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Why Does E=mc2? [Paperback]

Brian Cox , Jeff Forshaw
4.2 out of 5 stars  See all reviews (229 customer reviews)
RRP: £8.99
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Book Description

4 Mar 2010
This is an engaging and accessible explanation of Einstein's equation that explores the principles of physics through everyday life. Professor Brian Cox and Professor Jeff Forshaw go on a journey to the frontier of 21st century science to consider the real meaning behind the iconic sequence of symbols that make up Einstein's most famous equation. Breaking down the symbols themselves, they pose a series of questions: What is energy? What is mass? What has the speed of light got to do with energy and mass? In answering these questions, they take us to the site of one of the largest scientific experiments ever conducted. Lying beneath the city of Geneva, straddling the Franco-Swiss boarder, is a 27 km particle accelerator, known as the Large Hadron Collider. Using this gigantic machine - which can recreate conditions in the early Universe fractions of a second after the Big Bang - Cox and Forshaw will describe the current theory behind the origin of mass. Alongside questions of energy and mass, they will consider the third, and perhaps, most intriguing element of the equation: 'c' - or the speed of light. Why is it that the speed of light is the exchange rate? Answering this question is at the heart of the investigation as the authors demonstrate how, in order to truly understand why E=mc2, we first must understand why we must move forward in time and not backwards and how objects in our 3-dimensional world actually move in 4-dimensional space-time. In other words, how the very fabric of our world is constructed. A collaboration between two of the youngest professors in the UK, "Why Does E=MC2?" promises to be one of the most exciting and accessible explanations of the theory of relativity in recent years.

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Product details

  • Paperback: 256 pages
  • Publisher: Da Capo; First Thus edition (4 Mar 2010)
  • Language: English
  • ISBN-10: 0306819112
  • ISBN-13: 978-0306819117
  • Product Dimensions: 13.2 x 19.7 cm
  • Average Customer Review: 4.2 out of 5 stars  See all reviews (229 customer reviews)
  • Amazon Bestsellers Rank: 2,095 in Books (See Top 100 in Books)

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To get at the origins of E=mc2, the poster-child for Einsteins's special theory of relativity, [Cox and Forshaw] must delve into deep principles of science and wield a good deal of mathematics. They do it well...They have blazed a clear trail into forbidding territory, from the mathematical structure of space-time all the way to atom bombs, astrophysics and the origin of mass. --The New Scientist

"The authors do a great job of answering the question in the book's title, and of tying it to the cutting edge of 21st century physics. But they do much more besides. First, they give a real sense of revelation as the<BR>equation emerges from the seemingly unrelated concepts of space and time. Second, they're not afraid to take on questions often asked about the equation."<BR> --BBC Focus Magazine

Brian Cox and Jeff Forshaw, two physicists, have managed to produce an account of relativity physics accessible to a wide range of various publics. If you're not a physicist (or not yet a physicist) and you want to understand what Einstein and relativity theory are all about, you would do well to read this book. The writing is clear, sparkling in places, and totally without vanity. Relativity theory, Einstein's supreme gift to us, is at the heart of the way science currently looks at physical reality, and anyone with an adventurous mind should be intrigued by what two smart physicists say about it in plain language... Read this book. It's your world, isn't it? <BR> --The Huffington Post


"The authors do a great job of answering the question in the book's title, and of tying it to the cutting edge of 21st century physics. But they do much more besides. First, they give a real sense of revelation as the
equation emerges from the seemingly unrelated concepts of space and time. Second, they're not afraid to take on questions often asked about the equation."
--This text refers to an out of print or unavailable edition of this title.

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Customer Reviews

Most Helpful Customer Reviews
207 of 211 people found the following review helpful
3.0 out of 5 stars Why does E=mc2 28 Jun 2011
By TomCat
Before I start this review, just let me tell you where I stand re: popular science. I'm a complete beginner! The most amateur of amateurs. I'm intrigued, interested verging on passionate - but I've only read a handful of science books. So, I came to this book knowing nothing about the famous equation other than "energy equals mass times the speed of light squared" which, pre facto, was pretty much meaningless to me.

As I understand it, the success of this book varies wildly depending on the individual reader's pre-existing knowledge of science/quantum physics etc. As such, this is a review for people like me: utter beginners in the field.

In brief: the first half of the book is brilliant! Informative, well-written and mind-blowing in the way that high-concept astronomy often is. The second half of the book, however, is an incredibly difficult, long-winded explanation of vectors and the so-called 'master equation', most of which flew right over my head. I read it all, and bits of it made sense to me but, like many people here; this just feels like two books. The first half is clearly for people like me (beginners) whereas the second half is a radically different reading experience, which I imagine is much more suited to hardened afficianados of popular science.

Now for more detail: The first 150 pages or so don't explain the famous equation, as such; rather, they explain the things we *need* to know in order to understand the equation; such as the relative nature of time and space. All of this is articulated with very helpful diagrams, metaphors and fictional anecdotes. Any basic maths here (such as Pythagoras) is re-capped for the forgetful student(i.e. me) and parts of the book are also strikingly funny.
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20 of 20 people found the following review helpful
4.0 out of 5 stars Not Quite a Classic 21 Oct 2010
With so many books to read and so little time to read them, it's rare to find one worthy of being read repeatedly; however, for me, why does E=mc² certainly fits into that category and I found my latest reading to be just as enjoyable as the first. Undoubtedly, Cox and Forshaw have produced one of the outstanding introductory texts to Einstein's theories of relativity, presenting their arguments in an absorbing prose that stimulates the imagination and challenges one's intellect. That said, this book is not without its shortcomings and, consequently, I am not quite convinced that it qualifies as a popular science "classic".

Firstly, whilst acknowledging that Cox and Forshaw did not intend to write "a book about mathematics", the concept of special relativity does benefit from a comprehensive mathematical explanation: its simplicity is what makes the idea so beautiful and the authors fail their readers by simply presenting information without bothering to demonstrate its derivation (for instance, the time dilation equation (p.127)). In essence, readers without the requisite scientific or mathematical training are simply required to accept such assertions (or seek their explanations elsewhere) and that dilutes the impact of the reasoning. Ironically, this is as much a presentational failing as anything else and the authors could have avoided this problem, without a significant increase in explanatory text, by simply improving the quality of some diagrams and including the stepwise transformations of Pythagoras' theorem.

Secondly, notwithstanding my (genuine) praise for the authors' lucidity, there are times when the prose becomes unnecessarily convoluted.
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16 of 16 people found the following review helpful
By Tsuchan
Format:Paperback|Verified Purchase
For me, the high point of the book is in Chapter 3, where we get an overview of Special Relativity, and - astonishingly - get to prove it with something as simple as Pythagorus!

But Cox and Forshaw have this annoying, matey style which is something like having a Radio 2 DJ for a teacher. They're always telling you what's coming up soon, how interesting it will be - and with minimum of complexity. When the explanation actually starts, there are lots of digressions, apologies for digressions, spot checks on where we've got to, how far we've got to go, motivators to say how well we're doing and how worthwhile this will be when we've got there.

But after all, I don't feel I'm spared any complexity, just worn out with the whole journey. If only the excess chatter had been put into better explanations, this would be a much better book.
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137 of 143 people found the following review helpful
5.0 out of 5 stars Now I know why! 8 Oct 2009
By fatima
Format:Hardcover|Verified Purchase
I really enjoyed this book. Recommended by my son who is interested in all things cosmic, I anticipated a better understanding of modern physics, something I never got to grips with at school.

It wasn't an easy read because of the formulae and maths - I think a few more occasions where the formulae were written out in words would have helped. I found myself having to flip back to remember what the letters stood for until they eventually sunk in.

Having said that, once past the fog, it was great, and very satisfying to gain some understanding of curved space, mass and the speed of light. Now I wish I had paid more attention at school. The writing style is entertaining, engaging and not at all patronising.A great journey, well guided - I intend to read it again to make sure it stays in my head.
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Most Recent Customer Reviews
5.0 out of 5 stars Five Stars
Exactly as expected.
Published 5 days ago by jancis ham
5.0 out of 5 stars Five Stars
Very happy with item
Published 7 days ago by John M. Dowell
5.0 out of 5 stars Five Stars
excellent book came on time
Published 14 days ago by graham d cook
5.0 out of 5 stars Books on Science
It is a well written and very accessible for a book on such a complex issue. I rate it highly and recommend it to people interested in science at any level
Published 19 days ago by Mr. B. Wood
5.0 out of 5 stars Five Stars
Published 25 days ago by mrs c e davey
4.0 out of 5 stars A crash course of higher level physics
Interesting and surprisingly comprehensive, "Why does E=Mc^2?" is not meant to provide any particularly controversial or revolutionary theories. Read more
Published 26 days ago by Simonhsj
5.0 out of 5 stars Five Stars
Great book, fantastic buy, great service, thanks.
Published 26 days ago by Geoffrey Hold
5.0 out of 5 stars As I haven't heard to the contrary I assumed she liked it.
This book was a present to a great-niece who is interested in science. As I haven't heard to the contrary I assumed she liked it.
Published 1 month ago by Booklover
5.0 out of 5 stars Five Stars
A really good read.
Published 1 month ago by David Martel
4.0 out of 5 stars Really easy to read (for Relativity) and nicely explained through...
Really easy to read (for Relativity) and nicely explained through concept rather than mathematics.
Note: if you're a 1st year Physics Undergrad at the University of... Read more
Published 1 month ago by potplant
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