It's About Time: Understanding Einstein's Relativity

Porque había leído uno de sus artículos de relatividad en AJP

Worth knowing you can understand something of Einstein... Clear exposition of an important theory which has turned out to be so true.

I just finished this book, and as I was finishing the last few chapters, like climbing a mountain, I was thinking "this is hard, this hurts, I can't go on". But having finished this book, with much effort, time and dilligence on my behalf, I can say that the book was definitely worth it! I feel my understanding of Special Relativity is much sharper now than it was.I am currently a Mentor for an online course on Special Relativity, I completed the course about 6 months ago and this Coursera course was my first exposure to Special Relativity. N. David Mermin's book has definitely sharpened my understanding of Einstein's Relativity since taking the online course.However, I think that this book is probably not the best book to be reading if you are new to Special Relativity. Why? As others have mentioned, the ways in which the author derives most of the main ideas and conclusions within Special Relativity are unique and original; he certainly does not use what you could call a traditional or classical approach. I think if I was reading this book without any prior understanding, I would have possibly not have had such a strong sense of what relativity is about or what it says about the nature of time, space and our universe. Also, in approaching the material in this creative, original way left me without the "wow" factor. Time dilation and length contraction, the way it is derived here, just seemed to be missing that magic; such magic I got from taking the Coursera course, and had me thinking: "wow! Space and time are changing all the "time" depending on how (and how fast) we move!". This book, whilst creative and powerful in its approach, just seemed to take some of the focus away from the magic of Special Relativity, and onto the magic of showing a new way to derive it all. The traditional approaches just seem to leave more spacetime for the magic to seep through.Having said that, if you put the effort in to work through this book, it does pay off. The maths used is accessible, and the majority of the derivations are relatively straightforward to follow. However, there were a few instances where I felt some more details and explanations could have helped. In particular, Chapter 8 (The Interval Between Events) had a section that I laboured over for hours, only to find that it was given a proof (with diagrams) in Chapter 10. Chapter 10 was also good but very abstract; like much of this book, I found it easy to follow the analysis with effort, only to find that I had lost a sense of the bigger picture of what the analysis was saying: a case of "missing the forest for the trees".There were some real gems in this book, though. I have to say that in Chapter 10, the author gives an analysis of the "Twin Paradox" problem, in a way that is the best I have ever come across. Not only that, but he then does a parallel analysis of the "Twin Paradox", this time detailing what each twin would actually see - he uses Doppler factors to illustrate what each twin would actually see on each other's clocks, in a way that conforms to the predictions of Special Relativity and shows how the travelling twin has aged less. And then in Chapter 12 he revisits the "Twin Paradox", this time giving an analysis of it framed entirely in the context of General Relativity, and showing how the exact difference in the ages of the two twins is due to the non-symmetrical acceleration / deceleration (as an equivalent gravitational field) of the travelling twin! If you want to understand the "Twin Paradox" from many angles, these parts of the book alone makes it worth the price of admission.To conclude, if you are new to Special Relativity, then I suggest you "cut your teeth" with books that use a conventional approach. Then come back and get this book as a resource to deepen and sharpen your understanding. I believe this book has a worthy place in any serious student's library of books. However, in my opinion it may not be the best book to get started with on your journey.

I really enjoyed this book, as I found it gave a particularly forensic analysis of things SR and showed the reader how to do the same. I would imagine it would be a good book for an A Level or undergraduate student of physics hoping to develop their analytic approach. It also seems suited to the interested layman or hobbyist (it has some mathematics in it but it is not advanced and I would have thought that even if that is not your thing that you could still get plenty from this book from the 'natural' language).

This book si excellent because it explains the counterintuitive facts of special relativity in a very simple and clear way, with a little BASIC mathematics, giving a real understanding of this beautiful and strange theory. I think that anyone can (and should) read this volume.

L'auteur introduit la Relativité Restreinte en utilisant un outil mathématique très simple mais en insistant sur les bases physiques. Les exemples choisis sont décrits minutieusement, avec clarté; il reste, cependant, au lecteur à produire un effort constant pour bien appréhender les raisonnements. Un petit reproche, commun à tous les auteurs anglo-saxons: leurs cours possèdent un plan rigoureux mais ils ne l'affichent pas, contrairement aux auteurs français plus cartésiens ( avec un I, 1°), a,b, ... ). Ce qui facilite la lecture et permet de s'y retrouver plus facilement. En résumé un livre intéressant, à étudier mais d'un abord pas si facile que cela.