots cycle of 11 years.
1859, Richard Carrington observed the first solar flare ever observed. this story was shocking in every detail. His personal and professional life is something about which I feel as if I must now read an entire book.
Carrington's history was a definitely highlight of this book
1890, Lord Kelvin "proved" that solar disturbances could not affect the earth..... but he was wrong.
1908 Hale discovered that sunspots have strong magnetic fields, which really fast forwarded research into sunspots because magnetism is key.
Hale also realized what looked like an 11 yr cycle was really a 22 yr cycle. The key to this finding was understanding magnetism on the sun and understanding that poles can flip.
Hale's personal story was almost as interesting as Richard Carrington's. His rise to fame and his construction of the Mount Wilson Observatory was told so beautifully, I welled up tears of joy while reading. He, along with Hubble, started the Astrophysical Journal. His career was tragically cut short. I was devastated by the time Choudhuri was finished with Hale's story.
1933 Cowling announced famous antidynamo theorem
1955 Parker developed the dynamo equations and proposed the first theoretical model of the sunspot cycle.
1958 Parker developed The theory of the solar wind which was discovered in a few years later.
Lord Kelvin and Herman Helmholtz, who realized that if energy is conserved, then some other type of energy must be driving the song. Some other energy from the interior of the sun must be converted . Into heat and light. Helmholtz and Lord Kelvin were both studying the new field of thermodynamics at the time. They identified this energy as gravitational energy.
In addition to adding details about the personal lives in sunspot researchers throughout history, Choudhuri also wrote about his own personal experiences. That alone was worth reading. He talked about the awe he felt when working certain researchers, the conflicts (shocking) he had with colleagues, the excitement of breakthroughs, the angst he felt over trying to decide if he wanted to make his life easy and work on sunspots here in America (having access to the right scientific tools, grants, fully funded labs, etc) or going back to India to try to help the country participate in important science.
One thing I had not thought much about were the H and K absorption lines in the spectra of stars, like our sun. Choudhuri mentioned this at the end of the book, but didn't pay it nearly as much attention as I would have liked. Learning about these, in great detail, has become an absolute obsession for me in the past month since I finished reading this book. I think a whole book could be written about this process. I thank Choudhuri for piquing my interest.
March 21, 2019
A well-written and non-technical overview of solar physics. This is a book for a general audience but pitched about right for readers with a reasonable conceptual grasp of physics (angular momentum, gas laws, the relationship between electric and magnetic fields...)
The author chose to structure the book along historical and autobiographical lines, which worked quite well. It gives the book something of a narrative flow, and does a superb job of presenting science as a process of building and testing models. He also gives some insight into the sociology of science on an international scale through his own life experiences.
The author chose to structure the book along historical and autobiographical lines, which worked quite well. It gives the book something of a narrative flow, and does a superb job of presenting science as a process of building and testing models. He also gives some insight into the sociology of science on an international scale through his own life experiences.
January 3, 2018
An unusual book
Click the above link to read about the author (who happens
to be my university professor) and my formal review of this book.
Click the above link to read about the author (who happens
to be my university professor) and my formal review of this book.
May 28, 2018
Obviously loved the book. Given the illustrious career of the author and the impeccable writing style there was no other way but to fall in love with it.
I first came to know about the book the author himself when he asked us to refer it and one other technical book, at the end of his presentation at IAUS Symposium 340. I am an aspiring Astrophysicist and the subject matter on which Sir was given the lecture and the subject matter of this book, have the interests of mine since a long time. Finishing this book now presents me with all the numerous topics and things that were heather-to unknown to me. I especially liked the impressive further reading section and the notes, where the author has provided the references of his studies. Also, the appendices at the end of the book act as the much sought after technical explanations.
The chapters are very well designed and tell the reader the whole story of the Sunspot Cycle and much more very effectively. The author also manages to include a little about his own life, career and experience in a seemingly third world nation. All in all, the book is must read for anyone interested in the mysteries of the beautiful world we live in.
I first came to know about the book the author himself when he asked us to refer it and one other technical book, at the end of his presentation at IAUS Symposium 340. I am an aspiring Astrophysicist and the subject matter on which Sir was given the lecture and the subject matter of this book, have the interests of mine since a long time. Finishing this book now presents me with all the numerous topics and things that were heather-to unknown to me. I especially liked the impressive further reading section and the notes, where the author has provided the references of his studies. Also, the appendices at the end of the book act as the much sought after technical explanations.
The chapters are very well designed and tell the reader the whole story of the Sunspot Cycle and much more very effectively. The author also manages to include a little about his own life, career and experience in a seemingly third world nation. All in all, the book is must read for anyone interested in the mysteries of the beautiful world we live in.
May 2, 2020
A book which I would recommend any aspiring solar physics student to read. You shouldn't substitute this for a textbook (as the author himself hints), but it will most probably cause you to pick up a textbook. In addition to the science concepts, the author also presents a summary of the whole field of solar activity evolved over the years. Aspirant readers may also benefit from a first-person-view of scientific work culture and associated procedures.
tl;dr: Has autobiographical content and the history of the field. Concepts are brilliantly explained and represented with a flow. Amateur enthusiasts are suggested to read.
tl;dr: Has autobiographical content and the history of the field. Concepts are brilliantly explained and represented with a flow. Amateur enthusiasts are suggested to read.
September 21, 2019
Great overview on sun science.
December 2, 2019
Quality evaluation of the state of Solar/Magnetic understanding, but most critically the connection between Solar Activity and Climate
to-finish-reading
July 13, 2022"Light or any other signal will not be able to escape from the surrounding region. We call such an object a black hole." What about gravity? Gravity is "able to 'escape' from" a black hole... "Nobody [in the beginning of the 19th century] bothered about the origin of life because it was believed that living creatures spontaneously arise out of inanimate matter." Don't "scientists" still believe the same thing? But instead of "rotten meat broth" it's the primordial soup? "Light is a form of electromagnetic wave." I thought was in discrete quantized packets known as photons? "Almost everyone in the ancient world held (and, unfortunately, quite a few even today hold) the view that stars can influence our lives." The stars we are born under DO indeed have a considerable influence on are lives, this is a proven fact, since they correspond with the seasons. Heliologists should stick to what they know.
Notes:
1. While Bishop Ussher believed that God created the world on 10/23/4004 BC, "science's darling" Isaac Newton believed that God created the world on c. 4000 BC.
2. Neutrinos have never been directly observed, their "detection" has only been inferred.
Notes:
1. While Bishop Ussher believed that God created the world on 10/23/4004 BC, "science's darling" Isaac Newton believed that God created the world on c. 4000 BC.
2. Neutrinos have never been directly observed, their "detection" has only been inferred.
March 7, 2022
Once upon a time, people would worship the sun as a deity. It provided much of what sustains life on our planet. Then came industrialization and we mostly forgot the sun. But just because we stopped paying attention doesn't mean that it lost any of its importance or the fact that the sun is far more complex than many realize. That's why Choudhuri's handy and important book is worth a read.
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. Not too shabby when many scientific books do more to muddle the reader than to enlighten.
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. Not too shabby when many scientific books do more to muddle the reader than to enlighten.
May 21, 2020
One of the best popular science books that I have read so far. It gives a personal and exciting account of how our understanding of the Solar magnetic fields has evolved in the last few decades and what are its implications for us. The explanations in the book are physically insightful and easy to grasp. Highly recommended to all who are interested in astrophysics.
December 31, 2022
One of the best books I have read to date on the Sun. It explains very clearly and in simple language the magnetic activity of the Sun. Fascinating read.
December 14, 2024
A great introduction to the solar science with historical context and it's not too heavy on the equations. And a gripping personal tale to boot!
Displaying 1 - 14 of 14 reviews