Review by Choice Review
Black holes are incredibly fascinating objects, and many books have been written about their exotic nature. In Gravity's Engines, Scharf (director, Columbia Astrobiology Center) does not focus exclusively on the nature of black holes themselves; instead he tells the story of how black holes affect the environment around them, including Earth's home galaxy, the Milky Way. After reviewing the history of theoretical predictions and observational discoveries of black holes, Scharf details his personal observations of the X-ray light emitted from a particular supermassive black hole found in a distant galaxy. He shares with readers the questions he pondered about these supermassive black holes, and explains clearly the laws of physics that illustrate that these relatively tiny objects have an outsized effect on the structures, like galaxies and galaxy clusters, that they inhabit. He ends this story by showing how the cumulative effects black holes have had on the universe, like their influence on star formation, may have been crucial for life to begin. Scharf also provides detailed notes for interested audiences who want to delve deeper than he was able to in the book. Summing Up: Recommended. All levels/libraries. C. Palma Pennsylvania State University
Copyright American Library Association, used with permission.
Review by Booklist Review
From descriptions in speculative fiction and science best-sellers by Stephen Hawking, most people harbor an image of black holes as star-swallowing, astronomical monsters that future space explorers would do best to avoid. According to astrophysicist Scharf, this bad reputation is long overdue for a makeover, given recent evidence suggesting that the massive, lightless objects may be vital to the proliferation of star systems like our own. As Scharf points out in this superbly accessible layman's guide to select exotic astronomical phenomena, black holes actually spew out large clouds of matter as much as they gobble it up. In nine captivating chapters with fanciful titles like The Feeding Habits of Nonillion Pound Gorillas, Scharf convincingly demonstrates that black holes are far more critical to stellar evolution than was previously believed and that life on Earth may have been impossible without them. Although astronomy buffs are the likely audience here, Scharf's breathtaking cosmic vision will appeal to anyone whose curiosity is aroused by gazing at a star-filled sky.--Hays, Carl Copyright 2010 Booklist
From Booklist, Copyright (c) American Library Association. Used with permission.
Review by Publisher's Weekly Review
"Weird, destructive, time-warping, overwhelming, alien... fearsomely noisy and rambunctious," black holes are the bad boys of the universe. And according to Scharf, director of Columbia University's Astrobiology Center, black holes also play a critical role in shaping the universe. With gravity so great that not even light can escape, massive black holes are invisible. The only way to detect these "lords of gravity" is by looking for the energy from the shock waves created as they gulp down matter. Thanks to X-ray telescopes like the Chandra Space Telescope, astronomers have found energy coming from the hearts of galaxies, including our own Milky Way. After a quick, nontechnical overview of how black holes are created, Scharf discusses how they power galactic dynamics. The most massive grow dim relatively quickly, exhausting their food supply, while a smaller black hole can burn for billions of years, varying from "simmering" beast to "blazing pyre" and back. They cast off ripples of energy, pushing galactic dust and gases outward and slowing stellar formation. Scharf's explanations are vivid and accessible, evoking the awe of cosmic grandeur in a way that's as humbling as it is fascinating. Agent: Deirdre Mullane, Mullane Literary Associates. (Aug.) (c) Copyright PWxyz, LLC. All rights reserved.
(c) Copyright PWxyz, LLC. All rights reserved
Review by Library Journal Review
The subtitle of this most readable book about supermassive black holes exemplifies Scharf's (director, Columbia Astrobiology Ctr.; Extrasolar Planets and Astrobiology) playful tone, similar to that in his "Life, Unbounded" blog for Scientific American. Several of the chapter titles also illustrate his light, accessible approach to astrophysics (e.g., "The Feeding Habits of Nonillion-Pound Gorillas," as do his hand-drawn figures (e.g., "The Whale's Dilemma"). In the first three chapters, Scharf offers an excellent brief history of discoveries foundational to contemporary knowledge of black holes and includes interesting biographical sketches of scientists from John Michell to Albert Einstein to Edwin Salpeter, with many in between. Explanations are clear, e.g., his discussion of the components of Einstein's field equations. He makes apt use of metaphors and personification to describe "hungry" black holes of all sizes at the core of galaxies (including the rather small one at the center of the Milky Way), which devour matter and expel energy. VERDICT Highly recommended. Teen and adult fans of astronomy, as well as scientists looking for ways to explain black holes to nonscientists, will all enjoy this text.-Sara R. Tompson, Univ. of Southern California, Los Angeles (c) Copyright 2012. Library Journals LLC, a wholly owned subsidiary of Media Source, Inc. No redistribution permitted.
(c) Copyright Library Journals LLC, a wholly owned subsidiary of Media Source, Inc. No redistribution permitted.
Review by Kirkus Book Review
An intelligent explanation of a weird but essential feature of the universe. Black holes are bodies so massive that they are invisible because their light cannot escape. Although permitted by relativity, nobody, Einstein included, believed they existed. It turns out they are everywhere, writes Scharf (Extrasolar Planets and Astrobiology, 2008), director of Columbia University's Astrobiology Center. As stars age, cool and shrink, most, like our sun, will become white dwarves: tiny and immensely dense but still shining. As larger stars shrink, their greater gravity squeezes them into even smaller, denser neutron stars. In stars more than three times our sun's mass, gravitational collapse continues, distorting space-time so much that the star's light curls back on itself, producing a "singularity," an infinitely small point containing the entire mass. Physicists dislike infinities, so there may be a better explanation, but there's no denying that black holes happen. Their gravity attracts material, including stars, which disappear inside. Other material orbits in a huge "accretion disk" whose high-speed interactions generate torrents of radiation. Supermassive black holes at the center of every galaxy may pour out more energy than a billion stars. This energy plays a vital role in controlling the size of galaxies and the formation of stars, which means, ultimately, the formation of planets and life. Written for educated laymen, this should not be treated as an introduction to cosmology (for that try Brian Clegg's Gravity or Chris Impey's The Living Cosmos), but Scharf provides a rich, satisfying and usually comprehensible account of an extraordinary phenomenon.]] Copyright Kirkus Reviews, used with permission.
Copyright (c) Kirkus Reviews, used with permission.
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