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Title: Six Not-So-Easy Pieces: Einstein's Relativity, Symmetry, And Space-Time
ISBN: 0465023932
Author:
Richard P. Feynman
Publicate Date: 2005-04-05
Publish: 2005-04-05
List Price: $14.95
Average Customer Rating: 4.5
Format: Paperback
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Amazon Lowest New Price: $8.49
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1: Good book
This book is more difficult than Six Easy Pieces: Essentials of Physics By Its Most Brilliant Teacher, but it is still understandable without too much experience with calculus. Feynman's lectures, as always, are very solid and interesting. This book is definitely worth the small price.
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2: Learn Relativity from the maestro Richard Feynman himself
In the introduction to this book, Roger Penrose, another great theoretical physicist of our times, states that "Relativity is not airy-fairy philosophy, nor is space-time mere mathematical formalism. It is a foundational ingredient of the very universe in which we live." On that note, it is encouraging for many readers that this book offers a great opportunity to take that extra step to learn the mathematical constructions for the effects of Lorentz transformations, Einstein's equations, relativistic dynamics; equivalence of mass and energy, Lorentz contraction and transformation of time. It requires undergraduate level physics, but comes with easy to follow instructions from the great maestro himself. Frequent references to his three volume book, Lectures in physics is valuable for readers who are familiar with his work.
Position and time measured in one frame of reference (one observer) is different from another frame of reference (another observer). Therefore Lorentz transformation must be examined to understand physical reality. When we look at an object, we find that it has an apparent width and depth, but they are not fundamental properties of the object, because if we look at it from a different frame of reference it would look different. In Lorentz transformations we see is a mixture of space and time. An event (physical reality) is defined by both space and time because the position of an object is characterized by the time. The description of the object also depends upon the frame of reference (observer). If the observer is travelling at the speed of light, his perception of the object would be different from someone in a stationary state. The difference between spacetime, and space and the interval provides interesting sense of reality. For example, anything happening to Sun "now" will affect earth only after 8 minutes (that is how long light takes to reach us.) Thus an event "right now" can not be defined, it is a mystery, because we are not affected by it right now, but can be affected later after eight minutes. The "now" is an idea or a concept of our mind, it is not physically definable at the moment, and we have to wait to observe it separated by distance in (light) time. The example of page 64 establishes that simultaneity is not a unique thing in the universe, because it means different things to different observers.
Relativistic dynamics; objects moving at high speeds (during forward motion) comparable to the speed of light shortens its physical length, and also time slows down (time-dilation) for the stationary observer, but the time remains the same for the moving astronaut. Thus for an observer moving under uniform velocity will not know he is in motion. The uniform velocity can not be detected without looking from outside, but the uniform rotation about a fixed axis can be detected without looking from outside. As noted earlier, the moving objects become heavier proportional to the speed given by the famous Einstein's equation, and at close to the speed of light the mass becomes enormous, and hence sufficient energy is not available to move anything beyond the speed o light.
There are many websites that explains the transition from Newtonian mechanics to the theory of relativity to explain physical reality. Some of them are referenced below, but is great to read Richard Feynamn, because he did not like scientific ideas without a good physical foundation, and his approach is strikingly original. His efforts are strenuous in teaching and making the reader understand the basic concepts. I especially recommend chapters 3 and 4 for a quick appreciation of the subject: Highly recommended to all readers interested in physics of reality.
[...]
3. The Pleasure of Finding Things Out: The Best Short Works of Richard P. Feynman (Helix Books)
4. The Feynman Lectures on Physics including Feynman's Tips on Physics: The Definitive and Extended Edition
5. The Feynman Lectures on Physics
6. Einstein's Theory of Relativity
7. Special Theory of Relativity (Routledge Classics)
8. Space and Time in Special Relativity
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3: A Gem
Any review reflects the biases of the reviewer. My qualifications are in organic chemistry, and, despite the common view that there is nothing outside computation, in chemical theory. The latter interest forced me to teach myself some physics, which was mainly classical mechanics, electromagnetic theory and quantum mechanics. I purchased Six Not-so-easy Pieces simply out of interest.
Feynman has an almost unique ability to locate the genuinely fundamental aspects of physics, and by emphasizing these, concepts that others seem to make extraordinarily turgid, in Feynman's hands become remarkably clear. Yes, you need some mathematical ability to follow this, but not exceptional mathematics. As an example, in discussing curved space, where most authors simply present a barrage of equations, Feynman shows, using elementary geometry, how curved space works.
Nothing is perfect. The role of symmetry in physics is explained well, but the discussion on the chirality of alanine, while correct as far as it goes, seemed to me to be taking the previous discussion a little out of bounds, and the discussion of the phase of the wave function has to be qualified for multiple particles. Also, a footnote on how an electron could possibly outrun a photon left open the question, given the derivation of the Lorentz contraction, why is that not a function of refractive index? But those are quibbles. The book is brilliant, and, as a challenge, if an organic chemist can follow it, why can't you?
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4: Gotta love Feynman!
Great book. Bought this book for my son, the Physicist, and he loves it. Detailed but an easy read if you understand physics.
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5: Harder than 6 easy pieces, but not extremely hard.
The title of this book probably scares off many readers, but it need not do so. This book is a sequel to Feynman's "Six Easy Pieces". Both books consist of lectures taken from Feynman's three volume lecture series, which was used for a two-year introductory physics course at Cal Tech. "Six Not So Easy Pieces" is not as easy as "Six Easy Pieces". The latter is accessible to most high school students, but the former is not. The not so easy pieces are:
?? Vectors
?? Symmetry in Physical Laws
?? Relativistic Energy and Momentum
?? Space-Time
?? Curved Space
"Six Easy Pieces" was a bit unfocused because it covered a number of different topics. In contrast, "Six Not So Easy Pieces" is focused on just one topic, Relativity Theory. Feynman uses each topic to build up to Einstein's theory of gravitation, which is not the easiest subject to grasp.
Relativity theory is generally covered in one of two ways. Some books give a general treatment, focusing on the many implications of the theory, with no mathematics. At the other extreme are texts that require considerable knowledge of matrix algebra and differential equations. This book takes a middle ground. There is some math, but only some simple algebra and vector analysis. (The vector analysis does go beyond what is taught in high school, venturing into 4 dimensional vectors, but Feynman shows this to be only a modest extension from the typical 3 dimensional vectors.) Feynman dispenses with the usual introduction to relativity theory that employs moving trains and lightening strikes. Instead he starts with a superb analysis of the Michelson-Morley experiment (alone this is worth the price of the book) and the Lorenz transformation that was developed to explain the null result that Michelson-Morley obtained. He then uses this as the starting point for the analysis of special relativity. This is followed with a discussion of relativistic energy and momentum, subjects that are generally left out of "popular" treatments of relativity theory. The final chapter discusses curved space and Einstein's theory of gravity. These topics will be hard for people without some basic physics background, but are not too advanced for the intended audience of college undergraduates, although Feynman admitted that only the best students did as well as he had hoped.
As with all of Feynman's books there is a wealth of knowledge packed a small package (in this case a bit less than 150 pages) and while these six lectures are not a substitute for a complete course in the special and general theories of relativity, it does hit the highlights and as usual provides very valuable insights for readers with all levels of knowledge.
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