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Chargement... A Brief History of Black Holes: And why nearly everything you know about them is wrongpar Dr. Becky Smethurst
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Inscrivez-vous à LibraryThing pour découvrir si vous aimerez ce livre Actuellement, il n'y a pas de discussions au sujet de ce livre. Nice book. A bit light, which was nice, but also interesting overview of the astronomy and astrophysics which has led us to our current understanding about black holes. I hadn't previously encountered the physics of accretion discs and how the radiation pressure limits the rate of growth, nor the intensity of the very energetic radiation that can result from accretion. Written in a nice jaunty style. ( ) Becky Smethurst is an astrophysicist with a great love of black holes, and a desire to share her enthusiasm for them with the rest of us. She tries to cover, concisely but with absorbing detail, everything important about them, starting with the important facts that they're not black, and they're not holes. They're not black because an active black hole has an accretion disk which generates a great deal of light and other radiation. They're not holes, because that absolute darkness inside the accretion disk isn't a void. It's an immensely dense accumulation of matter, usually many, many times the mass of a star--certainly our star. Smethurst compares black holes to mountains, which I find not personally satisfying, but entirely reasonable. More unexpected is her comparison of black holes to sofas; things get swallowed up and lost in them, never to be recovered. But this isn't just a book of what we should compare black holes to (she says she prefers "dark stars," but admits that's a lost chance), but their history, formation, development, and possible end. The formation of stellar mass black holes is, apparently, pretty well understood. If a collapsing star at the end of its life is massive enough, when it collapses, it will collapse not into a neutron star, but a black hole. The problem is supermassive spring holes. There simply doesn't appear to have been enough time since the birth of the universe for supermassive black holes to form. And yet, we're now reasonably certain that every galaxy has a supermassive black hole at its center. Where do they come from? Perhaps from the collision of smaller black holes? It's one of the things Smethurst looks at. She also discusses the first detection of gravity waves, the first picture of a black hole, and the fact that black holes will, eventually, evaporate. They'll evaporate very slowly, though, and only after they've stopped growing, and it's not at all clear that the largest black holes will have time to evaporate before the end of the universe, depending on what sort of end the universe is going to have. However, we do still have a shot at finding a primordial black hole, very small in size, which might have had time to evaporate. If we detect that, we may be able to detect Hawking radiation, which we're unlikely to be around to detect from any supermassive black hole. There's lots of fascinating information in this book, and Smethurst has both an engaging enthusiasm, and a lively sense of humor. She also has a good reading voice, which overall makes this a wonderful book to listen to. Recommended. I bought this audiobook. aucune critique | ajouter une critique
"The Moon goes around the Earth, the Earth goes around the Sun, the Sun goes around the centre of the Milky Way: a supermassive black hole. As you read this you are currently orbiting a black hole. Money might make the world go round, but black holes make the universe go round. Black holes are not just a curiosity; they are some of the most important objects for understanding how our universe works and how it came to be. And yet they are incredibly misunderstood; take everything you think you know about black holes and get rid of it. This book will be a book about black holes like no other; it will journey beyond the event horizon and consider what the 'inside' of a black hole is truly like, and flip it on its head. It will take black holes and turn them from something beyond comprehension for the average person on the street to a level of understanding you never thought possible, through unique analogies and ideas the human brain has a hope of actually picturing"--Publisher's description. Aucune description trouvée dans une bibliothèque |
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Google Books — Chargement... GenresClassification décimale de Melvil (CDD)523.8875Natural sciences and mathematics Astronomy Astronomical objects and astrophysics Stars Stellar evolution Terminal stages Black holesClassification de la Bibliothèque du CongrèsÉvaluationMoyenne:
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