No comments about Nobel Laureates and Twentieth-Century Physics.

1 comments about Theory and Experiment in Gravitational Physics.

1. This book is not objective. There is no mention of the three degree cosmic background radiation which calls into question the relativistic and variance foundation of general relativity. This is an enormous problem for the validity of general relativity. Review made by Dr. Hubert Lipinski.

1 comments about Bowled Over: The Case of the Gravity Goof-Up (Kinetic City Super Crew series).

1. The Kinetic City Super Crew is my favorite books

1 comments about The Grip of Gravity: The Quest to Understand the Laws of Motion and Gravitation.

1. For me, a well-written science history contains three things. It establishes the context for the discoveries and developments. It accurately describes the relevant details of the experiments so that the results, interpretations and conclusions can be understood. Finally, it discusses the implications of the developments. The author accomplishes all three to my satisfaction in this book.
   The story of gravity involves many subplots. Each part contributes a piece to the developing concept of gravity. The author skillfully weaves the pieces into a coherent story. Along the way he presents details that challenge common misconceptions about gravity, clarifies myths about the familiar personalities who have demystified aspects of gravity and introduces less familiar but influential contributors to our still-evolving understanding of gravity.
   The book is comprehensive enough to satisfy my requirements for a well-written science history, but not so over-burdened with detail that it becomes cumbersome to follow the main plot. It reads like a suspense story for a reader who's interested in science history.

1 comments about Einstein's Dream: The Search for a Unified Theory of the Universe.

1. As an engineer I feel obligated to keep up to speed with things scientific, and I also have an interest in Physics. This book definitely updates modern Physics to an average reader, and has many interesting stories to supplement the material. It has just the right mix of science, history and math to keep the reader interested. I seriously recommend it to all interested in Physics.

No comments about Artificial Black Holes.

2 comments about Gravity and Strings (Cambridge Monographs on Mathematical Physics).

1. It's a rather impressive piece of work. However, despite the size, this book should not be counted as one of the textbooks of string theory. It focuses on various solutions of general relativity and its extensions - supergravity - which arise as low energy limits of string theory.
   
   The characteristic physics and mathematics of string theory (such as perturbative string theory and conformal field theory) is not discussed too thoroughly. In this sense, the book is not a competitor of Polchinski's "String Theory" or Green+Schwarz+Witten's "Superstring Theory", but it can still be a useful source of various classical solutions.



2. This is a very ambitious book, it covers a very diverse set of topics in gravity. One of the good things about this book is that it covers a lot of material that isn't usually covered in books on general relativity or string theory, especially at this level of detail. It's certainly not an introduction to general relativity or string theory. I would recommend readers unfamiliar with these topics to study Wald and Polchinski first.
   
   The book opens with chapters covering differential geometry and Nother's Theorem. The intent isn't to teach the readers these topics, but rather to establish notation and provide a high level review.
   
   When gravitation is introduced it's not the usual geometrical approach, but it is approached as the theory of massless spin two particles, as in Feynman's lectures on gravitation. It's an interesting approach showing that starting with a linear theory non-linear terms must be included for consistency and this leads to general relativity which leads to a geometric interpretation of gravity. It also includes a nice discussion of the gravitational energy momentum psuedotensor. More detailed consideration of the non-localizability of gravitational energy is give throughout the book.
   
   Following this the gravitational action is covered in a fair amount of detail. In addition to the more common approach of considering the metric as the only independent variable of the theory, he also covers the approach where the metric and the connection are independent variables. Although it's less common to see the Palatini formalism it is hardly uncommon. It's also the foundation of the approach to a non-string theory approach to quantum gravity, i.e. is loop quantum gravity. I enjoyed the discussion of torsion in general relativity, this was covered in more detail than one usually sees.
   
   Up until this point the book as covered classical gravity, however the approach isn't the standard one. The approach to general relativity is one that will be useful in understanding the material on quantum gravity. None of this material is particularly obscure (with the exception of teleparallelism), but I think it's fairly unusual to see it all covered in one place with so much depth.
   
   Next, the author extends the Poincare algebra by including fermionic generators to give supergravity. He restricts his coverage to only N=1 and N=2 supersymmetry. This is followed by more extensive coverage of energy in general relativity, mainly focusing on the non-localizability of gravitational energy and energy conditions.
   
   The next few chapters deal with various solutions in general relativity. The first couple, Schwarzschild and Reissner-Nordstrom solutions, are covered in most (the former essentially all) books on general relativity. However, the coverage here goes way beyond the normal. After quickly getting the Schwarzschild solution its thermodynamics and higher dimensional analogs are covered. In the Reissner-Nordstrom case there is an even greater amount of material beyond the normal. This included: the Proca Lagrangian, the Majumdar-Papapetrou family of solutions, static solutions of multiple extremal black holes, gravitational solitons, more discussion of localizability of gravitational energy, thermodynamics, electromagnetic duality (including an extension he relates to the T, S and U dualities of string theory), monopoles, Chern-Simons terms and higher dimensional solutions.
   
   Over the next couple of chapters more solutions are described, some in a fair amount of depth: Taub-NUT, Taub-bolt, BPS states, instantons, plane fronted gravity waves, Kaluza-Klien black holes, the Bogomol'nyi bound, Dehn twits and dilaton black holes. It's nice seeing all this covered in one place; however, at times it reads a catalog and I wasn't really sure what main point was.
   
   After a chapter on supersymmetry the book moves on to study string theory. This comprises the final third of the book. The introductory string material is presented at a lightening rate. I would guess most readers being exposed to string theory for the first time would be overwhelmed. Naturally branes are also covered. The emphasis for most of this part is on the duality symmetries of string theory and how they relate various solutions.
   
   The string part of the book finishes off by describing black hole solutions in string theory. One interesting inconsistency in the book is that he describes the Schwarzschild solution as the gravitational field of a massive pointlike particle. What makes this interesting is that earlier in the book he went to great lengths to explain that the Schwarzschild solution was not the gravitational field of a massive pointlike particle, the easiest way to see this is that the singularity of this is spacelike so that the source can't be a massive particle.
   
   On the whole I liked this book a lot, I thought it had many strengths. I wouldn't choose it as a first book on general relativity or string theory, but that's not its intent anyway. The approach to developing gravity isn't the usual one (interestingly he uses a +--- signature which is fairly uncommon, these days, outside of the study of spinors), but it is a good compliment to it and one that students of gravitation should be aware of. Not only because it provides a bridge to the study of quantum gravity, but also because it is interesting in its own right. Another strength is that a lot of interesting, often neglected, topics are developed in much more detail than is usually provided.

1 comments about Three Hundred Years of Gravitation.

1. this is the best book on gravitation. each and every physics student should work out with this book.this is a real genius' intellect.
   it describes everything from newton's theory to einstein's work.so just have it .....if you want to expand your brain. each and every time you read this book you will learn something new.

No comments about Space and Time in Contemporary Physics: An Introduction to the Theory of Relativity and Gravitation.

3 comments about Relational Mechanics.

1. This book has two parts, the first concerning Classical Mechanics and Mach's ideas. The second criticizes relativity and introduces an alternative theory ("relational mechanics") of the author. To the first one I rate 5 stars, to the second I rate zero stars so actually the 3 stars above represents 2.5.
   The first part of this book is a time machine: You can breath the construction of Mechanics since Newton until Mach. It sends you to exactly 100 years ago, 1904, before Einstein's special relativity, so you can understantd (with the eyes of the epoch) what problems Classical Mechanics was presenting to the physicists of the time. It is a really beautiful exposition of the ideas and critics to Classical Mechanics at that moment, broadly grouped under Mach's name. Although Mach had good points about what was wrong with classical mechanics, he proposed no theory to substitute the Newtonian one. He gave just general ideas. One can say that the theory proposed by the author in the second part of the book is a candidate which "implements" (at least in the particular interpretation of Mach's ideas adopted by the author) a theory that Mr. Mach would find better.
   But if Mach had time to live until nowadays he would be the first to discard this proposed theory, just because it can not explain the most simple data we have (e.g, clock's delay in gravitational fields, muons life-time in atmosphere, redshift, etc, etc). So now I explain the zero star I gave to the second part: it's not because I like or dislike his theory, but because the author's presentation in this part of the book is not honest. He tries to criticize Special and General relativity, but the arguments just show how much he does not understand of the theory. To find the error in his arguments can be a good "seven errors game" to a physics student, e.g., the author misunderstanding of standard relativity topics (like the "twin paradox" for example). The author adopts a particular interpretation of Mach ideas, and when he verifies that his particular interpretation is not implemented in General Relativity, his conclusion is that Einstein theory is wrong. In another words, the position presented in the book is that "If the theory does not fulfill my philosophical prejudices, it's wrong.".
   It is not a question of to be "open minded" or "follower". It is just a question of comparison of theory and experiments. In this regard, relational mechanics is wrong: It does not explain nature as we see it by the experiments. It's simple. No big deal here about conspirations, followers or discriminated geniuses.
   In the end of the day, this is a instigating book. It makes you think, even when it is wrong.



2. This masterpiece summarizes Dr. Andre Assis' studies of the basis of two main Mechanics theories in Physics from the last millennium: Classical Mechanics, founded by Sir Isaac Newton, and Relativity Mecahnics (both, Special and General), founded by Albert Einstein.

   All the criticisms presented by Ernst Mach to the Newton's theory, which Einstein tried to overcome in his theories but failed to do so, are revised and explained in details.

   Beyond a clear historical perspective of the problems faced by these two main theories, Dr. Assis presents his own theory of Mechanics (Relational), one that suceeds in implementing the Mach's Principle.

   After reading this book, with an open-minded attitude, it will be difficult to support the Mecahnics theories currently accepted by the establishment!




3. I sought out this book immediately on reading the following abstract of a paper entitled The Principle of Physical Proportions
   
   ABSTRACT. We propose the principle of physical proportions, according
   to which all laws of physics can depend only on the ratio of
   known quantities of the same type. An alternative formulation is that
   no dimensional constants should appear in the laws of physics; or that
   all "constants" of physics (like the universal constant of gravitation,
   light velocity in vacuum, Planck's constant, Boltzmann's constant etc.)
   must depend on cosmological or microscopic properties of the universe.
   With this generalization of Mach's principle we advocate doing away
   with all absolute quantities in physics. We present examples of laws
   satisfying this principle and of others which do not. These last examples
   suggest that the connected theories leading to these laws must be
   incomplete. We present applications of this principle in some fundamental
   equations of physics.
   
   Goodness, he's seen it too I thought. No mealy mouthed beating about the bush. He takes no prisoners but declares royal abundance. Moreover, this is no crackpot or crank as you might imagine but someone who has a large corpus of perfectly conventional publications, as you will discover if, like me, you bother to do an elementary google search.
   
   Mind you - this is not a book for students - unless they are unafraid of losing their faith.
   
   But for anyone who appreciates only too well the cracks and fissures the have been steadily growing wider in the fabric of physics, for anyone who has done hands on research and had the ineffable experience of digging up jewels that the "dark unfathomed caves of ocean bear" [like the power laws for water vapour for example], for them, this book is a treasure beyond rubies.