Very appropriate title, especially if one has not read complete lecture series. One more book that needs to re-read.Classic Feynman otherwise.

Whew! This one was not-so-easy. My Algebra, Trigonometry, and Vector Analysis skills are very rusty. However, that being said... the ONLY way to see the ultimate beauty of Einstein's theories is to "do the math."

Feynman is awesome.

This is a very entertaining book by an amazing teacher. As a Physics student, reading this book gave me a great advantage while taking courses on modern Physics. The book is a series of lectures intended for second-year Physics students at Caltech, so do not despair if you cannot grasp every single idea in the book. I highly recommend reading it after reading Six Easy Pieces.

A very enjoyable book that is aimed at the physics enthusiasts.
In many ways I have found this book easier to digest than Six Easy Pieces, just because of the use of math throughout. The concepts within this book however, are much harder than in the preceding one.

Same as with Six Easy Pieces it sits firmly somewhere between popular science books and a textbook, so be warned and be prepared to do some figuring out when reading it.

Wow

The most incredible mix of intuitive description of concepts and actual equations I've ever read. The math is eminently followable. How Feynman is able to reduce big theories to their essence is incredible.

good overview of all topics presented but i feel that invariant mass is an odd place to start for teaching special relativity and many things in the general relativity section could have been worded better.

For the mathematically inclined, this is a fun discussion in theoretical physics. Feynman uses his outstanding ability to clarify the nebulous to discuss the development of the theory of relativity and discoveries of symmetry and asymmetry in nature.

I frequently find that popular science books force themselves to avoid the mathematical descriptions of difficult physical concepts. While I understand this, "appeal to the masses" approach, I find that it actually makes it less clear just how parameters factor into reality. For example, knowing where the 1/√(1-v²/c²) falls into the equations of Newtonian physics is massively helpful for my own understanding of behavior of objects as their velocity becomes relativistic. Feynman does not hesitate to use equations, analogy, and experimental results to explain hard material.

If you are not well-versed in mathematics, following these lectures will be difficult or impossible. You will need at least a basic understanding of differential calculus to follow Feynman's not-so-easy pieces.

আসলেই নট সো ইজি। একটু সময় লাগলো বেশি। ফাইনম্যান বরাবরের মতই ফাইন যদিও।

Remarkably well done

I’ve been reading pop physics books for a long time and this one has by far the best explanation of curved space and relativity I’ve seen. I recommend getting the hard copy (paperback) rather than the kindle version. The equations in the kindle version are impossibly small as are the graphics. The presentation detracts from the overall experience. Nonetheless, this is well worth reading

An interesting book about an interesting subject, but the fact that there wasn't any mention of the double slit experiment. It is much more detailed than "Six Easy Pieces"but that was expected.It did further my comprehension of relativity. And much to Feynman's annoyance, unfortunately the book did show his disregard for philosophy, symmetry does make philosophical sense, and without the symmetry physics would break down. In spite of it containing the anti-philosophical chapter, and attitude, the book was enlightening as far as relativity symmetry and space time is regarded.

The book like its successor is an amazing introduction to the wonders of physics. However, due to the subject of this book, it does demand a certain aptitude and effort from the reader (it is not-so-easy as the name honestly suggests). If you have a background in Science, you can really reap the benefits of this book if you are willing to scribble a few equations onto your notebook. But even if you aren't able to understand the mathematics of the concepts discussed, the consequence of the theories discussed is spectacular and it is worth knowing about the weird ways in which nature works.

It’s all relative
Unlike the earlier publication, this selection of the Feynmann’s Lectures is focused on a single Physics “piece”. Chapter after chapter, in a crescendo of complexity, the reader is ushered into one of the most fashionable, while the less understood Physics subject. The author’s craftiness becomes evident as, starting from vectorial transformations, he demonstrates in an understandable and easy to remember way first the Special, then the General theory of Relativity. While the editorial work could not erase a couple of reference to some of the Lectures’ chapters, the book is self consistent and works well both as a student support or as a pleasing recreational read.