2 comments about The Cartoon History of Time.

1. Sometimes the cartoons get in the way of the subject. There were some pages I had to read several times to figure out where the thread of the text was. Once you follow it, however, the book does cover many of the basics in an entertaining way. And it is shorter than the Hawking work.



2. This is perhaps my favorite book I've read it around 20 times (the start more than the end) and I don't understand it but its been fun every time and every time I get a bit more, I'm only 17 and don't know half of the stuff you need to know to understand it properly but this is a VERY good read. UP THE CHICKEN!

1 comments about Prophet's Manual.

1. Prophet's Manual : (Fractal Supersymmetry of Double Helix) is over 450 pages of fairly small print. The cover claims that the book connects the Egyptian concept of Zep Tepi (the First Time of Osiris) with apocalyptic texts from ancient civilisations, and the end of the 13-baktun cycle of the Maya, explaining the physics behind the forthcoming quantum leap. The result of its publication is predicted to be a recognition that it is the "...long awaited revelation of Holy Grail of knowledge with unprecedented consequences that are bound to shake the world from its foundations." Daniel Srsa is from Croatia, so this explains why the explanations on his website, and in posts he has made to discussion groups are in a rather awkward kind of English. However, I expected the book to be a different matter. In fact, it reads like the scribbled notes of someone writing a shorthand account of a conversation between Albert Einstein and John Nash. Here is an example - the first half of the first paragraph in Chapter One
   
   "In a 3D context, a constant is a derivative of two equal and opposite variables . Constancy is a changeless pattern between two interfering variables (C=d/t=const). Constancy is singular, while variability is its equal and opposite infinity. The Difference between a constant and its equal and opposite variability is infinite, because the difference is exponential. An Exponential difference is a fractal dimensional difference. One constant is an infinity of fractal variables, just as a 3D cube is an infinity of 2D surfaces. 3D is always double the fractal difference - it is two equal and opposite infinities (variabilities) of a singularity (constant)."
   
   I am told by a language-teacher friend of mine, that the Croatian language is structured like this, but this text should really have been checked by someone who speaks fluent English. However, even when the missing words are inserted, this excerpt is still hard to understand for non-physicists. There is a glossary that includes explanations of the terms constant, fractality, variable, infinity and singularity, but these definitions tend to use other terms that have to be looked up in the glossary, and so do they, and so on. Since this is from the start of chapter one, the above excerpt is actually easier to understand than most of the text.
   
   I have read A Brief History of Time by Professor Stephen Hawking, who is generally recognised as "the Greatest mind in physics since Albert Einstein" and it was an absolute doddle compared to this. If Professor Hawking can make his ideas understandable to the non-specialist, then surely it is possible that the concepts being explained by Daniel Srsa (an engineer) could be phrased in a way that could be understood by people who are not Croatian scientists. I sadly don't have time to get my head round this book, so if anyone out there has read and understood it, and speaks and writes fluent English, then how about writing a synopsis for the diagnosis2012 website?

1 comments about Physics for Scientists and Engineers: Vol. 3 Modern Physics, Quantum Mechanics, Relativity, & the Structure of Matter (Physics for Scientists & Engineers, Chapters 36-41).

1. Good book for people taking a class requiring it the book. It is a little hard to understand in certain chapters. Overall a good book.

1 comments about Relativity.

1. If you are a ambitious highshool student or a physics freshman this is the best place to get started on special realtivity.
   It is far less mathematically demanding then many books out there and clear on physical concepts.
   (ch.1) Good review of classical ideas.
   (ch.2) Need for special relativity, good explanations of
   galaian and lorentz transformation, and uses of the latter.
   (ch.3) Good introductions to spacetime geometry (the invariant
   interval) and relativistic mechanics.
   
   (ch.4) Good introduction to basis of general relativity and cosmmology.
   
   One of the great things about the book is that it takes the common 'popular' accounts one step further by intoducing physics in precise languge and formulas. So that you can apply your knowldege to actully solve some problems and gain further understanding. There are problems at end of each chapter and they are (mostly) supplemented by answers in an appendix.
   
   One thing that is left out completely is relativistic electrodynamics, of course that's only sutibale for a more advanced book. I would've liked to see the power of four vectors utilized more and see the role of tensors.

1 comments about State of the Universe 2008: New Images, Discoveries, and Events (Springer Praxis Books / Popular Astronomy).

1. This book should be in the reading list of every educator who is involved in teaching Astronomy. Martin Ratcliff has collected in one publication information that would require many hours of research from the worlds leading authorities in each subject. I particularly liked the references given to each entry and have been able to contact via e-mail a number of the contributors to raise questions and gain further information.
   
   A must in any library.
   
   Frank Gear F.R.A.S.
   Director/Presenter
   NIAS Planetarium

3 comments about Secrets of the Old One: Einstein, 1905.

1. I just read this book and very much enjoyed it. I am a theoretical physicist and last year gave several public lectures on Einstein's work of 1905. I wish I had had this book at hand then. It "suffers" the "Adam and Eve problem", as my sister and I used to denote my father's approach to answering our questions: Bernstein starts way at the beginning and gives a lot of physics background to the questions Einstein tackled. I believe this gives a much deeper and enjoyable understanding. I even learned some new things about Copernicus. The treatment of relativity is very lucid and I think at an excellent level for the general public. Bernstein uses some high-school math but nothing beyond using the Pythagorean theorem for the distance between two points. This enables him to capture the essence and also the profundity of Einstein's arguments. It is fair to say that without math one will always only scratch the surface. I was surprised to see how well Bernstein could explain the content of the relativity with so little math.
   
   The only down side of the book is that there is a fair number of typos in the second half, which will hopefully be corrected in the second edition.



2. The arguements are not as simple to follow as claimed.



3. The author of this book is a gifted writer. His clarity of expression is significantly above average. In this book, he discusses both historical issues as well as very technical ones, all pertaining to Einstein's 1905 papers. The historical snippets, which include several mini-biographies of various scientists, make for extremely pleasant reading. On the other hand, regarding the technical discussions, we have what I perceive as a mixed bag: some of them are quite clear from beginning to end, while others, although they start off very clear, seem to be missing a few important details before their conclusions are suddenly presented. Consequently, readers who want to learn some of the technical details on special relativity, etc., while minimizing their likelihood of becoming confused, should look elsewhere; there are many excellent books at all levels on these topics. On the positive side, this book does have a lot of information that would not likely be included in, say, a textbook; thus, it would likely complement a more technical source very nicely. Unfortunately, the book contains many typographical errors that, in the long run, can become quite annoying. But overall, this is a pleasant read, although it can be heavy going at times. This book would likely appeal to science buffs who are more interested in science history than in complete, although popularized, scientific expositions of Einstein's 1905 papers.

No comments about From Being to Becoming: Time and Complexity in the Physical Sciences.

No comments about Special Relativity.

No comments about Relativity, Astrophysics and Cosmology.

1 comments about Lorentzian Wormholes: From Einstein to Hawking (AIP Series in Computational and Applied Mathematical Physics).

1. Some of the words in this book have appeared in movies and science fiction stories, but in this book they take on a mathematical/scientific meaning, thanks to the efforts of the author. Although the concepts in the book are still far-removed from experimental verification, one must credit the author with writing of a book that may be standard reading in centuries to come. When reading the book, one can only hope that its ideas, or some similar to them, will eventually allow humans to traverse time and space routinely. The reader will need a strong background in general relativity and quantum field theory to really appreciate the book, but after reading it will obtain a solid understanding of what might be calle, in the words of the author, "non-boring" physics.

   After a brief overview of general relativity and quantum field theory, the author devotes the first part of the book to the history of wormhole physics. I was surprised to learn that the study of wormholes goes as far back as 1916 in paper by the physicist L.Flamm. But it was the desire of A. Einstein and N. Rosen to build a geometrical model of an elementary particle that is finite and singularity-free that set the tone for the research that continues to this day. Their ideas are reviewed in detail, and the author shows that viewing elementary particles as they did predicts they have internal structure, contrary to experiment. The contributions of J.A. Wheeler, namely his interest in topological issues in general relativity, and his geon/spacetime foam ideas are discussed also. The role of wormhole physics in developing a quantum theory of gravity, via the quantization of weak field gravity and the subsequent appearance of gravitons is treated also. The author lists the things that be done with quantized linearized gravity and gives references for research that counters the idea of spacetime foam. "Back-of-the-envelope" calculations are given for the importance of quantum fluctuations in the gravitational field at Planckian scales. A very interesting, and critical discussion is given of topology changes of spacetime via quantum fluctuations. The author states (but does not prove) various theorems regarding the topology of spacetime if a Lorentz metric is put on it. These results are pretty restrictive in limiting the existence of certain topology changes, but as the author remarks, one can abandon the idea of spacetime being everywhere-Lorentzian if one gives up the strong equivalence principle, an idea he clearly is not comfortable with. Given his remarks, it is interesting to ask whether quantum fluctuations could force a violation of the strong equivalence principle. The author does consider the role of quantum tunneling in changing spacetime topology, but concludes that it is not a meaningful question. However, he does devote a brief paragraph to the consideration of an energy-dependent effective topology which is the one of relevance to physics. Based on the "quantum claustrophobia" effect arising from the tendency of a particle to avoid small regions (i.e Heisenberg uncertainty), some regions of spacetime may thus not be visible from a quantum point of view. The author gives one example of this, but this idea has far-reaching consequences: not just for physics but for mathematics. If viewed from a quantum perspective, many of the usual mathematical structures in topology and other areas of mathematics are changed considerably. One can then perform a kind of interpolation between "quantum" and "classical" mathematical constructions.

   The author switches to more modern developments in part 3, with the idea of a traversable wormhole due to M. S. Morris and K.S. Thorne leading off the discussion. These wormholes are shown to violate the weak, strong, and dominant energy conditions, implying the existence of negative energy density near the throat of the wormhole. The existence of this energy will remind the reader of the Casimir effect, and the author does discuss this effect in detail. In addition, the thin shell formalism is discussed as a tool to analyze traversable wormholes without spherical geometry. Global techniques and the topological censorship are used to give a mathematically precise definition of a traversable wormhole, although the censorship theorem is not proven.

   Part 4 attempts to remove the idea of time travel from pure fantasy science fiction and give it more of a scientific foundation. The author is convincing in his efforts, via his thorough analysis of causality conditions in spacetime, and the explicit constructions of simple time machines, which in the author's words are a consequence of general relativity being "infested" with geometries that produce them. The van Stockum, Godel, Kerr, and Gott tiem machines are discussed in detail, and the author shows explicitly how to construct time machines via wormholes. He also addresses the problems that arise in the actual construction of these time machines, such as the possibility of a non-Hausdorff topology, the problem of unique histories (Novikov conjecture), the breakdown of unitarity in the quantum realm, and the Hawking chronology protection conjecture.

   Section 5 is an overview of the quantum field theory needed for a study of wormhole physics. The author shows that time- and space-orientable spacetimes are incompatible with the Standard model. He discusses in detail the result that the ANEC condition can be violated by scale anomalies. Readers will have to have a very detailed knowledge of quantum field theory in curved spacetime to follow the discussion. The calculation of van Vleck determinants, familiar as Green function techniques, are done also. The stress-energy tensor is calculated explictly for traversable wormhole spacetimes. The Wheeler-DeWitt minisuperspace formalism is used to shed light on the quantum aspects of Lorentzian wormholes, and the Wheeler-DeWitt equation for Einstein gravity on minisuperspace is solved exactly.

   The last part of the book is more of a send off to the reader and an encouragement for further reading on the issues in the book A list of research problems in given for the ambitious and curious reader.