Albert Einstein is the unquestioned founder of modern physics. His theory of relativity is the most important scientific idea of the modern era. In this book Einstein explains, using the minimum of mathematical terms, the basic ideas and principles of the theory which has shaped the world we live in today. Unsurpassed by any subsequent books on relativity, this remains the Albert Einstein is the unquestioned founder of modern physics. His theory of relativity is the most important scientific idea of the modern era. In this book Einstein explains, using the minimum of mathematical terms, the basic ideas and principles of the theory which has shaped the world we live in today. Unsurpassed by any subsequent books on relativity, this remains the most popular and useful exposition of Einstein’s immense contribution to human knowledge. In this work Einstein intended, as far as possible, to give an exact insight into the theory of relativity to those readers who, from a general and scientific philosophical point of view, are interested in the theory, but who are not conversant with the mathematical apparatus of theoretical physics. The theory of relativity enriched physics and astronomy during the 20th century.

# Relativity: The Special and the General Theory (ebook)

Albert Einstein is the unquestioned founder of modern physics. His theory of relativity is the most important scientific idea of the modern era. In this book Einstein explains, using the minimum of mathematical terms, the basic ideas and principles of the theory which has shaped the world we live in today. Unsurpassed by any subsequent books on relativity, this remains the Albert Einstein is the unquestioned founder of modern physics. His theory of relativity is the most important scientific idea of the modern era. In this book Einstein explains, using the minimum of mathematical terms, the basic ideas and principles of the theory which has shaped the world we live in today. Unsurpassed by any subsequent books on relativity, this remains the most popular and useful exposition of Einstein’s immense contribution to human knowledge. In this work Einstein intended, as far as possible, to give an exact insight into the theory of relativity to those readers who, from a general and scientific philosophical point of view, are interested in the theory, but who are not conversant with the mathematical apparatus of theoretical physics. The theory of relativity enriched physics and astronomy during the 20th century.

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5out of 5Orhan Pelinkovic–Albert Einstein (1879-1955) in this book introduces to the general reader his theory of relativity: the special and the general theory. We see that special relativity, which has emerged from the Maxwell-Lorentz theory of electromagnetic phenomena, shows that the laws of science appear to be the same for all moving observers regardless of their speed, all in the absence of gravity. On the other hand, in general relativity, which can be considered Einstein's theory of gravity, we understand that the Albert Einstein (1879-1955) in this book introduces to the general reader his theory of relativity: the special and the general theory. We see that special relativity, which has emerged from the Maxwell-Lorentz theory of electromagnetic phenomena, shows that the laws of science appear to be the same for all moving observers regardless of their speed, all in the absence of gravity. On the other hand, in general relativity, which can be considered Einstein's theory of gravity, we understand that the laws of science ought to be the same for every observer no matter how they are moving. In general relativity gravitation is a result of the curvature of the four-dimensional space-time continuum. Einstein refers us to Hermann Minkowski's (1864-1909) four-dimensional "world" and states how important Minkowski’s (one of Einstein’s teachers) idea was for the development of his theory of relativity. So, what did these moving and stationary observers notice? Their pocket watches that were perfectly synchronized at first recorded a different time after their observation was complete. Some dials were ahead, and others behind. So, time is relative, not absolute. The book does not concentrate only on science, but is also a tiny bit philosophical. The writing is simple, straightforward, and easy to understand, although at first, the theory is somewhat complex, but at the end of the day easier to understand than visualize. It's difficult to visualize three dimensions, let alone four. Einstein's intention in writing this book is to present the special and general theory of relativity to the broader public with simplified examples and equations. Einstein gives a lot of recognition to his predecessors, such as Euclid, Newton, Galilei, and Gauss, and does not overthrow or disregard their science theories and laws, but rather upgrades them. I am astonished at Einstein's capability on how he utilizes the available mathematical equations which he modifies and adapts so well to suit his revolutionary theory. We also notice that in general relativity no point of view is more important or preferred over any other point of view. I wonder if we can extend this conclusion to other subjects. Are all perceptions, coming from different angles, of equivalent importance? This is something to keep in mind while considering other people’s points of view. My five star rating is for the quality, accuracy, and importance of the theory.

5out of 5Prerna–I could write an elaborate review praising Einstein's brilliance and list all his eccentricities. I could attach one of those many goofy pictures, in which he's making weird faces at the camera, or I could attach a more sombre one, after all, there are plenty of both online. I could also attach a really philosophical quote of doubtful authenticity and marvel over how his brain was studied in hopes of finding an anomaly. But I won't. It's been more than a hundred years since he first published hi I could write an elaborate review praising Einstein's brilliance and list all his eccentricities. I could attach one of those many goofy pictures, in which he's making weird faces at the camera, or I could attach a more sombre one, after all, there are plenty of both online. I could also attach a really philosophical quote of doubtful authenticity and marvel over how his brain was studied in hopes of finding an anomaly. But I won't. It's been more than a hundred years since he first published his revolutionary theory, and now, as always, we must let Einstein speak for himself. As he does in this book. Nothing else can compare.

5out of 5Riku Sayuj–Some years ago in France a book by Jean-François Gautier appeared, entitled Does the universe exist?. Good question. What if the universe were a concept like cosmic ether, or phlogiston, or the conspiracy of the Elders of Zion? Philosophically, Gautier’s arguments make sense. The idea of the universe, as the totality of the cosmos, is one that comes from the most ancient cosmographies, cosmologies, and cosmogonies. But can one describe, as if seeing it from above, something within which we are cont Some years ago in France a book by Jean-François Gautier appeared, entitled Does the universe exist?. Good question. What if the universe were a concept like cosmic ether, or phlogiston, or the conspiracy of the Elders of Zion? Philosophically, Gautier’s arguments make sense. The idea of the universe, as the totality of the cosmos, is one that comes from the most ancient cosmographies, cosmologies, and cosmogonies. But can one describe, as if seeing it from above, something within which we are contained, of which we are part, and from which we cannot exit? Can there be a descriptive geometry of the universe when there is no space outside it on which to project it? Can we talk about the beginning of the universe, when a temporal notion such as “beginning” must refer to the parameter of a clock, while the universe must be the clock of itself and cannot be referred to anything that is external to it? Can we say, as Eddington does, that a hundred billion stars constitute a galaxy and a hundred billion galaxies constitute the universe, when, as Gautier observes, while a galaxy is an observable object, the universe is not, and therefore we would be establishing an improper analogy between two incommensurable objects? Can we postulate the universe and then study with empirical instruments this postulate as if it were an object? Can a singular object exist (surely the most singular of all) that has as its characteristic that of being only a law? And what if the story of the big bang were a tale as fantastic as the gnostic account that insisted the universe was generated by the lapsus of a clumsy demiurge? Basically, this criticism of the notion of the universe reiterates Kant’s criticism of the notion of the world. After all, the cultivated person’s first duty is to be always prepared to rewrite the encyclopedia. P.S. The reflections are directly borrowed from Umberto Eco's lectures, but are genuine concerns of this reviewer too. Questions are addressed to Einstein, of course.

5out of 5E. G.–Preface Note to the Fifteenth Edition --Relativity Appendices: 1. Simple Derivation of the Lorentz Transformation 2. Minowski's Four-dimensional Space ("World") 3. The Experimental Confirmation of the General Theory of Relativity (a) Motion of the Perihelion of Mercury (b) Deflection of Light by a Gravitational Field (c) Displacement of Spectral Lines towards the Red 4. The Structure of Space according to the General Theory of Relativity 5. Relativity and the Problem of Space Bibliography Index Preface Note to the Fifteenth Edition --Relativity Appendices: 1. Simple Derivation of the Lorentz Transformation 2. Minowski's Four-dimensional Space ("World") 3. The Experimental Confirmation of the General Theory of Relativity (a) Motion of the Perihelion of Mercury (b) Deflection of Light by a Gravitational Field (c) Displacement of Spectral Lines towards the Red 4. The Structure of Space according to the General Theory of Relativity 5. Relativity and the Problem of Space Bibliography Index

5out of 5Adam–The theory of relativity is amazing and important, but contrary to what the tagline says, Einstein himself is probably not the best person to have explain it to you. I read this class for Freshman Studies in college, and I honestly have to admit that I wouldn't have gotten much of it without the significant aid of in-depth lectures and classroom discussions. This is not because the ideas themselves are too complex, but because Einstein fails in his attempt to make his ideas understood to a layma The theory of relativity is amazing and important, but contrary to what the tagline says, Einstein himself is probably not the best person to have explain it to you. I read this class for Freshman Studies in college, and I honestly have to admit that I wouldn't have gotten much of it without the significant aid of in-depth lectures and classroom discussions. This is not because the ideas themselves are too complex, but because Einstein fails in his attempt to make his ideas understood to a layman. I don't know what book you ought to read instead, but there are certainly many alternatives, of which some must be good. Einstein does not assume any knowledge of physics, but he does kind of glide over what his variables mean or where they come from, and this makes it hard to grasp what the math means and how it fits in.

5out of 5Rob–edit: i wrote the 4-star review below before reading the fifth appendix. i mean, who could imagine that an appendix could change anything? well, this one did. all the chapters in the body of the book are 2 or 3 pages. Appendix V is a 20-page essay, written 36 years after the rest of the book and just 3 years before einstein died. it is a tour de force on the history, philosophy, and psychology (i kid you not) of the scientific understanding of empty space. it was shocking, thrilling, amazing. th edit: i wrote the 4-star review below before reading the fifth appendix. i mean, who could imagine that an appendix could change anything? well, this one did. all the chapters in the body of the book are 2 or 3 pages. Appendix V is a 20-page essay, written 36 years after the rest of the book and just 3 years before einstein died. it is a tour de force on the history, philosophy, and psychology (i kid you not) of the scientific understanding of empty space. it was shocking, thrilling, amazing. the book now gets 5 stars. careful, i think some editions don't have Appendix V. original "4-star" review: the subtitle of this slim book is "a clear explanation that anyone can understand", but unfortunately i'm afraid that's far from true. there's not too much math in the book, but there is enough that "anyone" really needs to be replaced with "any egghead". but if you are already familiar with relativity, this is a great book, with lots of deep philosophical underpinnings as expounded my the man himself. i found his writing style to be exquisite - not too dry, not too colloquial. the treatment of special relativity is wonderful. but trying to teach general relativity in 45 pages with no math is just too tall an order. he even warns us as things start to get rough: "...I am guilty of a certain slovenliness of treatment, which as we know from the special theory of relativity, is far from being unimportant and pardonable. It is now high time that we remedy this defect; but I would mention at the outset, that this matter lays no small claims on the patience and on the power of abstraction of the reader." indeed, the treatment of GR is in very broad strokes, with rather obscure connections. still, quite enjoyable to find this readable text by one of my great heroes.

4out of 5Forrest–Needs more gods rolling dice . . .

5out of 5Robert–The aim of this book is to introduce people without a strong physics (or even scientific) background to the special and general theories of relativity - theories that Einstein was the primary developer of. Einstein assumes the reader has passes a "university matriculation exam." What that meant in the first half of the 20th Century, I don't know but in practice what's required is the level of algebra I had by age 16 plus a smattering of mentions of the square root of minus 1. I also found basic The aim of this book is to introduce people without a strong physics (or even scientific) background to the special and general theories of relativity - theories that Einstein was the primary developer of. Einstein assumes the reader has passes a "university matriculation exam." What that meant in the first half of the 20th Century, I don't know but in practice what's required is the level of algebra I had by age 16 plus a smattering of mentions of the square root of minus 1. I also found basic calculus useful for one section, though it is possible to do without it. For the most part this book is excellent, introducing the minimal amount of mathematics and formal language necessary to understand the most important and fundamental concepts of Einstein's theories in a way that is accessible whilst concise. It might be possible to do it better with a bigger book, a less formal style and a lot more diagrams but it very interesting to get Einstein's unique perspective as originator of the theories and insight into his thought processes. A few sections are remarkable in contrast with the rest, for being unclear. The section on addition of velocities in special relativity leaves rather more to the reader than anything else in the book, mathematically, and when I looked it up it turned out to be much easier to work out using basic calculus than algebraic division - and the bit that wasn't clear was that a division of two equations was what was required. This section could be skipped without losing much. The remainder of the muddy sections come at the back end of the section on general relativity. The simplest precise mathematical formulation of this theory is expressed using tensors - and tensor algebra is way beyond what anybody encounters in standard school maths or physics curricula. Einstein makes no attempt to explain it and in fact never shows the fundamental equation of general relativity. This makes it very hard for him to explain how gravitational fields and space-time interact, which leads to the lack of clarity in the latter stages of this part of the book. Things get easier and clearer again when he moves on to relativity and cosmology. The final part of the book is a collection of appendices expanding on things discussed earlier on. I required pen and paper to check the derivation of the Lorentz Transformations from first principles - but this section could just be skipped if the maths bothers you - it doesn't add a lot but it is interesting to see it, if your algebra is up to it. The most rewarding thing for me, since nothing here is completely new to me, was listening to Einstein's voice. He seemed to come at things from a viewpoint much more generally philosophical than most present day physicists would, discussing Kant, Descartes and Hume, for instance. The section on the concept of "empty space" was fascinating - he concludes that general relativity precludes this notion - one cannot have space-time without it containing "fields." What he means is fields of force - the electromagnetic field, gravitational field etc. This implies the notion of a field being present even if its magnitude is zero - which is a bizarre concept. Modern quantum mechanics backs these ideas to the hilt and leads me to think that one of the most important areas of inquiry for fundamental physics as it stands is the connection between the classical idea of space-time and the quantum idea of the vacuum. The fundamental nature of both is obscure - and in some sense they should be the same thing. Overall this is an excellent introduction to special relativity and at least the conceptual underpinnings of general relativity, if not of the full theory, which really just can't be explained properly without knowledge of tensors.

4out of 5Sanjay Gautam–This book by Dr. Einstein is very well written, though you will find the anatomy of sentences a little unusual. Well this should not be a problem considering the theory's difficulty level. Though the theory is very simple mathematically (special theory of relativity I'm talking about), but the case is reverse when it comes to understand it intuitively. It defies the common sense. And that's what the book is about. It changes your outlook, the way you see the nature and gives you a new and better This book by Dr. Einstein is very well written, though you will find the anatomy of sentences a little unusual. Well this should not be a problem considering the theory's difficulty level. Though the theory is very simple mathematically (special theory of relativity I'm talking about), but the case is reverse when it comes to understand it intuitively. It defies the common sense. And that's what the book is about. It changes your outlook, the way you see the nature and gives you a new and better understanding.

4out of 5Erik Graff–As a kid my serious interests were scientific. I collected feathers, insects, rocks and fossils; maintained an aerospace scrapbook; kept a journal about space exploration; and read a lot of science books ranging from popular stuff and textbooks to serious works from the library which I hardly understood. My greatest intellectual interests by junior high were in cosmology and astronomy. During middle school, or possibly during the freshman year in high school, I started going to the library to rea As a kid my serious interests were scientific. I collected feathers, insects, rocks and fossils; maintained an aerospace scrapbook; kept a journal about space exploration; and read a lot of science books ranging from popular stuff and textbooks to serious works from the library which I hardly understood. My greatest intellectual interests by junior high were in cosmology and astronomy. During middle school, or possibly during the freshman year in high school, I started going to the library to read Einstein. Like many, I thought him the ne plus ultra and believed that mastering his work was of great importance. Having learned some algebra, trigonometry and geometry in school, I was able to read a little bit of his notation, but not much. Basically, it was beyond me. In high school, starting freshman year, geopolitical concerns started commanding my attention. I'd been raised under the mushroom cloud like the rest of my generation and we were at war in southeast Asia. History and politics seemed more important, ethically and personally, than science. Sophomore Chemistry sealed the matter. My lab skills were terrible, the teacher was poor, the textbook boring. That was my last physical science class until a single physics course in college. Being laid off from Loyola and working now only part-time gave me the opportunity to pursue some of the things I'd foregone. So, I picked up Einstein's Relativity, a book he wrote about the relativity theory for the general public.

4out of 5Owlseyes–(The Times from Nov. 10, 1919, left; Nov. 16, 1919, center; and Dec. 3, 1919) "He was living alone. A friend, Janos Plesch, once said, “He sleeps until he is awakened; he stays awake until he is told to go to bed; he will go hungry until he is given something to eat; and then he eats until he is stopped.” In:A Century Ago, Einstein’s Theory of Relativity Changed Everything By DENNIS OVERBYENOV. 24, 2015 http://www.nytimes.com/2015/11/24/sci... Awesome, see here:http://www.economist.com/r (The Times from Nov. 10, 1919, left; Nov. 16, 1919, center; and Dec. 3, 1919) "He was living alone. A friend, Janos Plesch, once said, “He sleeps until he is awakened; he stays awake until he is told to go to bed; he will go hungry until he is given something to eat; and then he eats until he is stopped.” In:A Century Ago, Einstein’s Theory of Relativity Changed Everything By DENNIS OVERBYENOV. 24, 2015 http://www.nytimes.com/2015/11/24/sci... Awesome, see here:http://www.economist.com/relativity

4out of 5Heather Cawte–Read on my Kindle, free from Project Gutenberg. The biggest problem I had with this was actually one of presentation. The team which had prepared it for release had presented all the equations as jpegs, a reasonable idea when reading it in HTML, but not a good one when reading it on a Kindle! Still, who am I kidding - the equations probably wouldn't have made sense to me anyway.... I am an arts graduate trying to understand relativity. I've read Hawking, and I've read Cox, and I thought I should r Read on my Kindle, free from Project Gutenberg. The biggest problem I had with this was actually one of presentation. The team which had prepared it for release had presented all the equations as jpegs, a reasonable idea when reading it in HTML, but not a good one when reading it on a Kindle! Still, who am I kidding - the equations probably wouldn't have made sense to me anyway.... I am an arts graduate trying to understand relativity. I've read Hawking, and I've read Cox, and I thought I should really look at the source. I wasn't expecting to understand much, but I was amazed by how much I really did 'get'. Every version of the theory explains it in a slightly different way, and with each version I read, I discover and comprehend a little more. This is by no means an easy read, but it was much more comprehensible than I expected. It was written for the general public, which certainly helped, and it was an extraordinary experience to be reading such an iconic book and finding that at least some of it made sense...

5out of 5Joseph Sciuto–After reading Walter Isaacson's brilliant biography, "Einstein" and finally coming away with an understanding of Einstein's theories, I felt I could make the leap and actually attempt to read something written by the most famous genius of the twentieth century whose theories would transform science and the world. I chose Einstein's, "Relativity: The Special and General Theory." The book was written by Einstein so that the average person, who was not a physicist or mathematician, but was intereste After reading Walter Isaacson's brilliant biography, "Einstein" and finally coming away with an understanding of Einstein's theories, I felt I could make the leap and actually attempt to read something written by the most famous genius of the twentieth century whose theories would transform science and the world. I chose Einstein's, "Relativity: The Special and General Theory." The book was written by Einstein so that the average person, who was not a physicist or mathematician, but was interested in his "theory of relativity" could easily understand it in layman's terms. Well, except for the portions of the book that used mundane objects such as a train, an embankment, Times Square or a clock to describe the most famous theory of all time, the rest of the book (a good 60 percent) was incomprehensible to me. It could have just as well been written in Latin. I strongly recommend that unless you have a scientific background, you should not start off by reading this book if you are at all interested in understanding the mind and theories of this, undeniable, genius. I recommend the Isaacson's book I mentioned above as a good starting point. Not to be deter, I will nevertheless continue my interest in physics and when I have the time and patience I will start reading books about Galileo and Newton's theories, so much seems to have originated from their work. They are constantly mentioned throughout by Einstein.

4out of 5Stuart Kelly–When I was at university the lecturers recommended books on relativity and I even read a few. I gleaned a vague understanding of the subject. None of them recommended Einstein's book. I can't remember where I found it but I'm very glad I did. It's the best and easiest to understand book about relativity I have ever read. I recommend it to students who are struggling with the concepts and all of them so far have had the "Aha!" moment thanks to Albert himself. It's just been returned to me from ano When I was at university the lecturers recommended books on relativity and I even read a few. I gleaned a vague understanding of the subject. None of them recommended Einstein's book. I can't remember where I found it but I'm very glad I did. It's the best and easiest to understand book about relativity I have ever read. I recommend it to students who are struggling with the concepts and all of them so far have had the "Aha!" moment thanks to Albert himself. It's just been returned to me from another student, and I'm planning to re-read it just for fun. Great book. Not too thick, written well, covers the subject well. If you're at all interested in relativity, this is the book for you.

4out of 5Arya Tabaie–The best "for dummies" book ever. Written by the master himself, explaining it all with great depth and as simply as possible. I feel that the General Theory was not covered in any real sense, probably because it would have been too difficult for us. While still appreciating Einstein's visual demonstrations and thought experiments, I wouldn't have minded a few more equations and formulas either, to combine the powers of intuition and precision. The best "for dummies" book ever. Written by the master himself, explaining it all with great depth and as simply as possible. I feel that the General Theory was not covered in any real sense, probably because it would have been too difficult for us. While still appreciating Einstein's visual demonstrations and thought experiments, I wouldn't have minded a few more equations and formulas either, to combine the powers of intuition and precision.

4out of 5Falk–This year is the centennial of the publication of Einstein's general theory of relativity. I got my hands on the Pi Press edition, which was published 10 years ago (coinciding with the centennial of the special theory of relativity.) Yesterday, the New Horizons spacecraft flew past Pluto, sending huge volumes of information back to Earth - and the day before, CERN announced that the LHC has found proof of the existence of the pentaquark. Science continues to reach new frontiers, though nothing t This year is the centennial of the publication of Einstein's general theory of relativity. I got my hands on the Pi Press edition, which was published 10 years ago (coinciding with the centennial of the special theory of relativity.) Yesterday, the New Horizons spacecraft flew past Pluto, sending huge volumes of information back to Earth - and the day before, CERN announced that the LHC has found proof of the existence of the pentaquark. Science continues to reach new frontiers, though nothing that can compete with the relativity revolution ushered in by Einstein a century ago. This edition has an introduction by Roger Penrose which focuses on Einstein's theories in the history of science – where he argues (and he’s certainly not alone about that) that the special theory of relativity had in fact long been in the works in 1905 and would have been formulated eventually also if there had been no Einstein. But it is the general theory of relativity that is Einstein’s unique contribution, and which proved to be so thoroughly revolutionary. The book also includes an essay by David C. Cassidy titled "The Cultural Legacy of the Relativity Theory" which examines the impact of the theory outside of physics. This proved to be an interesting read and for me it contained lots of new information. On the reception of the theory among the general public he writes: "Relativity was not just another important new theory. It profoundly challenged the common understanding of everyday physical concepts — space, time, mass, simultaneity.(...) Even the very name "theory of relativity," coming after the rise of Darwin's theory of evolution, seemed to confirm the decline of old absolute values and beliefs, together with the old world order, and the triumph of a universal relativism. Einstein, of course, objected to such interpretations. Relativity theory had nothing to do with relativism, he insisted. In fact, he had first called it the "theory of invariants," for its emphasis on the unchanging character of natural laws within different reference frames." Though Einstein’s objections were indeed to the point, they also regrettably didn’t help much. It would seem that the real problem was - and still is - the widening gap between specialists and non-specialists; between scientists and the general public. My first read of Einstein’s Relativity contained only his own text as published in 1916. After the read I didn’t really feel a whole lot wiser, but rereading Einstein's text was definitely useful. It also helped that this time I knew the disposition of the text and could attack it proceed with more patience. I also identified what had hampered me so much on the first read: that pesky Lorentz transformation! It wasn't quite as daunting this time around. Still, in comparison Gaussian coordinates is a piece of cake. So when Einstein states the general principle of relativity as "All Gaussian coordinate systems are essentially equivalent for the formulation of the general laws of nature," I feel rather relieved that I can say ok I get that - somehow. Stephen Hawking writes in A Brief History of Time that "seventy years ago, if [Arthur] Eddington is to be believed, only two people understood the general theory of relativity." Which really brightened my day -- if only for a split second however, since he goes on to say: "Nowadays tens of thousands of university graduates do, and many millions of people are at least familiar with the idea." I liked that he used the term "familiar", I feel it applies to me as well. Also included in this edition is a commentary by Robert Geroch which provides some useful elucidations expanding on the explanations Einstein uses in the various chapters. Einstein’s own examples aren't necessarily the best, so for myself Geroch's comments were very welcome and mostly quite helpful – and he also describes more recent developments in this field. I’m certain it would have made a difference if I had started out with this edition, and I’d recommend it to anyone. This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.

4out of 5Mohamed–How dare I give this masterpiece less than 5 stars ?! Although I could hardly claim that I understood 10 percent of the book ! What he was talking about ?! Moving reference bodies, Euclidean geometry, Newtonian theory of gravitation, ..... What ?! We don't see the real length of things as everything is moving in the space ! Length is relative as well as mass ! So what is real ? Is there one single thing that all human can agree on it ?! Relativity can be applied on other aspects of life other th How dare I give this masterpiece less than 5 stars ?! Although I could hardly claim that I understood 10 percent of the book ! What he was talking about ?! Moving reference bodies, Euclidean geometry, Newtonian theory of gravitation, ..... What ?! We don't see the real length of things as everything is moving in the space ! Length is relative as well as mass ! So what is real ? Is there one single thing that all human can agree on it ?! Relativity can be applied on other aspects of life other than Physics. What is right and what is wrong ? true and false, good and bad, right and left ! Everything depends on your reference body and everything is relative ! What about the keyboard I am using right now, could it be anything else on another planet ?! Creepy Craze ! However, I will try to read more about it. Einstein said "Any intelligent fool can make things bigger and more complex. It takes a touch of genius, and a lot of courage to move in the opposite direction." yet he couldn't write his theory in a more easier way. I think it would be better if it used more diagrams and drawings ! Good luck for those brave ones who are planning to read this :)

5out of 5Matt–Before Einstein’s English edition was published in 1920, the publisher made a request to the translator stating he should make: the description of its contents as intelligible a possible to the ordinary man. Our travellers tells us that there is complete ignorance in the public mind as to what Relativity means. A good many people seem to think that the book deals with the relations between the sexes. Perhaps you could explain the meaning of the word and say something about the epoch-making chara Before Einstein’s English edition was published in 1920, the publisher made a request to the translator stating he should make: the description of its contents as intelligible a possible to the ordinary man. Our travellers tells us that there is complete ignorance in the public mind as to what Relativity means. A good many people seem to think that the book deals with the relations between the sexes. Perhaps you could explain the meaning of the word and say something about the epoch-making character of the book and how Einstein’s discovery affects Newton’s law. Most people have heard of Newton and his apple and that will give some kind of clue. Pg. 246. Modern readers probably have a better grasp on the basics of relativity so this book, designed to be digested by the “ordinary” person, is a little easier to consume. I didn’t expect this to be as easy (and that term is used relatively as well) to read as it was. Einstein mercifully limits his use of mathematics to describe the relations between an observer and acceleration, speed and time, and the need to expand beyond Euclidean geometry to conceptualize space-time. Einstein’s thought experiments avoid appropriating Newton’s apple, but he makes use of moving trains to help readers understand some aspects of relativity. The publisher may have wanted more Newton in this book, but I’ve attempted to read Newton’s The Principia and Einstein’s approach is far more friendly to the mathematically-challenged like myself.

4out of 5Bob Nichols–(Review was revised August 27, 2022). Despite Einstein's best intention to make his theory comprehensible to the non-specialized public, this book is difficult. The commentary at the end of the book by Robert Geroch is helpful. In the Special Theory of Relativity, Einstein states that space and time are not fixed properties, that they are intimately connected to each other (hence, spacetime, "ST"), that time and space are shorter and slower as an object moves closer to the speed of light, and th (Review was revised August 27, 2022). Despite Einstein's best intention to make his theory comprehensible to the non-specialized public, this book is difficult. The commentary at the end of the book by Robert Geroch is helpful. In the Special Theory of Relativity, Einstein states that space and time are not fixed properties, that they are intimately connected to each other (hence, spacetime, "ST"), that time and space are shorter and slower as an object moves closer to the speed of light, and that mass increases with the addition of energy and decreases with the loss of energy (Geroch writes that a running rabbit loses mass because it is expending energy, i.e., it is converting mass into energy). In the General Theory of Relativity, Einstein says that space and time are modified by gravitational mass, which warps or curves them. In his commentary, Geroch clarifies, helpfully, that there are two forms of mass: passive gravitational mass (that is acted upon) and active gravitational mass (that acts). On a second reading of this book, perhaps the most significant clarification comes from Geroch's statement that space, time and mass "exhibit different values, depending on the speed of the measured object." From this, and especially at scales approaching the speed of light, I take it that, in shooting us out of the Newtonian world, things we take to be fixed are not fixed after all and this removal from our everyday common experience is what makes Einstein so challenging. I can't say with confidence that I know what any of this means, but it does prompt questions: Is ST a way of locating an "event" or is it something more? If gravity from a mass pulls ST, are ST particles (that gravity can exert its force upon)? Are the sun and earth gaining mass by pulling ST particles onto/into themselves? If gravity pulls ST, is mass a concentration of ST? Does the big bang scenario (and some Black Hole scenarios) create ST, "exploding" it (them) outward, and is it this that makes ST variable and not absolute? If gravity (the Big Bang and Black Hole scenarios) pulls matter into infinite density (a singularity), is matter (and quantum phenomena) destroyed, leaving undifferentiated energy as the only primal cosmic reality (and is this why mass and energy are ultimately equivalent)? In an interesting footnote (p. 67) Einstein writes that "The general theory of relativity renders it likely that the electrical masses of an electron are held together by gravitational forces." Off hand, this statement suggests a relationship between quantum level forces and gravity. Is this pertinent to the attempts to unify the four forces (or, are three of the forces subsidiary to the fourth, gravity)? Is the speed of light/expressed energy (outward force) the polar opposite of gravity/mass as concentrated energy (inward force), and are cosmic processes governed by the relative power relationship between these two poles (force and counter-force)? While gravity is referenced as an attractive force between two bodies, isn't there also a factor of (inertial) resistance to being moved (depending on relative mass and distance)? The ending essay quotes Einstein as saying that, "All religions, arts and sciences are branches of the same tree. All these aspirations are directed toward ennobling man's life, lifting it from the sphere of mere physical existence and leading the individual toward freedom." This is a nice thought. I don't know what it means.

4out of 5Andrew–Albert Einstein was a really smart motherfucker. He was smart not just because he was able to conceive of the theory of relativity (both the special and general theories) - he was working on things that people before him had already worked on. What was really smart about him is that he was able to make it all explicable - if not entirely comprehensible - to your average person. I'm not going to go into the general and special theories of relativity, because I honestly only understand the theorie Albert Einstein was a really smart motherfucker. He was smart not just because he was able to conceive of the theory of relativity (both the special and general theories) - he was working on things that people before him had already worked on. What was really smart about him is that he was able to make it all explicable - if not entirely comprehensible - to your average person. I'm not going to go into the general and special theories of relativity, because I honestly only understand the theories in metaphor, and Einstein's metaphors are much more eloquent, nuanced, and specific than mine. Plus, I don't really remember exactly what it was all about. Basically, that Euclidean geometry is always going to fail in the face of a universe that is infinitely more complex than we can possibly imagine. But there are some constants and things you can do with math that help make calculations a lot closer to and reflective of actual observation. Einstein was hoping, I think, for some universal constant, but never got there (or didn't share it, fearing that it would give physicists nothing to do but make little pig statues out of pink erasers and thumbtacks). The math, a lot of it, is far beyond me, but I'm sure the mathematic illustrations and references to quantum physics documents are really helpful to people who know about that stuff. I was a good math student in high school, and a lot of it is still light-years out of my league. But like I said, the important thing about the book is that it explains things without needing the math. Anyone can relate to that feeling of being on a train (or in a car, nowadays), your focal point being the side of a moving car, and feeling as if you're moving backward even though the car beside you has moved forward, when in reality, you're both on the planet Earth, rotating on its axis and around the sun, which is moving in relation to our galaxy, which...you get the point. You can measure the speed of the car moving next to you, giving you that sick feeling in your stomach, but you're never going to get it quite right, except as it relates to wherever you happen to be. Pretty short read, too.

4out of 5Aiman Faruqi–While a number of other books cover the topics of special and general relativity, only this one, written by the creator of the theories themselves, conveys a sense of profound understanding that is unparalleled by other books on the subject. What is most remarkably about this book is that it provides an excellent framework for the special and general theories without necessitating the understanding of advanced math. As someone who loves math, this is not something I would normally laud, but, in While a number of other books cover the topics of special and general relativity, only this one, written by the creator of the theories themselves, conveys a sense of profound understanding that is unparalleled by other books on the subject. What is most remarkably about this book is that it provides an excellent framework for the special and general theories without necessitating the understanding of advanced math. As someone who loves math, this is not something I would normally laud, but, in this case, it works and it works well. Einstein starts his discussion with special relativity; he describes the reason for its existence by explaining the conflict between electrodynamics as established by Maxwell and the classical principle of relativity as established by Newton. Einstein expertly guides the discussion on why it is that both space and time are not absolute by a readily understandable thought experiment. Einstein further builds on his special theory of relativity by describing the need for a general theory. Again, he manages to expertly craft a discussion on not only the content of the general theory but why it must exist. This book is perhaps the epitome of scientific writing that is not overly pedantic but expects a thoughtful and intelligent audience. While this book is very short, with roughly 130 pages excluding appendices, it is by no means dilute. These 130 pages will be more dense than many 400 page works in science. This is not a book you can read passively; Einstein expects much from his readers and, in the end, you will appreciate him even more for it.

4out of 5Sam Henington–Years ago,in my college physics class,I had to actually learn and try to explain Einstein's theory of relativity. With the complex math and all the workbooks, it was a task I really hated. I thought I understood it and was able to get through the tests. But I never really paid close attention to what it really meant. At that time, all I wanted was to be able to answer queations about it to get grades. Then, I changed my major and went into other subjects that I really cared about. After so many Years ago,in my college physics class,I had to actually learn and try to explain Einstein's theory of relativity. With the complex math and all the workbooks, it was a task I really hated. I thought I understood it and was able to get through the tests. But I never really paid close attention to what it really meant. At that time, all I wanted was to be able to answer queations about it to get grades. Then, I changed my major and went into other subjects that I really cared about. After so many years, I read this book, but this time I was reading out of own curiosity and not for grades. i think that made all the difference. This book was actually written by the man himself but he wrote it for the general public. Not for the Physicists and scientists. When I read it just to get inside the head of the graet scientist and try to understand his reasoning, it was really interesting. It is a good read as long as you are just trying to understand what he is talking about without really attempting to get all the maths and calculations about his theory.

4out of 5Bipul Roy–I call it epic book, not only in terms of the knowledge it gives. But it is sure to create a storm of queries and enthusiasm in your mind provided you enjoy mathematics form the core of the heart. It surely imparts some best lessons for life, that keep your subconscious alert and curiosity should be the prime element of every thought process. The thing that Einstein got the idea of relativity while going home in a car, he saw the time in clock mounted on top of church, and it gave him the storm t I call it epic book, not only in terms of the knowledge it gives. But it is sure to create a storm of queries and enthusiasm in your mind provided you enjoy mathematics form the core of the heart. It surely imparts some best lessons for life, that keep your subconscious alert and curiosity should be the prime element of every thought process. The thing that Einstein got the idea of relativity while going home in a car, he saw the time in clock mounted on top of church, and it gave him the storm that he is watching that clock because light from the clock reaching his eyes, what will happen if starts travelling exactly at the speed of light, then the light from the clock will never reach his eye every moment and time in the clock will appear to be stopped. This was the the striking point for this great theory. Also liked the explanation. :) "When you sit on the hot stove for a minute, it seems like an hour and when you sit with a pretty girl for an hour, it seems like a minute, that is relativity."

5out of 5A.L. Buehrer–This book helped me reach a new milestone: I am no longer afraid to read books with equations in them. At least with this book, I came to realize that the equations were only symbolic translations of what was being said in the text, and once I realized that, they actually made some sense to my arithmephobic mind. As for how readable and accessible this book is, I’d say, for the typical layperson, it’s moderately difficult. I really think Einstein handled it pretty well, though. He gives it to y This book helped me reach a new milestone: I am no longer afraid to read books with equations in them. At least with this book, I came to realize that the equations were only symbolic translations of what was being said in the text, and once I realized that, they actually made some sense to my arithmephobic mind. As for how readable and accessible this book is, I’d say, for the typical layperson, it’s moderately difficult. I really think Einstein handled it pretty well, though. He gives it to you in small sections, two to maybe eight pages at once. I can handle just about anything in those doses. Also, if this topic interests you enough to pursue this book, I suggest this approach: read two or three paragraphs at a time without worrying about whether you’re getting it at all. Read the words. I think you’ll find that every two or three paragraphs, it clicks. Just one more tip. I wouldn’t suggest diving into this book if you know nothing about relativity at all. It helps to have some idea of where you’re going.

5out of 5Satyajeet–For me, the best part was the paradoxes. Einstein uses lot of paradoxes to explain his ideas, and they are strikingly amazing! Translator did a good job in making it readable for people who are not conversant with the mathematical apparatus of theoretical physics. A must read I'd say. For me, the best part was the paradoxes. Einstein uses lot of paradoxes to explain his ideas, and they are strikingly amazing! Translator did a good job in making it readable for people who are not conversant with the mathematical apparatus of theoretical physics. A must read I'd say.

4out of 5George Florin–No matter what the title says, this book is not for everyone. Albert Einstein is known for a lot of things, but explaining the Theory of Relativity in the simplest manner is not his best skill. I can't even describe how wonderful of a job Albert Einstein did with this theory and the amazing implications it had thereafter. He is pretty much the most famous scientist in the world, and in this book he tried to explain what he was thinking about in simpler terms. He did do what he was set out to do, No matter what the title says, this book is not for everyone. Albert Einstein is known for a lot of things, but explaining the Theory of Relativity in the simplest manner is not his best skill. I can't even describe how wonderful of a job Albert Einstein did with this theory and the amazing implications it had thereafter. He is pretty much the most famous scientist in the world, and in this book he tried to explain what he was thinking about in simpler terms. He did do what he was set out to do, but you still need some advanced Physics knowledge to understand the meaning of his words. All in all, I would rather watch some YouTube videos where someone explains the theory to me, rather than reading this book.

5out of 5Elliott Bignell–Given Einstein's universally-acknowledged genius and the reputation for intractability still enjoyed by general relativity a century after its birth, this work is a paragon of clarity and simplicity of explication. It is very light on mathematics, only requiring basic algebra, and works almost entirely through illustrative models such as that of an observer on a moving train. Einstein was one of those who had been forced to rethink our universe based on the contradictions raised by the apparent Given Einstein's universally-acknowledged genius and the reputation for intractability still enjoyed by general relativity a century after its birth, this work is a paragon of clarity and simplicity of explication. It is very light on mathematics, only requiring basic algebra, and works almost entirely through illustrative models such as that of an observer on a moving train. Einstein was one of those who had been forced to rethink our universe based on the contradictions raised by the apparent anisotropy of the fixed speed of light in vacuo on a moving Earth. His solution was simple but profound, representing another Copernican revolution, in that he abandoned the twin presuppositions of fixed time and position. As he writes here, everything else in Special Relativity follows as a matter of simple logical consistency, and his new universe is perfectly coherent, if weird. The General form extends this to the abandonment of a fixed coordinate system altogether, hence the name of "General Relativity", but it entails some important further considerations. GR space is Gaussian rather than Euclidean. Its geometry is Riemann, and as a profound consequence we can infer that the Universe is finite but unbounded: Look far enough into distant space and you would see the back of your own head. Hereby is an important inconsistency arising out of Newtonian physics dissolved, as a Newtonian Universe would require a centre and a finite size; a sphere uniformly filled will at sufficient size exert infinite gravitational forces at its bounds. Our Universe can be unbounded and uniformly filled at the largest scales without contradiction. Gravity - and acceleration - also bend space. Measure pi by sitting on a spinning disk and measuring along the circumference and perpendicular across the axis and the foreshortening along the direction of motion will yield a lower than Euclidean value - space has curved for the fly on the wheel. Einstein's work is unquestionably one of the two or three most successful in scientific history. He explains and predicts phenomena that could be observed at the time, such as the precession of Mercury's orbit and the gravitational shift in the positions of stars close to the line-of-sight of the Sun. Yet he also makes predictions which could not have been observed at the time, and I think it is correct to say that all have since been confirmed. QED and QCD might compete with Relativity for predictive and explanatory power, but they were the work of many great minds. Einstein, along with perhaps Newton and Darwin, earns unique credit for being the single mind associated by history with the entire edifice, even if this picture is not entirely fair in all cases. It is a joy to find he also writes so gracefully. As an aside, I just encountered Einstein's name today in a discussion of Muslim behaviour towards non-Muslims. It could be said that the WW2 allies won the war and then the Cold War because we got the best German Jews. We got Einstein, it transpires, via Albania, where virtually all native Jews and thousands of refugees survived the Shoah under the protection of the Muslim majority.

4out of 5Becky Douglas–Relativity is Einstein's attempt to explain Special and General Relativity to a general audience. He states at the beginning of the book that he's trying to keep it concise and at a level where most people should be able to understand the small amounts of mathematics he uses. He mentions that it would be elegant, feeling he ought to leave that to artists but that, with a little effort on behalf of the reader, it should provide an adequate understanding. It's hard for me to tell whether Einstein w Relativity is Einstein's attempt to explain Special and General Relativity to a general audience. He states at the beginning of the book that he's trying to keep it concise and at a level where most people should be able to understand the small amounts of mathematics he uses. He mentions that it would be elegant, feeling he ought to leave that to artists but that, with a little effort on behalf of the reader, it should provide an adequate understanding. It's hard for me to tell whether Einstein was just hopelessly optimistic about the efforts his readers might put in and about their mathematical prowess, or whether the education system in 1916 Germany was just a lot better than it was when I went to school. If I wrote a book about relativity I would not take the same approach but then, I'm not about to volunteer. I understood just fine, but then, I have just finished a PhD approximately related to the subject. I think perhaps we just have a more clear definition now of what is a popular science book and what is a textbook. This seems to sit on the line between the two, clearly the aim is to educate rather than entertain but since the goal seems to be to educate a reader without a scientific background it does seem to assume a high level of knowledge. Even just a few more diagrams might have helped a bit. Still, it makes a good read if you already have some background in the subject area and I did find a few new ways of explaining one or two things, which is always good. I think it would be a good handbook for an undergraduate student to read alongside their lectures on the subject. A casual reader might want a more modern pop-sci text instead.

5out of 5Tara–Overall this was a very strong book, although, as another reviewer pointed out, “trying to teach general relativity in 45 pages with no math is just too tall an order.” I thought Einstein made an excellent point regarding the relevancy of the special theory of relativity, given that the special theory has been relegated to being “merely” a limiting case contained within the general theory: “No fairer destiny could be allotted to any physical theory, than that it should of itself point out the way Overall this was a very strong book, although, as another reviewer pointed out, “trying to teach general relativity in 45 pages with no math is just too tall an order.” I thought Einstein made an excellent point regarding the relevancy of the special theory of relativity, given that the special theory has been relegated to being “merely” a limiting case contained within the general theory: “No fairer destiny could be allotted to any physical theory, than that it should of itself point out the way to the introduction of a more comprehensive theory, in which it lives on as a limiting case.” In my opinion, this is a large part of why science is such a wonderful thing. I also enjoyed the description of the non-Euclidean geometry that comes about when gravity makes space go a bit wonky. Einstein described why, for example, the ratio of a circle’s circumference to its diameter would not be pi in this case. His description was both fun to think about and very easy to understand. He then went on to introduce, in place of a rigid reference body, a “reference-mollusc” (this is a direct quote, and reading it led to a fit of giggles on my part because molluscs). Strange geometry? Space molluscs? Do I detect a whiff of H.P. Lovecraft?! Seriously though, it was a great explanation. Lastly, the fifth appendix, which is an essay on the concepts of space and time as they pertain to the realms of physics, psychology, and philosophy (is “empty space” even possible?) was pretty nifty too.

4out of 5Daniel–While I cannot say that I understood this book in its entirety, I can say that it was extremely well written and informative. My failure to grasp the complexity of Einstein's Special and General Theory of Relativity is a result of my inexperience in the field of Physics. I am slowly expanding my knowledge, and while I started off with a basic understanding of Special and General Relativity, this book has been a gem in the pool of information. I won't try and give a summary of the book itself, an While I cannot say that I understood this book in its entirety, I can say that it was extremely well written and informative. My failure to grasp the complexity of Einstein's Special and General Theory of Relativity is a result of my inexperience in the field of Physics. I am slowly expanding my knowledge, and while I started off with a basic understanding of Special and General Relativity, this book has been a gem in the pool of information. I won't try and give a summary of the book itself, anyone familiar with the two theories of Relativity should be able to follow (or like me, read along and occasionally turn to google if there is a concept you don't understand), the book is broken into three sections (1-The Special Theory of Relativity, 2-The General Theory of Relativity, 3- Considerations on the Universe as a Whole) with an Appendices section that should not be overlooked. Each section is made up of chapters that are 3-4 pages in length which makes getting through the book so much easier and also clarifies what each section is talking about which is a huge help in keeping up with the mind of Einstein. Keep in mind that most physics students don't touch Relativity until their last year of undergrad, so if like me you did not do a physics degree, it's ok to not understand or follow everything, that's what science is about; pursuing the unknown and coming away with more questions that you entered with. Confusion is a wonderful thing because it opens up avenues of further exploration and discovery, revel in it.