Agujeros negros y tiempo curvo: El escandaloso legado de Einstein (Drakontos)

by Kip S. Thorne, Javier García Sanz (Translator)

“Durante treinta años –nos dice Kip S. Thorne, profesor del California Institute of Tecnology- he participado en una gran búsqueda para comprender el legado dejado por Albert Einstein a las generaciones futuras. Esta búsqueda me ha llevado por laberintos de objetos exóticos: agujeros negros, enanas blancas, estrellas de neutrotes, singularidades, ondas gravitatorias, distorsiones del tiempo, agujeros de gusano y máquinas del tiempo.” Muchos investigadores, comenzando por el propio Einstein, se negaban a aceptar algunas de las fantásticas consecuencias que podían deducirse de la teoría de la relatividad. Han sido científicos de una nueva generación, y en especial Roger Penrose y Kip S. Thorne, quienes han llevado esta búsqueda a sus últimas consecuencias. Si los libros de los dos primeros –Historia del tiempo y La nueva mente del emperador- descubrieron al lector medio la nueva imagen del universo, Agujeros negros y tiempo curvo le conducirá adentro y más allá.

Thorne comienza llevándonos a un viaje a los agujeros negros y, desde allí, nos hace seguir el descubrimiento de las nuevas concepciones, desde Einstein hasta nuestros días, en una especie de relato histórico sazonado de anécdotas vividas, a lo largo del cual vamos aprendiendo los conceptos básicos hasta llegar al punto en que agujeros de gusano y máquinas del tiempo nos parecen posibilidades lógicas y comprensibles. Si Stephen Hawking ha calificado este libro como “un relato fascinante”, otro de los protagonistas de esta historia, el gran astrofísico ruso Igor Novikov ha dicho: “es uno de los mejores libros de divulgación científica que he leído: todos cuantos aman los misterios científicos disfrutarán con él”.

 

Genres: Science, Physics, Nonfiction, Astronomy, Space, Popular Science, History

1311 pages, Kindle Edition

First published September 22, 1994

About the author

Kip Stephen Thorne is an American theoretical physicist and writer known for his contributions in gravitational physics and astrophysics. Along with Rainer Weiss and Barry C. Barish, he was awarded the 2017 Nobel Prize in Physics for his contributions to the LIGO detector and the observation of gravitational waves.
A longtime friend and colleague of Stephen Hawking and Carl Sagan, he was the Richard P. Feynman Professor of Theoretical Physics at the California Institute of Technology (Caltech) until 2009 and speaks of the astrophysical implications of the general theory of relativity. He continues to do scientific research and scientific consulting, most notably for the Christopher Nolan film Interstellar.

Reviews

[Jen · Rating 4 out of 5]

There are some advantages to growing up very southern. In addition to being born with impressive trigger discipline, you squirrel away an arsenal of colloquialisms to fall back on in times of befuddlement or great stress. Case in point: When your effete boyfriend, decides he’s had enough of the cloistered life of a scribe, and begins to masquerade as a man. To wit: laboring with a spare tire on the side of the road in the dead of winter for hours. You grow concerned, step out of the car, and say: “It’s colder than a well digger’s ass in Idaho out here. Want me to help you with that, darlin?” Not to be emasculated by the object of his affections, he dismisses you and attacks a lug-nut with revitalized purpose.

“Bless your cotton socks.” You say.

Sensing an opportunity to stake out the narrow band of human accomplishment that has defined his academic life, he rises, doffing his chapeau, he carefully intones: “I think your idiom is all wrong here.”

Snatching the tire iron away from him you say: “It’s a sorry excuse for a functional intellect that don’t know a fulcrum from his asshole. Say that highfalutin shit to me again and we’re finished, Reginald!”

“I...” He stammers.

“So help me GOD, if you bring up Heidegger right now, I will knock a turd outta you that’ll whizz like a wire-nail!”

Sufficiently chastened he goes back to work. You get back into the car, slamming the door, and putting some Hank on to soothe your savage soul. Another hour passes and you glance out the window to see Reginald writhing on the ground, making obscene snow angels, muttering about pure reason’s ability to count a horse’s teeth before it opens its mouth. Seizing the opportunity to gloat, you step out of the vehicle and loom over the poor bastard like the shadow of death. In a voice that would make a snowman shiver, you say: “Where’s your post structuralism now?”

We’re getting way off track here right out of the gate. My question is: Have you ever, while searching for the perfect way to capture the effect a book had on you, said: “It’s enough to knock a slop-hound offa gut-wagon.”? Did the shockwave of its profundity reduce all chatter at the dinner table to nothingness? Did someone come up to you afterwards, nursing their cocktail, and proceed to compliment your unique vernacular? Did you then reply acidly: “It’s been a dream of mine to choke someone to death with the laryngeal nerve of a giraffe.”? Well, I’m not sure what that says about your inclination to read this book, and you’re starting to develop an odd obsession with giraffes, but let me take a moment to explain to you how badass Black Holes are. There’s a few kinds, but here are two:

CHADS are really big stars, who inevitably get fed up with the monotonous routine of fusing hydrogen into helium, which prompts CHADS to shake it up a bit and try some heavier elements. But they come to the horrifying realization that it’s turtles all the way down. At which point CHADS say: “It’s enough to make a billy goat puke!” And go on the awfullest self destructive spree you’ve ever seen. Tearing up the stellar neighborhood like right bastards, before exiting so dramatically from the scene that they punch a damn hole in the fabric of space-time.

TIMS are smaller fellas who are just fucking fed up with everything, they’re sick to death of the whole game, and they’re trying to quit drinking. But they’ve got a friend that’s constantly hanging around them and handing them shots. They’re the ultimate enabler: BILLS (a binary star). The whole time TIMS are pleading with BILLS: “I gotta quit this shit. If I should have a few more hydrogen-sours; I’m gonna overcome my electron degeneracy pressure and go on a real tear, BILL. A real goddamn tear.” But BILLS don’t give a shit and just keep egging TIMS on until, as suggested, they go on a hellacious tear and rip space-time’s breeches.

In both cases, these catastrophic events create what are known as Singularities, and the thing about ‘em is; you ain’t even allowed to look at ‘em. See, light ain’t even fast enough to outrun the gravitation of a Black Hole, (that’s why it’s black!) but light is overconfident (because it’s a cosmic speed limit, and that gives it the big-head) and it’s always trying its damndest to give it a go. So you got this circle of light delineating the outer edges of a Black Hole, where light is sprinting with everything it has, but like a kid being held by her suspenders, it’s just running in place. That’s a warning my friend, you cross that line and something so horrible happens to you that physicists had to make a term up for it. It’s called Spaghettification. I ain’t joking. Look it up. Anyway, it’s presumably unpleasant as all hell, but probably pretty brief as far as unpleasant as hell things go.

Now here’s an interesting thing about TIMS, since they always get a certain amount of booze in them before they go swarpin' about, we know their peak luminosity, and since we know from some big brains that the intensity of light falls off with the square of the distance, we do something nifty with it. If we know an object’s absolute brightness we can calculate how far away it is based on how dim it is when it arrives at our light collectors. Now there are some further complications to this, but I ain’t gonna get into that. That’s what this book is for. Anyway, they’re damn handy.

One more thing before I go that’ll make you shit through the eye of a needle without touching the sides: At the center of our galaxy is a Black Hole that’s all the time going off on the most destructive row you’ve ever seen in your life. LENNY here has a mass about 4 million times that of our sun. And he don’t stop for nothing. Beats the piss outta TIMS, and BILLS, and JOEYS, and FRANKS, and CHADS. And he don’t stop at giving them a concussion. He EATS the bastards!

[Travis Hull · Rating 5 out of 5]

Want to learn what happens to stars when they die, but you lack a post-doc in astrophysics? You've come to the right place. Thorne has done an excellent job of putting just about anything you'd want to know about the topic in layman's terms, but the math and physics is also there if you want it. He blends the science and the history together and comes up with an interesting read not only about what we know about stellar death, but how we got there. In the last chapter he presents some of his own research on how black holes may be used to create time traveling wormholes. You don't get much cooler than time-traveling wormholes. Seriously.

[nastya · Rating 4 out of 5]

This book is part history of discovery from the times of Einstein up to the early 90s, part explanation of the science, and a tad of science fiction, written in an accessible way for laymen like me ( I mean it is not impenetrable Penrose (I’m still gonna try to penetrate him though! Or I wish))

And I loved the human side of this journey of trials and errors and crazy ideas, how sometimes you must be brave and risk your ego to be able to make a leap of faith. And how in the end it’s a beautiful teamwork, even with introverted loners, even between curious scientists from the West and USSR. Science seems to be a great unifier.

The only problem is that it’s a quite old book, published in the early 90s, before Kip Thorne won his Nobel Prize, I was born in the 90, I would know. (It’s so charming how he compares primitive computers poor physicists had to work with in the 30-50s compared to the advanced ones they have in the early 90s) And I can only assume physics evolved a lot and perhaps proved or disproved some “newer science” from the 90s.
So now I’m very curious to read the rest of the 30 years on the topic. And what about quantum gravity?!

Is the science part of the book hard? It is but it also never goes too deep. Do I fully comprehend laws for quantum fields in curved spacetime and is it obvious to me how black holes evaporate? My first reaction is always: “but intense gravity!” I’m really such a basic Newton’s laws gal. But it’s still fascinating and at least I know about them now, eh?

[Jose Moa · Rating 5 out of 5]

Kip S. Thorne is one of the most important researchers in gravity and black holes.

I this book,after a introductin as a sf short tale where a spaceship goes to the evet horizon of different sizes of black holes to investigate,the author explains clearly the principle of relativity is to say that the physical laws are the same in all inertial reference frames,this priciple is the origin of the special relativity theory (the special relativity theory could have been discovered many years before because the Maxwell equation for a electromagnetic wave is invariant under Lorentz transformations and not in galilean transformations,in this sense the electromagnetic theory by Maxwell is the first classic field relativistic theory)second the equivalence principle that is the origin of the generl theory of relativity where the spacetime is curved by the presence of matter and energy and the light follows geodesics ,the short lines between two points that are not in this case straight lines,for example in a sphere surface the geodesics are maximun circles or meridians.

In the following chapters the author tells the birth and evolution of the concept of neutron star and black holes by the work of Scharzschild,Chandrasekhar,Oppenheimer and others and the idea of the Hawking radiation .After this ,the search of astronomical black holes as result of imploding massive stars and the big black holes in the galactic nucleus,recently confirmed,also the search of gravitational waves,the last test of the theory and also recently confirmed.

Te book ends with two speculative subjects,the structure of the hipotetical singularity inside a black hole as a quantum space time foam as quantum gravity predicts and the existence of womholes in the spacetime sustained by exotic matter and its possible use for interestellar trips or time machines(here the movie" Interestellar").

Also other point of the book is the sociology of science,the science in USA versus soviet union and the history of the independent discovery of the Teller Ulam design of the termonuclear devices(by Sajarov in the soviet union).

A reference book of popular science on relativity,black holes,wormholes,time machines and its history.

[Berlioz · Rating 4 out of 5]

Most of us are not invested by the question of big explosions or by the compression of the universe. Those ideas are just way too far away from us (both in time and in the minds of individuals) that it can be not interesting for some to read about it. But then black holes are mentioned! Those excite us, those arouse our curiosity.

Suppose we made a trip to a black hole. What would we see? A black hole is a cluster of negative matter, or it is the absence of matter—we hope to find out before the trip. How much time will we have for this trip? Most likely just a little, because the human body is not adapted to practically anything at all—we will be destroyed by the hundred degrees of cooling, or perhaps right in the ozone layer. When does a black hole end? The concept of black holes suggests that there is a white hole on the other end, which is called a wormhole—a hypothetical structure connecting disparate points in spacetime, which is based on a special solution of the Einstein field equations. And where does this wormhole lead? To all the other galaxies, universes, and even times! Big mass and big matter change the matter of time. It is still unclear whether we can go through a black hole. As a mother and a father, as a son and a daughter, as a boss and as an employee—most likely not. We will be able to pass through a black hole only as stardust, as a pair of oscillating waves, as chemical elements. So would it be possible to build some kind of a drone or a robot and find out what is on the other side? Even if it succeeds, it is only 50/50 whether we will find out if it did, because the drone may simply become out of reach in both time and space.

This was an incredibly interesting book to read. Thorne turned everything there is about black holes and time warps upside down, inside and out, and put it neatly on shelves in my brain with their own labels. This book leaves you with an incredibly strange (but good!) aftertaste. I would recommend it to pretty much anyone. Humanity, after all, spends enormous resources, both monetary and labor-wise, to study physics! Why not get to know it a little?

[Philip of Macedon · Rating 5 out of 5]

This is another of many books I’ve had for ages that I finally got around to reading later than I should have. Having been a long time admirer of Kip Thorne’s work I was sure it’d be good. It was, of course, excellent. Kip Thorne is a theoretical physicist, one of the leading experts on general relativity’s applications to black holes and astrophysics. The book tells the story of how this field came to be, how it grew out of our evolving understanding of Einstein’s revolutionary impact on physics, and it brings to life the stories of dozens of the significant scientists around the world who were, and still are, involved.

I expected an enjoyable explanation of GR and black holes intended for the public, but did not expect it to be just as much, if not more, a history and a storytelling experience that conveys the excitement of doing theoretical physics research, the power of discovery, the thrill and challenge of tackling difficult problems.

Thorne starts by explaining the relevance of Einstein’s special and general relativity in a world that was understood in Newtonian terms. This revolutionary work and its phenomenal predictions, and even more phenomenal validations, would pave the way for the most productive century of physics the world had ever seen. Throughout the book, Thorne makes complex ideas simple, and the figures strewn throughout offer fantastic visual aids for almost every concept he breaks down into simplified, non-mathematical explanations.

Even early on we see a huge cast of important physicists, lest we mistakenly believe Einstein was the only one pumping out revolutionary ideas. His were the most vital and impactful, but alongside him and long after, others carried the torch, sometimes in different directions, and produced rapid, radical, and significant discoveries. World War II played a role in black hole research I was not previously aware of. With the nuclear weapon developments of the US, and later Russia, theoretical physics reached a place of sophistication and frightening power, as well as comprehension of new, never before seen things. This would have massive repercussions on the direction black hole research took over the next decades. The tensions between the US and Russia were not reflective of the relationship between US and Soviet theoretical physicists, who became colleagues over the seas, friendly competitors in a race no longer of weaponry but of understanding astrophysical phenomena. And they became collaborators on difficult problems.

Eventually, the US, Russia, and Britain dominate theoretical black hole and GR research. The prominent scientists from these nations comprise the main cast of the story. And because knowledge like this requires focused mentorship to begin, it may be no surprise that many of the most relevant scientists in this field go on to teach and train students who become the best in the field, and who then train the next generation of the best in the field, until we have a few small communities of somewhat incestuous but powerful theoretical physics researchers, who all know each other on a first name basis.

Thorne gives a lot of space to the interplay between scientists, like Chandrasekhar and Eddington’s disagreements about the fates of stars, or Einstein’s reluctance to believe the predictions that fall out of his own theories, because his intuitions differed from Schwarzschild’s discovery, which points to black holes. This pattern holds throughout the entire 20th century, with physicists disagreeing about critical pieces of theory, like Zwicky’s predictions about neutron stars meeting fierce resistance for not being rigorously argued, or the post-World War II era seeing Oppenheimer proving Landau wrong, or his battle with Wheeler over whether stellar implosion produces black holes. Or Thorne’s own bets and disagreements with Stephen Hawking. John Wheeler, by the way, probably wins the prize for producing both the highest quantity and quality of expert students to go on to shape the field (his student Robert Wald wrote the main text book from which I learned the mathematics of general relativity, but the Soviet theorist Lev Landau wrote maybe the most influential set of theoretical physics text books ever conceived, from which I also learned some GR), and also for shaping the field himself.

The satisfying thing about these episodes, and the dozens of other disagreements between high profile and high quality scientists, is that it illustrates the way science is done, particularly theoretical physics.

While giving plenty of space to these giants and their disagreements, he gives more space to their work, their background, who they are as people and scientists, and why their work matters. He fits it all into the wild and quickly changing world of theoretical general relativity research and black hole speculation. This aspect of the book is my favorite, because most of the physicists that star in this cosmic tapestry are legends to me, titans I learned about in college and graduate school. They’ve always been more than names to me, but they manifested mostly in their ideas and their contributions, the final products of their discoveries. Here, they are breathing people struggling against uphill challenges, unlikely odds, obscure concepts, unfamiliar territory, and the facts of their lives come into play, almost inevitably showing us something incredible. To me, most of the people in this book were already heroes, but now they’re heroes whose stories I know better.

Thorne untangles these dynamic scenes and noteworthy, high caliber science dramas while also taking the time to patiently explain the relevant physics concepts, like wave particle duality, the uncertainty principle, the curvature of spacetime, nuclear fusion, cosmic radio waves and synchrotron radiation, white dwarfs and neutron stars and supernovas, vacuum fluctuations, quantum foam, black hole evaporation, entropy, interferometry, hyperspace, worm holes, a hundred other things. He has a way with making highly mathematical and complicated ideas understandable for lay audiences.

He shows the revelations that experimental physics and observational astronomy brought to bear on theoretical astrophysics, and how these disciplines combined forces with relativity to pursue the holy grail of GR, finding the elusive black holes in our real universe. Thorne’s characterization of the Golden Age of gravitational physics research is one of epic intellectual successes and battles, an age of heroism. The novel methods devised by physicists to detect gravitational waves becomes the focus at one point, and Thorne discusses the development of these ideas and his own work with LIGO, the gravitational wave detector he helped devise and for which he would go on to win the Nobel Prize in 2017.


To give acknowledgment to the vast breadth of ideas or people Thorne discusses at length would take me too much time. Thorne is a modest man who, for the whole book, gives credit to everyone but himself, except toward the end. He outlines some of his insights and publications and his work, and I loved his reflections on solitude and its importance to his work, his lengthy calculations, his clarity of thought. But he gives far more attention to those who came before, to the exemplary physics minds of the 20th century who paved the way for others, and the others who came to mastery and thus paved the way for the future generations, and he shows over and over how each generation of physicists cooperated, competed, and struggled, to leave their followers with a more exciting, more challenging, and more profound set of questions and tools for understanding some of the most remarkable physical phenomena in the universe.

[Boudewijn · Rating 4 out of 5]

Written by Nobel Prize winner Kip Thorne, this book gives an easy to read and understandable overview of the development of black hole theory

Starting with the Newtonian physics, the Michelson-Morley experiment and the subsequent development of Einstein’s theory of special relativity Thorne sets the framework for the following chapter.

Immediately after special relativity was accepted by the scientists, the mathematics predicted the existence of black holes. Thorne describes the initial scepticism until the embrace of the black hole concept later on. Besides that, he also describes the search for these objects and the later on developments in the black hole theory.

Accompanied with easy understandable illustrations, I was pleasantly surprised how well I could follow the concepts and understand them in a large degree. The behaviour of space and time in the black hole’s singularity became understandable. Not a small feat for such a difficult topic.

Toward the end, Thorne deals with the more specalutative questions such as wormholes and time travel. This was nice to read, but not the main part of the book. The book describes the search for gravitational waves - which have recently been found and resulted in Thorne’s Nobel Prize.

All in all, I can surely recommend this book to anyone with an interest in science and astrology in particular. Thorne’s easy reading style and easy to understand explanations makes this a worthwhile read. 4 stars.

[Peter Tillman · Rating 5 out of 5]

Kip Thorne, the Feynman Professor of Physics at Caltech, is best known to the general public for his 1988 wormhole "time machine" proposal. Press coverage included a photo of the author doing physics in the nude on Mt. Palomar. "Embareassing," but didn't hurt the book sales. The wormhole work grew out of a request from Carl Sagan for a plausible FTL transport scheme for his 1985 science-fiction novel Contact (which I recommend). Sagan's request made Thorne realize the value of thought experiments that ask, "What things do the laws of physics permit an infinitely advanced civilization to do, and what do the laws forbid?" This style of speculation by world-class scientists has become popular (and somewhat respectable) in the last decade, and has resulted in some very stimulating reading, such as K. Eric Drexler's Engines of Creation (1986), and Hans Moravec's Mind Children (1988) and Robot (1999).

My full review (1999): https://www.sfsite.com/10b/bh67.htm
It's one of my better ones.

[Andrés Conca · Rating 5 out of 5]

Uno de los mejores libros de divulgación sobre física que he leído. No es nada sencillo de leer y de entender, los conceptos que se explican pueden ser un poco duros y muy abstractos si no se tiene una base de física así que no es para todo el mundo. No sólo se habla de los agujeros negros en sí, también del proceso histórico que llevó a deducir su existencia a partir de las leyes de la Relatividad, con sus conflictos entre científicos. Esta parte es también interesante y está bien narrada. He aprendido mucho aunque el texto se haya quedado desfasado en algunas cosas (ondas gravitacionales, expansión acelerada del Universo, etc), hay que tener en cuenta que se publicó en 1993.
ENGLISH:
One of the best popular books on physics that I have read. It is not an easy book to read and understand, the concepts explained here can be a little hard and very abstract if you one does not have a background in physics. It is not for everyone. Not only does it discuss the black holes themselves, but also the historical process that led to the deduction of their existence from the laws of relativity, and the conflicts between scientists. This part is also interesting and well narrated. I have learned a lot even though the text is out of date in some things (gravitational waves, accelerated expansion of the Universe, etc), it was published in 1993.

[Taha Ansari · Rating 5 out of 5]

Incredible. What a masterpiece!
Thoroughly detailed without being overly complicated. Kip Thorne, a recent Nobel laureate awarded for his immense contributions in gravitational wave detection, goes through the most important junctures in 20th century physical research, explaining along the way the most important concepts in relativistic physics. After detailing Einstein’s endeavors to formulate the two theories of relativity and establishing his field equations, and qualitatively explaining them by means of ingenious thought experiments and beautiful spacetime and embedding diagrams, he then dives into the many attempts to solve these equations, a quest taken by the leading physicists of the twentieth century, each one manipulating them in their own unique way hoping to derive solutions that could explain the century’s biggest questions: What is the ultimate fate of a star? Do physical laws allow the formation of black holes and naked singularities? Can an “infinitely advanced civilization” create time warps and keep them from collapsing in on themselves? Do the laws that govern the universe allow time travel or does nature’s abhorrence of time machines protect the universe from the many paradoxes associated with them?
Kip Thorne approaches each question by first giving the general historical circumstances in which the theoretical and experimental efforts were at their peak (world war two for instance and the international effort put into building and developing the atomic bomb), he then introduces the main characters involved, and what makes this book so unique, is that the author not only focuses on the final results of their endeavors, but instead shines as much light on the process, including the successes and the failures. Kip also gives a brief account of each character’s background, describing the constraints and the advantages that had had influence on their work (mostly political and financial constraints). What also makes this book stand out, is the important implication of the author in most topics approached. He describes in detail the kinds of relationships that connect physicists including himself to other scientists (Mathematicians, astrophysicists, etc.) and displays through many examples the importance of interdisciplinary communication. (And apparently physicists are keen on making bets)
For those who are wondering if this book is outdated, most explanations given in this book still remain valid, some of which have even been proven years after the book was published (Gravitational waves for example). Most importantly, this book is not only for those who want to expand their knowledge in relativistic physics, it is also a great demonstration of how scientific knowledge is built and a great source of historical information. I cannot recommend it highly enough!

[Steve · Rating 5 out of 5]

This classic was first published in hardback in 1994. It is one of the best books written on the topic by one of the key players in the field. This book stands out for a number of reasons: 1)quality of the writing,
2)An excellent bibliography, and 3) very well done illustrations. I have lost count of the number of astronomy books published in the last 14-20 years with poor quality photos or drawings. I wish Dr. Thorne would write a revision of the based on the recent discoveries made by the Hubble and Chandra Space Telescopes. This book is worth your time, and a careful reading will give you a good understanding of how our knowledge of black holes developed and what may come next.Christopher Nolan, director of the forthcoming movie "Interstellar" based the movie on some of the ideas in this book. Dr. Thorne was a consultant to the movie and is listed as one of the executive producers of the film.

[Pedro · Rating 5 out of 5]

Si pudiera resumir este libro en una frase sería: "La unión de la intuición con el frío y preciso razonamiento humano en la lucha por desentrañar uno de los más grandes misterios del universo" pero si quieren leer lo que me costó acuñar esta perspicaz frase, sigan leyendo, por favor.

Había oído hablar de Kip Thorne a través de @caiomriberio en twitter como "el hombre que le dio a Carl Sagan la idea del viaje espacio-tiempo en Contacto", lo descargué pero al darme cuenta que estaba pésimamente escaneado y las ilustraciones y el texto eran prácticamente ilegibles (sin mencionar que nunca se me ha dado leer en la computadora y no se podía convertir en Calibre), desistí. Fue a mediados del 2011 que lo encontré en un Liverpool, pero por conflicto de agenda no lo pude empezar hasta Noviembre, fue hasta ese punto en el que lo abrí y encontré la pequeña letra libro, easy as pie, right?

A primera vista Agujeros negros y Tiempo Curvo (de ahora en adelante el Libro) parece un libro de texto, pero el primer capítulo es un pequeño relato de ciencia ficción, cuando la humanidad haya alcanzado un agujero negro y probar sus propiedades de manera empírica. El prólogo es lo más difícil pero a manera que uno progresa desearía regresar al prólogo y esconderse un rato.

Después Kip empieza a recorrer lo que nos llevó a descubrir esta singularidad, los descubrimientos de Einstein, cómo nos las ingeniábamos con Newton, intenta dejarle al lector algo de la Relatividad Especial (fácil) y la General (difícil, incluso para físicos consagrados) y aquí es donde te empiezas a dar cuenta que Kip, va a volar tu mente varias veces en el transcurso de este libro pero no va a ser fácil, como lector tienes que poner de tu parte para entender los diversos recuadros, ilustraciones y ejemplos con los que Kip intenta dejarte algunos conceptos claros, y puede no entenderos si te nace pero te facilitará el libro y en especial los últimos capítulos, recomendable tomar una paliza al principio que ya al final, todo esto ocurre del primero al cuarto capítulo del libro.

Y una cosa que tengo que aclarar antes es que no es matemáticamente pesado, sí, vas a manejar algo de álgebra, algunos números gigantes y muy pequeños representados en notación científica pero en el texto principal lo más pesado que encontré fue un binomio y algo de trigonometría, pero si lo deseas la matemática está allí, al final del libro.

El capítulo 5 al 8 serán el ojo del huracán, Kip te cuenta la historia de las bombas nucleares, sus fuerzas y la influencia de la guerra mundial y la guerra fría en la investigación de estos objetos celestes, las increíbles personalidades científicas y la búsqueda de estos extraños objetos en el cielo, creo que en general son los capítulos más increíbles que haya leído.

Y de allí en adelante, serás agitado hasta los cimientos por las increíbles descripciones de un agujero negro "sin pelo", agujeros en rotación, ondas gravitaciones, fluctuaciones electromagnéticas, espuma cuántica, paradojas temporales y terminará muy abruptamente, no hay final feliz aquí que buscar porque la ciencia nunca termina a pesar de que el libro tiene un epílogo.

Desearía más, pero quedo sorprendido por lo increíble que es la intuición humana: Zel'dovich comparando un agujero negro con una bola de metal, Einstein imaginándose las propiedades del tiempo y del espacio, mientras arrullaba a su hijo con un brazo. Y la gente que prefiere los hechos duros y fríos: Oppenheimer usando cuartos llenos de computadoras, Chandrasekhar escribiendo papeles en un barco. Uno siente que no llegamos a estas conclusiones por pura casualidad, que esto no es una película donde en la primera pizarra resolvieron el problema. En este libro te das cuenta que crees saber todo lo que hay detrás de un fenómeno tan extraño como los agujeros negros, pero que sólo es la versión de Disney.

Lo único que espero a cambio de leer este libro es que el prólogo no reciba el adjetivo de ficción por mucho tiempo, que algún día sea realidad.

[Rama Rao · Rating 5 out of 5]

Everything You Always Wanted to Know About Black Holes

Kip Thorne is an eccentric author who reveals scientific enterprise of quantum gravity and black holes research in a simple language. This book is rich in history, and classical (Newtonian physics and theory of relativity) and modern physics (quantum mechanics) are presented in non mathematical form. We get rare first hand insights of scientific styles and temperament, and his personal involvement in various aspects of black holes research and his interaction with scientists all over the world especially those from former Soviet Union and the impact of communism on black hole research. The first part of the book describes theory of relativity, concept of spacetime fabric of the universe and curvature of spacetime in presence of matter (stars, galaxies, etc.) to generate gravity. The author gives us a good historical background to build his case for black hole concept. Theory of relativity predicts the existence of black holes but Einstein refused to accept it and so is Arthur Eddington another leading exponent of theory of relativity. The idea of black holes remained in academic obscurity among few who believed in it and it progressively became clear that dying giant stars undergo implosions in which nuclear force the strongest of all four forces of cosmos buckles under gravitational force creating a blackholes. Black holes have been discovered in the center of dying giant stars and in centers of galaxies, and efforts are underway to detect the black hole gravitational waves carried to earth from distant parts of the universe and to seek the secret of what is inside a black hole: a route to another universe? The author warps up the second part by discussing the possibility of constructing wormholes with exotic matter (tunnels in space connecting two widely separated locations in the universe) through hyperspace for interstellar travel and back to the future. He is one of the leaders in proposing interstellar travel. Physicists and academics are too conservative to get involved in space travel research as it is traditionally linked to science fiction and Star Trek junkies. The author can mesmerize the reader with his incredible knowledge and ease with which he can communicate to the reader; at the same time he is eccentric enough to work in one of his laboratory (Palomar Mountains) nude and draw criticisms from peers. He is also crazy enough to take bet with peers for things such as Penthouse magazine and annoy his wife and family with Mormon heritage. This book is free of marketing strategies of the publisher as the author shares his knowledge with the reader to his best of abilities to make everyone understands it even by offering few simple calculations and formulas. Do not be discouraged by the size of the book (619 pages). The text flows well and it is deeply engrossing. Anyone interested in black hole and space travel must have this book.

[Whitney · Rating 3 out of 5]

I have always been interested in anything related to quantum physics. I didn't expect this to be an easy read but I didn't really expect to have any problem getting through it since I've been researching this type of stuff since I was in 8th grade. I underestimated this book. It's written in a way that's fairly easy to understand, but the theories themselves were giving me a hard time. If you are interested in learning more about black holes and time warps and are willing to reread every paragraph until you understand then I definitely recommend this book.

[J.D. Steens · Rating 3 out of 5]

Thorne provides an extensive overview of 20th century physics. The book at times promised to provide clarity for the layperson regarding this history, but then it lapsed into language and concepts that I found hard to understand.

Thorne was in the middle of much of modern physics, particularly, in the effort to tie Einstein’s relativity to quantum physics. This book is mainly about this topic as it pertains to the work done on black holes. Thorne unites relativity and quantum physics and calls it the theory of quantum gravity. As I understand it, gravity in Einstein’s theory of relativity results in the collapse of mass-energy into itself (1). Relativity’s logic in other words leads to a singularity phenomena, as black holes, when the star’s outward pressure (via “electron degeneracy”) (2) eventually gives way to the inward pull of gravity to some ultimate contraction state where time and space are reduced to a what is understood to be a “singularity .”

Before this point of singularity, Thorne spends a lot of time on the horizon phenomenon and what lies between it and a “naked singularity.” But the latter is, for Thorne, where the unification of relativity (gravity) and quantum physics occurs. In uniting the two, Thorne seems to be saying that the inward direction of gravity forms the condition for black hole formation but beyond that formation the quantum world takes over. (3) The pure logic of the singularity leads to an infinite point (hence, the “singularity” term), but the word “point” itself is misleading as it suggests dimension. Many writers on black hole and singularity phenomena use the word “infinity” instead, but this word Thorne says typically means a “mistake,” and that something else is going on. Thorne says that in a singularity scenario space and time become “unglued” from each other. Time does stop (matter and energy pulled into a nothing state where there is neither a before nor after), he states that with space “quantum gravity probably replaces these infinities by quantum foam,” which is a “random and probabilistic froth.” I guess that suggests some sort of mush, but it is hard to conceive this nebulous term as non-dimensional. (4)

Given the logic of Einstein’s spacetime curvature, is it possible that our “known” universe not only keeps expanding outward at an ever-expanding speed (via escaping from gravitational effects per Gamow 1947) but also moves around itself to return to its beginning, thus uniting the infinite expansion concept with the contraction concept? If this logic of a spherical universe should pertain, it would also tie physical phenomena into the philosophical-religious thoughts of a cyclic universe, with each cycle lasting for seemingly endless time. Then the question becomes whether Reality is endless and perpetual.

1. This bumps into the question whether gravity is a “force” that attracts or pulls on the one hand, or is merely the product of geometry (lesser bodies follow the curved lines that lead toward bodies with higher mass, which depress spacetime). The geometric explanation seems to beg the question about why bodies with higher mass form in the first place to create spacetime curvature: How do bodies with higher mass form in the first place? Isn’t this a function of energy-matter attracted to itself, and isn’t this “attraction” a force, and not merely a geometric, geodesic line function?

2. Under intense pressure, such as in a solar mass, electrons are pushed together so closely that they repel each other, pushing outward, and it is this (and not the expansive release of heat) that counters the gravitational “pull” (if it is that - see footnote 1 above) inward. Eventually, this tension breaks down and gravity prevails, leading in the case of larger star masses to the formation of black holes.

3. In his glossary, Thorne describes a singularity as a region of spacetime where spacetime becomes so strong that the general relativistic laws break down and the laws of quantum gravity take over.” Is this is a “unification” proper or is it a sequence where the laws of one cease and the laws of the other take over from the other?

4. Gamow (1947) also resists the notion of singularity in the purest, infinite sense. He says that the laws of relativity do pertain, and collapse matter-energy into itself, but to a point, always short of infinite contraction, where quantum effects take over and create a rebounding effect where big bang type of explosive effects are initiated.

[Raúl Rama · Rating 5 out of 5]

Un libro que debe leer CUALQUIER interesado en la física, no es un libro difícil en sus matemáticas porque no contiene, toda la física descrita la desarrolla mediante el entendimiento profundo de los conceptos. Si eres una persona curiosa léelo, si además estudias física profundiza seriamente en el! Me ha encantado ver la visión de uno de los grandes, como el es capaz de transmitirte con palabras el diferente comportamiento de un agujero negro, cargado o no, combinando teoría de campos o no, cosas que están muy lejos de ser fáciles se convierten en simples imágenes mentales muy precisas, es el mejor libro de divulgación que he leído sin duda. (Para los que les de reparo leer un libro divulgativo un libro de física que no contenga formulas matemáticas, olvídate de todo lo que hayas podido leer, este libro es diferente, su ausencia de matemáticas no implica ausencia de dificultad, lo vas a disfrutar, vas a estar horas leyendo una y otra vez las mismas páginas para asentar todos estos conceptos, buscando cosas externas al libro para cautivar aún mas a tu mente y apoyar al disfrute del texto) Este libro también es capaz de contextualizar todo en la historia, como la física en esos años fue revolucionada, como todos tuvieron que dejar atrás sus conceptos preconcebidos de espacio y tiempo que experimentamos en nuestra vida cotidiana y con ellos enfrentarse a grandes paradojas. Es alucinante ver como toda esa revolución fue surgiendo poco a poco, pasando por cada uno de los grandes físicos como Wheeler, pero no solo eso, también esta es una gran época de unión, aquí el trabajo importante no lo hicieron un par de genios, fue la unión de toda la comunidad física la que contribuyó en la comprensión de todo lo posterior al golpe de Einstein. En fin, leed el libro, no te imaginas cuánto te pierdes.... no solo verás los topicos que tan "quemados" tenemos de la divulgación (pese a que cada vez que nos lo cuentan nos emocione igual que el primer día), no solo verás relatividad especial, agujeros negros y de gusano, la relatividad general constituye un marco teórico mucho mas emocionante, experimentarás también conceptos de termodinámica, teoría de la información, innovación en los nuevos métodos matemáticos, y el surgimiento de las primeras teorías de gravedad cuántica, todo contado por un partícipe en toda esta historia, compañero de muchos grandes físicos, y profesor de otros, todos unidos por amor a la física.

[Clif · Rating 4 out of 5]

I had read Einstein's book "The Evolution of Physics" (reviewed) and with the introduction that he supplied, felt I was ready to fall into black holes. I had seen a cover blurb describing Kip Thorne's book (subtitle: Einstein's outrageous legacy) as exemplary science writing and, though it is somewhat dated (1993) bought a used copy.

Thorne wastes no time, initially taking the reader on a visit to black holes of various sizes, though widely separated in distance, in our galaxy. Relativity is seen by the wildly different amount of time experienced by the astronauts compared to that on earth during their absence. A trip to the center of the Milky Way at light speed would only be 30 years for the voyagers but many thousands of years would pass on earth, many thousands more for the return trip!

This a result of what Einstein found - that time is relative. There is no independent time, alike for everyone everywhere. Only the speed of light is constant everywhere and always. It is this adjustment of our dimensions of height, width and depth to accord with the constant of light speed that results in the weird stretching and compressing of objects and of time.

The central theme of the book is gravity and what happens when it becomes far more powerful than we know it to be in our solar system. Even as early as the 18th century there was speculation about what would happen if a star was so massive that its gravity would prevent even light from escaping.

Thorne takes us on the investigation through physics that really took off after Einstein came up with the concept of spacetime, which is curved by gravity. Because spacetime is a dimension that we can never see, limited as we are to the 3 dimensions that we know, Thorne uses what are called embedding diagrams to give a sense of how curvature of spacetime can result in the three angles of a triangle summing to more or less than 180 degrees, or the shortest distance between two points not being a straight line as we would see it.

The best way I've found to think of spacetime is as follows: light must always follow the shortest path between two points and it must do so at the fixed speed of 186,000 miles per second. Einstein showed that light has mass, though very little, and is therefor affected by gravity.

The intense gravity of the sun is enough to bend the path of light that passes near it. If we look at the light of a star with high precision, we note that if the sun's edge passes near the position of that star, the star's light will be offset from where it would otherwise be, shifting the position of that star in relation to all the other stars seen in that part of the sky. As the sun moves away, the distant star appears to move back into its normal place.

Now, if light cannot change speed and must be coming to us from that distant star by the shortest path at all times, then it is the path, through Einstein's spacetime, that is distorted because of the sun's gravity. Were the sun a black hole, the distant star's light passing near it would be greatly displaced, just as the text in a book would be moved and distorted as you pass a magnifying lens over it.

Surprisingly, the author is able to make the strangeness he describes comprehensible. The idea that as stars become increasingly massive their fate takes them to different endpoints - white dwarfs, neutron stars and finally black holes, is clearly explained with many diagrams and side comments. I only had difficulty in the last chapter where he goes into time machines. There, the level of abstraction went where I could not follow, and abstraction is what the cutting edge of physics is all about.

You will get a great introduction to great minds in math and physics of the 20th century, many of them friends of Kip Thorne. There are plenty of personal accounts and a good bit of humor to humanize what might be a dry subject. There is excellent coverage of the instruments used, such as the radio telescope or the X-ray detecting satellites. Thorne does a great job of catching the reader up in the excitement of the professionally curious who are forever asking why.

Something I had not considered before, the author relates how traditional optical astronomy, starting with the naked eye, only reveals a relatively quiet universe. The rip-roaring world of X-rays, gamma rays and gravity waves cannot be "seen" without special instruments that have only been practical within the last 75 years. An exciting part of the book for me was the story of Grote Reber, a hobbyist in Wheaton, Illinois, who built his own backyard radio telescope and detected (with low precision) strong radio sources before professional astronomers knew about them. So impressive was his work that astronomers from the Yerkes Observatory traveled to visit him.

Thorne takes you across the electromagnetic spectrum, from light through radio and X-rays up to the latest area of investigation, non-electromagnetic gravity waves, being sought as the inevitable result of black holes in collision. Since Kip Thorne recommended the construction of the first gravity wave interferometer at Caltech, he's well placed to discuss the search. Because of the age of this book, I was curious to see what happened with this particular project, called LIGO. As it happens, it was built and operated for several years but detected no gravity waves. It has been dismantled and a successor instrument is about to take up the search.

Black holes are discussed in great detail, as you'd expect, but not as you'd expect the discussion can be followed without difficulty through the decades, as one great mind after another puts up an idea to be either upheld against fierce criticism or destroyed by the math of another. Behind it all lies Einstein's relativity that opened up a chapter on the search for truth by minds that have to model places in the universe where matter and energy take on magnitudes unknown to human experience.

I had to chuckle when Thorne would describe untold hours and even years of work being upset like this: After X had been working on the problem, trying to tie together the different loose ends, Z showed that, after all, everything could be explained by looking at the math in a different way, that, really, there was no difficulty after all. You can imagine the real storm and strife of egos behind a summary statement like this, with someone screaming, WHY DIDN'T I SEE THAT!

Join Kip Thorne for this inside story on what is real, though it may contradict our experience. There are more weird things in this book than in a carnival freak show, yet all of them have stood up to the best testing that has been devised.

[Devastatingwildness · Rating 5 out of 5]

Del epílogo:
"Ha pasado casi un siglo desde que Einstein destruyera los conceptos newtonianos de espacio y tiempo como algo absoluto, y empezase a sentar las bases de su propio legado. Durante los cien años transcurridos, el legado de Einstein ha crecido para incluir, entre otras muchas cosas, una distorsión del espacio-tiempo y un conjunto de objetos exóticos constituidos única y exclusivamente por dicha distorsión: agujeros negros, ondas gravitacionales, singularidades (vestidas y desnudas), agujeros de gusano y máquinas del tiempo.
En una u otra época de la historia, los físicos han considerado cada uno de estos objetos como escandalosos."

[Menglong Youk · Rating 5 out of 5]

Since my bachelor's thesis and the current master's degree research are related to black holes, I have tried to read any books related to its developments started from the Einstein's field equation up to now to get a better understanding (and some motivation and excitement) in this subject because ploughing through the dense mathematics and physics of differential geometry and general relativity whose calculations fill pages after pages, is not enjoyable sometimes. I heard of this book before, but because it was an old one, I thought the ideas presented were probably outdated already, so I read other more recent books instead. While those books are okay at explaining the flashy bits that are attractive to general audience, I felt like they were not enough to scratch my curiosity itch because they didn't really provide much background. So I decided to pick this book up since Kip Thorne was one of the author of the GR bible (MTW gravitation), and I was surprise how much new background history I've learnt. Names where I only read in research papers and equations like Bardeen, Bekenstein, Carter, Chandrasekhar, Kerr, Landau, Misner, Price, Wald, Wheeler, Zel'dovich, etc., I've now seen them in action and how each of their contributions played out in the development of black hole theory. This book of course needs updating, but it is the most thorough one that I know of (without the mathematics and physics) to describe the history in this field between the revelation of general relativity up to the early 1990s.

[J.D. Steens · Rating 4 out of 5]

This book about gravity and black holes seems more like a detailed history of the last 100 years of physics, particularly the effort to unite quantum mechanics with Einstein's relativity theory. Throughout the book, Thorne discusses the personalities of the titanic thinkers involved and this provides the reader with a welcome relief from the long, technical story about black holes (for most, probably more information than you want to know).

Thorne refers to spacetime "fabric," but it's not clear how space or time is a "fabric." The effects of massive gravitational bodies on space is easier to grasp than the effect on time. The book's title includes "time warps" but "time" throughout this book remains a mystery. His diagram on time and space (p. 95) confused me. If one is moving in space, one is moving in time, yet his diagram has "time" as stationary, as a fixed moment of time. In a tucked away footnote, Thorne restates Einstein's formula that mass and energy "are really different names for the same concept." As mass and energy lie at the heart of all cosmic things, referring to them as a concept struck me as wrong. Also, if they are the same, what is it? Is it matter, energy or something else common to both? On gravity, we know that mass attracts matter and energy, but what is it about mass that gives it the power to attract? Thorne is silent or I missed it if he did discuss it. Thorne states that a free particle "moves solely under the influence of its own inertia" ("no external forces push or pull") and also states that a body resists "being accelerated by forces that act on it." Does this mean that freedom - where the basic impulse of matter and energy is to move freely - lies at the heart of the cosmos? Thorne states that "when gravity is present a [free] particle is one "on which no forces act except gravity." How is a particle then free if it's affected by gravity? Also, is there any place in the cosmos where a particle is not affected by gravity? Thorne writes about gravitational waves ("ripples of spacetime curvature"), gravitons or particles assocated with gravitational waves, and gravitational radiation. While these are central to his discussion of black holes, as presented these terms were hard to grasp.

When gravity is weak, Thorne states that the Newtonian paradigm and Einstein's curved spacetime "are almost identical," but Newton's theory doesn't work at extreme scales, as with black holes, which is where Thorne sees the effects of quantum mechanics. I don't know what that means of course, but this is still all mind-blowing stuff. Thorne is among the best out there in terms of what he writes about, the writing itself, and his ability to move the general reader along toward a greater understanding of a reality that is totally unlike anything we know on earth.

[GridGirl · Rating 4 out of 5]

Kip Thorne, author of Black Holes and Time Warps, is one of three Nobel laureates for Physics of 2017. He and his colleagues Barry Barish and Rainer Weiss have been honored for their contribution to the observation of gravitational waves. In September 2015 physicists were able to measure those gravitational waves – which are an experimental reassurance of Einstein’s general theory of relativity – for the first time in history.
Thorne wrote this book in 1993 and therefore twenty-two years before they had first observed gravitational waves. Nevertheless, the book goes into the general theory of gravitational waves and the process of developing a suitable observatory for these waves – all of this, without using complicated formulas or the like.
This is a theme throughout the whole book. Thorne does an incredibly good job in explaining black holes, general relativity, spacetime curvature and time travel (or rather the possibility of time travel) in a very easy, narrative way that doesn’t ask too much of an intent and interested reader. He uses analogies whenever the concepts get very complex. In no way, shape or form you have to be a doctor of physics or anything like that to understand the general concepts of this book. On the contrary, it is a great way to dive a little deeper into the topic for everyone who likes documentaries about space or is into science-fiction in space.
Don’t be afraid if you don’t like maths. The most complicated formula in this book is literally (a+b)² = a² + 2ab + b² and it this is just additional information for mathematically interested readers according to Thorne.

Basically, I can sum up what I wrote above in just two words: READ THIS. I know it seems intimidating, because it’s a thick book about physics. The truth is, I’m a physics student and it still took me half a year to read it. But nobody expects you to gulp down a 600 page NF about physics in one sitting. The time it takes is very rewarding, because you educate yourself while getting a general idea about what has been going on in physics for the last 100 years.

Sidenote: Kip Thorne won a bet against Mister Stephen Hawking once and if that’s not impressive, I don’t know what is!

4/5

[Karl · Rating 4 out of 5]

In this book, Thorne tried to write a pop-science book giving the state of play in theoretical astrophysics (in 1995, so obviously a bit dated) but at the same time making it accessible to the non-practitioner. He presents the development of physics up to the then-present day in a combination of theoretical sidebars and some very basic mathematics held together by character sketches, anecdotes, and biographies of those involved.

My father bought this for me in about 2001, just after I'd dropped out of university. I read it cover to cover, twice, and came away with a combination of understanding and deep confusion - not from any problems with the delivery, but because the subject matter itself is deeply complex. I have a terrible habit of skim-reading, which one definitely cannot do with books of this ilk. The topics within - particularly the sections on relativity and event diagrams - require the reader to spend some time turning them over in the mind to reach an intuitive understanding.

Having now finished my mathematics degree, I re-visited BH&TW to see if my opinions had changed. They haven't. It's still an excellent book, although, as pointed out earlier, somewhat dated. Nonetheless Thorne's writing has a comfortable, informal style and, as a (semi-auto)-biographical work on the most influential physicists of the last century, this book is well worth a look.

[Hunter Pratt · Rating 5 out of 5]

Very entertaining. This book was giving to me as a supplementary read along with my primary textbook "gravity's fatal attraction". I actually preferred this book over the latter because of how engaging it was. Nobel prize winner Kip Thorne clearly wrote this book with the reader in mind. I can feel the excitement for science that he has and I couldn't help but feel excited myself as well (although I have a preexisting bias for astrophysics). Love this and will definitely read again.

[daniel · Rating 5 out of 5]

I had goosebumps multiple times. This book (along with Cosmos by Sagan) made me miss lecture halls and studying physics at uni.

[Sergio Rodríguez · Rating 5 out of 5]

El mejor libro que he leído, libro completísimo, muy bien referenciado, una obra de arte.

[Laura · Rating 4 out of 5]

Después de dos años que ha estado cerradito el libro, lo he terminado en periodo de exámenes. Es un libro para tener en mano, ya que 1/4 del libro son las notas facilitas pero interesantes sobre ecuaciones y física en las que no profundiza en el libro.

Historia muy bien contada sobre el s XX, con curiosidades, contexto (bomba atómica, telescopios, detectores, URSS...) y breve vida de algunos teóricos. Super entretenido de leer.

[Daniel Caballero López · Rating 5 out of 5]

En esta obra Thorne nos presenta la historia del descubrimiento de los agujeros negros y su estudio de una manera sublime.

Empieza el libro con una historia de ciencia ficción, pero lo grueso del libro viene a partir del capítulo 2, con la aparición de Einstein y sus ecuaciones, a partir de este momento el autor nos sumerge en la historia de la ciencia de agujeros negros, pasando la antorcha de unos a otros.

Recomiendo este libro a todos los que amamos los agujeros negros y la física en general.

[Arko · Rating 5 out of 5]

This book is one of the finest work I have come across till date in terms of the content and clarity for any layman with an interest in Physics. Brilliant to the core. It is Kip Thorne's tour de force to form an account of the history and the details about black holes and study on the nature of spacetime in terms of classical & quantum analysis. He being the pioneer in gravitational wave detection strategies and expert in black hole & wormhole theories , some chapters are more like is personal account itself.
This has turned out to be a perfect way to start my new year along with the wonderful discoveries of gravitational waves from merging black holes and neutron stars in the last couple of years.
The grandeur of this book is the dive into the nature of reality itself which we learn through studying black holes/wormholes or singularities.
Whatever we perceive is well attached to which frame of reference we are on.
It reminds me of few lines from the work of William Blake here:
"To see a world in a grain of sand
And a heaven in a wild flower,
Hold infinity in the palm of your hand
And eternity in an hour."

[James F · Rating 4 out of 5]

My only problem with this book (apart from its being twenty years old) is the title; wormholes and "time machines" are discussed briefly in the last 45 pages, but the book is actually a popular account of every aspect of black holes, at an above-average level of popularization -- about as high as one could expect without much mathematics.

Thorne, whose field is general relativity, begins with two chapters outlining special and general relativity -- Einstein's "legacy". The third chapter explains the prediction of black holes, which were not taken seriously as existing in the real world. The next two chapters are on white dwarfs and neutron stars and the Chandrasekhar limit, and the next two explain why massive stars must implode to form black holes. The 7th chapter is on the "Golden Age" of black hole research and what was discovered about them; the 8th chapter is on the search for actual black holes. The ninth chapter is on massive black holes in radio galaxies and quasars. Then there is a chapter on gravity waves, one on different ways of considering black holes, one on the discovery that black holes can evaporate, and one on the interior of black holes and the problem of singularities. The last chapter is the one on wormholes and the theory of time machines.

The book combines the history of the discoveries with the actual science in a very interesting manner; this is probably the best of the books I have read this month, apart from the classic by Weinberg, and the historical approach means that although the science is somewhat outdated the book really never becomes outdated, because the history is still the history.

[Erickson · Rating 5 out of 5]

It is an eye-opening book for gravitational physics, even for physics students trained in GR as it covers very broad topics and development of general relativity and black hole physics.

What's nice to this book is that it has a lot of personal elements - how different important figures are different in their characters and the way they guide their students and how they come to accept and reject certain ideas, or even how certain people gets attention or not by the community by virtue of his character. It also contains various clashes between people that is hallmark of science as human endeavour. Kip Thorne nicely put in these elements which prevented the book from being just another watered-down physics popularising book.

I especially like the way the experts guide their students in this book explained in every bit of important development and how ideas come to be disagreed or agreed between students and mentors.