Black Holes: The Key to Understanding the Universe (2024)

It’s always tempting to bask in the self-congratulatory delusion that if I just really concentrate on something hard enough I’d be able to understand it. But this book proved me wrong from the very first spacetime Penrose diagram that slowly sent my protesting brain over the event horizon and to the singularity while being simultaneously vaporized and spaghettified.

I suppose owning a “Schrödinger’s cat: Wanted dead and alive” t-shirt didn’t actually qualify me to understand this book (although it certainly increased my nerd cred).

And yet I enjoyed it even if a lot of it sailed right over my head, probably at the speed of light, quantumly. The authors are clearly very excited about black holes and did their best to be accessible, and it’s not their fault that when it comes to information of Mona Lisa level my brain gets stuck in an equivalent of a clumsy sidewalk chalk drawing by an overexcited toddler.

But the things that I did understand were quite fascinating, although my brain slid off a few pages that looked like this and gave me a flashback to a college physics textbook that may have caused a few nightmares a couple of decades ago.

I would advise a bit of a science background and perhaps a few other easier books in the subject first if you want to get the most out of this book, but if you don’t mind a bit of challenge and denser stuff flying over your non-physicist head then like me, you can brave it, and maybe you’ll like it, too.

3.5 stars.

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Thanks to NetGalley and Mariner Books for providing me with a digital ARC in exchange for an honest review.

‘At the heart of the Milky Way, there is a distortion in the fabric of the Universe caused by something 4 million times more massive than our Sun. Space and time are so warped in its vicinity that light rays are trapped if they venture closer than 12 million kilometres. The region of no return is bounded by an event horizon, so named because the Universe outside is forever isolated from anything that happens within. Or so we used to think when the name was coined. We have named it Sagittarius A* and it is a supermassive black hole.’

‘In the film Interstellar, Matthew McConaughey dives into a black hole called Gargantua and emerges inside a multi-dimensional reconstruction of his daughter’s bookshelves. That’s not what happens in Nature. But what is the fate of an astronaut who decides to embark on a voyage beyond the horizon into the interior of a black hole? We are now equipped to answer that question for black holes that do not spin, according to general relativity…For our purposes, we are going to recruit three more astronauts to join Red and Blue from the previous chapter in their exploration of the supermassive black hole in M87.’

Also, as a reader who is not using these texts for any academic purposes, I think Cox’s writing is so much easier to ‘digest’ (and much more enjoyable in general) than Hawking’s (only comparing this to a few of Hawking’s books that I’ve previously read). I think it might be important to clarify that – I’m not comparing them based on ‘who’s the better (astro)physicist’ or whose ‘work’ was more ‘important’; but only of whose writing/books I had found more ‘enjoyable’. Hope that helps?

‘But in science, unlike modern-day politics, principles matter. If Hawking was right, black holes would render the Universe fundamentally unpredictable and the foundations of physics would crumble. We now know that Stephen Hawking was wrong – information is not destroyed and physics is safe – as Hawking himself came to accept with delight, not regret, not least because the ongoing programme of research stimulated by his original claim continues to propel us towards a new understanding of space and time and the nature of physical reality.’//

‘Today, the study of black holes appears to be edging us in a new direction, towards a language more often used by quantum computer scientists. The language of information. Space and time may be emergent entities that do not exist in the deepest description of Nature. Instead, they are synthesised out of entangled quantum bits of information in a way that resembles a cleverly constructed computer code. If the Universe is designed, it seems, the designer is a programmer. But we must take care…we are in danger of over-reaching. The role of information science in describing black holes may be pointing us towards a novel description of Nature, but this does not imply we were programmed. Rather we might conclude that the language of computing is well suited to describing the algorithmic unfolding of the cosmos. Put in these terms, there is no greater or lesser mystery here than Wigner’s miracle of the appropriateness of the language of mathematics for the formulation of the laws of physics. Information processing – the churning of bits from input to output – is not a construction of computer science, it is a feature of our Universe. Rather than spacetime-as-a-quantum-computer-code pointing to a programmer, we might instead take the view that earth-bound computer scientists have discovered tricks that Nature has already exploited. Viewed in this way, black holes are cosmic Rosetta Stones, allowing us to translate our observations into a new language that affords us a glimpse of the profoundest reason and most radiant beauty.’//

‘This is the ultimate vindication of research for research’s sake: two of the biggest problems in science and technology have turned out to be intimately related. The challenge of building a quantum computer is very similar to the challenge of writing down the correct theory of quantum gravity. This is one reason why it is vital that we continue to support the most esoteric scientific endeavours. Nobody could have predicted such a link.

‘Be clearly aware of the stars and the infinity on high. Then life seems almost enchanted after all’, wrote Vincent van Gogh. The study of black holes has attracted many of the greatest physicists of the last 100 years because physics is the search for both understanding and enchantment. That the quest to understand the infinities in the sky has led inexorably to the discovery of a holographic universe enchanting in its strangeness and logical beauty serves to underline Van Gogh’s insight. Perhaps it is inevitable that human beings will encounter enchantment when they commit to exploring the sublime. But it’s bloody useful too.’

Whether on stage, television or in a podcast, Brian Cox is one of the most approachable science popularisers alive today. And black holes remain some of the most alluring phenomena in astrophysics, which is why it's a surprise that Black Holes, a marriage of a subject that captures our imagination with an author usually so adept at firing our imagination, turned out to be a tough and overly-academic read.

It starts promisingly, with Cox positing that black holes are "cosmic Rosetta stones" (pg. 21) that give us many valuable – and unexpected – scientific insights. They are, the book's subtitle has it, "the key to understanding the universe", and after providing an overview of black hole research, from Einstein to Hawking, Cox leads us deeper into the rabbit hole with discussions of worldlines, the 'Kerr wonderland', quantum gravity and the idea of the universe as a hologram.

Leads us, but soon leaves us behind. I recently attended one of Brian Cox's Horizons Live lectures in Manchester (which I reviewed here), where Cox proved to be engaging and able to explain difficult concepts clearly to a general audience. He was also keen to impress a sense of wonder about the makeup of the universe. This, to my great surprise and dismay, wasn't really replicated in Black Holes, even though the topic was much the same. This book, co-written with Jeff Forshaw, one of Cox's colleagues at the University of Manchester, reads for the most part like a dry textbook for undergraduates. It is packed full of diagrams (moving far beyond the Penrose diagram which Cox utilised in his live show), graphs and equations of rapidly increasing complexity.

Now, as a general rule, whenever someone produces a graph I reach for my revolver, but I imagine even those readers who are more inclined to jump through the various mathematical hurdles Cox and Forshaw erect will find them a bit excessive. I once read a popular science book (The Universe in Your Hand by Christophe Galfard) which gamely introduced the reader to all the wonders of then-contemporary astrophysics with the promise that only one equation (Einstein's famous E=mc2) was needed in order to understand it. Black Holes doesn't do this – not even close – and my eyes began to glaze over every time a new equation was introduced and then explained in a dense and academic series of paragraphs without much in the way of respite.

Very well, you might say – what did you expect? And certainly I didn't go into Cox's book expecting an easy time of it. The topic is an intense and difficult one, even before you get to the cutting-edge stuff which the authors discuss in the final chapters. And yet, it did feel like a textbook, like there might be an exam waiting at the end. "It is worth checking that you understand the diagram well enough… before you read on," Cox writes on page 59. If I had, I might well still be on page 59. I have read – and mostly understood – a fair chunk of popular science in my time, and found this book severely wanting when it came to popular science's most important task: bringing the reader along.

It's a great shame, because the cutting-edge ideas delivered, however imperfectly, in the book are fascinating and profound. The 'Rosetta stone' analogy proves apt, as the authors show that a study of black holes leads us to a greater understanding of the makeup of the universe and the nature of spacetime, gravity and reality itself. This is why, the authors argue at the end of the book, "it is vital that we continue to support the most esoteric scientific endeavours", because no one could have predicted that we would find such links in studying black holes (pg. 263).

It's a fair point, but the book itself doesn't do enough to bring those esoteric ideas into the minds of the mainstream reader, and the impact of this profound discussion is consequently diminished. In the Horizons Live show I attended, Cox joked about performing an 'equation solo' in the arena (which is usually reserved for musical acts), but Black Holes' equations are less a blistering thirty-second solo of astonishing impact and more like those indulgent twenty-minute soloes where you wish the guitarist would bring it home and we can get back to the song itself. Too often, I was left wondering who Cox and Forshaw believed they were talking to in the book – surely they must have noticed many of their readers had fallen behind?

On page 210, the authors write that "there are electrons in your hand and electrons in the Andromeda Galaxy, separated by over 2 million light years, [but] linked through quantum entanglement". It's a good line, and the sort of thing that readers of popular science like myself lap up. But such lines are too rare in Black Holes, which too often forgets to invoke this sense of wonder. It's noteworthy that the page immediately following this line provides not one or two, but four equations. As a science book, I'm sure this must be a remarkable and accurate piece, but as a popular science book, it must be considered something of a failure.

So very woman in STEM of me to listen to this while crocheting as a former astrophysicist. I have no idea how anyone who doesn’t have some knowledge of astrophysics and/or maths could ever hope to understand this book, it’s highly technical throughout but there were some witty moments which added some levity

O grande feito deste livro foi fazer com que uma ex-estudante de Humanidades, que tinha uma vaga ideia de Física, se sentisse apta a responder a um questionário a esse respeito.

Os mistérios do universo - a maravilha do espaço infinito, inexplorado - e do espaço conhecido, que não deixa de fascinar quem se dedica a estudá-lo.

Foi fácil perder-me e sentir-me a flutuar no espaço enquanto trabalhava. Em suma: consegui traduzir e, ainda assim, aprender e maravilhar-me.

A banda sonora do Interstellar ajudou muito a criar o ambiente perfeito para explorar estes temas.

Aconselho MUITO!

It’s a great overview of “black-hole-history”, starting with theoretical black holes, the discovery and properties of real ones, and further speculation, including what it means for our worldview. It’s a nice book, even though it really lacked the explanatory power of “The Quantum Universe: Everything That Can Happen Does Happen”, which I loved. In “Black Holes” some topics are only brushed upon, and I wish the authors provided a deeper understanding through metaphors and analogies, which they're great at.

The book starts with an extremely engaging “Brief History of Black Holes”, which got me instantly hooked. The first few chapters explain the idea of spacetime interval, special relativity and spend a lot of time introducing Penrose diagrams. It was really informative and helped a lot with the understanding of the following chapters. There’s time dilation, as well as the twin paradox – I liked the idea that you can “gain time” compared with stationary observers while accelerating, but this also can cut you off from some regions of spacetime (now some ideas in Death's End by Liu Cixin make more sense!). Minkowski spacetime diagrams are however touched upon very briefly, and meeting them again in the later chapters I was a bit confused.

First we learn about theoretical Schwarzschild black holes. They were explored in depth (haha), and some concepts were really challenging (like how space and time change places inside the black hole), but the youtube videos helped making some sense of it. Kerr black holes with their wormholes got me scratching my head though. Following the “Kerr Wonderland” chapter there’s “Real Black Holes from Collapsing Stars” chapter, which got me relieved – thank God the Kerr wonderland isn’t “real”. Or is it? I don’t know.

Then we follow with several challenging, but very interesting chapters on black hole thermodynamics. Black holes are seemingly featureless – just spacetime geometry and mass. So if you throw a high-entropy object into it, the entropy of the universe would decrease? Since it contradicts the second law of thermodynamics, they (Bekenstein) came up with the solution: the information, and so, entropy of infalling objects remain on black hole’s event horizon, inscribed onto it in bits of Planck-length, making black holes the highest-entropy objects in all the universe.

Now, I’m not sure how this works (no sh*t), but from what I understood, it’s from the point of view of the external observer that information rests on the surface, but maximally-scattered as if the infalling person was vaporized. Meanwhile a person crossing the black hole event horizon would feel nothing out of ordinary (except for being spaghettified), but the spacetime is stretched out so much that the outside observer would never see the infalling person cross the event horizon, so the information about them would rest on the surface? This results in a paradox of essentially creating two copies of the same object / person: one spaghettified, one vaporized. Some say it’s no problem, because they can never meet again, some say otherwise, but I’m not sure I understand exactly what they say lol.

Anyway, now we come to another “real” (in a sense that it was observed) property of black holes - Hawking radiation. Empty space constantly creates pairs of virtual particles, which annihilate each other in a moment. What if this pair was created right on the event horizon? One would lead inside towards singularity, and the other one would remain outside. Then the black holes would emit radiation (in a form of virtual particles), which indeed they do! Yay!

Then another problem – radiation doesn’t carry information, it’s just plain heat. But does that mean that the information about its insides is forever lost? (I don’t fully understand how this relates / doesn’t relate to the event horizon entropy?) Anyway, here the authors speak about the Hawking particles (the virtual pairs) and their entanglement. Quantum entanglement is explained beautifully, and I have a sense it’s the authors’ forte. Anyway, the two particles would be entangled, and one of them escapes, while the other one remains inside the hole. However, black holes are VEEERY VERY slowly evaporating. Would the particles inside it simply disappear, thus breaking quantum entanglement? Or would they evaporate too at some point, following their “siblings”? If so, the entropy of the black hole would start falling at some point, when the escaped particles would start matching their friends from before.

The last few chapters explore the possible ideas of connecting quantum mechanics with gravity, as well as a theory that the world might be a hologram. If all of the contents of a sphere could be completely described by its surface (as in black-hole thermodynamics), then maybe “volume” and “gravity” are secondary properties, that arise only from quantum entanglement interactions on the surface? Surface of what? We don’t know and my head is spinning.

In short, I really liked this book, but wished it had more thorough explanations, and maybe a clearer differentiation of purely theoretical from “verified”, but that might be the noob in me talking. If the same authors were to write a book “Black holes explained very clearly in 500 pages or less”, I would be the first in line to read it.

4 stars!

The beginning started strong but there were certain chapters which I preferred over others. I am familiar with some concepts and theories but the lesser known concepts required me to research outside this book.

This is definitely for readers who already have some knowledge on the Schwarzschild Radius, Black Hole Thermodynamics and The Theory of General Relatively.

Overall this book and the theories put forward interested me, especially with our understanding of nature and how space defies this. We cannot apply the usual laws of nature to space and this is a big obstacle to overcome. We have to disregard laws of nature and use our knowledge to explore unfamiliar concepts like Black Holes, Stars and Gravity.

As stated on page 37, "Nature doesn't care about your point of view, and the interval is a fundamental property of Nature".

(For the above quote, the interval relates to the different times and distances measured between events.)

Not sure how to rate non-fiction books at all but I really enjoyed this one😂🤷🏻‍♀️

Through reading this book I proved (yes I...as in little old me), that Einstein's Theory of Special Relativity is indeed correct. E (my level of enlightenment) was indeed directly related to the mass M (or density of my brain) multiplied by C squared (where C is the speed of light). The more the authors enlightened me about Black Holes, the denser my brain became until I eventually passed through the Event Horizon (my ability to read further) which resulted in a Singularity....or headache.

Disappointingly I have to concede defeat. This book was just far too complicated for me to get my head around! Generally Cox is really good at simplifying complex ideas but here, except for the odd paragraph or two, he failed. I’m sure this is an excellent text for undergraduates but as a popular science book it fell short.

Definitely not a light read. More in depth than any TV science stuff which was interesting but not really sure how much I understood.

Prachtig boek dat beschrijft hoe de natuurkunde van zwarte gaten verweven is met de wiskunde van quantum computing. Ook zonder de wiskunde te begrijpen, goed te volgen. De beschrijving van de formule voor de temperatuur van een zwart gat is natuurlijk ook superhandig om te hebben voor als je ooit in de buurt bent.

I will be rereading This book as it felt to me like one of the most simple and complex books on black holes , that neither made me feel smart or dumb. I would highly recommend, and challenging folks to keep reading it over time.

Whilst the science presented in this book is sound, the way in which it is presented is unnecessarily complicated and obtuse. Even as an astrophysicist with a background in theoretical physics, coming to the end of my PhD, this book was near incomprehensible for a casual read. Admittedly, perhaps in written (rather than audio) form this book would have been more understandable, but with the academic "level" of language used in the book being so far beyond layman I am not convinced it would have been. Whilst I do not dispute that the physics of black holes is complex and intricate, the detail included in this book compresses concepts explained (at length) in undergraduate physics courses into dense, rapid fire paragraphs. Hardly the "presenting complicated scientific ideas in an engaging way" touted by the synopsis as being Brian Cox's hallmark style. A rebranding as a primer for undergraduate physicists studying relativity might be a more apt categorisation for this book.

Very readable and up-to-date. I especially appreciated the clear explanations of Penrose diagrams and their use to explain different types of black holes. The last three chapters, however, concerning the relationship between quantum entanglement and spacetime were something of a slog. I'd like to see another book that gave those topics a clearer treatment.

Really interesting, but have to confess I only understood about 5 % . A good reminder of the incredibly complex, interlinked and fascinating world we live in explained probably as simply as it could be which was still really really complicated.

Blackholes are fascinating. These mysterious objects out there play an important role in the shape and design of this universe. After the movie Interstellar, this Blackhole thing haunts my mind. Wanted to know more and more about this nature's wonder.

In this book "Blackholes,the key to understanding the Universe,” authors Brian Cox and Jeff Forshaw provided a captivating and insightful exploration of this nature's mysterious creations - blackholes.

Albert Einstein's general theory of relativity, developed in 1915, laid the theoretical foundation for the existence of black holes. The equations of general relativity describe how matter and energy influence the curvature of spacetime, and they predict the formation of singularities, regions where gravity becomes infinitely strong, as in the center of black holes.

Stephen Hawking, in the 1970s, made significant contributions to the understanding of black holes. His work on black hole thermodynamics and the concept of Hawking radiation revolutionized our understanding of these cosmic entities. Hawking radiation theorizes that black holes are not entirely black; they can emit radiation and gradually lose mass over time.

In the 1930s, the proud Indian, the scientist from Chennai, Subrahmanyan Chandrasekhar developed the concept of the "Chandrasekhar limit," which describes the maximum mass that a white dwarf star can achieve without collapsing into a neutron star or a black hole. Chandrasekhar's work laid the groundwork for understanding the conditions under which massive stars can evolve into black holes, contributing significantly to the theoretical framework of stellar astrophysics and the formation of black holes.

It's not just Einstein, Hawking, and Chandrasekhar. Many other scientists have played a part in studying black holes. This book goes into detail about different studies done in this area, providing a lot of information. Reading this book will help you understand black holes better.

“Einstein was wrong when he said, ‘God does not play dice’. Consideration of black holes suggests, not only that God does play dice, but that he sometimes confuses us by throwing them where they can't be seen” !!! -
Stephen Hawking.

It is that time of month again when I write a book review for a book that I chose to read out of an obligation to read it. This month, I chose to read Black Holes: The Key to Understanding the Universe by Brian Cox. Recently in my Physics class, we had a short unit on Black Holes, which intrigued me, so when I saw this book, that interest sparked. Right after opening the book, on the backside of the cover, the book claims it’s “the key to understanding the universe.” This is immediately a red flag considering in Physics we learned how little humans understand the universe, so I doubt this book will fix that. This book does go deeper into Black Holes then we went in physics, and instead of talking about Black Holes in a more general way, it will explain some of the little things that make Black Holes different from one another. There are also equations through out the book, some of which I understand from Physics, others are way beyond my comprehension. Overall this is a decent book, but I will rank it 3.5 out of 5 stars for the lie that this book is “the key to understanding the universe.” I don’t care if some of the top experts in Black Holes helped write this book, they still don’t completely understand the universe.

Now I understand why the book is titled in such a way. At first, I thought it was just a catchy title to attract readers. But, by the end of this book, you will understand, why black holes are indeed the key to understanding the Universe.

The author starts from a simple theoretical eternal non-spinning black hole, Schwarzschild's solution of Einstein's General Relativity. This is a bit unusual start (at least for me, a nonphysicist who learn only from popular science book), because I always learn about a black hole from a physical process (the collapse of a star), not a purely theoretical one like Schwarzschild's. But it is intriguing, to learn purely theoretical black holes derived only from Einstein's General Relativity. And, I didn't expect that I would learn the Penrose diagram to understand the infinities of spacetime.

With this book, we will explore the possibilities of the interior of a black hole, starting from Schwarzschild's eternal and non-spinning black hole, Kerr's eternal and spinning black hole, Hawking's non-eternal (radiating) black hole, until the duality of our reality: the Holographic Principle. I can't hold my excitement when the author introduces Quantum Computing with its relationship with the Holographic Principle to simulate our spacetime reality. It is new information for me, and it is mind-blowing.

This book, however, requires you to trust the math behind all the black hole physics and their interpretation. The author did write some equations but it is in the simplest form. There is no detail on the derivation (of course, because this is not a textbook), so we need to trust what the author said. As weird as it may seem, they did the math, experiment, and research more than I did. Hence, I trust them.

ประทับใจความพยายามอธิบายหลุมดำด้วย Penrose diagram และสมการต่าง ๆ ซึ่งลึกมาก สำหรับ pop science และอธิบายได้ชัดเจน แสดงให้เห็นถึงการวางแผน การ organize โครงสร้างของบทต่าง ๆ อย่างดี เพิ่งรู้สึกว่าตัวเองเข้าใจ black hole complementarity กับ information paradox ขึ้นมาหน่อยก็จากเล่มนี้ เพิ่งอินกับคำถามว่าหลุมดำทำลาย information มั้ย และพอจะเชื่อมโยงให้เห็นภาพรวมได้ หนังสือได้ให้สิ่งที่ผู้อ่านคาดหวังจากปกได้แบบเต็ม ๆ ผู้เขียนตั้งใจอธิบายจริง คนอ่านต้องตั้งใจคิดตามภาพที่ถูกบรรยาย สองบทสุดท้ายยากจนปวดหัว พูดถึง hologram กับ Anti-de Sitter spacetime ยังไม่เข้าใจ แต่อ่านแล้วสนุก และน่าตื่นเต้น

A mostly accessible delve into black holes and what they mean for like, everything. Lost me towards the end.

I'm not smart enough to understand, but the vibes are cool

A deep dive to the science of black holes and the whole universe

This is definitely a hard read. I had to read some chapters again and again to understand ( not fully though). So if you are going to read this book, and understand it thoroughly, you should spend some time on it.

While saying this, I think the authors try their best to convey these complex ideas to the layman. I have read considerable amount of books about the universe and this is the hardest so far. But even though this it's hard to read, I think we can see through these theories from a mathematical point of view. Because at the end of the day it's all about maths.

The authors try to describe the spacetime by something called Penrose diagrams. I think I did a good job understanding it to some extent. But when it came to quantum entanglement in the last chapters, I kind of gave up. Because the equations involved with those chapters were more complex than the rest.

But if you like to know more about the universe, and would like to really like to see how the real scientists go about it, try this book. It'll be challenging. But you'll learn a lot. I know I did.

Didn’t learn much about black holes but helped me fall asleep. Shame it wasn’t Brian Cox narrating on the audiobook so I could think about his perfect smile

The problem with listening to this is that there are no PDF attachments of the diagrams which leaves the reader lacking the knowledge and understanding

Insightful read, by one of the best science communicators, on the cutting edge of black hole research; this may be the key to understanding the foundations of the universe and merger of quantum physics and general relativity. Keep in mind, although not academic in nature, the book uses many diagrams and concepts that are not intuitive and can be on the technical side that builds as you read. Careful reading for understanding especially in the early chapters is important. Or prior engagement with concepts such as Penrose diagrams, entropy, and general relativity help.

A great video to get a primer on the topic (they reference this title): https://youtu.be/6akmv1bsz1M?si=3sYCf...

Way over my head but the stuff I understood and will take away from it were fun to learn about.

Having read some other reviews, I’ll read some more of their books to see if the message is a bit clearer, or I just don’t get it...

I request just about every book on NetGalley that covers topics in astrophysics, even though the field doesn't chagne that fast and many titles strike me as oversimplified. I'm glad I requested this one, because it's a sleeper. It started off very basic, simple enough for most educated readers to follow along, but around 30% it really got into the science of black holes and the space around them. It was a very pleasant surprise, as I found myself working hard to keep up with the author as he took Penrose diagrams in a new direction, and explosed the Information Paradox and other black hole basics in new ways. He ended on a high note, taking the Holographic Principle to new and surprising heights. Highly recommended for educated readers who can kepe up with a little hard science that hasn't been overly diluted for general consumption.

Oh boy. Not an easy read.At some point I am going to have to reread this... slowly. I was surprised at the link between entanglement and space and black holes and quantum computing. But there you go, nature is very surprising.

I was surprised at how good this book was. Obviously I know Cox is a great science communicator and his previous books with Forshaw have been really well received. I bought this book because I’ve been reading a lot about black holes and general relativity lately, including Sean Carrol’s latest book on The Biggest Ideas in the Universe (highly recommend).

My reason for being sceptical is that I assumed this book would be a fairly watered-down affair with the usual dose of hand-wavy analogies that end up obscuring or misconstruing most of the real physics. Well, I was very wrong!

The first sign I was wrong is when I noticed a myriad of Penrose diagrams throughout the book - that is not something I’ve see in popular science books before. Sometimes you will get spacetime diagrams and usually very simple ones at that. As someone who studied physics 20 years ago as an undergraduate (and took a subject on relativity) I can honestly say I’d never seen a Penrose diagram before and I found them a really useful learning tool in the book. As I said, I’ve read a lot of books on this topic and adjacent ones (Thorne, Greene, Smolin, Carrol, etc) and I was genuinely glued to this one.

There’s an old saying I think by Stephen Hawking that every equation you include in a popular level science book will half the effective book sales. Well, Cox and Forshaw deserve credit for taking a brave plunge (and by my estimate forgoing 99.999999% of their book sales based on Hawking’s formula) because one of the highlights of this book is the scattering of equations that are accompanied by careful explanation and insight.

In summary, my take with books like these is if you are going to read almost 300 pages about black holes, the nature of space and time and the fabric of reality itself, you might as well learn at least a little bit of the true math and physics if even at a highly superficial level. If you’re up for that, this book is a spectacular success.

As a side note, I do recommend reading this one in parallel or subsequent to reading Carrol’s above mentioned book which will give you a great basis in special and general relativity. This book by Cox and Forshaw could almost fit into Carrol’s as a replacement for his chapter on black holes - on steroids!