4 comments about Feynman's Thesis: A New Approach to Quantum Theory.

1. The section on quantum superposition and the essential difference between classical and quantum approaches, found in the article "Space-Time Approach to Non-Relativistic Quantum Mechanics", is mind-blowing stuff. This is a great book.



2. I did a course on quantum theory in the 1970s with John Ward who was recommended for the Nobel Prize in 1965 (Feynman, Schwinger and Tomogana shared it). Those close to the action will know of Ward's Identity. John (died in 2002 from memory) used Feynman's lectures as his course notes.
   
   I must confess a soft spot for Feynman. I would have loved to have been in his lectures (buy his audio tapes and you will get the feel for his delivery). He was truly a great physics communicator and often understated his mathematical abilities (after all he had won the Putnam Prize at some stage so he was no mathematical slouch).
   
   His development of QED is simple to understand and that says it all about his genius. He took the view that if he couldn't give a simple explanation then he really didn't understand the topic. The current crop of tool polishers should heed this.
   
   Anyone who is really serious about physics (and maths) should read the original papers and this is a classic example. I suggest that you fill in the gaps in the derivations. If you can't do that then you haven't really understood it.
   
   It is fascinating to compare Feynman's approach with Schwinger's more abstract approach. I prefer Feynman's but Schwinger does a hugely impressive job in stripping QED down to its logical (almost truth functional) essentials.
   
   Buy this book and see how a first class mind works.
   
   Peter Haggstrom
   BONDI BEACH AUSTRALIA



3. The book is not bad but also not in the same class as his lectures. Good for undergraduates as a quick read.



4. Having access to the early ideas that lead R. P. Feynman to the eventual development of his path integral theory of Quantum Mechanics is invaluable.

5 comments about Quantum Leaps in the Wrong Direction : Where Real Science Ends...and Pseudoscience Begins.

1. The real value of this book is in the first three chapters, which contain a simple yet powerful description of how science works, and why pseudoscience is, well, pseudoscience. The remainder of the book covers a variety of pseudosciences grouped into five major categories. While detail is a bit thin on the individual entries, the authors do an excellent job of showing why pseudoscientific hypotheses fall down in the face of science. Hard-core skeptics will find nothing new in the pseudoscience sections, but it's always valuable to have so much information in one place to use as a handy reference. The cartoons by Sidney Harris add humor and include some classics - don't be surprised if you find yourself thumbing through the book just to find the next cartoon. This book could easily be used as the basis for a course on Science and Pseudoscience.

   A few words about the 'Editorial Review' above - It's clear the reviewer needs to read the book again, because he or she completely missed the point. The reviewer ignores the excellent initial chapters on the nature of science, and then makes a series of gaffes. The fact that Graphology has a better reputation in Europe than in the US doesn't make it any less pseudoscientific. The truth is not a popularity contest. Similarly, the fact that true believers in creationism won't be converted doesn't matter. Converting true believers isn't the point - providing information to those who haven't made up their minds yet is far more important. Holocaust denial is an excellent example of a pseudoscience that doesn't fit the standard 'debunking the UFOs' model of skepticism, and shows how to apply the techniques of critical thinking more generally. Finally, anyone offended by the chapters on near death experiences and life after death hasn't done a good job of reading them. The question is about science and how it works - theology is left untouched. The point is to show that NDE's aren't good, scientific evidence of anything mystical. If you make a scientific claim, you'd better be ready for scrutiny of that claim. Belief in souls is either a question of faith, and so outside the purview of science, or it's a scientific question open to review like any other. You can't say it's scientific when there's evidence you want to use in favor, but then make scrutiny off limits because you're squeamish about violating religious dogma.




2. Whew! Quite a lot is covered in this small book, but very little detail is given as references. As a skeptic myself these authors were 'preaching to the choir' with me. I think their idea that "people who disagree with them" will read and possibly change their opinions is a bit far-fetched. This book is perfect for those who dabble on the edge of pseudoscience, sometimes leaning one way then the other. This gives easy to understand examples, and some ammo to fight off unscientific beliefs.

   I would really have liked to see the authors use footnotes throughout the book as an aid to researchers. I know that they were right on with their claims, but would like to see where they got their information. The glossary was very helpful, and can see using it in the future. If you have a friend or relitive who is always bothering you with pseudoscience claims, and you never quite know how to explain your skepticism, then this is the book for you. Carry it on your person, always!




3. When we're younger, and think we have the whole world figured out, we look for patterns while also looking for a means to be different. What we are too often led to is the subject matter of this book.

   The authors cover a whole series of fads and pseudosciences by which we're frequently insulted, e.g., astrology, tarot cards and I Ching, and a host of others. The subjects are handled with a bit of wit, but not the cutesy angle of the "idiots guide to..." books.

   I'm pretty well read on skeptical literature so for me there was little new. However, the silly fads covered in the book are often considered far more acceptable than critical analysis or thinking. Therefore, the book should be assigned to maybe high school seniors or college freshmen, those inclined to fall into such traps, i.e., into believing such nonsense. At least, then, when they get through their post adolescent turmoil, they'll have had a direction, a reference to put the foolishness in perspective. I'm not so naive to think that young people won't pass through such fads--most of us did at one point or another in our lives. But, again, seeds will be planted when most mature to a more complicated world in which we rely on evidence to come to conclusions.

   And they DO cover what constitutes a scientific examinination of something, i.e., a contrast to the "intuitive," testimonial or anecdote-based, or merely "faith" angle they're trying to refute. That is a valuable contribution to the seed for future critical thinking.

   The book does, however, have its weaknesses. One petty one, for instance is that the authors referred to the Greek gods for whom the planets are names. I believe their named for ROMAN gods (the biggest, gas giant, for example, being Jupiter, not Zeus). And, in retrospect, I wish they'd covered some of the trendy "therapies" which are draining the pockets of many, who, after these functionless raps still think for some reason that they're morally superior to the rest of us. But I suppose they make up a different genre of the stuff of which we need to be wisely informed.

   The book is a fine primer for those thus far ill-informed of its subject matter. As such, that's not a criticism but a perspective. It's a wonderful, step-by-step primer for those new to skepticism, e.g., young people experimenting with it or their parents trying to reason their kids off of astrology kicks and so forth. But I wouldn't recommend it to those who've read far more sophisticated stuff on the subjects already.




4. This book, appearing to be written for children, is itself a quantum leap in the wrong direction. The authors treat many complex topics with inaccuracy and superficiality. For example, they state the Egyptian pyramids were made of "relatively soft limestone...(that)...could be quarried with hard stone tools". The interior of the Great pyramid at Giza is partially made of hard granite, too hard to be the work of either stone or copper tools, and that pyramid appears to have initially had 144,000 sixteen- to twenty-ton limestone casing stones made to an accuracy of flatness of ten thousandths of an inch, undoubtedly impossible to accomplish with "stone tools". They attempt to dismiss various psi phenomena by citing a few examples of fraud and instances where something failed to work, ignoring the large body of fine scientific work (Houck, Radin, Puthoff & Targ, Hasted and many others) clearly establishing the reality of many of the various phenomena discussed. Instead of relying on any scientific data, the authors rely on hypotheses, the views of a magician and ridicule by a cartoonist. The book is an unworthy attempt at treating its subject matter, lumping real scientific phenomena with obvious error, such as holocaust denial, and itself represents pseudoscience and yellow journalism.



5. This small 189 page book is a great read and an excellent introduction to both science and critical thinking.
   
   After introducing information about how the scientific method works, the authors proceed to describe various paranormal phenomonon with an eye towards what science says about:
   
   -- Visits by ET (science hasn't authenticated any but it sure is trying);
   
   -- Past life regression (invariably a trick of faulty memory or purposeful deception);
   
   -- ESP and related phenomenon (more the provence of a magician's trickery than anything else);
   
   -- Creationism vs. evolution (render to science its legitimate purview and to faith its legitimate purview); as well as other interesting issues like
   
   -- The Loch Ness monster, Bigfoot and crop circles (all confessed to be purposeful falsifications for which there's been no reliable evidence).
   
   As can be seen the issues are without exception interesting stuff and a great way to show lay people the scientific method in operation.
   
   Highly recommended!

3 comments about Introduction to Quantum Mechanics: A Time-Dependent Perspective.

1. The idea behind David Tannor's book is simple - instead of going the traditional route, in which one solves the eigenvalue problem of some hamiltonian and call it a day, Tannor chooses to examine the time evolution of simple quantum systems. He deals with scattering of wavepackets, bound particles (e.g. particle in a box, harmonic oscillator, etc ... ) and illustrates the features of quantum theory through such examples. It makes you wonder why no other book does the same - after all, the really interesting part of QM is quantum dynamics, isn't it? For example: the fact that the eigenfunction of an infinite well is a sine function is all very nice, but how do particles actually behave in such a well? And so forth.
   I recommend this book for anyone who has already had a first course in QM the "traditional way" and now wants to learn how exactly quantum systems behave in a time dependent way.



2. The first part of Tannor's book presents a clear and easily accessible first pass at the basics of quantum dynamics. It takes the generic "wave packet" chapter, common to many traditional quantum physics texts, and expands it into a highly effective tool for building quantum intuition about nuclear dynamics in molecules, motivating fundamental theorems and important mathematical concepts and techniques. Part two develops the theory behind various approximate methods for treating quantum dynamics, and part three gives some excellent applications providing, for example, a well developed and approachable theoretical framework of modern pulsed laser nonlinear spectroscopy methods, and an especially nice chapter on control of chemical reactions by femtosecond pulse sequences, just to mention a couple of examples from the broad scope of applications given. The text is ideal for students of Chemistry, Physics, and engineering, accessible and challenging to both experimental and theory students alike. It is clearly written, with lots of interesting exercises. At Boston University we offer three semesters of graduate quantum mechanics: First, a semester of traditional quantum chemistry, the basics and an introduction to ab initio electronic structure methods. Next a semester introducing quantum dynamics based on Tannor's book, and finally a semester which applies these ideas to molecular spectroscopies, focusing on femtosecond nonlinear methods. Tannor's book serves as the intellectual bridge between these courses, and does so admirably. Over recent years I have taught our Quantum II class with three different drafts of the text and watched it evolve and expand into the concise, well written text that has now been published. It is a pleasure to teach from and a wonderfully clear book to read. The students in these recent classes have been very vocal with their praise for Tannor's book.



3. This new book is a beautiful exposition of quantum mechanics from a somewhat unfamiliar orientation - the time dependent perspective. The use of wave-packets and their time evolution fits in very naturally (but not completely!) with classical intuition. This makes the quantum aspects of the system much more explicit and clear. Also, it is a more modern perspective for studying time-varying Hamiltonian (and even non-Hamiltonian) systems.
   
   However, the standard eigenvalue perspective is not fully abandoned. It is taught in parallel to the time dynamics, augmenting and enhancing understanding of various examples throughout.
   
   The book also contains some unique and highly accessible and intuitive overviews, hard to find anywhere else at this level. Specifically, Wigner and correlation functions are introduced in a very compelling manner. Also, scattering is taught both in the standard beaten track of scattering eigenstates, but also with the more modern and computationally useful Moller operator formalism. The numerical methods chapter is a gem, suitable for a modern course on quantum mechanics, which naturally includes computer simulations of quantum dynamics.
   
   The book fills in a long overlooked void connecting advanced undergraduates with graduate studies. More specialized topics such as solid-state physics, field theory and many-particle systems are hinted at, but correctly left open for more specialized and advanced texts.
   
   The Applications are geared towards chemical physics, working mainly on molecular-photon interactions with ultra-short pulses. These sections nicely summarize a very broad field, and bring the reader up-to-date with some exciting and modern results. This is especially enjoyable when compared to standard textbooks on quantum mechanics, which usually bring the student up-to-date with the early fifties of the previous century...
   
   The book contains a very nice assortment of exercises, which if gone through carefully, give confidence and a sense of understanding. Also, the extensive reference list is an added special feature.
   
   I studied with this book, and have been using the methods in it ever since, to good effect. I recommend it without reservation.

2 comments about Classic Dynamics of Particles and Systems: Student Solutions Manual.

1. This solutions manual is a great help. The only problem is that it is over-priced for what you get. It helps with about four problems per chapter. I guess that should be enough to get you on track for doing the rest independently. I would think that this solutions manual should sell for about $20.



2. As you read this book, you'll find that what it does explain, it explains fairly well. However, when you get to doing the problems at the end of the chapter, it is vaguely familiar at best based on the material that is in the chapter. The examples are somewhat simple, but it seems that the problems are very disconnected at times, leaving you high and dry at 3 in the morning. And by the time you go buy the answer booklet, which has the answer to pretty much NONE of the important questions, you've already shelled out enough money to invest in some nice Uggs ... not that I'd ever buy those. But same goes for this book if I were you ... unless you have to, which is probably the case. I'm sorry.

2 comments about An Introduction to Quantum Computing.

1. For a beginner like me, I think this is a great book. I used to spend lots of time on N+C book but still got confused.
   
   This introduction to Quantum computing book has lots of illustrations explaining how things are done step by step inside those complicated algorithms. If you study on your own with this book, there should be no problem. Then you can go back to review N+C's book and things would be much more clear.



2. This book is geared for the reader who has an undergraduate education in a technical field and who has a solid background in linear algebra, including vector spaces and inner products. Prior familiarity with topics such as eigendecomposition and more advanced mathematical topics is not required. The book reviews all of the necessary additional material. There are some places in the book where group theory is referred to, but these sections of the book are self-contained so that the reader can skip them if needed. It is a very accessible introduction to a complex subject that is fairly detailed and complete. Exercises are integrated into the body of the text. Each exercise is designed to illustrate a particular concept, fill in the details of a calculation or proof, or to show how concepts in the book can be generalized or extended. The following is a brief overview of the book:
   
   1. Introduction and Background - Presents some fundamental notions of computation theory and quantum physics that will form the basis of what follows.
   
   2. Linear Algebra and the Dirac Notation - Familiarizes the reader with the algebraic notation used in quantum mechanics, reminds the reader of some basic facts about complex vector spaces, and introduces some notions that may not have been covered in an elementary linear algebra course.
   
   3. Qubits and the Framework of quantum Mechanics - Introduces the framework of quantum mechanics as it pertains to the types of systems that are considered in the book. Here the author also introduces the notion of a quantum bit or "qubit", which is a fundamental concept in quantum computing.
   
   4. A Quantum Model of Computation - The circuit model of classical computation can be generalized to a model of quantum circuits. In such a model you have logical qubits carried along "wires" and quantum gates that act on the qubits. For convenience, the discussion is limited to unitary quantum gates.
   
   5. Superdense Coding and Quantum Teleportation - Looks at our first protocols for quantum information. Examines two communication protocols that can be implemented using the tools which can be implemented using the tools developed in previous chapters. These protocols are known as superdense coding and quantum teleportation. Both of these are inherently quantum - there are no classical protocols that behave in the same way as these.
   
   6. Introductory Quantum Algorithms - Describes some of the early quantum algorithms that are simple and illustrate the main ingredients behind the more useful and powerful quantum algorithms described in subsequent chapters. Since quantum algorithms share some features with classical probabilistic algorithms, the chapter starts with a comparison of the two algorithmic paradigms.
   
   7. Algorithms with Superpolynomial Speed-Up - Examines one of two main classes of algorithms: quantum algorithms that solve problems with a complexity that is superpolynomially less than the complexity of the best-known classical algorithm for the same problem. That is, the complexity of the best-known classical algorithm cannot be bounded above by any poynomial in the complexity of the quantum algorithm. The chapter starts off by studying the problem of quantum phase estimation, which leads naturally to the Quantum Fourier Transform (QFT).
   
   8. Algorithms Based on Amplitude Amplification - Discusses a broadly applicable quantum algorithm - quantum search - that provides a polynomial speed-up over the best-known classical algorithms for a wide class of important problems.
   
   9. Quantum Computational Complexity Theory and Lower Bounds - Quantum computers seem to be more powerful than classical computers for certain problems. However, there are limits on the power of quantum computers. Since a classical computer can simulate a quantum one, a quantum computer can only compute the same set of functions that a classical computer can. This chapter examines this and some related issues.
   
   10. Quantum Error Correction - Quantum computers are more susceptible to errors than classical digital computers because quantum mechanical systems are more delicate and more difficult to control. If large-scale quantum computers are to be possible, a theory of quantum error correction is needed. This is the issue discussed in this chapter.
   
   Overall, I found this book well suited to self-study, particularly for someone with an engineering background. Highly recommended.

5 comments about The Quantum Theory of Fields, Vol. 3: Supersymmetry.

1. Great book, contains a lot of material, will be useful to many as a reference on supersymmetry for years to come. Highly Recommended!



2. If the two first volumes of "The Quantum Theory of Fields" were considered masterpieces in a modern and original presentation of the basics of quantum field theory and its penetration in the recent development of particle physics, with the machinery of spontaneously broken gauge theories, the new volume embraces the wide subject of supersymmetry in Weinberg's typical style, which always means a self-contained treatment of the subject, from its foundations and motivations, to its most recent application as a possible scenario for new physics beyond the Standard Model.

   A complete review is published in CERN Courier, May 2000




3. Finding good introductions to supersymmetry can be difficult. Most introductions concentrate on N=1 supersymmetry in four dimensions, and there the superfield forumlation can be useful. However, when you go to N=2 supersymmetry (e.g. when considering theories in five or more dimensions), component fields can be better. Many times it's a matter of taste. For those cases, you have to go to review articles. Anyway, Weinberg concentrates on N=1 4D supersymmetry and supergravity using the superfield formalism. However, he ventures into the N=2 strong-weak coupling results of Seiberg and Witten, which are now a fundamental part of (supersymmetric) field theory. The text is, as the previous volumes are, a fantastic resource for learning the subject, and as a reference (for things like gravity- and gauge-mediated supersymmetry breaking, as well as the minimal supersymmetric standard model, which are open areas of reserach). As for all modern areas of research, the body of knowledge is stacked higher every year; but the topics covered here stand as solid fundamentals of supersymmetry. For more advanced topics, one is forced to go to the recent literature.



4. The whole current production run of this book has a defect. A glue is bleeding through on the inside of the hard cover fold, front and back. This does not seem to affect the structural quality of the book and is not visible from the outside. If you need this book and get it with this defect, don't bother trying to exchange it.



5. I'm a beginning graduate student in theoretical physics, who learned SUSY from the ground up from Weinberg's text. Weinberg is (in my opinion) by far the best text I could find on SUSY. It is totally self-contained* - every equation can be checked by the reader; the idea's are solidly explained, and the choice of topics is extremely relevant. However, I should say that this is probably not a book for those looking for a quick introduction, or a sketch of the subject (which are valuable in their own right).
   
   In the very beginning (I knew very little SUSY) my impulse was to avoid this book, as the "notation" seemed kind of heavy, there were too many long equations (superfield identities), and it was clear that reading the book was going to be a serious endeavor**. Instead I was looking for a quick fix. However, having found the other sources inadequate***, I gave Weinberg another try. I learned how to read his book (from the point of view of a beginner; a veteran can easily use it as a reference)~ read it actively, checking the equations at the level of looking for typos. I poured in many hard hours, and have a binder full of derivations to show for it****. But as a result one is very well equipped to tackle the literature.
   
   I especially appreciate how Weinberg builds SUSY from the ground up. He makes it come together so logically, and coherently, it is nice to watch, and I feel one is rewarded in deeper understanding.
   
   His treatment is often original and improves in many ways upon the original literature. For example, his treatment of SUSY representation theory and constructions of superfields. Also his treatment of holomorphy arguments is the best I've found anywhere (literature included). His treatment of Seiberg-Witten is his own pedagogically minded retelling of that story ~ it takes a slightly different angle than the original work, and fills in many of the details. Reading the original Seiberg-Witten afterwards was much facilitated.
   
   A word on prerequisites: A basic knowledge of QFT is needed ~ if you have Weinberg's Vol I, II, this is overkill. However, you should be comfortable with the representation theory of the Lorentz group ~ especially spinors. Weinberg provides useful appendices on spinors in Vol III, and has the rep. theory in Vol I (an understanding of angular momentum at the level of say Sakurai ch 3 helps here). To understand the interesting non-perturbative results (chapter 29) you must be comfortable with 1-loop beta functions in YM, and the chiral anomaly (covered in Vol II as well as many other texts).
   
   A caution on typos: There are many minor typos which you probably won't notice unless you rederive the particular offending equation. I know of about fifty (over a range of about 300 pages). The nature of the subject is such that there could have been many more though (lot's of long equations with many indexes). Luckily, the errors often do not propagate ~ subsequent equations are usually typo free. There doesn't seem to be an errata website, which is unfortunate.
   
   Finally, there are a few exercises after each chapter. Some of them seem intellectually gratifying, and some are rather messy algebra.
   
   
   
   * With the exception of some of the MSSM stuff, but this is clearly stated, and totally reasonable.
   ** But alas, for a beginning student, this is the nature of the subject.
   ***There is one fantastic supplement to Weinberg (after you've gone through the first couple of intro chapters), these are Argyres' notes. They nicely cover Seiberg duality which Weinberg doesn't talk about (but he does a great job with Seiberg-Witten).
   **** The meat of the book can in principle be covered in < 2.5 months by a super-dedicated student (skipping the SUGRA chapter) and of course depending on one's incoming background and interest!

No comments about The Spiritual Technology of Ancient Egypt: Sacred Science and the Mystery of Consciousness.

3 comments about Condensed Matter Field Theory.

1. This book is a good introduction to Field Theory applied in condensed matter physics. In dealing with two difficult subjects the authors do it in a very simple language. This is very important either to beginners or experts. There are very good solved examples to illustrate each section. Besides, there are small boxes citing the people behind the development of the issue.



2. This is an extremely well-written book, which covers almost all the modern topics in condensed matter physics while keeps the physics and mathematics clear and simple.
   
   It is an invaluable reference or textbook for graduate students who are interested in theoretical condensed matter physics, esp. in strongly correlated systems.
   
   It is almost the best book I have seen for a graduate student to study the functional method, renormalization-group theory, etc., applied to condensed matter systems.



3. This book is really incredible. It is one of only a handful of really readable physics texts, and it carefully moves from very friendly explanations of basic concepts, such as a two page review of Gaussian integrals (things like this make it a great reference), to very advanced material. The last chapter on topology, for example, doesn't hold back from using the full machinery of differential geometry, but also provides a great tutorial on the subject.
   
   Also, a closer read reveals that this book's point of view is thoroughly modern, in the sense that it puts symmetry concepts and non-perturbative techniques front and center. The authors do readers a huge service by promoting the idea that one of the keys to understanding complex quantum systems is to correctly identify their fundamental excitations.

4 comments about Problems and Solutions on Quantum Mechanics: Major American Universities Ph. D. Qualifying Questions and Solutions.

1. I study physics in Chile, and this book has been pretty useful for a first course in QM, but I have to note that the first 170 pages are titled "Problems and Solutions on Electromagnetism"! I hope someone gets word to the editor....

   Other than that, I'm pretty sure this book will find a place on your private shelf.




2. Sometimes it is very difficult to teach a course in quantum mechanics because there are few problems that have solutions that do not require months of research and numerical methods to solve. I have found that in my own courses on quantum mechanics, I take a lot of notes and I do a lot of homework assignments, but I don't have a whole lot of concrete, well-explained problems and solutions to show for all of the work. Since I found this book and those that accompany it, however, I have a very good source for problems and their solutions in QM. These problems are an excellent study aid for the solutions provide insight into the basics of the field. Strongly recommended.



3. All of these books titled "Problems and Solutions on (subject): Major American Universities Ph.D. Qualifying Questions and Solutions" are invaluable tools for a physics graduate student, in my experience. For quantum mechanics in particular, solved problems often illustrate difficult concepts better than any explanatory paragraph in a text.

   Criticism: Sparse index and contents. You'll find yourself adding notes to pages in the book quite often.

   If you are a student in physics, I suggest that you get your hands on these books.




4. I'm glad to pursache this book of problems of quantum mechanics because it is a great variety of them from varios universitys. Thank you.

2 comments about Techniques and Applications of Path Integration (Dover Books on Physics).

1. The first line of chapter one reads, "The best place to find out about path integrals is in Feynman's paper." This is the paper "Space-time Approach to Non-relativistic Quantum Mechanics" (Rev. Mod. Phys. 20, p. 367 (1948)),
   which is included in "Selected Papers on Quantum Electrodynamics" edited by Julian Schwinger, also reprinted by Dover. So you may want to start there first.
   
   The current book has many short, readable chapters on various applications of path integration, each with copious references. The author's bias is toward non-QFT applications, which is fine as there are plenty of books on QFT.
   
   This Dover reprint includes a 60 page supplement with notes, errata, and further references.



2. The author collected many branches of modern physics abouut path integral.
   It included many references for advanced reading.
   Anyone wants to go into Feynman's path integral should read it.