This is the best first course quantum mechanics text book by far. I used it as a text in first semester QM. How do I know it is the best? During first semester qm I spent many hours in the school library reading qm books. The library had a large section of qm books. I used to take 10 to 20 books home at a time. I was always looking for better explanations of particular expositions, and I found that often one book gave the clearest exposition in a particular area. Also, Ifound it helpful to read how several books described, for example, solution to the step function and others. But David Griffiths book is the best written book of all those others I read.

The Griffiths book is easy to understand. That is what makes it a good book for the beginning student of qm. Let me give an example of what I am saying: Fourty five years ago, when I first studied calculus, there was only one text book. It was the then venerable Calculus and Analytic Geometry by George Thomas, Jr. This book was not easy to study. It is not a well written book compared to modern calculus text books. But now there are many good calculus text books. Now calculus is a fairly easy subject because the text books are well written. They are student friendly. I think that most qm books are like the Thomas book in that they are not student friendly, and the Griffiths book is the first student friendly qm book in my view.

The one criticism that students might have of the Griffiths books is that the problems are long and time consuming. This is true if you do not use Mathematica or some other math program. If you use Mathematica, the problems can be worked in minutes.

The Griffiths book uses wave mechanics notation throughout, which every physicist must learn. To learn the Dirac notation, the best book I found (and the most elegant qm book I found) is Quantum Mechanics, by Claude Cohen-Tannoudji, Bernard Diu, and Franck Laloe.

The book divides into three parts. Part I develops the mathematical tools used in the general theory of relativity. This part is very short, but self-contained. Readers who have never studied differential geometry will find the exposition too abstract, in my view. I suggest the reader first study one of a number of good texts such as, W. Thirring: A course in Mathematical Physics, Vol 1 or R. Abraham and J.E. Marsden: Foundations of Mechanics.

In the second part, the general theory of relativity is developed along traditional lines. The coordinate-free language is emphasized. Full use of Cartan's calculus of differential forms is made. The tests of general relativity are discussed.

The last part of the book treats important aspects of the physics of compact objects. Some topics, for example the cooling of neutron stars, are discussed in great detail.

On the whole, the book is rigorous. May I emphasize, the reader need a good background in differential geometry.

I have rated this book 4 stars because I think it does a good job providing an overview of the state of physics, without the reader needing a technical background. I think this book should be read by every high school student entertaining a physics career. I will say that serious technical study offers far greater understanding of the concepts suggested in this book that what can be gained by a non-technical reading.

There is one important subject that the author discusses that I would like to comment on. In chapter 5 and elsewhere the author compares spacetime to a frozen river and to a loaf of bread. The author seems to be saying that spacetime is a four dimensional block, perhaps with a frozen part and part with a dynamic part. The frozen river analogy suggests something solid but continuous. The author says, also, that spacetime incorporates past events and future events.

I think that spacetime is more complicated. Spacetime must, in my humble view, include only active space. That is, spacetime must include only space where something is happening, or, where motion is taking place. We know that time itself is dependent on motion, and is really an expression of motion. We know that we have never observed through a telescope spacetime that is not dynamic, or where motion is not taking place. And we know that we have never observed the future by looking through a telescope, despite the fact that Earth with the Sun and galaxy is moving at approximately 600 km/s (1.3 million miles per hour) relevant to the local cosmic flow. Motion relevant to the cosmic flow should, in theory, allow a view of future spacetime at distant locations. This is what the author says is the case when he slices the spacetime loaf at angles.

One conceptual difficulty with the frozen river analogy is that, by including past and future space-time, there is the suggestion of a "creation" event for the whole of space-time, not just a birth of spacetime. For example, if future spacetime exists, then all of future spacetime exists at once, and must have been created all at once. The frozen river analogy also implies a frozen part, that is, a part that once was in motion but is now a frozen and unmoving record. But observation does not support this. While past spacetime must be frozen, future space time must by dynamic and moving, with a boundary between the frozen and moving part. The boundary would be moving as more frozen history gets incorporated.

A better way to look at spacetime, in my view, is to think of it as a four dimensional space that includes all of active space, and includes only active space.

I would like to comment on Brian's description of time. In Chapter 5 and elsewhere Brian elevates time to the status of the three physical dimensions we all see. On page 452 he says, "Moments are timeless. Each moment - each event or happening - exists, just as each point is space exists." In Chapter 5 Brian describes spacetime as resembling a frozen river, or a loaf of bread, that can be sliced at the "now" slice to see current events. Former slices would reveal past events, and slices intersecting future spacetime would reveal future events. The question is, is this view of time valid? Is time a real dimension in the Cosmos, like the three visible space dimensions are real?

The answer to the above questions has to be, no. Time is a convenience invented by humans to make life simpler. Time allows us to calculate velocity. It allows us to plan activities, and coordinate events. Spacetime is a geometric and mathematical construct that allows trajectories in evolving space to be calculated. Spacetime need not be "real", for these calculations to be made.

What does exist is motion. Matter and the various micro-state particles are in motion relative to other matter. One year is nothing more than one revolution of the Earth around the Sun. One second is 1/ 31 millionth of an Earth rotation around the Sun. The universe has been in motion for the equivalent of about 20 billion Earth rotations of the Earth around the Sun.
When we look at a clock we see hands in motion, with a face calibrated in arbitrary units we call hours and minutes. We decided long ago to substitute a fictional thing called "time" for motion. Rather than use rotations of the Earth as a motion standard, we could use Rubidium gas optical frequency detection, or a number of other constant motion methods.

To see that motion is all there is, suppose all motion stopped. Suppose we could freeze every photon, every atom, every field particle, and everything else in its tracks relative to everything. But we would leave "time" unaffected. In this scenario would time exist? Would the arrow of time have any meaning? The answer is clearly, no.

The direction of the so called arrow of time is defined by the direction of increasing entropy. But the fact of motion makes increasing entropy possible, hence makes possible a direction for the arrow of time.

If spacetime exists, just as each point in three space exists, then we must ask: For what observer does spacetime exist? What observer stands outside the loaf, or outside the frozen river and observes the loaf. After all, by definition, spacetime is all there is, and every observer must be embedded in spacetime. If every moment in spacetime exists - just as every point in our familiar three space exists - then Abraham Lincoln exists in the frozen river eternally for some observer. But what observer? This observer does not exist. The only observers who ever met Abraham Lincoln are the ones who lived concurrent with him and near him. If spacetime is real, then Mount McKinley is a range extending throughout spacetime, rather than the simple mountain we and Abraham Lincoln might have seen.

Another problem with the frozen river analogy is this: Spacetime that is "behind" us is indeed frozen. Nothing that happened in the past can be changed in the slightest. On the other hand, the future (future spacetime) must be a dynamical space. The universe is expanding, and above all, motion is taking place at high speed on the micro and macro levels. So a real spacetime would have to have a boundary separating the frozen part from the developing or moving part. But this boundary would also be moving as more frozen stuff got incorporated behind it. Obviously the "boundary" is the moving front, and there is nothing behind or in front of it.

It is natural to ask how velocity is defined without invoking units of time. Velocity = distance / time. Usually velocity is expressed in feet per second, or meters per second, or knots (nautical miles per hour), etc. Without invoking units or time, velocity might be expressed in feet per 31 millionths of an earth rotation around the sun, etc. It is clear that a short way of writing 31 millionths of a rotation around the sun is needed, and the one we use is seconds. What we did long ago was substitute a new name for motion, and this new name was time.

One of the relativistic forms of the uncertainty principle is delta t times delta E is greater than or equal to hbar over 2. This could more properly be written, delta rotations around the sun times delta E is greater than or equal to hbar over 2. Again, it is obviously cleaner to use a short identifier substitute for rotations around the sun. This identifier is time.

Finally, since the special relativity correction term is dimensionless, special relativity is not affected by use of motion units instead of time units.

John McWorter claims that large numbers of blacks think racism remains a determining force in America, and that black advancement depends on maintenance of a victim image and white guilt. John suggests that, correct or not, these views have paradyne entrenchment in the black community. John does not suggest that reverse racism plays a part.

I suspect that there is some truth in John's views. What appears to be happening is that low group self esteem has a self fulfilling component. The image that blacks have of the race is perhaps one instilled by generations of inferior class privilege. The image has much inertia, and it will take time to change course. That great personalities like Colin Powell contradict the image are as yet insufficient to have much affect.

What is needed is large scale preaching to blacks that they possess equal potential; that progress can be made by individual confidence and hard work.

In case this is not convincing, the best way to change negative attitudes toward one-self is to excel.

A few years ago American media was almost entirely in the grip of left wing thought, so much so that CNN took it as the default position. Thanks to Fox News, a few newspapers such as the Washington Times, and a rising number of radio talk show hosts like Sean Hannity, public broadcast information is becoming more balanced. What I like about Sean Hannity is his very honest personality. His message make the best sense to me, and I am willing to listen to anybody who makes sense.

I grew up a Democrat. I worked on the John Kennedy campaign. I always voted Democrat. But I switched parties to vote for Senator McCain. It was a good switch. The Democratic party has become one of irrational attack, rather than the sensible party it once was. Sean Hannity symbolizes the honesty, objectivity, and proper oriention that will be best for America that more characterizes the new Republican party.

While Rush Limbaugh is for the most part on the right track (he is way off on the environment), Sean Hannity is close to perfection, in my view.

The book helps understand our current problems in the Middle East, in particular, our relation to Israel and the tensions and stresses between Israel, the Arab states and the United States.
The brilliance of Henry Kissinger is revealed. The intelligence and savy of Nixon was a supprise.

Beauty may be appreciated in several ways. Among the several forms, there is visual beauty, such as seen at a high Sierra overlook in winter. There is acoustic beauty sensed from good music, intellectual beauty felt in an elegant solution to a technical problem, and linguistic beauty heard and read. The chief aim of poetry is to produce linguistic beauty.

For example, perhaps the most beautiful line ever written is: Yea, though I walk through the Valley of the Shadow of Death, I will fear no evil...... And there is the short question: Am I my brothers keeper? These are blockbuster sentences even out of context.

"The Iliad" by Robert Fagles ranks, in my view, among the best examples of linguistic beauty. I think it is, on the whole, superior in this regard to the translation by Richmond Lattimore, although I recognize this may be a preference.

When comparing the Fagles and Lattimore translations, line by line, one sees that translation from the Greek is by no means exact, and the translator exercises a significant degree of interpretation. Furthermore the Greek hexameter cadence is lost, and the translator must replace it with a beat of his own. How the translator develops a cadence, selects words, and arranges words are all importance to the production of a beautiful work. Fagles does a remarkable job.

Rod Hug

Having worked for the nuclear submarine Navy as a civilian engineer for 30 years, I found much of high interest in this book, in addition to Scott Waddle's personal account of this tragic accident. Clearly Scott made a supreme attempt at objectivity and honesty. He pulls no punches with himself and with others.

This book raises many thoughtful issues. Scott ask in different ways, why did God let this happen? The question is asked by every generation. I would say to Scott, when God created our world He gave us the gift of freedom. In so doing He precluded even Himself from interfering with our activities. In fact, He set the Cosmos in motion with integrated rules that prevent Him from taking "hands on" control. God apparently chose not to exercise celestial tyranny as thought by the ancient Greeks. Thus evil may coexist with good, and ugliness with beauty. But we notice that we, being instruments of the Cosmos, gravitate to goodness and beauty, and when the Cosmos is left to its devices, beauty reigns.

Scott is also concerned with the dichotomy of close managerial control vs. maximization of freedom of expression. For Admiral Rickover, close managerial control provided a perfect safety record with Navy nuclear reactors. On the other hand, an allowance for self expression makes for happier people and improved productivity. But when public safety is paramount, or when team precision is essential, checks on the decisions and work of individuals must be made. People do make mistakes. Aboard USS Greeneville the web apparently had weak links.

Regarding the accident, it could probably have happened to any commander once the statistically unlikely series of causes came into alignment. Commander Waddle had some part in the supply of those causes. But he also had plain bad luck. The Navy resolution was about right in my view. It would have been wrong to take away his retirement, considering that he was so dedicated and such a hard worker. But he could not have been allowed to keep his command, otherwise the message to all commanders would be, having a collision in peacetime is not likely to result in loss of command. Much has been made of the politics, but in the end I don't think this influenced the Navy decision. While loss of 9 lives is a terrible tragedy, the Japanese folks should understand the going to sea in fishing boats is a risky profession.

Working aboard submarines during repair and at sea I have always been impressed by the quality of submarine commanders. Scott Waddle is no exception. And I know he will do well in civilian life. I wish him well.

Rod Hug