Gravity's Engines: How Bubble-Blowing Black Holes Rule Galaxies, Stars, and Life in the Cosmos (Anglais) Relié – 1 septembre 2012
|Neuf à partir de||Occasion à partir de|
Descriptions du produit
Aucun appareil Kindle n'est requis. Téléchargez l'une des applis Kindle gratuites et commencez à lire les livres Kindle sur votre smartphone, tablette ou ordinateur.
Pour obtenir l'appli gratuite, saisissez votre adresse e-mail ou numéro de téléphone mobile.
Détails sur le produit
En savoir plus sur l'auteur
Commentaires en ligne
Commentaires client les plus utiles sur Amazon.com (beta)
But I had to wade through galaxies of fluff and silly analogies to get there. The fluff most likely arises from the maxim that you lose readers when you include equations. As a result there are none in this book. Even worse, the author strives to avoid anything that sounds too sciency. Yes we get extended descriptions about matter crashing into itself to create the energy we can see, but no scientific explanation of how that energy is actually produced and why it is not sucked in by gravity. We also learn that "[s]uper computer simulations" of baby galaxy mergers "can create enormous whirlpools of turbulence." But nothing about the simulation inputs or how they work nor the nature or extent of the turbulence.
Then there is the writing. As another reviewer says, Scharf's analogies are all over the place. Many of them are at odds with the grandiose tone he sets in the first few chapters. Galaxies are eggs. Super hot gas clouds are water in a bowl then - in the same paragraph - partially successful soufflés. Meanwhile he is inconsistent in trying to express the scale of the universe. He tells us 10 million years (or light years when referring to distance) is tiny compared to the age and size of the universe. Then he later says the time it takes to travel between two cosmological elements is greater than all recorded human history, which I guess is around 5,000 years - yet the analogy suggests he is trying to awe us with this even tinier distance.
There are other issues as well. (E.g. the histories of radio astronomy and x-ray astronomy are underdeveloped.) But the bottom line is that Scharf simply does not have the writing chops of Brian Greene or Michio Kaku or the creativity of Kip Thorne (whose spaceship-to-a-black hole conceit worked extremely well at the start of Black Holes and Time Warps). All too bad really, as I like the idea of focusing on gravity and the role of black holes in shaping the look of the universe rather than on black holes per se. This book just does not deliver on the promise.
These are called black holes because they appear that way in the universe because they are so dense that no light escapes from them. They are billions of times more dense and powerful than our sun. Since there at least 100 billion galaxies in the universe with at least 100 billion stars in each (think about those numbers, they are mind boggling), there are least that number of black holes. These black holes perform a key role in the universe creating and re-creating the universe through the creation and destruction of stars and galaxies.
Most of the book is spent discussing the exploration of these monsters, both nearby (our galaxy and others within millions of light years from us) to billions of light years away. The author mentions one galaxy and black hole that he was involved in the discovery of that is 12 billion light years away from us. (The interesting thing is that they found this galaxy and black hole as it looked 12 billion years ago...) A picture is shown of these and other galaxies with their black holes in their middle.
It just happens that our galaxy and black hole are just right for life. The black hole in the middle of the Milky Way galaxy is hungry, destroying and creating a couple of stars each year, but not too destructive. This results in positive change in our galaxy that supports life on its fringes where our Sun and earth exist. The author goes into some detail on this explaining how important this is to life on earth.
At the end, the author actually gets somewhat poetic, and the prose is very uplifting and positive. The universe is a beautiful creation and these monsters, black holes, are key to the creation and continuation of this beauty. The pictures in the book just increase the value of the writing and thoughts provided. In fact, I like this book so much, that after purchasing the Kindle version, I plan on buying the hard copy (only the 2nd time this year that I have done that), so that I can offer this to others to read. I highly recommend this book for anyone interested in the universe and astronomy.
I found this book to be a good basic overall review of what black holes are and the part they have played and continue to play in our cosmological evolution, but now that I have finished the book, I find that did not get out of it as much as I had hoped to. True, I can explain to my co-workers what a black hole is, how they formed and where they likely are (if this topic ever comes up in our conversation), but not much else. I know that the book covers more about black holes, but none of it stuck, so I am at the point of not knowing which to blame for that, the book or myself. After I finished it, I still had to re-read the section on bubble-blowing to remember what the author wrote.
I'm a bit uneasy at the author's writing style and the overuse of colloquial references to what he was trying to get across. I felt that I was being slapped on the back and expected to smile at some of these comparisons, and that detracted from the subject material in my opinion. I know that this is not a text book, nor did I expect it to be one, but I would have rather seen a bit more Brian Greene and a little less David Sedaris.
Would I recommend this book to a friend? To my neighbor who is a retired factory manager, yes...to my neighbor who is a high school physics teacher, no. If you are reading this review to see if you should read it, well if you know little more about a black hole than its color, then yes, you should give it a try. Anything beyond that, I'd look elsewhere.
Anyway, the author's writing style makes the book a more difficult read than the technical information in the book.
This book does not have the ambitious scope of other science books about astrophysics, and almost felt light because of that, but you have to keep some perspective: many of the other popular astrophysics books are inordinately ambitious with respect to other types of mainstream science publishing. Many other astrophysics and cosmology books I have read want to explain the whole universe to you, from beginning to and and from top to bottom! Scharf's book is more focused than that. He sticks with the scientific developments that serve his points, explains the aspects of black holes which he wants to get across, and leaves with just a few suggestions about where the future of that study could possibly go. This book will not overwhelm you with the entirety of the cosmos like some others could.
Scharf's main points of interest seem to be the physics AROUND black holes and their role in shaping the universe as we see it today. He does not go into what happens inside of a black hole so much. His does not attempt to describe singularities or all the strangeness that happens within the event horizon. If you want a book to explore the mystery beyond the veil of the event horizon, this is not the book for you. This is a good thing! It helps to keep his book more focused, and it explains other very interesting aspects of black holes that other writers have glossed over in their pursuit of the enigmatic singularity. Besides, there are already other books which cover that area, notably Leonard Susskind, Stephen Hawking, and Kip Thorne. Scharf's concern is what happens outside a black hole, not inside. Scharf want to talk about how black holes influence the wider universe, and he does so very eloquently.
Some other reviewers have criticized Scharf's books for a few colorful analogies, but I think these criticisms are overstated. All populist science writers use analogies, and Scharf's are no more silly than many other highly regarded science writers. He does not liken the whole universe to a loaf of bread and does not use Homer Simpson to serve his point (I'm looking at you Brian Greene!) Other reviewers dinged him for being light on detail, and I would only slightly agree with this. He uses a few homologies in the place of a measured quantity, for example in one place he describes something that lasts the 'entire recorded history of humanity' but how long is that? I appreciate the attempt to give us perspective, but I would have also preferred both the homology and also a literal quantity. This does not occur very frequently though. There is also nearly 20 pages of notes in the back of the book for those who wanted more detail. I do think those notes would have been better used as footnotes on the same page they comment on.
Anyway, I think this volume is a great addition to books about black holes for a general readership. I learned a bunch of information which is not covered by other black hole books, and I want to thank Scharf for covering this gap in an accessible manner. Gravity's Engines is a terrific companion to those books which are more concerned with the inner workings of black holes, and if you want to know the greater story about black holes you will really want to read this book as much as those focused on the interior world of black holes.