Dove il tempo si ferma. La nuova teoria sui buchi neri

by Stephen W. Hawking, David Shukman (Introduction)

Alla metà degli anni Settanta, Stephen Hawking fece una serie di scoperte inquietanti, secondo cui i buchi neri potrebbero evaporare, o anche esplodere, e distruggere tutta l’informazione della materia caduta al loro interno. I fisici hanno impiegato i successivi quarant’anni a mettere ordine alle conseguenze di questo risultato, finora indimostrato. In queste due lezioni, Hawking ritorna sul tema chiave della sua ricerca per raccontarci qual è il punto della situazione, e cosa rimane da capire sullo spazio, sul tempo, sulla nostra parte nell’universo. “I buchi neri rappresentano una sfida al principio più fondamentale che riguarda la prevedibilità dell’universo e la certezza della storia”, scrive. E ci coinvolge nell’ultima puntata di un’appassionata disputa scientifica, iniziata parecchi anni fa, tra la fisica classica della relatività generale e la fisica quantistica.

Genres: Science, Nonfiction, Physics, Astronomy, Space, Popular Science, Collections

90 pages, Hardcover

First published May 1, 2016

About the author

Stephen William Hawking was an English theoretical physicist, cosmologist, and author who was director of research at the Centre for Theoretical Cosmology at the University of Cambridge. Between 1979 and 2009, he was the Lucasian Professor of Mathematics at Cambridge, widely viewed as one of the most prestigious academic posts in the world.
Hawking was born in Oxford into a family of physicians. In October 1959, at the age of 17, he began his university education at University College, Oxford, where he received a first-class BA degree in physics. In October 1962, he began his graduate work at Trinity Hall, Cambridge, where, in March 1966, he obtained his PhD degree in applied mathematics and theoretical physics, specialising in general relativity and cosmology. In 1963, at age 21, Hawking was diagnosed with an early-onset slow-progressing form of motor neurone disease that gradually, over decades, paralysed him. After the loss of his speech, he communicated through a speech-generating device initially through use of a handheld switch, and eventually by using a single cheek muscle.
Hawking's scientific works included a collaboration with Roger Penrose on gravitational singularity theorems in the framework of general relativity, and the theoretical prediction that black holes emit radiation, often called Hawking radiation. Initially, Hawking radiation was controversial. By the late 1970s, and following the publication of further research, the discovery was widely accepted as a major breakthrough in theoretical physics. Hawking was the first to set out a theory of cosmology explained by a union of the general theory of relativity and quantum mechanics. He was a vigorous supporter of the many-worlds interpretation of quantum mechanics.
Hawking achieved commercial success with several works of popular science in which he discussed his theories and cosmology in general. His book A Brief History of Time appeared on the Sunday Times bestseller list for a record-breaking 237 weeks. Hawking was a Fellow of the Royal Society, a lifetime member of the Pontifical Academy of Sciences, and a recipient of the Presidential Medal of Freedom, the highest civilian award in the United States. In 2002, Hawking was ranked number 25 in the BBC's poll of the 100 Greatest Britons. He died in 2018 at the age of 76, having lived more than 50 years following his diagnosis of motor neurone disease.

Reviews

[Apoorva · Rating 4 out of 5]

Got me interested in Black Holes now!

[Nemo ☠️ (pagesandprozac) · Rating 5 out of 5]

this is wonderful as an introduction to hawking's work, or as a reminder for people who read a brief history of time a while ago and would like to be reminded of the basic concepts. wouldn't recommend it for students of physics (just go straight for brief history) but excellent for the layperson.

if you don't know much about hawking's work or quantum physics/astrophysics in general i'd definitely say read this before anything else.

[Ammar · Rating 4 out of 5]

This is the transcript of the two 2016 Reith Lectures, that Stephen Hawking delivered on the topic of Black Holes. The illustration and comments are very helpful and they give the reader a wider understanding about this topic.

The book is short, but intense. Full of information about Black Holes, their history and various theories and hypothesis about their formation, characteristics, and purpose.

Interesting read for anyone interested in Science, Physics, the Universe or just want to be a cool geek.

[Omar Fadel]

A great beginner's guide to Black Holes. The illustrations were very useful as well as David Shukman's notes between the lines. While reading these two lectures, I was pausing at some points to watch a few scenes of the movie Interstellar in which the scientist characters explain several informations about Black Holes and the universe's dimensions in order to get a clearer understanding. However, I was surprised by his mentioning the movie.

Next Stephen Hawking read: A Brief History of Time.

[Ankit Saxena · Rating 4 out of 5]

Loved it..

Black Hole has always been my favorite topic of discussion and to study about since my childhood. This is the reason why I became fan of Stephan Hawking. His theories on Black Hole were always fascinating and logical to get more understanding of it. However, I never thought that Einstein was ever so close to the concept of Black hole. He seemed to be just stepped-in and made his way out to give the topic his touch but nothing else, though ironically, Einstein's Theory of General Relativity is something which is most helpful & relevant to get closer to the study of Cosmology and Black holes.

The best discovery in this whole matter, I guess, is; "During most of the life of a normal star, over many billions of years, it will support itself against its own gravity by thermal pressure, caused by nuclear processes which convert hydrogen into helium."

Also, Subrahmanyan Chandrasekhar showed in 1930 that the maximum mass of a white dwarf star is about 1.4 times that of the sun. This is something which results in the calculation of the Life of a star, evolutionary stages of massive stars and it's mass's impact while the creation of Black whole.

Stephan Hawking is the one who created that enthusiasm in the minds of youth about the existence of Black hole and the way to its creation. Theory of event Horizon was very much relevant and from it to singularity its worth to the level-up.

There I found some contradiction in editing as on page 20 it was mentioned Werner Heisenberg and on page 33 it was Walter Heisenberg, However, the actual is Werner Heisenberg.

For rest all the topics discussed with relevant theories is par excellence. language is good to read and understand but very simple for a book.

For me it's 4.0/5.0, 'coz It would have been in more details and would have contain more information on the Black Hole matter.

[muthuvel · Rating 2 out of 5]

A very brief history of black holes precisely. All the information and work sparsely depicted in the book for his research in black holes like super translations, quantum gravity theory are explained more clearly and profound enough in his books The Grand Design and The Universe in a Nutshell.

Just a recent lecture of the physicist who presented this publicly at Stockholm's Nordic Institute for Theoretical Physics last August (2015).


The tone of the book is way more opinionated than providing ample coherent information about Black holes. For instance, " The conclusion: My message here, then, is that black holes aren’t as black as they are painted. They are not the eternal prisons once envisaged. Things can get out of a black hole, both in this universe and possibly to another. So, if you feel you are in a black hole, don’t give up: there is a way out!" but the issue is its still a theoretical hypothesis anyway. It's still a theory anyway. Hawking was the one who came up with this idea of Hawking radiation in 70s and following decades he switched it from ditching and picking it up again and again. The answer to quest might be 50/50 and we are not yet there. This small book is an opinion/prediction of his upon black holes. Try Universe in a Nutshell, it will give more ideas on these stuffs with relevant contexts.

The issue with today's small pop science books is that they don't intend to provide coherent information about something but for commodifying the simplified works of complex minds to the public under the pretext of preaching that knowing the name of something is intelligent rather knowing about something and being able to clearly understand it.

It could have been a pamphlet but they made it a book with a lot of empty spaces and charging like it's worth ₹100 (5 US dollars in purchasing power parity).

A friend of mine defended that these kind of books really are the only way to get to know things for common people. I believe its right, Common people are too bothered with too many things. That's why these kind of books become bestsellers.

At the same time, there are free sources from MIT, Stanford to get more detail (and even a 12min youtube video better than this book, in my opinion) but common people like us will have to pay the price until we see the possibilities (at the same time, reliability) of various sources of knowledge.

[Muthuanand · Rating 5 out of 5]

So, if you feel you are in a black hole, don't give up: there is a way out, both in this universe and possibly to another.

A short and insightful read.

[Natalia Sobkowiak · Rating 5 out of 5]

uwielbiam stephena hawkinga za to w jak prosty sposób potrafi opisać fizyke

[Marius Paulsen · Rating 4 out of 5]

Super interesting and made me want to read more of Hawkings work!

[Varun · Rating 4 out of 5]

I must admit that I am attracted to black holes if not by their immense gravitational power then by the mysticism that surrounds their existence and functioning. These powerful, enormous cosmic entities, these mysterious objects have so much happening within and around them that even a thousand theoretical papers are not enough to capture the nuances of their existence.



And this beautiful little book with Hawking's lectures on black holes with some added comments by the journalist does provide some dew drops of knowledge to the reader. Simplistic language and to the point narration makes it a short impactful read. The illustrations in there are funny, but I was interested in the text. A couple of mind-blowing concepts in there such as alternate histories are something I would want to read more about.

My reaction after reading this book:

[Lynn · Rating 4 out of 5]

I think this book is an amazing journey through the history of theories about Black Holes! I always adore Stephen's way to explain difficult things in such easy sentences, and the only thing I have to criticize is that this book is too short. I just wish it had like 100 more pages and more in-depth explanations ~ #js

[Krutika Kalkal · Rating 5 out of 5]

Short and sweet, these lectures can be understood by anyone (at a high-level of course) with a basic background in Physics (*think taking Physics courses in high school*).

This was an entertaining and light read for me as I picked up physics/astronomy after quite a long time.

[Beatriz Sertório · Rating 3 out of 5]

"Uma lei científica não é uma lei científica se só for válida quando um ser sobrenatural decide deixar as coisas desenrolarem-se sem a sua intervenção." Um bom livro para despertar o interesse para a temática dos buracos negros, mas que não acrescenta nada de novo para alguém que já tenha lido mais sobre o assunto. No entanto, se não fossem os comentários de David Shukman às palestras, penso que seria muito mais difícil para um leigo conseguir entender os conceitos e teorias que Hawking aqui aborda. Infelizmente, apesar das piadas ocasionais, Stephen Hawking não possuía o dom que outros, como Carl Sagan, possuíam de tornar a ciência acessível e apelativa a todos.

[Theredheaded_Bibliomaniac · Rating 5 out of 5]

Sometimes you don't need to escape,
But something to feed your mind...
.
.
This book is for the curious minds out there.. Who need mental exercise every now and then..
A person who doesn't know what a black hole is should definitely read this one...
And others should also read as there are many surprising things about black holes that you will kno..
.
.
I really enjoyed reading this...
Those lectures by Stephen hawking shows he also had sense of humour... It's already known that the person with high IQs have good sense of humour..
.
.
These lectures were really interesting...
And now I wish to know more about Black holes...
.
.
Also I am not a person from science background and so the notes by David Shukman were really helpful...
.
.
If I had taken up science I am sure I would have loved to be a physicist 😄.
.

[Amelia Ūkas · Rating 5 out of 5]

Trumpai apie juodąsias skyles.
Juodoji skylė, tai žvaigždės masė pavirtusi į vieną tašką.

Iš juodųjų skylių negali ištrūkti jokia informacija, bet kartu juodoji skylė skleidžia Hawking radiaciją, kuri savaime yra informacijos šaltinis. Va toks fizikos paradoksas.

Skaitysiu ir kitas Hawking knygas. 🖤🖤🖤🎀

[Mustakim · Rating 4 out of 5]

3.8/5

[Karthick · Rating 5 out of 5]

Stephen Hawking never fail to impress us when it comes to cosmology.
I am awed by the mind bending theorems proposed by Hawking and Bekenstein. some concepts explained below

1. Berkenstein theorom suggest that whatever the information enter into the black hole is lost and no return. Information is lost in gravitational collapse. Nobody know how it is lost, but it is lost.
He implies that black hole should have entropy and its proportional to the surface of event horizon, a boundary beyond that nothing can escape the gravity of Black hole. So technically, entropy of black hole = lost of information/ no information about the particle to describe. (Disorder tends to increase always)

2. Hawking Radiation: Black holes indeed emit particles in terms of radiation. they are gradually evaporating at a very slow and steady rate. A pair of virtual particles popping into existence and annihilation. Vacuum was never empty at all.

2. Holographic principle: 3D information is stored in the 2D surface of black hole. this is deep! Imagine if this is the case (3D information in 2D boundary), then the universe we live in is nothing but a simulation, not real as we see.
(i.e.) the very boundary of the observable universe is also 2D surface encoded with info about real 2D object.

No Hair theorem: Black hole is defined by three parameters : Mass, electric charge and angular momentum.

[Furkan · Rating 5 out of 5]

this is the one of the best books i have ever read.when i first looked at the name of book and author i thought it's gonna be tough to read with bunch of equations but thanks to Hawking's way of explaining of theories with simple language and awesome pictures i could not put this book aside until i finished it at once.Even if i read this book that does not mean i will not read one more time.And one recommendation for whom wants to read is if you search names and theories mentioned in book and watch few videos about them you will never forget what this book wants to tell you and you will have more fun.

[Renata · Rating 4 out of 5]

tendi foi nada

[José Miguel (TheHudson) · Rating 4 out of 5]

Preciso y conciso. Una explicación simple de cosas que comúnmente parecen complicadas. Me gusta la idea de acercar la ciencia a la gente.

[Dominika · Rating 4 out of 5]

Fajnie napisana, obrazki i smieszne porownania ulatwily zrozumienie ae to nie zmienia faktu ze teraz moj mozg robi fikolki probujac to wszystko pojac

[Udit Nair · Rating 4 out of 5]

It's just a transcript of his two lectures he gave in 2016. Black holes fascinate everybody and I am also included in that list. Well Hawking also tried to explain the existing information paradox and other scientific aspects. Short read for anybody interested in black holes.

[nês ♡ · Rating 5 out of 5]

o problema deste livro é que ele acaba

[kayley anderson · Rating 3 out of 5]

black holes maybe aren’t pits that will rip you apart?? Go off

[Giovani Massinatori · Rating 4 out of 5]

Por ser o resumo de duas palestras, o livro é curto além de simples de ler

[Ibrahim Mousa · Rating 5 out of 5]

Felt the need to mark important things in this book, so...

"A singularity is what you end up with when a giant star is compressed to an unimaginably small point."

"A 'naked' singularity is a theoretical scenario in which a star collapses but an event horizon does not form around it - so the singularity would be visible."

"Quasars are the brightest objects in the universe, and possibly the most distant detected so far."

"Entropy means the tendency for anything that has order to become more disordered as time passes, for example, a well-shuffled pack of cards has higher entropy than an unshuffled one and therefore its description requires far more explanation, or information"

"The uncertainty principle, states that we can never locate or predict the precise position of the smallest particles. So, at what is called the quantum scale, there is a fuzziness in nature, very unlike the precisely ordered universe described by Isaac Newton."

"When a black hole is created by gravitational collapse, it rapidly settles down to a stationary state, which is characterized by only three parameters: the mass, the angular momentum(state of rotation) and the electric charge.
Apart from these three, it preserves no other details of the object that has collapsed.
If information is lost, which is apparently what is happening in a black hole, there should be some release of energy - but that flies in the face of the theory that nothing comes out of black holes. A paradox."

Or so we thought...

"Black holes seems to emit particles at a steady rate.
Quantum mechanics implies that the whole space is filled with pairs of virtual particles and antiparticles, which are constantly materializing in pairs, separating, and then coming together again and annihilating each other.
Now, in the presence of a black hole, one member of a pair of virtual particles may fall into the hole, leaving the other member without the partner necessary for mutual annihilation. The forsaken particle or antiparticle may fall into the black hole after its partner, but it may also escape to infinity, where it appears to be radiation emitted by the black hole."
known as Hawking radiation.

"The more accurately you know the positions of particles, the less accurately you can know their speeds, and vice versa"

"Although one can't predict the positions and speeds separately, one can predict what is called the 'quantum state'. This is something from which both positions and speeds can be calculated to a certain degree of accuracy."

[Metin Yılmaz · Rating 4 out of 5]

Göz gezdirirken okumaya başladım. İki dersden oluşuyor diyebiliriz. Tabi bir de uzun bir önsöz. Kısa ve öz bir kitap olduğu için çabuk bitiriyorsunuz. Fakat az biraz daha bilgiye ihtiyaç duyup, bi başka kitaba geçebiliyorsunuz. Hubert Reeves’in Atomlara ve Galaksilere İlişkin Yazılar kitabıyla pekiştirme yapma ihtiyacı duydum. Her ne kadar YKY’nin Doğan Kardeş serisinden çıkmış olsa da yetişkinler için de iyi bir kaynak.

[Betul Pehlivanli · Rating 5 out of 5]

En son Lise 1’de Fizik dersi almış biri olarak,tamamen kişisel ilgim üzerine okudum.Bu yüzden her şeyi tam anlamıyla anlayabilmek gibi bir iddiam da niyetim de yoktu.Aslında son derece ince bir kitap olmasına rağmen,biraz olsun anlamlandırabilmek için sürekli geri dönüşlerle okudum.Benim gibi bu konuda hiç fikri olmayan biri için elbette beyin yakıcıydı.Zamanın Kısa Tarihi’ni okumak buna göre kolay olacaktır diye umuyorum 😁

[Daniele · Rating 4 out of 5]

Una brevissima storia dei buchi neri, dalla loro teorizzazione al paradosso dell'informazione, che deriva dall'incompatibilità tra relatività generale e meccanica quantistica. Il libro è la trascrizione di due lezioni di Hawking, che fanno parte della serie delle "Reith Lectures" della BBC. L'argomento è interessantissimo e affascinante.

[Etienne · Rating 2 out of 5]

Je pensais en apprendre plus. Sans être un expert, j'ai une certaine base sur le sujet que je pensais approfondir ici, mais sans succès. Des images qui n'apportent rien, de nombreuses digressions de l'auteur/journaliste et finalement une place assez modeste à Stephen Hawking alors que son nom est écrit en grosse lettre sur la couverture (arnaque de marketing!!). Je ne recommanderais pas ce livre.