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Reinventing Gravity : A Physicist Goes Beyond Einstein by John W. Moffat — book cover

Reinventing Gravity : A Physicist Goes Beyond Einstein

by John W. Moffat
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Overview

Einstein's gravity theory—his general theory of relativity—has served as the basis for a series of astonishing cosmological discoveries. But what if, nonetheless, Einstein got it wrong?

Since the 1930s, physicists have noticed an alarming discrepancy between the universe as we see it and the universe that Einstein's theory of relativity predicts. There just doesn't seem to be enough stuff out there for everything to hang together. Galaxies spin so fast that, based on the amount of visible matter in them, they ought to be flung to pieces, the same way a spinning yo-yo can break its string. Cosmologists tried to solve the problem by positing dark matter—a mysterious, invisible substance that surrounds galaxies, holding the visible matter in place—and particle physicists, attempting to identify the nature of the stuff, have undertaken a slew of experiments to detect it. So far, none have.

Now, John W. Moffat, a physicist at the Perimeter Institute for Theoretical Physics in Waterloo, Canada, offers a different solution to the problem. The cap­stone to a storybook career—one that began with a correspondence with Einstein and a conversation with Niels Bohr—Moffat's modified gravity theory, or MOG, can model the movements of the universe without recourse to dark matter, and his work chal­lenging the constancy of the speed of light raises a stark challenge to the usual models of the first half-million years of the universe's existence.

This bold new work, presenting the entirety of Moffat's hypothesis to a general readership for the first time, promises to overturn everything we thought we knew about the origins and evolution of the universe.

Synopsis

Einstein's gravity theory—his general theory of relativity—has served as the basis for a series of astonishing cosmological discoveries. But what if, nonetheless, Einstein got it wrong?

Since the 1930s, physicists have noticed an alarming discrepancy between the universe as we see it and the universe that Einstein's theory of relativity predicts. There just doesn't seem to be enough stuff out there for everything to hang together. Galaxies spin so fast that, based on the amount of visible matter in them, they ought to be flung to pieces, the same way a spinning yo-yo can break its string. Cosmologists tried to solve the problem by positing dark matter—a mysterious, invisible substance that surrounds galaxies, holding the visible matter in place—and particle physicists, attempting to identify the nature of the stuff, have undertaken a slew of experiments to detect it. So far, none have.

Now, John W. Moffat, a physicist at the Perimeter Institute for Theoretical Physics in Waterloo, Canada, offers a different solution to the problem. The cap­stone to a storybook career—one that began with a correspondence with Einstein and a conversation with Niels Bohr—Moffat's modified gravity theory, or MOG, can model the movements of the universe without recourse to dark matter, and his work chal­lenging the constancy of the speed of light raises a stark challenge to the usual models of the first half-million years of the universe's existence.

This bold new work, presenting the entirety of Moffat's hypothesis to a general readership for the first time, promises to overturn everything we thought we knew about the origins and evolution of the universe.

Publishers Weekly

Gravity has long been the problem child of physics, creating difficulties in finding a Theory of Everything. To complicate matters, most scientists believe that there is a mysterious, unidentified "dark matter" that makes up most of the universe, and that an equally baffling "dark energy" is pushing the universe apart. Moffat, an affiliate member of the cutting-edge Perimeter Institute for Theoretical Physics in Canada, has developed a new theory that he calls Modified Gravity (MOG). Moffat says that both Newton and Einstein were wrong, and that Newton's gravitational constant is not constant across distances as large as galaxies and galaxy clusters. Scientists haven't been able to find dark matter because it doesn't exist: MOG values help account for rates of galaxy rotation. Perhaps more revolutionary is Moffat's claim that black holes don't exist either. His theory predicts a "grey star," a massive object with many but not all of the properties of a black hole. Moffat's theory thus far has withstood many objections. If MOG stands the test of time, Moffat will have created a paradigm shift not seen since Newton. Illus. (Oct.)

Copyright © Reed Business Information, a division of Reed Elsevier Inc. All rights reserved.

About the Author, John W. Moffat

John W. Moffat is professor emeritus of physics at the University of Toronto and an adjunct professor of physics at the University of Waterloo, as well as a resident affiliate member of the Perimeter Institute for Theoretical Physics in Ontario, Canada. He earned a doctorate in physics at Trinity College at the University of Cambridge.

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Editorials

Publishers Weekly

Gravity has long been the problem child of physics, creating difficulties in finding a Theory of Everything. To complicate matters, most scientists believe that there is a mysterious, unidentified "dark matter" that makes up most of the universe, and that an equally baffling "dark energy" is pushing the universe apart. Moffat, an affiliate member of the cutting-edge Perimeter Institute for Theoretical Physics in Canada, has developed a new theory that he calls Modified Gravity (MOG). Moffat says that both Newton and Einstein were wrong, and that Newton's gravitational constant is not constant across distances as large as galaxies and galaxy clusters. Scientists haven't been able to find dark matter because it doesn't exist: MOG values help account for rates of galaxy rotation. Perhaps more revolutionary is Moffat's claim that black holes don't exist either. His theory predicts a "grey star," a massive object with many but not all of the properties of a black hole. Moffat's theory thus far has withstood many objections. If MOG stands the test of time, Moffat will have created a paradigm shift not seen since Newton. Illus. (Oct.)

Copyright © Reed Business Information, a division of Reed Elsevier Inc. All rights reserved.

Kirkus Reviews

Canadian theoretical physicist Moffat describes efforts to explain several distressing new cosmological phenomena that don't fit comfortably into the theory of relativity. Readers will easily follow the first-time author's lucid prose as he lays out the story of gravitation research from the time of Aristotle (who taught that objects fell to earth because they belonged there) through Newton to Einstein, whose theory of relativity explains a great deal but not everything. For 50 years astronomers have known that gravitational attraction from visible matter can't explain the movements of stars and galaxies. For Einstein's theory to work, 90 percent of matter in the universe must be invisible. (Gas and dust don't qualify because astronomers can detect them.) This "dark matter" must consist of strange subatomic particles that no particle accelerator has yet produced. In 1998 more flies entered the ointment with the discovery that the expansion of the universe is accelerating, requiring an immense, hypothetical "dark energy." Explaining these has led to Rube Goldberg-like theories featuring many so-far undetected particles (supersymmetry) or complex mathematical systems impossible to verify (string theory). Twenty years ago, Moffat and others began suggesting that gravity can vary. This violates relativity but eliminates the need for dark matter and perhaps even dark energy. After initially turning up its nose, the establishment softened, and now a respectable minority of physicists is working to modify the theory of gravity. Following in the nuts-and-bolts footsteps of Brian Greene (The Elegant Universe, 1999) and Dan Hooper (Nature's Blueprint, 2008), Moffat does a fine job recounting hisfield's history until well into the 20th century, but readers who have forgotten their first-year college physics may struggle to understand the controversies that disturb today's theoretical physicists. Solid, mainstream popular science.

Book Details

Published
September 1, 2008
Publisher
HarperCollins Publishers
Pages
288
Format
Hardcover
ISBN
9780061170881

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