A Brief History of Time eBook Free Download

eBook details

  • Author: Stephen Hawking
  • File Size: 2538 KB
  • Print Length: 226 pages
  • Publisher: Transworld Digital (November 10, 2009)
  • Publication Date: November 10, 2009
  • Sold by: Amazon Digital Services LLC
  • Language: English

Was there a beginning of time? Could time run backward? Is the universe infinite or does it have boundaries?

These are just some of the questions considered in the internationally acclaimed masterpiece by the world-renowned physicist – generally considered to have been one of the world’s greatest thinkers. It begins by reviewing the great theories of the cosmos from Newton to Einstein, before delving into the secrets which still lie at the heart of space and time, from the Big Bang to black holes, via spiral galaxies and string theory. To this day A Brief History of Time remains a staple of the scientific canon, and its succinct and clear language continues to introduce millions to the universe and its wonders.

This new edition includes recent updates from Stephen Hawking with his latest thoughts about the No Boundary Proposal and offers new information about dark energy, the information paradox, eternal inflation, the microwave background radiation observations, and the discovery of gravitational waves.

It was published in tandem with the app, Stephen Hawking’s Pocket Universe.

Stephen Hawking, one of the most brilliant theoretical physicists in history, wrote the modern classic A Brief History of Time to help nonscientists understand the questions being asked by scientists today: Where did the universe come from? How and why did it begin? Will it come to an end, and if so, how? Hawking attempts to reveal these questions (and where we’re looking for answers) using a minimum of technical jargon. Among the topics gracefully covered are gravity, black holes, the Big Bang, the nature of time, and physicists’ search for a grand unifying theory. This is deep science; these concepts are so vast (or so tiny) as to cause vertigo while reading, and one can’t help but marvel at Hawking’s ability to synthesize this difficult subject for people not used to thinking about things like alternate dimensions. The journey is certainly worth taking, for, as Hawking says, the reward of understanding the universe may be a glimpse of “the mind of God.”

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 reading.

If you want to know how the world and the universe works then this book is certainly the one to read. From Quantum Mechanics, providing key sight into extremely small particles and matter that makes up the universe, to relativity (general and special) which describes how space and time works is what this book is all about. What I liked most was Hawking’s writing style where he inserts both humour where required (he opens with the Turtle challenge by a member of the audience) as well as plain and easy language to explain concepts about complex topics. Whilst the detail went a little over my head it was nice to go through and pick out areas that made sense. Then again I was able to read a GetAbstract summary on this book and get more out of it. It really depends on what you want to learn and how much.

Three key takeaways from the book:

  • 1. An expanding universe does not preclude a creator, but it does place limits on when he might have carried out his job!
  • 2. The universe is expanding by between 5 – 10% every thousand million years.
  • 3. The police make use of the Doppler effect to measure the speed of cars by measuring the wavelength of pulses of radio waves reflected off them.
Daniela Hill

Daniela Hill Author

Mrs. Hill is an avid reader and has a large collection of book on various subjects. She loves cooking and spending time with her family.

Leave a Reply

Your email address will not be published. Required fields are marked *