Why Does E=mc2?

Why Does E=mc2? : (and Why Should We Care?)

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The most accessible, entertaining, and enlightening explanation of the best-known physics equation in the world, as rendered by two of today’s leading scientists. 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, E=mc2. 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.show more

Product details

  • Paperback | 272 pages
  • 128 x 194 x 22mm | 399.99g
  • The Perseus Books Group
  • Da Capo Press Inc
  • Cambridge, MA, United States
  • English
  • Special edition
  • Special edition
  • 0306819112
  • 9780306819117
  • 10,117

Our customer reviews

This is a great book on the basic subjects of space and time in relativity, and how the revolutions in these concepts are central to current physics thought. It is told in a narrative style which is highly accessible, and enaging, to readers unfamiliar with the topic. The mathematics involved is complex, but is discussed in a very clear fashion, so even with minimal background, it's basically understandable. The book tackles some weighty issues, which certainly isn't unusual for a theoretical physics book, but one of the key features of this book is that the authors never lose sight of how important it is to confirm theory with experiment. Nor do they forget that the average reader doesn't care about esoteric concepts. They want to know why the theories are important in their lives. The physicists certainly address this concept.show more
by aira bautista
I learnt a lot reading this, and I even think I understood some of it. The first part takes you through the historical background to Einstein's famous equation, starting with Galileo's discovery that all motion is motion relative to something else (there's no absolute motion), then to the even more startling discovery that there's no absolute time, either (no 'big clock in the sky'), and the replacement of separate space and time with 'spacetime'. Spacetime must be curved (because Euclidian geometry won't work) and everything moves at speed through it (when I'm sitting down - not moving in space relative to myself - in one second I've still gone distance 'c' in spacetime). The authors make these strange concepts seem much more credible than I could ever do, and even explain why the concepts are bizarre to us (our conventional ones have been ingrained by natural selection). In the later part, the book looks at the implications of all this: how destroying mass creates a vast amount of energy (in an atom bomb, for instance), how stars burn and how E=mc2 explains other astronomical phenomena like white dwarves, neutron stars and black holes; what the scary-looking Standard Model equation means, and the world of very small elementary particles (which are, yikes, also waves), and how experiments are done nowadays at CERN and elsewhere to get them interacting. Among all this a lot of background gets pretty seamlessly filled in about how science works ('concepts must be testable by experiment'); what equations are for (allow you to predict the result of an experiment without having to conduct it); the mystery of why maths is so good at describing underlying natural phenomena; the importance of causality; and how light itself isn't special (it's just that its photons have zero mass and therefore always go at the universal maximum speed through space). For a reader like me (with long-ago O level Physics), it was fine - you have to know (or learn) that, for instance E=mc�² can become m=E/c�² but that's about it. The book also often tells you the same thing several times - but that's actually helpful, rather than annoying, in a complex subject like this. I've never read such a good popular-science book.show more
by Jonathan Pseud
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