Introduction to Quantum Mechanics (2nd Edition) Paperback Economy edition by. David J. Griffiths Paperback – September 17, 2015

After reading some critics, i feel like contributing to defend this text.First, when is this book useful?Based on the American educational system: when you're an undergrad student in physics, that is when you've already been exposed to the origins of quantum mechanics through a class often called "modern physics", and have some basics in calculus and linear algebra. But most importantly: if you intend to study physics further, because if you're just in for a tasting go for Susskind's or something similar.Now if you're a demanding or unusually advanced undergraduate student: relax !!!You will get to read many other books about QM so don't ask this one to be what it's not claiming to be:This is not an advanced text and by no means sufficient by itself if you're really committed to studying physics; it is not completely introductory either in the sense that you won't learn about the history of the subject or won't get a purely axiomatic, rigorous approach either. It is designed to make you USE quantum mechanics, sometimes (yes!) even before it tells you what you're doing, so that part of your deeper understanding is built out of your own experience studying examples or working through problems. This said, it also provides good insights and often takes the simplest route to make a point, with a language that i find as entertaining and clear as in his E&M book.Now studying QM will always be a tricky business because there are so many ways to approach the subject and try to make sense of it, while our brain is truly wired for classical mechanics. You will find the book that does it for you at some point but will have to read several of them no matter what: if you don't get a kick out of this one go somewhere else, but i personally found it extremely helpful and clear. My graduate text was Weinberg, which is fantastic when you're an advanced grad student but almost unreadable when you're not and i heavily relied on Griffiths and some other, popular intermediate books, to help decipher it.So this is a truly intermediate text and will take you to the meatier treatments of such as Sakurai, Merzbacher, Cohen-Tannoudji and others like a charm; if not, then just go straight to them. And if you're a Vulcan or a mathematician go straight to Weinberg!Good luck

Many people (actually just physicists) are rude to those who have learned the wonders of Quantum Mechanics from Griffiths. They say that the treatment lacks some of the mathematical rigor that you see in Shankar or Townsend (the two main competitors in the Intro to Quantum market). But — even if you take that as true (which I and many others wouldn't agree with) — that might actually just speak to this book's strength.Griffiths writes with a gusto and wit normally reserved for an investigative report rather than a physical explication. He makes quantum come alive. There is a common refrain among physics students that Professors lose the forest for the trees. They give you the tools (the matrices, the operators, the commutators) to see the probability of a given state, but they avoid talking about its consequence. Too often, students come out of physics classes with symbols in their toolboxes, but no real-world applications in their minds. Physics describes the universe. As much as many would try to remove it from such a noble, but dirty, pursuit they cannot. When I learn about quantum tunneling I appreciate an explanation that gives the formulae needed and then goes a step further and answers "why?" Why did that initial state lead to this final state? Why is the result not expected? Why does this result affect things in the world?Griffiths made that textbook. He answers the hard whys behind the mathematical ingenuity. Those whys are why we study physics and how we grow to become a better next generation of physicists. And for that reason, I give this textbook 5 stars.

Griffiths is a great writer, with a sense of humor that shines through some pretty heinous maths, clearly explained. The discussion of the philosophical realm of quantum mechanics, with wierdness and paradoxes, is accessible and clear while being great food for thought and a stimulating starting point. Like with many physics texts, we get the sarcastic "it is left to the reader to prove", with a deferral to the excercises instead of a detailed proof or explanation. In this text it only happens when it would really be of benefit to do the problems, unlike in some other texts where the omissions in the chapter smell of condescension, or worse, of laziness of omission. This was my college textbook for two successive courses, but it also proved to be fun reading.