A Brief History of Time by Stephen Hawking (PDF)

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#1 NEW YORK TIMES BESTSELLERA landmark volume in science writing by one of the great minds of our time, Stephen Hawking’s book explores such profound questions as: How did the universe begin—and what made its start possible? Does time always flow forward? Is the universe unending—or are there boundaries? Are there other dimensions in space? What will happen when it all ends?Told in language we all can understand, A Brief History of Time plunges into the exotic realms of black holes and quarks, of antimatter and “arrows of time,” of the big bang and a bigger God—where the possibilities are wondrous and unexpected. With exciting images and profound imagination, Stephen Hawking brings us closer to the ultimate secrets at the very heart of creation.

User’s Reviews

Reviews from Amazon users which were colected at the time this book was published on the website:

⭐Stephen Hawking’s A Brief History of Time is undoubtedly one of the classic casual scientific texts one should read to be well aware of the world around them and how it came to be. The author, an English theoretical physicist and cosmologist, seamlessly places the reader in the shoes of a student while diving deep into the questions we have always wondered but have never had the craving to research on our own time. Beginning with the relative basics of discoveries in the past centuries, Stephen Hawking explains in great detail the logic and reasoning behind the evolution of the human understanding of the universe. After getting the base knowledge out of the way, the book quickly dives deeper and deeper into theoretical possibilities and the observations which back them up. Due to the vagueness of the topic, the author helps readers visualize and truly understand the concepts that are being discussed with similes and analogies which relate to the real, observable world and the everyday life of the audience. When talking about the steps that must be taken for a star to transition into a black hole, Stephen Hawking connects the complex series of reasoning to a simple image, helping the reader visualize the theory: “It is a bit like a balloon—there is a balance between the pressure of the air inside, which is trying to make the balloon expand, and the tension of the rubber, which is trying to make the balloon smaller” (85). As a reader, such a vivid comparison makes the discussion of “sufficient gravitational attraction” seem a whole lot simpler and manageable to wrap your head around. Moreover, the lighthearted remarks which are tossed in throughout the text keeps you entertained and encourages you to continue reading, maybe not for the theories Hawking talks about but rather for his clever jokes which connect the material which was just discussed. During his discussion of elementary particles (matter and antimatter), the author includes a lighthearted remark which more or less summarizes the material that was just discussed: “However, if you meet your antiself, don’t shake hands! You would both vanish in a great flash of light” (71). The passage before this comment became complicated and very confusing to follow, however, after reading that joke, I couldn’t help myself but to turn a few pages back and reread his theory – all of this to understand his clever remark. Thus far, it seems like the perfect scientific book to read – it’s light, clever, and even funny at times. Yet, some parts of the text became extremely complex and impossible to follow. It didn’t help that the author expected the audience to have prior knowledge of the historical events which connect with the theories being discussed: “In fact bursts of gamma rays from space have been detected by satellites originally constructed to look for violations of the Test Ban Treaty” (115). While knowing exactly what the treaty was about is not directly necessary for a comprehension of the ideas in the book, it would undoubtedly be more helpful if a quick snippet of historical information was included in the text. The complexity of the theory’s descriptions, on the other hand, have absolutely nothing to do with the book itself. Stephen Hawking included an abundance of analogies and explained the complicated concepts of wormholes in as simple of language as possible. The issue is not with the author and the writing style – the subject itself makes it challenging to follow the ideas on the paper. If the idea of having to reread the same paragraph multiple times upsets you – A Brief History of Time is definitely not the book for you. All in all this is an outstanding scientific text, a classic even. The depth of the material that is being discussed in a syntax which an average teenager can understand is unbelievable at times. This book will answer the questions (and raise just as many new ones) you always had about anything to do with universe topics which are never discussed with the general public So, should you read this book? Heck yes.

⭐A Brief History Of Time explores some of the basic questions of existence, such as: How did the universe come to be? What’s going to happen to it? How does time work? The book covers the size and age of the universe, the beginning and end of it, black holes, various theories about time, and how the theory of general relativity fits in with the quest for a general theory of everything.Widely regarded as one of the greatest minds of our time, Hawking’s attempt to communicate complex science to the general public is written in a clear, almost elementary style, at least initially. (As more difficult concepts are introduced, the sentences become thicker, and the paragraphs longer.)For example, when introducing the “uncertainty principle”, Hawking writes:“The more accurately you try to measure the position of the particle, the less accurately you can measure its speed, and vice versa… Heisenberg’s uncertainly principle is a fundamental, inescapable property of the world.”What I Liked Least About ItBy far the most infuriating thing about this book was Hawking’s deliberate and repeated use of a non-standard way to communicate numbers. For example:“The idea of inflation could also explain why there is so much matter in the universe. There are something like ten million million million million million million million million million million million million million million (1 with eighty zeroes after it) particles in the region of the universe we can observe. Where did they all come from?”Nobody writes (or understands) numbers this way. The most common way to communicate large numbers in science writing is with scientific notation, something that’s common enough that the average person at least knows what you mean. Hawking could have saved quite a bit of space in the above paragraph by simply writing “10^80” (sorry, this text field won’t accept superscripts), which is how any other writer would have handled it. Did he expect that repeating “million” fourteen times would somehow impress someone?(Also, oddly enough, “ten” followed by fourteen instances of “million” would actually be one with eight-five zeroes after it, not eighty. So, it was not only a poor way to write the number, but inaccurate as well. It should have had “one hundred” with thirteen instances of “million”.)A second thing that began to bug me was the gratuitous use of the word “God”, in places where it didn’t seem to belong. Knowing as I do that Hawking admitted in 2014 that he doesn’t believe in God (“I’m an atheist”), and that he most likely didn’t believe in God in 1988 when he inserted these phrases about God, it seems disingenuous and misleading. As late as 2007, he was still saying “the laws [of science] may have been decreed by God”, though some who have known him since the 1970s say he has been an atheist the entire time.It’s not just a few mentions. The idea of God permeates this book. To be clear, I’m not complaining that he talks about God; nearly everyone I have ever known does that repeatedly. My complaint is that the talk of God seems wedged into the pages, even in places where it isn’t appropriate, despite the writer’s atheism. Here are two examples, the first using God in an appropriate manner, and the second not so much:“Newton was very worried by this lack of absolute position, or absolute space, as it was called, because it did not accord with his idea of an absolute God. In fact, he refused to accept lack of absolute space, even though it was implied by his laws.”“However, if we do discover a complete theory, it should in time be understandable in broad principle by everyone, not just a few scientists. Then we shall all, philosophers, scientists, and just ordinary people, be able to take part in the discussion of the question of why it is that we and the universe exist. If we find the answer to that, it would be the ultimate triumph of human reason — for then we would know the mind of God.”Those are the final three sentences of the entire book. Later, in 2014, Hawking weakly tried to defend this phrasing: “What I meant by ‘we would know the mind of God’ is we would know everything that God would know if there was a God, but there isn’t.” If that is what he meant, it is easy enough to say: “for then we would know what a god would know”. I can’t imagine anyone but a very small fringe of scientific-minded theists being pleased with his original wording.What I Liked Most About ItDespite regular accusations from the anti-science crowd that “science is a religion” (example), I found no leaps of faith or baseless assertions in this book (or in any other science-related book I’ve read recently). Where something is unknown, the author said it’s unknown. If something is assumed, he said it is assumed, and explained why it’s assumed. Hawking even questions the very foundation of how science formulates theories. For example:“It turns out to be very difficult to devise a theory to describe the universe all in one go. Instead, we break the problem up into bits and invent a number of partial theories. Each of these partial theories describes and predicts a certain limited class of observations, neglecting the effects of other quantities, or representing them by simple sets of numbers. It may be that this approach is completely wrong. If everything in the universe depends on everything else in a fundamental way, it might be impossible to get close to a full solution by investigating parts of the problem in isolation.”This kind of language is exactly why I like science. It uses terms like “as far as we know”, “to the best of our knowledge”, “recent studies have shown”, “with a few exceptions, which I will mention below”, and so on. When contrasted with the firm language of religion (“absolute”, “always”, and “every”), it shows that science is a quest for knowledge rather than an assertion of it. Science tends to recognize what it doesn’t yet know; in fact, what isn’t known is the very reason for the existence of science.Unlike the last book I reviewed, many of the ideas presented in this one did not make sense intuitively to me. Each of us grows up with an idea of the universe based on how it was first explained to us in our earliest days. It does not feel correct that the universe expanded out of an infinitely small point, or that it will someday contract back to that point — which is the most common scientific model of the universe. So when Hawking got to the point of explaining that it is possible, mathematically, for the universe to be finite without a singularity, I felt something like relief.“It is possible for space-time to be finite in extent and yet to have no singularities that formed a boundary or edge. Space-time would be like the surface of the Earth, only with two more dimensions. The surface of the Earth is finite in extent, but it doesn’t have a boundary or edge… so there would be no need to specify the behavior at the boundary.”In fact, each time I was starting to feel lost, Hawking would add something that grounded me just a little.Additional NoteOne thing that surprised me in several places were the dates of the discoveries, when compared to the dates I went to school and what I was (or was not) taught. For example, Hawkings says that the idea of electrons orbiting nuclei like planets orbiting a sun was an idea from the “beginning” of the 20th Century, and that it was overturned not too long after. Yet I was taught the old orbiting theory in the 1980s.He also mentions that quarks were discovered in the 1960s, and much more work was done on them in the 1970s. My science books in high school in the 1980s didn’t mention them. The proton, neutron, and electron were said to be the smallest indivisible particles known.It was frustrating to read these dates and realize that I was taught material that was known at the time to be incorrect. I thought quarks were discovered in the 1990s, because that’s when I first heard about them.Hawking addresses this problem somewhat later in the book, when he talks about the increased pace of scientific discovery:“In Newton’s time it was possible for an educated person to have a grasp of the whole of human knowledge, at least in outline. But since then, the pace of the development of science has made this impossible. Because theories are always being changed to account for new observations, they are never properly digested or simplified so that ordinary people can understand them. You have to be a specialist, and even then you can only hope to have a proper grasp of a small proportion of the scientific theories. Further, the rate of progress is so rapid that what one learns at school or university is always a bit out of date.”ConclusionI would recommend this book to anyone interested in science in general, or especially cosmology. I will probably read it again in a few years, to see if I feel any differently about it then.

⭐Had to re read some pages over and over to understand some theories and concepts but it’s a great read for any one who is mesmerized by the essence of physics and why things are the way they are..

⭐No doubt Mr. Hawking is brilliant and then some. The book seems well written but it is NOT an easy read for someone without a physics, cosmology background. There are a lot of theories, laws, principles etc that is not in the mind of a regular person.

⭐”What did God do before he created the universe? Augustine didn’t reply: He was preparing Hell for people who asked such questions. Instead, he said that time was a property of the universe that God created, and that time did not exist before the beginning of the universe.”Stephen Hawking takes us on a journey from the time when the world believed that Earth was the center of the universe and supported on the back of a giant tortoise to our age when we know better. Without the use of any mathematical equation, except the one famous mass energy equivalence relation by Einstein, he has explained the nature of our universe, from the smallest particles which cannot be seen to the biggest entities, the black holes in a simple language.The manner in which Hawking broke down complex concepts in theoretical physics, along with his adept use of humor, he clearly won over the readers who otherwise might have found themselves intimidated by physics and maths.I recommend it to all people who are interested in physics and cosmology but hate equations.

⭐Stephen Hawking summarises the difficulty of his book right at the end. Science has become ever more complex and specialised. All the grand, universal theories of A Brief History are actually the work of experts who only have time to understand their small patch. This breaking down of knowledge into pieces has been going on for centuries, gathering pace after 1776 when, in his Wealth Of Nations, Adam Smith described the future of industry as the division of labour. Then in 1988 Stephen Hawking comes along and has a go at explaining the whole of modern physics, with all its specialised fields and competing experts, to a general reader.Perhaps part of A Brief History Of Time’s remarkable success lies in a nostalgic reaction. People used to live in houses with one big room. Go to Anne Hathaway’s house in Stratford and you’ll see how a sixteenth century hall was split into the rooms of later centuries. Perhaps, in a figurative sense, we look into a tiny room in the attic – where the physicist has a study – and yearn to return to that big hall where everyone is in it together.So how did Stephen Hawking do? I have to admit to reading general books on physics that I have found much easier and more compelling – Superforce for example, by Paul Davies, an accomplished physicist in his own right. This is a book I read back in the 1980s after failing, on that occasion, to get to the end of A Brief History. But Stephen Hawking was one of the most famous physicists of modern times, isolated both by his esoteric field of expertise and his illness. Looking into the study of such a man increases the frisson.Overall I would say I caught the gist of at least some of A Brief History, without feeling I gained a deep knowledge of anything. Maybe that is an inevitable part of what us general readers might call the Dilettante Principle, our equivalent of the Uncertainty Principle. You can either know a little about a lot, or a lot about a little, but not both.I think if I’m honest I was more interested in the book not so much for what was in it – which I often had a tough time following – but for what it represents about the times we live in, where people know more and more about smaller and smaller areas. A lot of good books are like that. They catch a moment.

⭐I’d heard a lot about this book. It was certainly a best seller for its time. Also it’s a subject I’m interested in. But…..I’m not particularly bright but I don’t think I’m too slow on the uptake (I’ve two degrees for what they’re worth)…..but this book lost me completely. Hawking is a genius, no doubt. But he’s on a different planet to me. A different galaxy or universe even. It’s described as being accessible to “a layman”….whatever that is…..an astrophysicist professor? I admit he lost me completely. I read it all but know it swept over my head in a cloud of cosmic dust in the eons of time going backwards and forwards in time through wormholes encapsulated by gravity and disappearing into black holes at (just below) the speed of light. I gave it an extra star for the occasional bit of humour, obviously included as a nod towards thickos like me. I’m glad I read it though. I know where I stand in the Universe and The Big Bang. Pretty near the bottom of the class.

⭐(This is the updated version). What a book, I enjoyed it from beginning to end, reading only a chapter a day, so I didn’t get too bogged down and had time to digest it. Nevertheless, it is a lot to take on board. Being a sci-fi nut, a lot of the theory and concepts, in principle, we’re known to me but still, I am only a lowly Human Being, not a scientist! I loved the sense of humour and little asides, although I am a little perplexed by the notion that if time flowed backwards, you could see the result of a race and then place a bet on it, knowing the result. Surely you are still travelling time in the wrong direction to collect your winnings, or alternatively, everyone would be rich! Screws my brain up just trying think about it. Anyway, a jolly good book which I shall certainly read again.

⭐A brief history of time… What a fascinating book! This is probably the first time I read through an entire book where I only understood a fraction of what was explained, due to my limited understanding on the topic. In other circumstances I would have left it incomplete. However with this gem, it made me wonder about various principles I had heard about in high school, and search for some cool videos online explaining them in an easy to understand language.If you have wondered about the big bang, black holes, elementary particles, general relativity, quantum mechanics, space and time, or the laws of the universe, this book is for you!This book reminds one of how beautiful, fascinating and intriguing our universe is! I don’t think the author could have simplified things any further. I rate the book a 5-star for keeping me engaged, for making me explore concepts I wouldn’t have otherwise, and for reminding me of the wonders of the universe.

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