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El pequeño libro de los agujeros negros
Si hay algún fenómeno de la Física y la Astronomía que intriga y fascina al hombre, este es el de los agujeros negros, y fue Albert Einstein, cuando hace más de cien años elaboró la Teoría de la Relatividad, el primer científico que predijo su existencia como solución a sus ecuaciones. Steven S. Gubser y Frans Pretorius arrojan luz sobre uno de los mayores misterios del universo a través de ejemplos creativos y accesibles.
224 pages, Paperback
Published February 1, 2019
102 people are currently reading
1772 people want to read
About the author
Steven S. Gubser
5 books15 followersSteven Scott Gubser (May 4, 1972 – August 3, 2019) was a professor of physics at Princeton University.
His research focused on theoretical particle physics, especially string theory, and the AdS/CFT correspondence. He was a widely cited scholar in these and other related areas.
Gubser did foundational work in the AdS/CFT correspondence as a graduate student. In particular, his 1998 paper Gauge Theory Correlators from Non-Critical String Theory with his advisor Igor Klebanov and another Princeton physics professor Alexander Markovich Polyakov, made a precise statement of the AdS/CFT duality. It is one of the all-time top cited papers in theoretical high-energy physics, and is commonly known, along with Edward Witten's 1998 work Anti De Sitter Space and Holography, as the GKPW dictionary. After receiving a Ph.D. in 1998 from Princeton, Gubser became a Junior Fellow at Harvard University before taking a position as an assistant professor at Princeton. In 2001, he moved to the California Institute of Technology but returned to Princeton in 2002.
His research focused on theoretical particle physics, especially string theory, and the AdS/CFT correspondence. He was a widely cited scholar in these and other related areas.
Gubser did foundational work in the AdS/CFT correspondence as a graduate student. In particular, his 1998 paper Gauge Theory Correlators from Non-Critical String Theory with his advisor Igor Klebanov and another Princeton physics professor Alexander Markovich Polyakov, made a precise statement of the AdS/CFT duality. It is one of the all-time top cited papers in theoretical high-energy physics, and is commonly known, along with Edward Witten's 1998 work Anti De Sitter Space and Holography, as the GKPW dictionary. After receiving a Ph.D. in 1998 from Princeton, Gubser became a Junior Fellow at Harvard University before taking a position as an assistant professor at Princeton. In 2001, he moved to the California Institute of Technology but returned to Princeton in 2002.
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Displaying 1 - 30 of 69 reviews
October 13, 2017
Last week, I was chatting with B, a CERN friend. It was the day after the announcement of the 2017 Nobel Prize for Physics, and, without really thinking about it, I asked him whether he'd correctly guessed the winner in advance. B's reaction surprised me. Instead of saying that it was obviously a slam-dunk, who else was in the running but the gravitational wave people, he bristled and told me curtly that he didn't see why they deserved this honor. Wasn't the Nobel Prize supposed to be about making discoveries that benefit mankind? B's answer was absurd at so many levels that I couldn't even process it, and wondered what the hell was going on. Luckily, I didn't have to wonder for long; after reading this short but informative book, I'm up to speed. Previously, I'd known only the bare bones of the story - a large international team had built a gravitational wave detector which managed to detect a collision between two black holes - but now I was able to appreciate just how extraordinary that was, and why even people at mighty CERN might be feeling worried that someone had upstaged them.
The book starts off slowly for the benefit of readers who don't know any relativity theory, and for the first couple of chapters I felt a little impatient: I'd seen it all before. But as it progressed, there were more and more things that I didn't already know, and by the time we got to the central chapter on black hole mergers I was reading it with the rapt attention of a 10 year old science geek. Rather like the book, a black hole merger begins quietly, with two black holes orbiting each other and gradually getting closer as they lose energy through gravitational radiation. This "inspiral" phase takes billions of years; but as the distance between the black holes gets smaller, the rate of energy loss increases, and things move faster and faster. The final phase is so cataclysmic that even a supernova is tame in comparison. Whipping round each other at 60% of the speed of light, the black holes complete their last few orbits in less than a minute. At the end, when the actual merge takes place, the system converts the equivalent of two or three times the mass of the sun into gravitational waves within a second; it briefly manages to exceed the combined power output of every other star in the universe. Click on the picture below to see a stunning computer simulation of what this would look like to a nearby observer. If I understand correctly, it's not speeded up, it's real time.
Until 2015, we were blind to the gravitational wave spectrum and unable to perceive these majestic events that are happening all around us. Since then, three more have already been discovered. It's a completely new way of seeing the cosmos; people are comparing it with the invention of the telescope. The difference, unfortunately, is that a gravitational wave detector is not a tube with a piece of glass at each end, but a huge machine that spreads over several square kilometers and costs hundreds of millions of dollars to build. Despite the expense, new detectors are rapidly being constructed. This is a game that a lot of researchers want to get into.
Well, I can see why the CERN people are unhappy. Particle accelerators suddenly feel so twentieth century.
The book starts off slowly for the benefit of readers who don't know any relativity theory, and for the first couple of chapters I felt a little impatient: I'd seen it all before. But as it progressed, there were more and more things that I didn't already know, and by the time we got to the central chapter on black hole mergers I was reading it with the rapt attention of a 10 year old science geek. Rather like the book, a black hole merger begins quietly, with two black holes orbiting each other and gradually getting closer as they lose energy through gravitational radiation. This "inspiral" phase takes billions of years; but as the distance between the black holes gets smaller, the rate of energy loss increases, and things move faster and faster. The final phase is so cataclysmic that even a supernova is tame in comparison. Whipping round each other at 60% of the speed of light, the black holes complete their last few orbits in less than a minute. At the end, when the actual merge takes place, the system converts the equivalent of two or three times the mass of the sun into gravitational waves within a second; it briefly manages to exceed the combined power output of every other star in the universe. Click on the picture below to see a stunning computer simulation of what this would look like to a nearby observer. If I understand correctly, it's not speeded up, it's real time.
Until 2015, we were blind to the gravitational wave spectrum and unable to perceive these majestic events that are happening all around us. Since then, three more have already been discovered. It's a completely new way of seeing the cosmos; people are comparing it with the invention of the telescope. The difference, unfortunately, is that a gravitational wave detector is not a tube with a piece of glass at each end, but a huge machine that spreads over several square kilometers and costs hundreds of millions of dollars to build. Despite the expense, new detectors are rapidly being constructed. This is a game that a lot of researchers want to get into.
Well, I can see why the CERN people are unhappy. Particle accelerators suddenly feel so twentieth century.
September 10, 2021
The authors are experts on black holes and provide a succinct 170-page analysis of what physicists know about these enigmatic objects at least as of 2017. Nobel Prize winning physicist and mathematician Roger Penrose states on the dust jacket “I warmly recommend it to the general reader.” While the book is written for the non-scientist, I doubt this dense presentation will appeal to most general readers. With that said I think laypeople with a deep interest in the physics of black holes will find this a very worthwhile book.
The book dedicates the first two chapters to the review of special relativity and general relativity, both necessary to follow the discussions in the rest of the book. These chapters are straightforward, but will be best appreciated by those already familiar with the topics. They cover a lot of ideas in a small space. While there is little math, Einstein’s general relativity equation is presented and explained in broad terms. A solution to his field equations that define the curvature of spacetime in relation to matter gave birth to the idea of the black hole. We are introduced to the concepts of gravitational redshift aka gravitational time dilation and the equivalence principle which are important to understanding the geometric curvature of spacetime that is a black hole.
The authors discuss the different types of black holes, particularly the Schwarzschild black hole which is static and the Kerr black hole which spins and is common in the universe. We learn about their geometries, impact on spacetime and matter, thermodynamics, and entropy. We even get a brief exploration of using quantum mechanics to analyze the singularity within the black hole. General Relativity breaks down at the singularity where time ends. The authors are clearly excited by black hole collisions and the resultant gravity waves as recently discovered by the Laser Interferometer Gravitational Wave Observatory (LIGO). They believe gravity wave detection will improve and, in the future, allow collisions of neutron stars to be observed.
While this is more of a physicist’s discussion than a cosmologist’s, they do discuss the evolution of stars leading to black holes. They also leave us with the mystery of the origin of massive black holes at the center of galaxies. And while there is little lighthearted speculation in the book, they do ask “What really lies inside them? What would it be like to fall into one? Or – is it possible we’ve already fallen in and just don’t know it yet.”
The book dedicates the first two chapters to the review of special relativity and general relativity, both necessary to follow the discussions in the rest of the book. These chapters are straightforward, but will be best appreciated by those already familiar with the topics. They cover a lot of ideas in a small space. While there is little math, Einstein’s general relativity equation is presented and explained in broad terms. A solution to his field equations that define the curvature of spacetime in relation to matter gave birth to the idea of the black hole. We are introduced to the concepts of gravitational redshift aka gravitational time dilation and the equivalence principle which are important to understanding the geometric curvature of spacetime that is a black hole.
The authors discuss the different types of black holes, particularly the Schwarzschild black hole which is static and the Kerr black hole which spins and is common in the universe. We learn about their geometries, impact on spacetime and matter, thermodynamics, and entropy. We even get a brief exploration of using quantum mechanics to analyze the singularity within the black hole. General Relativity breaks down at the singularity where time ends. The authors are clearly excited by black hole collisions and the resultant gravity waves as recently discovered by the Laser Interferometer Gravitational Wave Observatory (LIGO). They believe gravity wave detection will improve and, in the future, allow collisions of neutron stars to be observed.
While this is more of a physicist’s discussion than a cosmologist’s, they do discuss the evolution of stars leading to black holes. They also leave us with the mystery of the origin of massive black holes at the center of galaxies. And while there is little lighthearted speculation in the book, they do ask “What really lies inside them? What would it be like to fall into one? Or – is it possible we’ve already fallen in and just don’t know it yet.”
March 6, 2021
Black holes are some of the most mysterious objects in the known universe. Since Einstein’s general relativity was first published in 1915 our knowledge of black holes has vastly improved. Exactly a hundred years later, gravitational waves from two massive black holes merging were detected. Each of these black holes had about 30 times the mass of the sun and the event took place approximately two billion years ago. That’s incredible.
This book starts with two chapters on special relativity and general relativity. These serve as a good introduction to relativity for someone who doesn’t know much of the subject (or needs at least a reminder), though it is advisable to have read about relativity before. The authors aren’t afraid of presenting technical terms, including some occasional equations, always taking the time to convey their meaning. Various terms that science writers usually avoid, such as tensors, the lapse function and the metric of general relativity (just to name a few) get a mention.
I thought that the best descriptions were presented in the two chapters dealing with Schwarzchild’s static black hole and Kerr’s rotating black hole solutions. The authors do a good job at guiding the reader through the properties of each of these black hole solutions, while also explaining the consequences. I was surprised at how much detail was actually presented, as in most popular science books these topics are often oversimplified, and I found it particularly interesting to read about frame dragging near rotating black holes.
The remainder of the book takes a tour through some of the observed black holes in the universe, namely the ones found at Cyg X-1 (a system involving a star with 20 solar masses and its “invisible” companion, a black hole with about 15 solar masses) and M87 (the origin of the first ever picture taken of a black hole by the Event Horizon Telescope), the gravitational waves detected by LIGO during the merging of two black holes, and some other theories which also involve black hole thermodynamics and quantum mechanics, with Hawking’s radiation (among other topics) getting a central role in the final chapter. All of these various subjects are well described, while always remaining engaging.
Overall, I found this to be a captivating book about a topic which is both mysterious and fascinating, and the best one I’ve read of the sort. It’s short, but informative and my knowledge of the subject has greatly improved. If you’ve read some physics books (namely, about relativity), are not afraid of a few equations and technical terms here and there (which the authors take time to explain), and want to deepen your knowledge of black holes, then this is the book you should read.
This book starts with two chapters on special relativity and general relativity. These serve as a good introduction to relativity for someone who doesn’t know much of the subject (or needs at least a reminder), though it is advisable to have read about relativity before. The authors aren’t afraid of presenting technical terms, including some occasional equations, always taking the time to convey their meaning. Various terms that science writers usually avoid, such as tensors, the lapse function and the metric of general relativity (just to name a few) get a mention.
I thought that the best descriptions were presented in the two chapters dealing with Schwarzchild’s static black hole and Kerr’s rotating black hole solutions. The authors do a good job at guiding the reader through the properties of each of these black hole solutions, while also explaining the consequences. I was surprised at how much detail was actually presented, as in most popular science books these topics are often oversimplified, and I found it particularly interesting to read about frame dragging near rotating black holes.
The remainder of the book takes a tour through some of the observed black holes in the universe, namely the ones found at Cyg X-1 (a system involving a star with 20 solar masses and its “invisible” companion, a black hole with about 15 solar masses) and M87 (the origin of the first ever picture taken of a black hole by the Event Horizon Telescope), the gravitational waves detected by LIGO during the merging of two black holes, and some other theories which also involve black hole thermodynamics and quantum mechanics, with Hawking’s radiation (among other topics) getting a central role in the final chapter. All of these various subjects are well described, while always remaining engaging.
Overall, I found this to be a captivating book about a topic which is both mysterious and fascinating, and the best one I’ve read of the sort. It’s short, but informative and my knowledge of the subject has greatly improved. If you’ve read some physics books (namely, about relativity), are not afraid of a few equations and technical terms here and there (which the authors take time to explain), and want to deepen your knowledge of black holes, then this is the book you should read.
October 13, 2017
I am always suspicious when a book has a comment on the back from a physics professor recommending it for the 'general reader', as in my experience, physics professors have little clue as to what works for a non-technical audience. But in the case of The Little Book of Black Holes, Roger Penrose has got it right... with one proviso. As long as the general reader has absorbed a good popular science title on special and general relativity first.
Without ever venturing into heavyweight maths, Steven Gubser and Frans Pretorius take us through the way that both Schwarzschild's non-rotating black hole and Kerr's rotating version were derived from Einstein's equations. And they help the reader explore many of the implications for such a body were it to exist in the real universe, from familiar aspects such as time dilation to the delightful zoom-whirl orbit. For an unfortunate individual passing towards the singularity we not only get spaghettification (though not named as such) but also consideration of what you would see when looking out of the hole and what influence matter outside a rotating black hole would have on a traveller within the event horizon.
Add in a chapter on gravitational waves, giving more detail of the mechanism that is normally provided, very timely given the recent discoveries and Nobel Prize, plus consideration of charged black holes and black hole thermodynamics, and it's clear that this is really will take the knowledge of anyone with a serious interest in black holes up to the next level. The presentation is not always 100 per cent clear - there are times when the authors think they've explained something but they haven't - yet on the whole, if you already have the basics and take it slowly, this will be a revelation.
So, The Little Book is genuinely fascinating and insightful stuff - but it is necessary to have read the background material elsewhere first. Gubser and Pretorius do provide brief introductory chapters on special and general relativity but they assume far too much existing knowledge. So I wholeheartedly recommend this book for a popular science reader who wants to get more depth on the nature of black holes and how general relativity made it possible to conjure them up - but do make sure you've read something like The Reality Frame first. This is, indeed, for the general reader as Penrose said - but only for one who is well prepared.
Without ever venturing into heavyweight maths, Steven Gubser and Frans Pretorius take us through the way that both Schwarzschild's non-rotating black hole and Kerr's rotating version were derived from Einstein's equations. And they help the reader explore many of the implications for such a body were it to exist in the real universe, from familiar aspects such as time dilation to the delightful zoom-whirl orbit. For an unfortunate individual passing towards the singularity we not only get spaghettification (though not named as such) but also consideration of what you would see when looking out of the hole and what influence matter outside a rotating black hole would have on a traveller within the event horizon.
Add in a chapter on gravitational waves, giving more detail of the mechanism that is normally provided, very timely given the recent discoveries and Nobel Prize, plus consideration of charged black holes and black hole thermodynamics, and it's clear that this is really will take the knowledge of anyone with a serious interest in black holes up to the next level. The presentation is not always 100 per cent clear - there are times when the authors think they've explained something but they haven't - yet on the whole, if you already have the basics and take it slowly, this will be a revelation.
So, The Little Book is genuinely fascinating and insightful stuff - but it is necessary to have read the background material elsewhere first. Gubser and Pretorius do provide brief introductory chapters on special and general relativity but they assume far too much existing knowledge. So I wholeheartedly recommend this book for a popular science reader who wants to get more depth on the nature of black holes and how general relativity made it possible to conjure them up - but do make sure you've read something like The Reality Frame first. This is, indeed, for the general reader as Penrose said - but only for one who is well prepared.
May 17, 2021
If you're a nerd like me, I think you would enjoy this book.
January 22, 2018
For me, there is nothing more important than learning about my place in the universe. The ultimate refutation to the myth of Sisyphus and raising my middle finger to those who outsource their beliefs to magical thinking is learning about the world through justified true beliefs. George Washington is quoted as saying “it’s up to us to learn through literature and science”. Every time we develop a new tool to see (or in this case ‘hear’) the universe differently major truths seem to follow. Space shimmies and we now have a tool to observe that dance with LIGO.
But to understand that dance one must understand various pieces that make it up. This book was rare among current popular science books. The authors never talked down to the reader and they assume that the reader really wants to understand the nature of reality. They will throw equations at the reader but only to provide context. I’m not a scientist or a physicist (definition of a physicist: ‘a brilliant person highly underpaid’), but I was never lost in the story telling.
I’d say this book is rare among all such pop science books. Even a specialist in the field can profit from this book since the specialist will know their particular area of expertise but they won’t know the background that their foreground lies in or what the pieces as a whole are saying.
At a black hole one can swap time for radius towards the singularity with space. At the beginning will be a white hole where nothing is allowed in but matter and light can leave it. One can think of gravity or acceleration equivalently and the authors provide many examples with Alice, Bob and Bill to illustrate their points. Einstein’s General Theory gives us that relationship and is dissected such that a reader can follow what is happening behind the scenes. Worm holes and Entanglement are also considered in detail. This book never really holds back in edifying the reader. All the pieces that are needed for understanding the shimmying of the universe are provided in this book even if it means that a casual reader will get left behind. The quantum system as a whole must balance out, but the pieces sometimes give us entanglement or the cause to effect relationship will get muddled as with black hole/white holes or worm holes all detailed within this book.
Everything we ever do or ever measure is an approximation. ‘Man is the measure of all things’ but our yardsticks will always have a measurement error. I never understood how the LIGO was able to get past that problem since they measure distances at about one ten thousandth of a proton (or some such ridiculously small scale) and a train miles away will cause vibrations beyond that. Well, now I know. There is a template for all reasonable scenarios with the field equation solutions solved and the measurement errors are convoluted out of the signal. One can only think that the addition of more LIGO like devices around the world will give us even more insights. The book makes the point before September 14, 2015 that our level of understanding for what happens when two black holes decide to get together was conjecture now it has empirical confirmation.
What a marvelous time period we live in and new tools mean new understanding. Regretfully, I see that this book laid a thud with the public as a whole. That’s too bad. Well, I can just say that it didn’t lay a thud with me and this book took me beyond almost all new pop science books that I have read recently. It is a difficult book to follow, but a non-scientist like me grasped it because the authors know how to write difficult concepts clearly and not talk down to the reader.
But to understand that dance one must understand various pieces that make it up. This book was rare among current popular science books. The authors never talked down to the reader and they assume that the reader really wants to understand the nature of reality. They will throw equations at the reader but only to provide context. I’m not a scientist or a physicist (definition of a physicist: ‘a brilliant person highly underpaid’), but I was never lost in the story telling.
I’d say this book is rare among all such pop science books. Even a specialist in the field can profit from this book since the specialist will know their particular area of expertise but they won’t know the background that their foreground lies in or what the pieces as a whole are saying.
At a black hole one can swap time for radius towards the singularity with space. At the beginning will be a white hole where nothing is allowed in but matter and light can leave it. One can think of gravity or acceleration equivalently and the authors provide many examples with Alice, Bob and Bill to illustrate their points. Einstein’s General Theory gives us that relationship and is dissected such that a reader can follow what is happening behind the scenes. Worm holes and Entanglement are also considered in detail. This book never really holds back in edifying the reader. All the pieces that are needed for understanding the shimmying of the universe are provided in this book even if it means that a casual reader will get left behind. The quantum system as a whole must balance out, but the pieces sometimes give us entanglement or the cause to effect relationship will get muddled as with black hole/white holes or worm holes all detailed within this book.
Everything we ever do or ever measure is an approximation. ‘Man is the measure of all things’ but our yardsticks will always have a measurement error. I never understood how the LIGO was able to get past that problem since they measure distances at about one ten thousandth of a proton (or some such ridiculously small scale) and a train miles away will cause vibrations beyond that. Well, now I know. There is a template for all reasonable scenarios with the field equation solutions solved and the measurement errors are convoluted out of the signal. One can only think that the addition of more LIGO like devices around the world will give us even more insights. The book makes the point before September 14, 2015 that our level of understanding for what happens when two black holes decide to get together was conjecture now it has empirical confirmation.
What a marvelous time period we live in and new tools mean new understanding. Regretfully, I see that this book laid a thud with the public as a whole. That’s too bad. Well, I can just say that it didn’t lay a thud with me and this book took me beyond almost all new pop science books that I have read recently. It is a difficult book to follow, but a non-scientist like me grasped it because the authors know how to write difficult concepts clearly and not talk down to the reader.
January 19, 2018
This book is exactly what it claims to be, a Little Book of Black holes. Steven and Frans provide all the basics you need to gain a rudimentary understand black hole dynamics. They make great use of Alice and Bob analogies. Some Alice and Bob stories are better than others. In particular, Steve and Frans shine when they depict Alice and Bob and another B named person (can't remember name), who are all 3 lined up at the black hole. They give one of the most intuitive explanations I have ever (and I have read many explanations) of why if both Bob and other B person wave at the same time, why would black hole dynamics make Alice, who is zooming off in her spaceship, see one of them wave first (even though they waved at the exact same time) and never, ever see the other person wave. This is such a crucial concept to explain to people and this book really simplifies it for the curious person, who doesn't want to get overloaded with info and yet still wants to have some type of understanding of this phenomenon.
The best thing about this book was the epilogue. The two authors wrote a letter to Einstein (something I have imagined myself doing a 100 times-- to Einstein, to Darwin, to Paul Dirac, and to others) to tell Einstein what advances in black hole physics have occurred since he predicted black holes more than 100 years ago. The letter was nothing short of magnificent. Perfect way to end this sometimes textbook like and very informative introduction to black holes.
The best thing about this book was the epilogue. The two authors wrote a letter to Einstein (something I have imagined myself doing a 100 times-- to Einstein, to Darwin, to Paul Dirac, and to others) to tell Einstein what advances in black hole physics have occurred since he predicted black holes more than 100 years ago. The letter was nothing short of magnificent. Perfect way to end this sometimes textbook like and very informative introduction to black holes.
November 4, 2020
Increíble. Me dio mucha pena tener un libro de una mente tan brillante como la de Steven S. Gubser, quién trágicamente perdió la vida en 2019. Es un libro relativamente actualizado, el mismo que incluye la explicación del funcionamiento de LIGO y de las ondas gravitacionales.
He leído algunas reseñas (de una estrella) de gente que lo cataloga como un mal libro, precisamente porque es complicado y no llena el criterio de "libro de divulgación". Verdaderamente puedo decir que el criterio de esas personas es irremisiblemente idiota. Sé que no escribe como Carl Sagan, quién muy aparte de ser cosmólogo era poeta, pero, ¿Qué verso sobre la distinción entre agujeros negros de Kerr-Newman y de Reissner-Nordstrom pueden causarme placer?. Obviamente que ninguno. Sé que no es un libro con citas como que "ay, eres polvo de estrellas, y nos amamos por ser parte del cosmos", pero, estamos leyendo un libro que trata temas como: relatividad especial y general, geometría diferencial, termodinámica de agujeros negros y conjeturas de singularidades desnudas.
La pregunta es: ¿Qué espera el lector de este libro?, o ¿de cualquier otro libro de este tema?. Yo no espero ver citas bonitas o explicaciones entrecortadas solo para satisfacer mi falta de comprensión lectora, o mi escaso background en el tema, yo lo que espero es aprender más, que el libro me sorprenda, que me haga googlear conceptos que no conozco, que me dejen con la boca abierta de idiota al terminar de leerlo. Ése es el criterio que deben de aplicar para leer libros de esta índole, sé que no es del todo fácil, pero créanme que se entiende más que la Fenomenología del Espíritu de Hegel.
En fin, a lo que iba es que sí, en efecto, para poder entender este libro bien, sugeriría leer un par de relatividad general (a pesar de que dos capítulos van dedicados a este asunto), recomendaría: "Los agujeros negros" de José Luis Fernández, "La frontera del infinito" de Paul Davies, y "Los Hoyos Negros y la Curvatura del Espacio-Tiempo" de Shahen Hacyan, precisamente porque se necesita una base un poco más solida; no es cualquier libro. Los autores tratan de ser amigables con la analogías que utilizan, y puede que sea un poco complicado asimilarla, pero el lector debe comprender que estamos leyendo un asunto crucial, un poco más técnico de lo habitual, en donde se debe de prestar atención total al asunto; no estamos leyendo un tema de fácil digestión. El lector debe de saber que Einstein, Carl Sagan, Hawking, Wheeler, Hoyle, Feynman, y muchos otros más murieron sin saber que en verdad existieron los agujeros negros supermasivos, murieron sin confirmar qué precisamente era un quásar y mucho menos, sin saber que podríamos algún día detectar ondas gravitacionales.
El lector debería sentirse alegre de vivir en esta época, donde hemos maximizado nuestra capacidad de percepción al punto que pudimos como especie darnos cuenta de que una fibra del espacio-tiempo se movió.
He leído algunas reseñas (de una estrella) de gente que lo cataloga como un mal libro, precisamente porque es complicado y no llena el criterio de "libro de divulgación". Verdaderamente puedo decir que el criterio de esas personas es irremisiblemente idiota. Sé que no escribe como Carl Sagan, quién muy aparte de ser cosmólogo era poeta, pero, ¿Qué verso sobre la distinción entre agujeros negros de Kerr-Newman y de Reissner-Nordstrom pueden causarme placer?. Obviamente que ninguno. Sé que no es un libro con citas como que "ay, eres polvo de estrellas, y nos amamos por ser parte del cosmos", pero, estamos leyendo un libro que trata temas como: relatividad especial y general, geometría diferencial, termodinámica de agujeros negros y conjeturas de singularidades desnudas.
La pregunta es: ¿Qué espera el lector de este libro?, o ¿de cualquier otro libro de este tema?. Yo no espero ver citas bonitas o explicaciones entrecortadas solo para satisfacer mi falta de comprensión lectora, o mi escaso background en el tema, yo lo que espero es aprender más, que el libro me sorprenda, que me haga googlear conceptos que no conozco, que me dejen con la boca abierta de idiota al terminar de leerlo. Ése es el criterio que deben de aplicar para leer libros de esta índole, sé que no es del todo fácil, pero créanme que se entiende más que la Fenomenología del Espíritu de Hegel.
En fin, a lo que iba es que sí, en efecto, para poder entender este libro bien, sugeriría leer un par de relatividad general (a pesar de que dos capítulos van dedicados a este asunto), recomendaría: "Los agujeros negros" de José Luis Fernández, "La frontera del infinito" de Paul Davies, y "Los Hoyos Negros y la Curvatura del Espacio-Tiempo" de Shahen Hacyan, precisamente porque se necesita una base un poco más solida; no es cualquier libro. Los autores tratan de ser amigables con la analogías que utilizan, y puede que sea un poco complicado asimilarla, pero el lector debe comprender que estamos leyendo un asunto crucial, un poco más técnico de lo habitual, en donde se debe de prestar atención total al asunto; no estamos leyendo un tema de fácil digestión. El lector debe de saber que Einstein, Carl Sagan, Hawking, Wheeler, Hoyle, Feynman, y muchos otros más murieron sin saber que en verdad existieron los agujeros negros supermasivos, murieron sin confirmar qué precisamente era un quásar y mucho menos, sin saber que podríamos algún día detectar ondas gravitacionales.
El lector debería sentirse alegre de vivir en esta época, donde hemos maximizado nuestra capacidad de percepción al punto que pudimos como especie darnos cuenta de que una fibra del espacio-tiempo se movió.
October 27, 2024
This book really sucked the life out of astrophysics, pun unintended.
June 25, 2022
The Little Book of Black Holes by Gubser and Pretorius
I liked this read as it was an up to date and a fresh perspective on black holes and relatively short so it can be read in an afternoon. Most of the topics can be understood by lay people with a science background. A little too much coverage of LIGOR detectors and not enough on Hawking Radiation and Kerr Black Holes which I wanted to understand better.
Here are some notes that I took.
1. Minkowski space time and hyperbolic geometry is quite interesting and as old a concept as the general theory of relativity.
2. The moving mirrors experiment allows us to use p=mv momentum equations and p=E/c for a photon and a horizontally set of moving mirrors says p sideways = v/c*(E/c) or mv= Ev/c^2 or E = mc^2. This is because the sideways momentum is v/c of the total.
3. The Pound-Rebka experiment was conducted in 1959 to detect gravitational redshift as photons were passed from emitter to transmitter. This was done to test Einstein's general theory of relativity. It was confirmed that as a photon is pushed away from earth (against gravity) that is redshifted (frequency was decreased) and the opposite effect of blue shifting is seen when sending the photon towards earth. The effect is numerically small such that your head is a few microseconds older than your feet (assuming you have been standing your whole life).
4. The Einstein Field Equations reduce to one tensor equation with ordinary gravity.
5. Schwarzchild metric - the lapse number is 0 at the radius and 1 infinitely far away.
6. Zoom Whirl Orbits can happen around blackholes due to space time effects and an orbit create four leaf clover patterns if done at proper velocity and trajectory.
7. Light rings can be formed around black holes as photons can wrap around a black hole to get to other side.
8. Spinning black holes are defined in part by Kerr equations and the Penrose process and because the frames of reference are rotating it is quite complex. I wish it were explained in more depth.
9. Inside spinning black holes and inside the event horizon there is another N inner horizon and then a ring singularity. The ring actually repels and the geodesic falls away!
10. There are many black hole stellar binaries like Cyg X-1.
11. Quasars are a second type of black hole and are massive and bright. Quasars are brighter than entire galaxies. They may have masses several billion times our sun. However scientists are not 100 in agreement that Quasars are actually black holes.
12. Hawking radiation and quantum entanglement. Quantum mechanical excitations can and do exit the black hole.
13. Black hole collapse is the most disorderly and irreversible phenomenon possible.
14. Wormholes should theoretically exist due to quantum entanglement but as of today there is no way to test or search for them
4 stars
I liked this read as it was an up to date and a fresh perspective on black holes and relatively short so it can be read in an afternoon. Most of the topics can be understood by lay people with a science background. A little too much coverage of LIGOR detectors and not enough on Hawking Radiation and Kerr Black Holes which I wanted to understand better.
Here are some notes that I took.
1. Minkowski space time and hyperbolic geometry is quite interesting and as old a concept as the general theory of relativity.
2. The moving mirrors experiment allows us to use p=mv momentum equations and p=E/c for a photon and a horizontally set of moving mirrors says p sideways = v/c*(E/c) or mv= Ev/c^2 or E = mc^2. This is because the sideways momentum is v/c of the total.
3. The Pound-Rebka experiment was conducted in 1959 to detect gravitational redshift as photons were passed from emitter to transmitter. This was done to test Einstein's general theory of relativity. It was confirmed that as a photon is pushed away from earth (against gravity) that is redshifted (frequency was decreased) and the opposite effect of blue shifting is seen when sending the photon towards earth. The effect is numerically small such that your head is a few microseconds older than your feet (assuming you have been standing your whole life).
4. The Einstein Field Equations reduce to one tensor equation with ordinary gravity.
5. Schwarzchild metric - the lapse number is 0 at the radius and 1 infinitely far away.
6. Zoom Whirl Orbits can happen around blackholes due to space time effects and an orbit create four leaf clover patterns if done at proper velocity and trajectory.
7. Light rings can be formed around black holes as photons can wrap around a black hole to get to other side.
8. Spinning black holes are defined in part by Kerr equations and the Penrose process and because the frames of reference are rotating it is quite complex. I wish it were explained in more depth.
9. Inside spinning black holes and inside the event horizon there is another N inner horizon and then a ring singularity. The ring actually repels and the geodesic falls away!
10. There are many black hole stellar binaries like Cyg X-1.
11. Quasars are a second type of black hole and are massive and bright. Quasars are brighter than entire galaxies. They may have masses several billion times our sun. However scientists are not 100 in agreement that Quasars are actually black holes.
12. Hawking radiation and quantum entanglement. Quantum mechanical excitations can and do exit the black hole.
13. Black hole collapse is the most disorderly and irreversible phenomenon possible.
14. Wormholes should theoretically exist due to quantum entanglement but as of today there is no way to test or search for them
4 stars
July 4, 2018
This is a thorough, in-depth survey of the physics of black holes. The author clearly knows his shit. I don't think it's a good book for readers new to the topic. Check out some Brian Greene first, then come back to this book when you're ready for some uncut physics.
April 25, 2020
Vi uma vez uma frase atribuída a Richard Feynman e sucintamente dizia “quando não consegues explicar um assunto à tua avó, então não o entendeste adequadamente”.
Neste contexto eu faço o papel de avó. Se tive dificuldade em acompanhar os autores, isso deve-se seguramente à minha formação em matemática, e que é demasiadamente baixa para acompanhar a teoria da relatividade geral e os conceitos e leis que dela derivam para a geometria dos espaços curvos e buracos negros.
Mas como disse o lapso é meu e não dos autores que, e esta parte deve ser sublinhada, sem infantilismos desnecessários ou impróprios deram ao tema a dignidade e a abordagem que merece. É por este motivo que acho que é um dos melhores livros que li sobre o assunto (ainda que com passos que não consegui acompanhar) e que seguramente quando me sentir mais confortável com os meus conhecimentos lerei de novo.
Neste contexto eu faço o papel de avó. Se tive dificuldade em acompanhar os autores, isso deve-se seguramente à minha formação em matemática, e que é demasiadamente baixa para acompanhar a teoria da relatividade geral e os conceitos e leis que dela derivam para a geometria dos espaços curvos e buracos negros.
Mas como disse o lapso é meu e não dos autores que, e esta parte deve ser sublinhada, sem infantilismos desnecessários ou impróprios deram ao tema a dignidade e a abordagem que merece. É por este motivo que acho que é um dos melhores livros que li sobre o assunto (ainda que com passos que não consegui acompanhar) e que seguramente quando me sentir mais confortável com os meus conhecimentos lerei de novo.
October 21, 2020
Sinceramente faccio fatica a comprendere quale sia il target di questo saggio.
A me serviva un libro divulgativo che mi facesse capire semplicemente più cose possibile sui buchi neri, perché ci sto scrivendo un articolo. Questo libro non è stato molto utile alla mia causa.
Non è un libro divulgativo, è un libro destinato a qualcuno che già la fisica la sa bene, perché dà per scontati moltissimi concetti che conosco a stento io (che ho dato parecchi esami di fisica all'università, pur non essendo fisica).
Forse è un libro destinato proprio ai fisici che magari si sono specializzati in altro, invece che in astrofisica. Però, boh, mi sembra molto ristretto come target, ecco.
Ho provato comunque a leggerlo, saltando i passaggi che non capivo, ma ho fatto davvero fatica, purtroppo.
A me serviva un libro divulgativo che mi facesse capire semplicemente più cose possibile sui buchi neri, perché ci sto scrivendo un articolo. Questo libro non è stato molto utile alla mia causa.
Non è un libro divulgativo, è un libro destinato a qualcuno che già la fisica la sa bene, perché dà per scontati moltissimi concetti che conosco a stento io (che ho dato parecchi esami di fisica all'università, pur non essendo fisica).
Forse è un libro destinato proprio ai fisici che magari si sono specializzati in altro, invece che in astrofisica. Però, boh, mi sembra molto ristretto come target, ecco.
Ho provato comunque a leggerlo, saltando i passaggi che non capivo, ma ho fatto davvero fatica, purtroppo.
November 18, 2017
In this 'little' book on a very big subject, the authors present a compelling narrative on the phenomenon of black holes, why they form, how many types there are, and the basic physics that governs our understanding of them. Their towering achievement is not that they tackle the depth of their subject in a mere 179 pages, but that they take their readers on this exhilarating journey without getting bogged down in differential equations and the intricacies of spacetime geometries. Instead, they provide a contextual overview of these ideas, and use thought experiments similar to Einstein's, to develop the physics and kindle the exciting, but very uncertain, world within a black hole as understood by scientists a great distance away.
The preface of the book begins with a remarkably simple explanation of what a black hole is using the concept of escape velocity. It dwells briefly on the basic tenets of relativity theory, with particular emphasis on what ideas they motivate about black hole dynamics. This leads to an exploration of the various types of black holes and what makes them different, and then gets into the theater of black hole collisions. The contribution of LIGO to the understanding of black hole physics and the importance of observing gravitational waves to advancing the science is very helpful to the lay reader. The book then culminates with black hole thermodynamics and quantum state entropies to help explain the apparent paradox of Hawking radiation coming out of black holes. The authors conclude with a 3-page letter to Einstein summarizing the major advancements in physics post his death, in which they cheekily conclude that quantum entanglement is real, and God does "play dice".
The sheer adventure of the subject matter makes the reader wish this book were only one side of a wormhole connecting it to a continuing, second part. Alas, the book is 'little', but the gist of its ideas and its masterful handling of content leave a 'big' impression on the reader...
The preface of the book begins with a remarkably simple explanation of what a black hole is using the concept of escape velocity. It dwells briefly on the basic tenets of relativity theory, with particular emphasis on what ideas they motivate about black hole dynamics. This leads to an exploration of the various types of black holes and what makes them different, and then gets into the theater of black hole collisions. The contribution of LIGO to the understanding of black hole physics and the importance of observing gravitational waves to advancing the science is very helpful to the lay reader. The book then culminates with black hole thermodynamics and quantum state entropies to help explain the apparent paradox of Hawking radiation coming out of black holes. The authors conclude with a 3-page letter to Einstein summarizing the major advancements in physics post his death, in which they cheekily conclude that quantum entanglement is real, and God does "play dice".
The sheer adventure of the subject matter makes the reader wish this book were only one side of a wormhole connecting it to a continuing, second part. Alas, the book is 'little', but the gist of its ideas and its masterful handling of content leave a 'big' impression on the reader...
March 20, 2022
Avendo solamente le basi della fisica mi sono approcciato a questo saggio con il timore di capire poco o nulla. Sono stato piacevolmente smentito: l’introduzione sulla teoria della relatività è chiara e fornisce un ottimo punto di partenza per capire la fisica dei buchi neri. L’approccio dei due autori è puramente divulgativo ma non scende mai nella banalizzazioni: con esempi semplici “accompagnano” il lettore/lettrice/ lettorə alla scoperta di questo mistero (perché sappiamo ancora molto poco) della fisica.
Consigliatissimo!
Consigliatissimo!
December 11, 2025
De los pocos libros que he leído de física, este es de los que más me ha enseñado.
Pese a no ser largo, el libro tiene mucha información sobre los agujeros negros y te entrega una base muy buena para entenderlos.
Sus capítulos son: 1. Relatividad especial, 2. Relatividad general, 3. El agujero negro de Schwarzschild, 4. Agujeros negros rotatorios, 5. Agujeros negros en el universo, 6. Colisiones entre agujeros negros, 7. Termodinámica de los agujeros negros.
Denso en información para la cantidad de páginas que tiene, y acompañado de buenas imágenes que ayudan mucho a entender lo que está hablando. Lo recomiendo porque es lo que quería de un libro de agujeros negros
Pese a no ser largo, el libro tiene mucha información sobre los agujeros negros y te entrega una base muy buena para entenderlos.
Sus capítulos son: 1. Relatividad especial, 2. Relatividad general, 3. El agujero negro de Schwarzschild, 4. Agujeros negros rotatorios, 5. Agujeros negros en el universo, 6. Colisiones entre agujeros negros, 7. Termodinámica de los agujeros negros.
Denso en información para la cantidad de páginas que tiene, y acompañado de buenas imágenes que ayudan mucho a entender lo que está hablando. Lo recomiendo porque es lo que quería de un libro de agujeros negros
July 3, 2020
4,5/5 ⭐
Uma leitura para se levar com calma, mas que merece efetivamente ser feita, pois tal como diz na contra-capa é um livro "também para o leitor não-especialista".
Já tinha em mente que poderia gostar, mas sinceramente nunca esparava dar uma cotação tão alta.
É um livro elucidativo muito acessível. Apesar de ter imensa física(principalmente nos 2 primeiros capítulos) é acessível ao ponto de eu (só com 1 ano de secundário em ciências e tecnologias) conseguir ler e entender, na sua grande maioria (confesso que me pode ter escapado 1 ou outra coisinha).
Arrisco-me a dizer que qualquer pessoa interessada no assunto ao ponto de estudar deliberadamente a teoria da relatividade de Einstein(que corresponde aos dois primeiros capítulos, dada a sua importância no assunto) consegue ler este livro e gostar, porque de facto nos ensina muito e visto que, o único problema que encontro é o facto dos capítulos se tornarem muito extensos(alguns) tendo em conta a quantidade de informação descrita ao longo das páginas.
Uma particularidade ótima é a utilização de exemplos, em alguns aspectos os escritores até usaram 2 e 3 exemplos, para uma interpretação e idealização do conteúdo mais acessível para o leitor.
Um livro excecional para quem quer descobrir mais sobre buracos negros, buracos brancos, vários outros buracos no universo e ainda outros assuntos astronómicos interessantes e curiosos.
E se restaram dúvidas, são aquelas cuja resposta, a própria ciência ainda não desvendou.
Uma leitura para se levar com calma, mas que merece efetivamente ser feita, pois tal como diz na contra-capa é um livro "também para o leitor não-especialista".
Já tinha em mente que poderia gostar, mas sinceramente nunca esparava dar uma cotação tão alta.
É um livro elucidativo muito acessível. Apesar de ter imensa física(principalmente nos 2 primeiros capítulos) é acessível ao ponto de eu (só com 1 ano de secundário em ciências e tecnologias) conseguir ler e entender, na sua grande maioria (confesso que me pode ter escapado 1 ou outra coisinha).
Arrisco-me a dizer que qualquer pessoa interessada no assunto ao ponto de estudar deliberadamente a teoria da relatividade de Einstein(que corresponde aos dois primeiros capítulos, dada a sua importância no assunto) consegue ler este livro e gostar, porque de facto nos ensina muito e visto que, o único problema que encontro é o facto dos capítulos se tornarem muito extensos(alguns) tendo em conta a quantidade de informação descrita ao longo das páginas.
Uma particularidade ótima é a utilização de exemplos, em alguns aspectos os escritores até usaram 2 e 3 exemplos, para uma interpretação e idealização do conteúdo mais acessível para o leitor.
Um livro excecional para quem quer descobrir mais sobre buracos negros, buracos brancos, vários outros buracos no universo e ainda outros assuntos astronómicos interessantes e curiosos.
E se restaram dúvidas, são aquelas cuja resposta, a própria ciência ainda não desvendou.
April 4, 2022
O texto mostra ps buracos negros como os verdadeiros laboratórios teóricos de leis da Física. Os dois professores da Princeton (a mesma universidade que marcou a fase final de Eisntein) apresentam ao público muitas possíveis aplicações do que estamos descobrindo com os buracos negros.
Excesso de massa vai se tornando insustentável. Estrelas podem colapsar formando um buraco negro e a nossa Via Láctea possui, um no seu centro, que contém 4 milhões de massas solares. São quantias quase além da imaginação. Einstein avançou muito no campo da compreensão do universo. Stephen Hawking ampliou a concepção e demonstrou que a teoria quântica está correta: os buracos negros emitem radiação.
Ao diminuir um pouco da minha ignorância sobre o universo, retive a sensação de como os humanos são infinitamente pequenos neste terceiro planeta, debatendo coisas tão minúsculas e estúpidas diante de mistérios maiores que nos convidam à pesquisa e à reflexão.
Buracos negros fornecem uma ampla perspectiva da nossa total insignificância.
Excesso de massa vai se tornando insustentável. Estrelas podem colapsar formando um buraco negro e a nossa Via Láctea possui, um no seu centro, que contém 4 milhões de massas solares. São quantias quase além da imaginação. Einstein avançou muito no campo da compreensão do universo. Stephen Hawking ampliou a concepção e demonstrou que a teoria quântica está correta: os buracos negros emitem radiação.
Ao diminuir um pouco da minha ignorância sobre o universo, retive a sensação de como os humanos são infinitamente pequenos neste terceiro planeta, debatendo coisas tão minúsculas e estúpidas diante de mistérios maiores que nos convidam à pesquisa e à reflexão.
Buracos negros fornecem uma ampla perspectiva da nossa total insignificância.
June 12, 2021
Una lettura decisamente più ostica rispetto a Onde nello spaziotempo: Einstein, le onde gravitazionali e il futuro dell'astronomia in quanto va più a fondo nella matematica e fisica dei Buchi Neri. Ma forse ero io che non avevo la concentrazione giusta per seguire certi passaggi.
Di certo non lo consiglierei a un ragazzino delle superiori, mentre il testo di Schilling è più accessibile anche a quell'età.
2 stelle e mezza.
Di certo non lo consiglierei a un ragazzino delle superiori, mentre il testo di Schilling è più accessibile anche a quell'età.
2 stelle e mezza.
December 26, 2017
An excellent introduction for a generally science-savvy layperson. Not much mathematics, and good examples illustrating most of the weird and beyond-weird aspects of black hole physics. Begins with a brief introduction to special and general relativity, and goes on to Schwarzschild and Kerr black holes, black hole thermodynamics and some of the more interesting connections of black hole physics with QM and ensuing paradoxes.
January 14, 2018
A very interesting but also very challenging read. This book does not fall into the popular science category, the way most other books do.
November 2, 2019
Divulgación científica puesta al día sobre los agujeros negros. Bastante completa aunque un pelín oscura en algunos apartados.
Read
July 28, 2020Muitas noções e termos técnicos.
December 22, 2019
Kosmicznymi obiektami, które zrobił największą karierę w pop-kulturze są czarne dziury. I dobrze, bo ich tajemniczość i pokutujące niezrozumienie istoty zjawiska, napędzają zainteresowanie pozwalając astrofizykom incydentalnie przebić się do mediów. Dwaj fizycy z Princeton, Steven Gubser i Frans Pretorius w książce „Czarne dziury bez tajemnic” postanowili przybliżyć naturę tych enigmatycznych obiektów, łącząc aktualną wiedzę teoretyczną z obserwacyjną. Książka pozornie jest dla każdego, ale faktycznie wymaga pewnej ‘kultury matematyczno-fizycznej’.
Struktura publikacji dość przewidywalna (ale inna być nie powinna), czyli zaczynamy od kilku fundamentalnych ustaleń szczególnej i ogólnej teorii względności, szczególnie tych ich elementów, które w opisie czarnych dziur są kluczowe. Niestety dydaktycznie ten wstęp nie poraża klarownością. Podana dyskusja jednoczesności, dylatacji czasu i skrócenia rozmiaru obiektów wymaga jednak od czytelnika wstępnego rozeznania i obycia z używanymi pojęciami. Zbyt duże skróty (mimo kilku poglądowych wykresów) nie dadzą satysfakcji czytelnikowi początkującemu. Jedyny ciekawy fragment wstępnej dyskusji, to opis pojęcia metryki, linii geodezyjnej i krzywizny (str. 49-57).
Kolejne rozdziały, to ciekawy opis dwóch podstawowych modeli czarnych dziur. Pierwszy to osobliwość Schwarzschilda (najprostszy model z nierotującą czarną dziurą), a drugi to bardziej realny model z obracającą się, zwany czarną dziurą Kerra. Oba rozdziały zdają relację z geometrii takich obiektów oraz ich nieintuicyjnego otoczenia, które płata figle naszym zmysłom oczekującym linearności i jednostajności upływu czasu. Niesamowite w przewidywaniach dotyczących czarnych dziur jest osobliwe zachowanie przestrzeni je otaczającej, w czym tkwi ich cała atrakcyjność. Na uwagę zasługuje fakt, że autorzy wyczerpująco opisali kluczową właściwość czarnej dziury Kerra, czyli wleczenie układu inercjalnego (str. 90-101). Nie znam pełniejszego popularnego opracowania tego zjawiska. Podobnie się ma z klarownością omówionego mechanizmu pozwalającego uzyskać czystą postać energii z obracającej się czarnej dziury w wyniku tzw. procesu Penrose'a (str. 102-105).
Pozostałe rozdziały są bardziej praktyczne i odwołują się do obserwacji z ostatnich lat. Przeprowadzona w nich dyskusja odkrycia fal grawitacyjnych w 2015 roku sprowokowała autorów do opisania przebiegu tego zjawiska na podstawie posiadanej już wiedzy (str. 146-154). Ten fragment powala na łopatki, jeśli się nie znało wcześniej detali. Dla tych kilku stron warto sięgnąć po lekturę książki! Z kolei rozdział o termodynamice czarnych dziur i ich entropii, to zawiła porażka dydaktyczna. Bez podstaw z mechaniki kwantowej ani rusz. Ostatecznie, szansa na zrozumienie promenowania Hawkinga w wykonaniu Gubsera i Pretoriusa jest mocno dyskusyjna.
„Czarne dziury bez tajemnic” dostarcza ciekawą garść fundamentów związanych z tytułowymi obiektami. Jednak brak słowniczka pojęć i skrótowość wywodu stanowią barierę dla części potencjalnych odbiorców. Za to czytelnikom mającym za sobą chociażby uniwersytecki wstępny kurs fizyki ogólnej i wiedzę z geometrii, lektura da sporo satysfakcji. Wzorów jest kilka, raczej takich podstawowych, a przytoczone tensorowe równanie Einsteina należy potraktować jako pewien konstrukt ustalający uwagę (chyba, że ktoś zna rachunek tensorowy, teorię równań różniczkowych i elementy teorii Riemanna). Duży plus autorom należy się za większość treści ostatnich rozdziałów, w których przedyskutowali bardzo zgrabnie możliwości obserwacyjne związane z czarnymi dziurami. Jak powstają, gdzie możemy ich oczekiwać w kosmosie, czym na dziś na tym polu detekcji możemy się pochwalić – to kawałek ciekawej lektury dla każdego. Jednak wspomniane wyżej przykłady fragmentów trudnych i podanych niejasno - zniechęcają. Grzechem autorów była próba zbyt dokładnego odtworzenia ustaleń analitycznych językiem bez wzorów. Posługiwali się przeskokami myślowymi, za którymi nie da rady nadąży ktoś, kto 'nie przetrawił' wcześniej problematyki. Moja ostateczna nota, to mix subiektywnych wrażeń i analizy przydatności lektury dla czytelnika 'mniej ścisłego'.
Opiniowana pozycja to momentami wymagająca lektura, ale generalnie warta uwagi czytelnika poszukującego wyjaśnień, czym te pułapki czasu są. Polecam zaawansowanym miłośnikom zjawisk ekstremalnych w kosmosie.
===========
Postscriptum
W książce wspomniano o projekcie EHT, czyli globalnym interferometrze radioteleskopów (czyli obserwatoriów naziemnych, które pracują jak jeden zsynchronizowany). Sensacją ostatnich dni (10.04.2019) jest opublikowanie wyników prac w ramach tego projektu, czyli pierwszych zdjęć cienia czarnej dziury w centrum olbrzymiej galaktyki eliptycznej M87. Polecam ciekawy tekst na stronie oficjalnego periodyku Polskiego Towarzystwa Astronomicznego, w którym dostaniemy więcej detali: https://www.urania.edu.pl/wiadomosci/...
BARDZO DOBRA 7.5/10
Struktura publikacji dość przewidywalna (ale inna być nie powinna), czyli zaczynamy od kilku fundamentalnych ustaleń szczególnej i ogólnej teorii względności, szczególnie tych ich elementów, które w opisie czarnych dziur są kluczowe. Niestety dydaktycznie ten wstęp nie poraża klarownością. Podana dyskusja jednoczesności, dylatacji czasu i skrócenia rozmiaru obiektów wymaga jednak od czytelnika wstępnego rozeznania i obycia z używanymi pojęciami. Zbyt duże skróty (mimo kilku poglądowych wykresów) nie dadzą satysfakcji czytelnikowi początkującemu. Jedyny ciekawy fragment wstępnej dyskusji, to opis pojęcia metryki, linii geodezyjnej i krzywizny (str. 49-57).
Kolejne rozdziały, to ciekawy opis dwóch podstawowych modeli czarnych dziur. Pierwszy to osobliwość Schwarzschilda (najprostszy model z nierotującą czarną dziurą), a drugi to bardziej realny model z obracającą się, zwany czarną dziurą Kerra. Oba rozdziały zdają relację z geometrii takich obiektów oraz ich nieintuicyjnego otoczenia, które płata figle naszym zmysłom oczekującym linearności i jednostajności upływu czasu. Niesamowite w przewidywaniach dotyczących czarnych dziur jest osobliwe zachowanie przestrzeni je otaczającej, w czym tkwi ich cała atrakcyjność. Na uwagę zasługuje fakt, że autorzy wyczerpująco opisali kluczową właściwość czarnej dziury Kerra, czyli wleczenie układu inercjalnego (str. 90-101). Nie znam pełniejszego popularnego opracowania tego zjawiska. Podobnie się ma z klarownością omówionego mechanizmu pozwalającego uzyskać czystą postać energii z obracającej się czarnej dziury w wyniku tzw. procesu Penrose'a (str. 102-105).
Pozostałe rozdziały są bardziej praktyczne i odwołują się do obserwacji z ostatnich lat. Przeprowadzona w nich dyskusja odkrycia fal grawitacyjnych w 2015 roku sprowokowała autorów do opisania przebiegu tego zjawiska na podstawie posiadanej już wiedzy (str. 146-154). Ten fragment powala na łopatki, jeśli się nie znało wcześniej detali. Dla tych kilku stron warto sięgnąć po lekturę książki! Z kolei rozdział o termodynamice czarnych dziur i ich entropii, to zawiła porażka dydaktyczna. Bez podstaw z mechaniki kwantowej ani rusz. Ostatecznie, szansa na zrozumienie promenowania Hawkinga w wykonaniu Gubsera i Pretoriusa jest mocno dyskusyjna.
„Czarne dziury bez tajemnic” dostarcza ciekawą garść fundamentów związanych z tytułowymi obiektami. Jednak brak słowniczka pojęć i skrótowość wywodu stanowią barierę dla części potencjalnych odbiorców. Za to czytelnikom mającym za sobą chociażby uniwersytecki wstępny kurs fizyki ogólnej i wiedzę z geometrii, lektura da sporo satysfakcji. Wzorów jest kilka, raczej takich podstawowych, a przytoczone tensorowe równanie Einsteina należy potraktować jako pewien konstrukt ustalający uwagę (chyba, że ktoś zna rachunek tensorowy, teorię równań różniczkowych i elementy teorii Riemanna). Duży plus autorom należy się za większość treści ostatnich rozdziałów, w których przedyskutowali bardzo zgrabnie możliwości obserwacyjne związane z czarnymi dziurami. Jak powstają, gdzie możemy ich oczekiwać w kosmosie, czym na dziś na tym polu detekcji możemy się pochwalić – to kawałek ciekawej lektury dla każdego. Jednak wspomniane wyżej przykłady fragmentów trudnych i podanych niejasno - zniechęcają. Grzechem autorów była próba zbyt dokładnego odtworzenia ustaleń analitycznych językiem bez wzorów. Posługiwali się przeskokami myślowymi, za którymi nie da rady nadąży ktoś, kto 'nie przetrawił' wcześniej problematyki. Moja ostateczna nota, to mix subiektywnych wrażeń i analizy przydatności lektury dla czytelnika 'mniej ścisłego'.
Opiniowana pozycja to momentami wymagająca lektura, ale generalnie warta uwagi czytelnika poszukującego wyjaśnień, czym te pułapki czasu są. Polecam zaawansowanym miłośnikom zjawisk ekstremalnych w kosmosie.
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Postscriptum
W książce wspomniano o projekcie EHT, czyli globalnym interferometrze radioteleskopów (czyli obserwatoriów naziemnych, które pracują jak jeden zsynchronizowany). Sensacją ostatnich dni (10.04.2019) jest opublikowanie wyników prac w ramach tego projektu, czyli pierwszych zdjęć cienia czarnej dziury w centrum olbrzymiej galaktyki eliptycznej M87. Polecam ciekawy tekst na stronie oficjalnego periodyku Polskiego Towarzystwa Astronomicznego, w którym dostaniemy więcej detali: https://www.urania.edu.pl/wiadomosci/...
BARDZO DOBRA 7.5/10
January 1, 2021
Es un libro corto pero bastante denso. Si bien está escrito con el propósito de hacer divulgación científica, es necesario tener nociones claras sobre geometría diferencial, relatividad especial y general, y algo de mecánica cuántica. Si no se tiene mucho conocimiento de relatividad o cuántica, el libro hace una muy breve introducción a estos tópicos, pero definitivamente es necesario conocer la matemática, o al menos de manera intuitiva, de la geometría diferencial y así comprender de una manera más emocionante el efecto de la gravedad desde una quinta dimensión y cómo la percibimos nosotros en una superficie embebida tetradimensional.
El libro da una vista general a la historia y actualidad del estudio de los agujeros negros, empezando por introducción a la relatividad y explicando los casos más simples de estos objetos: los agujeros negros de Schwarzschild, y pasando a objetos más complicados que implican rotación: los agujeros negros de Kerr, explicando todas las implicaciones físicas que introduce dicha rotación. También nos da una vista de los agujeros negros en el universo observable y cómo un sistema binario en la constelación del Cisne es considerado una estrella de neutrones orbitando un agujero negro. Una de las motivaciones principales del libro es la detección de ondas gravitacionales en LIGO, en la que se dedica un capítulo entero (capítulo 6) a las colisiones de agujeros negros, y cómo los ecos de ese colosal choque se reflejan ondas gravitatorias y fueron detectadas en La Tierra mil millones de años después, y el impresionante dato que el "chirrido" detectado sólo duró unas milésimas de segundo, justo en la fusión de esos dos agujeros negros, y la extravagante sensibilidad del interferómetro de 10 a la -14 m. El libro finaliza con un corto capítulo (el más complejo desde mi entendimiento) sobre la termodinámica de los agujeros negros, donde se introduce la radiación Hawking, la temperatura de Unruh, y cómo la termodinámica y el entrelazamiento cuántico se relacionan en el horizonte de los agujeros negros.
Definitivamente un libro muy recomendado y, desde mi perspectiva, ayuda a entender otros libros (como El Universo en una Cáscara de Nuéz de Stephen Hawking) y películas relacionadas (como Interstellar, por ejemplo la forma del agujero negro y lo que experimentan cuando lo atraviesan).
El libro da una vista general a la historia y actualidad del estudio de los agujeros negros, empezando por introducción a la relatividad y explicando los casos más simples de estos objetos: los agujeros negros de Schwarzschild, y pasando a objetos más complicados que implican rotación: los agujeros negros de Kerr, explicando todas las implicaciones físicas que introduce dicha rotación. También nos da una vista de los agujeros negros en el universo observable y cómo un sistema binario en la constelación del Cisne es considerado una estrella de neutrones orbitando un agujero negro. Una de las motivaciones principales del libro es la detección de ondas gravitacionales en LIGO, en la que se dedica un capítulo entero (capítulo 6) a las colisiones de agujeros negros, y cómo los ecos de ese colosal choque se reflejan ondas gravitatorias y fueron detectadas en La Tierra mil millones de años después, y el impresionante dato que el "chirrido" detectado sólo duró unas milésimas de segundo, justo en la fusión de esos dos agujeros negros, y la extravagante sensibilidad del interferómetro de 10 a la -14 m. El libro finaliza con un corto capítulo (el más complejo desde mi entendimiento) sobre la termodinámica de los agujeros negros, donde se introduce la radiación Hawking, la temperatura de Unruh, y cómo la termodinámica y el entrelazamiento cuántico se relacionan en el horizonte de los agujeros negros.
Definitivamente un libro muy recomendado y, desde mi perspectiva, ayuda a entender otros libros (como El Universo en una Cáscara de Nuéz de Stephen Hawking) y películas relacionadas (como Interstellar, por ejemplo la forma del agujero negro y lo que experimentan cuando lo atraviesan).
August 8, 2023
¿Qué es un agujero negro?
A mi entender, un agujero negro es un punto en el espacio cargado de una masa infinita y por ende tiene una fuerza de gravedad muy grande que es capaz de atrapar toda forma de materia que entre en su órbita (solida, gas, luz, etc) y una vez dentro no puede salir.
¿Cómo se forman los agujeros negros?
A mi entender, se forman debido al colapso de una ⭐ una estrella es una esfera de plasma, entonces, ésta al secarse se hace cada vez más pequeña hasta llegar al punto en que explota y el resultado de esa 💥 forma el 🕳️ negro. Que en si, no es ni agujero ni negro jajja, pero ya eso es más complicado de entender y explicar.
Es un tema sumamente complicado, porque se involucran muchos conceptos y teorias dificiles de entender como son: la teoria de la relatividad especial, la relatividad general, la termodinamica, entropia, tipos de 🕳️ negros, ecuaciones, etc. Son cosas que no aprendes leyendo un solo libro 🤷🏾♂️
Fue todo un reto leer este 📕, ya que me hizo salir de mi zona de confort en cuanto a lectura se trata. Me tarde mucho en leerlo, porque tenia que estar indagando en Google o viendo videos en Youtube para poder entender un poquito mejor. Absolutamente todo del 📖 era nuevo para mí y eso me gusto, también, me gusto conocer un poco sobre el universo, un tema fascinante.
Aunque es un 📕 complicado, sí lo recomiendo y lo recomiendo por dos cosas: 1. Ignorar menos sobre estos temas del universo y 2. Porque de vez en cuando tienes que salir de tu zona de confort como lector, debes llevar tu pasión lectora más allá, es decir, leer ya no como entretenimiento, sino como investigación para descubrir nuevos temas, nuevos universos.
Calificación: ⭐⭐⭐⭐
Nota: si es un libro muy complicado de leer, no te llevara de la mano para entender el tema, siento que esta escrito para personas que ya tienen algo de conocimiento al respecto, pero si vez videos e investigas un poco en internet estoy seguro de que entenderás y aprenderás.
A mi entender, un agujero negro es un punto en el espacio cargado de una masa infinita y por ende tiene una fuerza de gravedad muy grande que es capaz de atrapar toda forma de materia que entre en su órbita (solida, gas, luz, etc) y una vez dentro no puede salir.
¿Cómo se forman los agujeros negros?
A mi entender, se forman debido al colapso de una ⭐ una estrella es una esfera de plasma, entonces, ésta al secarse se hace cada vez más pequeña hasta llegar al punto en que explota y el resultado de esa 💥 forma el 🕳️ negro. Que en si, no es ni agujero ni negro jajja, pero ya eso es más complicado de entender y explicar.
Es un tema sumamente complicado, porque se involucran muchos conceptos y teorias dificiles de entender como son: la teoria de la relatividad especial, la relatividad general, la termodinamica, entropia, tipos de 🕳️ negros, ecuaciones, etc. Son cosas que no aprendes leyendo un solo libro 🤷🏾♂️
Fue todo un reto leer este 📕, ya que me hizo salir de mi zona de confort en cuanto a lectura se trata. Me tarde mucho en leerlo, porque tenia que estar indagando en Google o viendo videos en Youtube para poder entender un poquito mejor. Absolutamente todo del 📖 era nuevo para mí y eso me gusto, también, me gusto conocer un poco sobre el universo, un tema fascinante.
Aunque es un 📕 complicado, sí lo recomiendo y lo recomiendo por dos cosas: 1. Ignorar menos sobre estos temas del universo y 2. Porque de vez en cuando tienes que salir de tu zona de confort como lector, debes llevar tu pasión lectora más allá, es decir, leer ya no como entretenimiento, sino como investigación para descubrir nuevos temas, nuevos universos.
Calificación: ⭐⭐⭐⭐
Nota: si es un libro muy complicado de leer, no te llevara de la mano para entender el tema, siento que esta escrito para personas que ya tienen algo de conocimiento al respecto, pero si vez videos e investigas un poco en internet estoy seguro de que entenderás y aprenderás.
This entire review has been hidden because of spoilers.
December 6, 2018
Full disclosure: I have a bachelor's degree in Physics and have a reasonably good understanding of quantum mechanics. Going into this book, I had little knowledge of the inner workings of black holes.
I'm not sure who the target audience is for this book. I certainly enjoyed it but think it might be a bit too dense for the casual reader. That said, there isn't a great deal of hard core math in this book, so it will likely leave the advanced reader wanting quite a bit more.
What I liked about it was the descriptions of the Schwartzchild and Kerr black holes as well as discussions about wormholes and white holes. I wish there was more to chew on, but I realize and understand that we simply have no way (classically) to see what is going on inside black holes.
The discussions on and description of LIGO was good. I found it interesting to learn about the templates used to filter out noise in the search for gravitational waves. The September 2015 detection of the merger of two black holes was described as accidental. I'd like to know more about that.
I'm also curious to see what results LIGO gives us in the near future. Just last week, 4 new detections of gravitational waves were announced to make a grand total of 13 such detections. Fascinating stuff for those interested in physics.
I'm not sure who the target audience is for this book. I certainly enjoyed it but think it might be a bit too dense for the casual reader. That said, there isn't a great deal of hard core math in this book, so it will likely leave the advanced reader wanting quite a bit more.
What I liked about it was the descriptions of the Schwartzchild and Kerr black holes as well as discussions about wormholes and white holes. I wish there was more to chew on, but I realize and understand that we simply have no way (classically) to see what is going on inside black holes.
The discussions on and description of LIGO was good. I found it interesting to learn about the templates used to filter out noise in the search for gravitational waves. The September 2015 detection of the merger of two black holes was described as accidental. I'd like to know more about that.
I'm also curious to see what results LIGO gives us in the near future. Just last week, 4 new detections of gravitational waves were announced to make a grand total of 13 such detections. Fascinating stuff for those interested in physics.
August 10, 2019
Sono anni ormai che leggo libri scientifici divulgativi principalmente di Astrofisica e Fisica Particellare e uno dei miei argomenti preferiti, per il fascino che suscitano, sono i Buchi Neri. Quindi appena ho visto questo volume non me lo sono fatto sfuggire.. Devo dire che l'ho affrontato come una lettura estiva, non troppo impegnata, e ci sono dei passaggi che meriterebbero più di una lettura, per la loro difficoltà (per uno ignorante in materia), ma come sempre affronto queste letture non con lo scopo di capire al 100% (anche se ci provo) e di imparare tutto a memoria, ma con il fine di farmi affascinare da quanto la scienza ha scoperto e continua a scoprire giorno dopo giorno, nonostante il nostro punto di vista limitato da un piccolo pianeta in un angolo di un Universo incredibilmente vasto e pieno di sorprese. In conclusione, la mia votazione è 4,5 stelle, e se siete appassionati di buchi neri non posso che consigliarvi anche la lettura di [[ASIN:887578406X I Motori Della Gravità: L'Altra Faccia dei Buchi Neri]] che vi affascinerà indubbiamente, raccontando la duplice attività creatrice e distruttrice dei buchi neri fin dalle prime fasi di vita dell'Universo.
December 17, 2024
This book was so interesting and good at conveyed scientific information in a conversational, descriptive manner. The figures throughout really help visualize the discussion. I definitely know more about black holes now then before I read this.
Topics include: special and general relativity, Schwarzschild and spinning black holes, black holes of our universe, and black hole collisions and thermodynamics. While some of the background mathematics went over my head, I loved when discussions also touched upon the lifecycle of our universe, wormholes, and quantum mechanics. This book should be approachable for not just physics students, but also those who enjoy sci-fi with some science education who are curious to learn more about this topic.
This 2017 publication was written by two young Princeton physics professors, so the film "Oppenheimer" came to mind whenever they mentioned Einstein or their university. The epilogue is a literal love letter to Einstein--how cute is that?!
This broadened my perspective of the cosmos and I recommend to all those intrigued. Thank you to the Sherwood Regional Library of Fairfax County, VA for the physical loan!
Topics include: special and general relativity, Schwarzschild and spinning black holes, black holes of our universe, and black hole collisions and thermodynamics. While some of the background mathematics went over my head, I loved when discussions also touched upon the lifecycle of our universe, wormholes, and quantum mechanics. This book should be approachable for not just physics students, but also those who enjoy sci-fi with some science education who are curious to learn more about this topic.
This 2017 publication was written by two young Princeton physics professors, so the film "Oppenheimer" came to mind whenever they mentioned Einstein or their university. The epilogue is a literal love letter to Einstein--how cute is that?!
This broadened my perspective of the cosmos and I recommend to all those intrigued. Thank you to the Sherwood Regional Library of Fairfax County, VA for the physical loan!
July 26, 2021
I’m not going to pretend like I understood even 1/3 of the concepts, theorems, and general scientific ideas referenced in this book. By powering through it, I began to gather some semblance of grasping relativity in both its special and general forms as well as quantum theory and thermodynamics. The authors deemed each an important factor in the buildup to the study of black holes, which I hoped to gain in reading this. Luckily, I got that.
Black holes are perhaps some answer to “where” and “why” when it comes to questions about life’s future. This book didn’t answer those, of course. It simply described what black holes are, how they’re discovered theoretically and now physically, and what may happen to the poor sap who happens to fall into one someday, traversing into a web of constant forward spacetime until reaching damning singularity. But the book certainly broadened my understanding and made me want to learn more about these fascinating creatures, their power, and what their purpose is for the future of our galaxy.
Black holes are perhaps some answer to “where” and “why” when it comes to questions about life’s future. This book didn’t answer those, of course. It simply described what black holes are, how they’re discovered theoretically and now physically, and what may happen to the poor sap who happens to fall into one someday, traversing into a web of constant forward spacetime until reaching damning singularity. But the book certainly broadened my understanding and made me want to learn more about these fascinating creatures, their power, and what their purpose is for the future of our galaxy.
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