A Brief History of Time

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 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.

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 It

By 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 It

Despite 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 Note

One 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.”

Conclusion

I 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.