Customer Reviews

Ripples on a Cosmic Sea: The Search for Gravitational Waves

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

 

 

This book would have greatly benifited from the inclusion of a glossary. Any work covering a subject this complex needs definitions set out and collected together. The publisher's given web site was unavailable.

I too would have appreciated a glossary. Also illustrations would have been very helpful along with the explainations and descriptions of the various instruments used to attempt to detect gravity.

Overall this is an excellent treatment of a little considered but intriguing problem of physical theory, the direct observation of gravitational waves. Such waves seem to be demanded by Einstein's gravitational theory, general relativity, but, as gravity is by far the weakest of the fundamental forces, it is a phenomenon that presents great difficulty in terms of direct detection. In trying a little too hard to build interest in their thesis, the authors conjure a small blunder early on, but once they 'get down to business' the book unfolds as an exceptionally well-told story. The first chapter blunder is not particularly important to the thesis and many readers won't even notice it, so I'll return to it only as a closing thought, and only in the interest of defending science from misleading oversimplifications.

Paul Davies' foreword and the authors' prologue should not be missed, and when Blair and McNammara hit their stride, discussing the gravitational curiosities that are quite commonplace in our universe -- supernovae, black holes, white dwarfs, and neutron stars, especially pulsars which lend themselves so well to close mathematical examination -- the text is outstanding. The discussion of the processes that produce these objects is a real page-turner as is the examination of the objects themselves: A densely massive binary pulsar traveling at one-sixth the speed of light! Emitting the gravitational wave 'luminosity' of a hundred thousand galaxies! Talk about energy! If we could examine the gravitational wave spectrum, what kind of information might we glean? No one knows, but Blair and others want to. The text does become less interesting in protracted discussions of the mechanics and sensitivities of instruments employed in the search for gravitational waves and the myriad technical difficulties and challenges involved.

Okay, about that blunder: In a first chapter derision of "lies" taught "at school," the authors lament that students are taught "lies" about the correct nature of space-time, as opposed to other areas of scientific interest in which schools are said to teach "the truth." With uncharacteristic carelessness it is said that we are taught "the truth" about "the solar system," about "atoms," and about the biological "evolution of species." As a matter of sober epistemological integrity, such cavalier statements create an unwarranted mess. How can we teach "the truth" about the solar system if we are teaching "lies" about space-time?! Is "the truth" about atoms the so-called objective particles of the standard model or, are "particles" really field oscillations, the vibration patterns of string/M theory? Are "atoms" classical physical objects or pragmatic mathematical abstractions of 'something' rather 'immaterial'? Is "the truth" about biological evolution "the truth" of C. Darwin, "the truth" of L. Margulis, or "the truth" of S. Kaufmann? Is "the truth" of the evolution of species what R. Dawkins believes it to be, or is it what S.J. Gould argues, or is it what S.C. Morris thinks? Although each is held to be an 'authority', they do disagree. Strongly disagree. What a mess the authors create with just a couple of reckless sentences! If we must claim that we teach scientific "truths" we should do so cautiously, even tentatively (see R. Feynman). If we must call some things 'scientific truths' we should at the least restrict ourselves to what R. Penrose has wisely called our 'Superb' theories, as opposed to those that are merely 'Useful' or 'Tentative.' Superb theories are mathematically fertile, general relativity being an excellent example. There are only a handful of 'Superb' scientific theories and all fall strictly within the categories of mathematical physics. "The truth" of biological theories, such as the evolution of species for example, is unclear, and is at best an inductive or pragmatic version of "truth" and not a rigorous, mathematical "truth." (If biology has any theory that might advance beyond being 'Useful,' it is mathematical genetics.)

Anyway, once they've escaped the temptation toward bellicose grandiosities, the authors proceed to do a pretty good job. For those who might read and enjoy this book, I recommend a somewhat similar but even better book by cosmologist George Smoot, 'Wrinkles in Time.'

Please don't be discouraged from reading this book by some of the criticisms found here. This book is actually amazing in it's ability to describe general relativity and curved space-time in terms that a layperson can understand.

The subject of the book is Gravitational Waves, but before it gets to that, it spends some time describing, with crystal-clear writing, Newton's vs. Einstein's gravity theories, presenting numerous analogies so that readers with no math background can get an inkling of what curved space-time really is. Couple this with the infectious enthusiasm with which the authors write, and you get a book that is (at least for me) un-put-down-able.

Finishing this book you will almost certainly have a deeper understanding of gravity. I even recommend this book for people who have some knowledge of the mathematics of general relativity because there just might just be a new way of conceptualizing things that they might find here.

allowing for others comments, which i endorse; i was puzzled why there was no explanation or discussion of just why Einstein and the authors surmise there are, thoeretically speaking, gravitational waves.

Other than that , its a nice little read.

A well-written, easy to understand book, which introduces the lay person to the theories of gravity and gravitational waves.

For thirty years now, a new kind of astronomy called "state of gravitational wave" has been taking place as we get ready to "listen" to what is out there. Gravitational waves are "ripples in space time." These infinte waves when they do happen will not disturb the placement of objects in four-dimensional space time (what we live in), but they may change the distance between them by stretching space time itself in one direction while compressing it in the other. Einstein predicted this in 1916 in his general theory of relativity.

Now, in LSU Physics Department, the mathematicians and physists (college instructors, not astronomers) have built LIGO (Laser Interferometer Gravitational-wave Observatory. First, they used ALLEGRO to listen since 1991 but as yet no sound has come forth, to show us that there is indeed some intelligent species besides our own. In ALLEGRO, they used liquid nitrogen (77 degrees K) which can burn out pre-cancers but leave behind masses of scar tissue on a human's face. The second chamber used liquid helium (4.2 degrees K, the lowest temperature possible in nature).

The two LIGO detectors sensitive to different frequencies are waiting to hear the sound like a big, low-pitched bird. The Laser Interferometer Space Antenna (LIGO) is the latest in technology which will track three spacecraft orbiting the sun in formation. The gravitational wave detector outside Baton Rouge, Louisiana, will fliter out noise as it waits for the subtle shiver of a gravitational wave passing by.

These waves carry information about extreme astronomical processes now unknowable any other way. NASA and the European Space Agency are working together for an experiment with LISA in 2014. Astronomers have observed indirect evidence of this phenonenom with two white dwarf stars circling each other. As they spiral inward they will fuse into a single mass. We are eagerly awaiting ET as the changes in gravitational fields send shudders across the universe.

Thirty years of research and expensive equipment worldwide, but no evidence of what we are waiting or looking for. Maybe soon, if ET decides to come back to Earth. In the meantime, we wait and wonder.

To the publisher I would appreciate it if the publisher could produce an audio adaptation of this book. I would love to listen to this while I drive to work and to let my 16 month old son listen to it as a bedtime story. Arnold D Veness