A Brief History of Black Holes: And why nearly everything you know about them is wrong

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It is also worrying that Smethurst seems to put those who 'challenge the existence of dark matter' on a par with flat earthers - 'It came about after over three decades worth of observations and research pointed to no other plausible conclusion' - this simply isn't true. The reality is that dark matter particles have never been detected, while modified gravity theories arguably explain more than dark matter does. Both theories have flaws, but at the moment, it's all too common for popular astronomy/astrophysics books like this to give a casual dismissal of anything but those elusive particles. That simply isn't good science. Just like when Kepler wasted many years trying to explain whole celestial mechanics using 5 (perfect!) Platonic Solids! His main goal is to give an overview of the subject, but he also attempts to explain some complex mathematics. A pesar de estar escrito para un público "no científico" no puedo decir que creo que sea un libro accesible al 100%. Es cierto que Hawking cumple su promesa de no incluir ni una fórmula matemática (excepto la conocida fórmula sobre la teoría de la relativdad E=MC²) pero los conceptos en sí pueden ser difíciles de imaginar y comprender. De toda la información que Hawking intenta explicar en este libro, ha habido cosas que notaba que se me escapaban. Quizá con algo más de material gráfico habría resultado más sencillo.

A brief history of black holes - Phys.org A brief history of black holes - Phys.org

Carla Rodrigues Almeida does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment. Partners In the 1996 edition of the book and subsequent editions, Hawking discusses the possibility of time travel and wormholes and explores the possibility of having a Universe without a quantum singularity at the beginning of time.că fizicienii au propus, la sfîrșitul anilor 60, un așa-zis Principiu antropic (îl comentează într-un articol și I. P. Culianu), care li s-a părut unora argumentul suprem al unei evoluții „dirijate după un plan” (un argument creaționist), dar mai știu că acest Principiu (comentat cu entuziasm odinioară de Penrose și Hawking) nu dovedește nimic. Formularea lui pare o imensă tautologie: „Vedem universul aşa cum este fiindcă, dacă ar fi diferit, noi nu am exista să-l observăm”. Altfel spus: „Vedem universul aşa cum este întrucît existăm". Afirmația lui Hawking seamănă cu alta, la fel de misterioasă, tot a lui: „Dezordinea creşte cu timpul, întrucît noi măsurăm timpul în direcţia în care dezordinea creşte”. Nimic mai limpede... fine, mai știu ce a afirmat Roger Penrose despre singularități și găuri negre (universul nostru provine dintr-o singularitate): „O stea care suferă un colaps datorită propriei gravitaţii este prinsă într-o regiune a cărei suprafaţă se reduce la dimensiunea zero. Şi deoarece suprafaţa regiunii se reduce la zero, aşa trebuie să se întîmple şi cu volumul său. Toată materia din stea va fi comprimată într-o regiune cu volum zero, astfel că densitatea materiei şi curbura spaţiu-timpului devin infinite. Cu alte cuvinte, există o singularitate conţinută într-o regiune a spaţiu-timpului numită gaură neagră”. I loved this book! Not only because I’m a scientist and space enthusiast but also because it was just enjoyable to read. You do not need to be an astronomer or astrophysicist to understand what’s happening in this book. The author is really great at putting physics into the most simplest terms so that almost anyone could grasp hold of the basics. Throughout, the book weaves in entertaining stories of the key scientists involved, bringing humanity to the tale of this scientific journey. The author has an engaging and conversational tone that makes you feel like you're learning from a friend. A highly articulate summary of the history of astrophysics and its breakthroughs from its origins to 1996 (updated edition). I wish I had had such an introduction to physics and chemistry when I was in secondary school and high school! The layout of the book allows a layman to follow the development of the discipline and its fields over time, while Stephen Hawking never scorns an evocative image to give a better notion to the reader of what, say, the electromagnetic spectrum, thermodynamics or gravity are all about. I definitely recommand to all of you in awe before the universe and its strange marvels :)

A Brief History of Black Holes – The Wire Science A Brief History of Black Holes – The Wire Science

Stephen Hawking's book is easy to read, but harder to comprehend. In every chapter came a point where my brain couldn't hold another permutation of a theory, and as the book progressed, I ended up taking the same approach as I do when reading a Norse saga for the first time. With sagas, I just read, even if my brain doesn't seem to retain all the information about who is related to who and what they named their horse. Inevitably, at the end, I have a reasonable basic grasp of the saga, and then I have to read it over again to fit more information into that basic understanding. This is the first book I have ever read about science.This is one of the best selling book of the century.I have found it really infomative and my interest in science seems to build. This book is free from mathematical equations (except E=mc2) which is the best thing about the book. This book is so simple that even a lay person with basic knowledge of science can understand it. but as it turns out, after reading this book, I have come to the conclusion that a lot of theoretical physicists seem to live in the same world that he does. Okay, they probably don't spend their time at the comic book store, or arguing whether Babylon Five is better than Star Trek (actually, one of my primary school friends is a theoretical physicist, and we did have such an argument), but they do seem to see the world in a way that we ordinary people would consider strange.Smethurst is a little hazy on some aspects of history - for example, she says that it wasn't until the 1920s that some nebulae were considered to be galaxies, even though Herschel, amongst others, had suggested this significantly earlier. Also, and how many times do we have to say this, she repeats the myth that Giordano Bruno was the first to suggest the the stars were suns in their own right - he appears to have got the idea from Nicholas of Cusa. Schwarzschild also predicted the existence of a critical circumference of a body, beyond which light would be unable to cross: the Schwarzschild radius. This idea was similar to that of Michell, but now this critical circumference was understood as an impenetrable barrier. But 10 years before the general theory was unveiled, there was the foundational special theory of relativity. And its foundations were in turn laid by mathematicians around the world, whose contributions Einstein built upon to create his overarching theory. If we understand space and time to be combined as one entity called spacetime, as special relativity requires, it’s because of the work of Georg Bernhard Riemann, Hermann Minkowski, Marcel Grossmann, Tullio Levi-Civita, Gregorio Ricci-Curbastro and David Hilbert, among others. But there are quite a few people, whose curiosity and desire to find out more, to explore the truths of this vast universe, never dies. They are always always on the lookout for answers to questions deemed unanswerable , and then to ask new questions , that one by one, fills the gap between us and the truth and makes our understanding of this universe and it's secrets a bit more clearer and deeper,

A Brief History of Black Holes: And why nearly everything you

The concept of a body that would trap light, thereby becoming invisible to the rest of the universe, had first been considered by the natural philosophers John Michell and later Pierre-Simon Laplace in the 18th century. They used Newton’s gravitational laws to calculate the escape velocity of a light particle from a body, predicting the existence of stars so dense that light could not escape from them. Michell called them “dark stars”.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. Smethurst has pulled off a real coup here and something few science writers have managed as well as she has. Super accessible and *fun* read about the misconceptions, the discoveries and the personalities behind our still very early understanding of the universe’s greatest mystery. Okay, maybe the people that win these prizes are actually really smart, but then again, the guys who set up Long-Term Capital Management also won a Nobel prize, which proves my point.