"In fact, mathematics is, to a large extent, invention of better notations."

Kendisi de ünlü bir fizikçi olan Feynman tarafından kaleme alınmış bu kitap, Einstein'ın Görelilik Kuramı'nı ve onunla ilişkilendirilebilecek diğer kavramları anlaşılır kılmayı amaçlıyor. Kütleçekim, uzayzaman, yüksek hızlarda hareket gibi kavramlar pek çok açıdan insan algısının sınırlarını zorlayan türde şeyler. Bu durum fiziğe mesafeli olanlar kadar, ortalama fizik bilgisine sahip olanlar açısından da böyle. Kolaydan zora doğru sıralanmış 6 bölümden oluşan bu kitap, üst düzey fizik bilgisine sahip olmayan okuyucuların da bu hayli soyut kavramlar hakkında az buçuk fikir sahibi olabilmesini sağlıyor.

Ancak ne yazık ki kitabın teorik altyapısı yeteri kadar sağlam kurulmamış. Denklemlerle anlaşılması daha kolay olabilecek bazı kavramları basitleştirmek için kullanılan günlük hayattan seçilmiş örnekler yer yer zorlama kalabiliyor ve bana kalırsa bu durum anlamayı daha da güçleştiriyor. Bunda beceriksizce yapılmış çevirinin de payı olabilir belki.

Sonuç olarak, çağımızın en önemli kuramlarından biri olan İzafiyet Teorisi hakkında genel fikir sahibi olmak isteyen herkese bu kitabı okumalarını tavsiye ederim. Fizik ile teması hangi seviyede olursa olsun temel bilgilere erişmek isteyen herkesin bu kitaptan bir şeyler alabileceğine inanıyorum. Kuram hakkında genel bakışa sahip olup konuda derinleşmeyi amaçlayanlara ise bu kitapla zaman kaybetmeden başka okuma listelerine yönelmelerini öneririm.

I love it!

The mere fact I was able to follow this book at all is a glowing testament to Feynman's explanatory process. He makes Einstein's deductions of the mysteries of spacetime seem as straightforward as beginner's algebra.

Effettivamente sono sei pezzi meno facili: la matematica diventa più complessa, perché deve descrivere una fisica che si fa più complessa e meno immediata. Pieno di riflessioni scientifiche e punti di vista sicuramente originale, alla Feynman. Forse ancora un po' difficile da leggere in alcuni punti non conoscendo bene alcuni argomenti nello specifico, comunque leggibile e comprensibile, meno scorrevole dei "Sei pezzi facili": titolo azzeccato, Mr. Feynman!

Let me start with a one-sentence summary: this is a thoroughly enjoyable little book explaining, in a beautifully intuitive and holistic way, the main core features of Einstein's relativity, without getting bogged down into too much mathematical detail.

The target audience of this book is the interested layman with high school mathematics knowledge and a passion for physics: it falls into the particularly tricky (from a pedagogical standpoint) grey territory between popular science and real science. And Feynman manages, almost in a magical way, to strike a reasonable compromise, within so little space, between accuracy and level of detail on one side, and accessibility on the other side.

Now, I have read more comprehensive works on relativity, with much more emphasis on its mathematical foundational underpinnings; and I can tell you that, if you are looking for something significantly beyond the introductory level, you will not learn much from this book. However, having said that, I would still recommend this book even to a more intermediate level reader, as the way how Feynman manages to get to the core of things with lucid rigor, and simplicity, and how he manages to holistically connect all the different aspects of the physics he is explaining, is something magic and a great pleasure to experience.

Feynman is a wonderful teacher, who can get right to the core of topic with amazing clarity, and he has the gift to make even the potentially most complex concepts seem like the most obvious and commonsensical thing. Because of this, this book is highly recommended to whoever has a minimum knowledge of maths and wants to start looking at relativity from a more detailed perspective than what offered by many generic popular science books.

To make the book perfect, I would have loved to see at least some treatment of the mathematical underpinning of relativity, which would have probably made, in my opinion, some critical parts of the book more clear and rigorous: for example, there is no mention of the 4-dimensional Minkowski vector space, and its tensor (metric) whose expression is represented by equation 3.9 of the book, (which is presented in the book as a "given"). And I would have loved at least a brief introduction to the concept of geodesics and of the stress-energy tensor (and of tensors in general), which would have allowed at least a qualitative treatment of Einstein's Field Equations.
And, to be honest, I do not see much value in the first two chapters of the book, which are not much more than a very cursory introduction to mathematical objects that anybody should have learned in high school anyway (apart maybe from the concept of "symmetry")- maybe this space could have been used more efficiently by getting into some more detail in other areas.

But I realize that there is a very delicate balance between mathematical complexity and accessibility and clarity, so it must be said that it would be extremely difficult to improve on Feynman's pedagogical approach in his book.

In summary, this is a jewel of a little book that I thoroughly enjoyed and which deserves a full 5-star rating. Highly recommended. I loved it.

I found this book at a retired St John's College professor's house in Spring 2019. Here's my review.

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This Feynman guy's pretty great! The first two chapters took a while to understand, but I got there eventually. The chapters on Relativity and Space-Time (3 4 5) were real confusing though.

Most memorable for me was his talk on symmetry (2). Left and Right being actual things in the universe is pretty damn cool.

I found it hard to follow the equations stated in the book, especially the Lorentz transforms and other equations in Relativity. For me, the issue was that he didn't fully explain where the equations came from. He pretty much said this:

There was an issue with Newton's laws, but this smart guy realized that if you changed them to include sqrt(1-(u/c)^2) then they were fixed.

How did he come up with that? I say, either make a book completely rigorous or make it for the most basic of laymen.

Or maybe I only understand equations if there's practice problems to do, and since I'll never do practice problems for a book I'm reading a book for fun, that's why I didn't get the equations.

Anyways, it did get me (kind of) excited for physics and stuff!

I've been binge-studying lately. You know, lose-your-sleep-over-it-and-forget-to-eat kind of binge-studying. I barely even remember that I have a phone anymore because I make sure to keep it out of sight. I'd love to say it's because I'm passionate about physics and that the muses smiled upon me and I've been struck by great inspiration, but frankly it's only because my exams dates have been announced. And now it's like I've consumed mescaline after idling away the past year. I remember someone telling me about the Feynman technique of studying back in undergrad. I also remember being inspired. But now I'm tangled up in physics, and for the life of me I can't detangle, un-entangle, un-intertwine or whatever from it. I even dream of Greek letters even though I can't speak a word of Greek. How am I supposed to explain any of these obscure symbols to anyone? Fortunately, we have Feynman.

This book consists of excerpts from his three-volume lectures on physics. I had no intention of reading it, but a friend lent me his copy a couple of months ago and so I used it as light reading. But it isn't for a layman, not without the previous lectures. I wonder if I'll ever read all the three volumes linearly and at a stretch, instead of just picking out whatever catches my fancy and skimming through it.

(This was written on my Insta on the 15th of July)
I finished this one last week Sunday. I would say this is for people who are actually studying physics or are really into it to the point they are well acquainted with the equations. However, whoever does want to have a go at this, you might actually find it interesting and educational. When I started reading the book, I made it my challenge of sorts to see how much I would understand from it, I'd say I understood close to at least a third of it. Again, it's a really great book in my opinion, just that if you are expecting more generalized explanations on different topics in physics you would be able to understand without having read anything on the subject in years, then this will be confusing and boring to you to a degree. Personally I like it ^^.

I enjoyed QED better, but still an excellent book. The way he approaches explaining complex topics in physics is truly genius.

Very well written, albeit brief, but I suppose that's the point - to get to the point, quickly, leaving further study for those who are interested.
However, don't let the good-natured title fool you. This book requires at least a little background knowledge before or after reading (and re-reading) to be understood to, at least, an appreciable extent.

This man could write a book on how to boil an egg and I would still read it.