Stephen HawkingA Brief History of Time

A Brief History of Time by Stephen Hawking is about modern physics for general readers. Its aim is not just listing some topics, but introducing modern physics by examining current scientific answers, although not complete, to fundamental questions like: Where did we come from? Why is the universe the way it is? Was there the beginning of time? Is there an ultimate theory that can explain everything? We don't have such a theory yet.I have read the first edition when I was a high school student around 1990, and this book is the revised version (revised in 1998). Compared to the first version, there are little changes. But there is one noticeable change in his point of view on the ultimate theory. According to him, recent findings on "dualities" seem to indicate that it would not be able to express an ultimate theory in a single fundamental formation. Instead, we may have to apply different theories to different situations, but in the areas which they overlap, they must coincide.The book has a lot of merits. Firstly, non-native English users including myself would feel comfortable and find it easy to read. He doesn't use difficult words and his writing style is clear. In the sense, he is better than other English scientific authors like R. Penrose, J. Gleick and I. Stewart. Secondly, the level of the book is well-chosen for general readers and the total page number is just less than 200 pages. If they read the book, at least, they would be able to learn more about how the universe began, how the stars have been formed, and how we have come here as the result of the evolution of the universe. More than that, the book contains interesting stories of some Nobel Prize winners in physics with their results related to the mentioned fundamental questions. This will help readers understand the 20th century's progress in physics.Thirdly, among the physicists who have contributed in searching an ultimate theory, the author himself is distinguished. He showed that a black hole radiates light, so we can say that a black hole is not completely black. Up to the time he presented this theory, everyone believed that a black hole can only absorb everything around it, but radiates nothing. To find the ultimate theory, we have to consolidate general relativity and quantum mechanics, but the two theories are inconsistent in many cases. But Hawking skillfully applied both of them to black holes, and obtained the result. The physicist, L. Smolin regards his finding as a starting point toward the ultimate theory. That we can read a book where Hawking himself explains about his theory for general readers is thrilling.As I mentioned above, this is my second reading of the book. When I first read the book as a high school student, it was impressive for him to explain that at the beginning of the universe, there was a singularity where the energy density is infinite, and so the law of physics including general relativity, cannot hold. But at the second reading, I found out that what Hawking really wanted to say was not that we cannot know the beginning of the universe, but that we need another theory that can explain the beginning by considering both general relativity and quantum mechanics. Actually, in the book, he introduces his "no boundary" theory which explains it without the singularity. But this theory has been neither verified nor disproved by experiments until now.Here is my advice for a reader. Don't think that you have to understand every word and sentence. Less than 200 pages, the book contains a lot of things and the author does his best in explaining them easily. For example, its explanation about the history from the beginning of the universe to the first living things on earth is outstanding. And about time travel, its arguments are ever clear and reasonable for me. But, in a few parts, the explanations are just sketchy, so if a reader is not already an expert, he could not fully understand them. When you meet such parts, just move forward. The most important thing is to learn some things and enjoy the reading.

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.