Customer Reviews

Reinventing Gravity: A Physicist Goes Beyond Einstein

5 star:		(17)
4 star:		(4)
3 star:		(4)
2 star:		(1)
1 star:		(0)

 

 

This is a very well written book on some pressing issues in cosmology/astronomy
and gravity.

The author presents a complete historical view starting from Aristotle's physics
(including also the pioneering contributions of Aristarchos) and ending to his own contributions of asymmetric gravity theory. These are some major points:

(a) this book could easily be considered a layman's book on astronomy and cosmology,
since it has a nice introduction of structure formation, cosmic microwave background, as well quite lucid discussions of dark matter and energy

(b) the author is a down-to-earth scientist paying the due respect to data and
experience; his discussions on string theory and scientific method should be read by all young scientists, since they present the tradition that made science the central focus of our societies from the time of ancient greeks to present (as nicely depicted in the book)

(c) the various alternatives to general relativity are honestly presented with
nicely structured arguments and with a progressing degree of difficulty

(d) I did not like the complete absence of mathematics as well as the fact that
some of the discussions despite their honesty and insight did not treat some
important concepts with adequate detail and depth.

Overall, this is a book that everybody with interest in modern cosmology/gravity
could read with interest. I particularly recommend it for young people that
are thinking of following careers in science.

The kindle edition of this book, like all the other science books with math or other symbols offered in the kindle format, leaves much to be desired. There is no indication for superscripts, so that "ten to the power of forty" is presented as 1040, obscuring the context.
It is surprising to me that nobody checks this and the other science books when they are offered in kindle edition. No quality control whatsoever.
In terms of content, the book is wonderful (see other reviews). I also bought the paper version, because of the errors in the kindle version.

For amateurs interested in modern cosmology, this book is a fabulous treat. It poses all the problems and offers solutions that are empirically testable. No more dark matter. No more big bang. Wow!

Moffat's solutions derive from "MOG," or Modified Gravity theory. MOG, as Moffat explains, is similar to MOND, a modification of Newton's theory to accommodate observational data, such as the rapid rotation of galaxies. However, where as MOG has background independence as required by Einstein's theory of relativity, MOND does not. String theory does not have background independence either. So in this respect MOG is superior to both of these theories.

MOG eliminates the singularity at the centre of black holes. Hence, there is no event horizon surrounding the final state of a collapsed start, and no singularity at its centre. This nicely solves the black hole information-loss problem treated extensively in a recent book by Leonard Susskind.

MOG neatly handles the miracle of creation problem. No need to posit a big bang that defies the second law of thermodynamics. At the beginning of the MOG universe, both negative and positive time evolve with increasing entropy and cancel out.

MOG does not have dark matter, but instead posits a stronger gravity at the beginning of time than the standard model. The CMB does not need to arise from a big bang at all. In addition, the flatness and uniformity problem is solved by suggesting that the speed of light is not constant, but rather the ratio of G to c is. Hence, if G is stronger, c is faster, allowing all parts of the early universe to communicate.

I found that Moffat's book was best read in conjunction with Lee Smolin's recent book, "The Trouble with Physics." In his book, Smolin praises Moffat as a friend whom he respects for his boldness and originality. Perhaps they will write their next book together.

This is an excellent book written by a highly knowledgable physicist with 50 years of practice. It is equally accessible to both the interested amateur, such as myself, and to the serious student of physics who desires an overview to Moffat's theory of modified gravity.
I was already aware that Newton-Einstein theories of gravity fail to explain how galaxies hold together given the high velocities of their outer stars.
The mainstream explanation for the galaxy rotation question has been to postulate "dark matter" in enormous quantity - much larger than all visible matter. But the "dark matter" defies detection.
These theories also fail to explain the tiny deceleration anomalies of the planetary probes and the gravity waves of Einstein's theory have yet to be detected by the expensive LIGO instruments.
All this leads me to wonder if some paradigm shift in the theory of gravity is in the offing.
In essense that is what Moffat is introducing in this book, though serious students would need to read Moffat's papers in the refereed journals to gain a deep understanding of his model.
"Reinventing Gravity" has no math whatever - not one equation - which I consider a virtue. It is my view that the concepts of physics can always been described in words and diagrams, and I take for granted that the mathematical foundations of his theory have been proofed by peers in his published papers.
In the book's epilogue, the author states, "I hope that [you] have come away with a better understanding of how fundamental paradigms in physics are created, and the sociological and technical difficulties faced by those who attempt to shift established paradigms in science."
He succeeds very well in this regard, though as regards the "sociology" of physicists I was already aware of the dissing and clique behaviors that beset this elite group of highly erudite intellectuals.

I'm loving this book...in plain language, John Moffat writes about the discovery of gravity...the search for alternative gravity theories and for dark matter...he explains dark energy...and writes about the development of MOG (Modified Gravity Theory). The book is also subversive because by telling the story of gravity theory he demonstrates how close-minded the establishment of physics has been (and still is?), and how physicists come to believe ideas just because they are reiterated for decades rather than being proved. Very interesting.

The later sections of the book are somewhat more demanding technically than the early ones (but if you want more challenges Moffat offers footnotes at the back too...). But even if you miss some of the technical details, a sweep of the book allows a fascinating overview of the sociology of science, especially how difficult it is to shift established paradigms. No one yet wants to believe that Einsteins' theory of gravity could be wong! ...Well, this book is a perfect primer for what just might be the future of physics.

The book got me asking questions about some basic ideas that we all have absorbed regarding gravity and the universe. If Moffat's MOG theory continues to stand the test of time, it has a strong chance of replacing Einstein's theory of gravity, which is incredible. This is so exciting and a must read for anyone interested in science.

Reinventing Gravity by Moffat is a "must read" for anyone who is thinking about modern physics and the role of gravity in it. To put it simply, Moffat gives a very compelling alternative to dark matter. At the time of this review dark matter is said to compose at least 23% of the universe. However; this substance has yet to be directly detected in any lab and its existence is inferred by the application of General Relativity. In a nutshell; Moffat's book presents what could very well be an answer to the "galactic rotation problem" and a myriad of other conundrums in astrophysics. Further; his revolutionary theory is quite sound and takes a much needed step into a review of the overall correctness of Einstein's General Theory of Relativity.
Other physicists such Milgrom (MOND) and Bekenstein (TeVeS) have proposed changes in the theory of gravity. Moffat's addition of modified gravity (MOG) is another important concept that should not be over looked.
Too many physicists are wedded to the concept of dark matter and refuse to contemplate that just as Newton's theory had to be modified by Einstein that Einstein's theory cannot be the last word. MOG by Moffat is a carefully crafted theory that just might make dark matter obsolete. Dark matter is beginning to appear more ad hoc as time passes and clearly the standard theory of gravity may be at fault. I for one encourage both physicists and non-physicists alike to read this book. MOG, as Moffat presents it in Reinventing Gravity, can be understood by the layman as well as the specialist. It is a theory that makes testable predictions and presents a sound alternative to our present understanding of gravity. Moffat also emphasizes that we must buck the trend" in modern theoretical physics of "indulging in speculations that can never be proved or falsified by reality" by once again developing theories that can be tested.

First, science does not know what gravity is. Science knows what gravity does. Science also knows selected things that gravity is not. Now, at this point in astrophysics as phenomena is revealed within and among galaxies and galactic clusters, Einstein's general relativity is up for debate, as usual. There seems to be 2 basic schools and one place we just won't go.

General relativity is:
1. On the money, BUT because we observe strange gravitational phenomena, we are driven to try to explain it within our long studied paradigms originating with Newton & Einstein. The strange phenomena we observe cannot be dismissed. What is seen is impossible to explain within our accepted paradigm. We are required to revisit basic gravitational assumptions. Most seem to have settled on the notion that what is observed may be an illusion caused by demonstrated gravitational lensing. The mass required to create the correcting lens is huge. One approach is to `plug' mass far beyond what we can reconnoiter with our senses and instruments into the equation to produce the lensing. The mystery stuff is variously called dark matter & energy and it is a crazy huge volume on the order of ninety-some % of the total mass in the observable universe. The dark matter plug and assumption is adequate to hold the universe together. Acceptance of the plug is increasing among theorists and others ... and, you can tell that there may be overexposure on the science when the esoteric subject enters pop music lyrics and high school vocabulary. My neighbor's kids are even 'convinced' ... scary
2. Dynamically in error at the galactic and intergalactic level but correctable through several competing theoretical perturbations. Dr. Moffat inhabits this school of thought. Dr. Moffat posits in his MOG theory, a new fundamental weak force that dwells in intergalactic space. This new, weak force ... impossible to prove, is every bit as strange as the undetectable dark matter and energy that must otherwise surely be everywhere, but unseen.
3. Wrong ... and that's just too hard to accept from 100 years of evidence.

Reinventing Gravity is written against the backdrop of the herd instinct of theorists toward dark matter and energy to make sense of general relativity, gravitational operation and accelerating expansion in the universe. Dr. Moffat is and has been a dissenting opinion. His work is well published for those looking for the nuts & bolts of his scalar-tensor-vector gravitational theory.

Dr. Moffat has a long history of counter main stream thinking. He has posited variable light speed theory attracting adherents and a non-local quantum field theory (which might be testable with the LHC).

Reinventing Gravity takes the reader back to basics and builds forward from pre-Newtonian and Newtonian thought through general relativity to MOG theory in the trajectory that Einstein might have proceeded. This is a book based on Moffat's self-reflection as the roll up the sleeves experimental physicist archetype. The story is fascinating and reflects the body of work developed from an Einstein protégé. This is an important book. It must be considered.

The reader should understand that extrapolation beyond the bounds of the observable and comprehendible is always a problem. Although Moffat is optimistic regarding technological advancement to make his case, the fact remains that like all cosmological theory, we will be long gone from the planet before the truth is revealed. The experimental design to prove MOG is vastly difficult in its simplicity ... simulate intergalactic distances, inject a new force of nature and press "on".

Where I separate from the MOG theory is in the proposition of an eternal universe that never began. After traveling along Moffat's logic to MOG, one looks back on the path to discover that the theory is conveyed from an uncaused beginning. At the risk of stating the obvious, science is based on cause and effect. MOG is not of that nature. I believe that where there is no cause, there is no effect. Yet we exist and in MOG, we exist as the remarkable byproduct of non-causality. MOG requires a faith and imagination that is somewhere beyond science. If MOG is correct, physics must swallow some flavor of natural non-causality as the underpinning of the universe.

My position in no way detracts that Moffat might be right, but rather, is MOG's postulation comprehendible. The conceptual framework is rigorous as Moffat walks the reader to the precipice where a decision must be made regarding the nature of reality. I am simply too obtuse to comprehend a scientific theory of 'natural non-causality'. Perhaps the H.Sap. mind cannot grasp this inexpressible. What is a thing that did not "begin"? What is a thing without cause? Without a beginning, what is becoming? Is there another natural non-causality to compare in the universe?

Beyond Gravity is a thorougly readable book for the physicist and the interested. Moffat's style of writting is refreshingly fun. For reading pleasure, this is 5 star work. For content believability, I give it a 2 star deduction. 3 stars ... but read it. The dark matter and energy argument demands a plausable rebuttal and Mofatt delivers an alternative to consider.

For the layperson, Reinventing Gravity may not be an easy read. However, the flow of the narrative reveals interesting facts about our universe, i.e., "the matter of life" as we have come to know it.

In a systematic approach, the author challenges the status quo by offering a new theory of gravity that is solidly backed by current data without resorting to any unexplained "dark or black matter".

This fascinating book takes the reader on a historic journey - i.e., from the discovery of gravity, to the on-going research of its many associated elements - and helps to unlock the mystery of the universe!!

John Moffat's new gravity theory is exciting and important to understand, let us not be bound by limited thought and imagination. Reinventing Gravity is on my Christmas gift list - I highly recommend it for your list too!

Where to begin?

I've been reading a lot of these sorts of books lately. Moffat is very good at presenting the way things are, and the way he wishes they could be. It is a bit of a stretch, though, to propose a fifth force, variable speed of light, and variable gravity all in one go. Not to mention an as yet undiscovered repulsive force that would prevent the formation of gravitational singularities. Oh, and he proposes a sort of steady state universe - no big bang. Just a universe that winds down to thermal equilibrium, then, through quantum perturbations and his fifth force, builds back up into an ordered cosmos with understandable and consistent physical characteristics. Maybe I missed the part about accounting for the CMB, but I'm sure it's in there somewhere.

The whole point of the book is to account for everything as it has been observed without the need for dark matter or dark energy. It's a very inventive look at the universe, explained very well. It will make you think. I found myself, in spite of myself, saying to myself "That would explain a lot if it were true" many times while reading. Moffat is nothing, if not an original thinker. MOG is very worrying in some circles, and not explained away entirely by the currently accepted lambda cold dark matter model.

Read it, if not for any other reason, just to use it as a comparison for more "acceptable" ideas. Lately, while reading Einstein's Telescope, I found I was thinking "You know, MOG has a more elegant way of accounting for this" several times. If you get nothing else out of this book than the idea that our current understanding of the universe may not be entirely correct, then it is probably worth the read.

I gave it five stars for originality and the clarity of the explanation. I like a guy who is willing to make the effort to swim against the tide to make others view their own work more critically.

Einsteins's General Theory of Relativity is one of the crown jewels of human thought. Created in 1915 it quickly became the standard model for understanding gravity. Within the last few years, however, data has begun to accumulate that the theory cannot account for. As an example the speed of the rotation of galaxies is much greater than the theory predicts. To try and fit these latest findings into the present theory scientists have postulated the existence of such things as dark matter. The hunt for dark matter has become the cause celeb of physics and yet to date no one has been able to find it. Within the pages of this book Dr. Moffat argues that the reason that dark matter hasn't been found is that it doesn't exist and that instead it is the theory that is wrong.

This book is Dr. Moffat's way of presenting his ideas to the general public. If he is right in his modified gravity ideas then many things we now take for granted just aren't so, i.e. the speed of light can vary under certain circumstances, there are no black holes, and dark matter and dark energy do not exist. He did his best to keep it simple but remember that this is a physicist's idea of simple. Still all in all he did a pretty creditable job. For science history buffs his recap of the history of gravitation theory is worth a look all by itself. In defending his theory he takes you through all the latest findings, experiments, and theories. If you are interested in physics but know little about it this book is a nice place to start. Weather his modified gravity theory has any merit I am not qualified to say. But in raising the question he reminds us that nothing in science is sacrosanct and that the quest for knowledge never ends.