Serija od 7 predavanja fascinantnog znanstvenika Stephena Hawkinga pisana je na način da bude razumljiva svima, a ne samo usko specijaliziranim fizičarima :) Hawkingova predavanja pokrivaju cjelokupnu teoriju nastanka svemira, od teorije Velikog praska do teorije struna. Meni osobno ova je knjiga fascinantan izvor znanja i činjenica, ali ako niste baš uopće upućeni u osnove kvantne mehanike, zakona termodinamike, gravitacije i opće relativnosti, predlažem da prije čitanja ponovite gradivo, inače teško da ćete skužiti o čem Hawking priča. ;)

Ok moral of the story is you really don't need to read like all of these Stephen Hawkings books. In fact just one ("A Briefer History of Time" would be my recommendation) is sufficient. And if someone is so inclined to continue our unofficial, unlicensed and uncensored lesson in Physics I'd spread the love, check out Rovelli or Tyson.

As a stand alone book "The Theory of Everything" is a good, broad strokes lesson of astrophysics with a little more time spent explaining prevailing theories of the past that have been disproved as well as contemporary theories put forth that will probably be disproved.

Not a novel per se but a collection of lectures by Mr Hawking, which explores the origins of the universe and tries to find the answer to "Why does the Universe exist, anyway?".
Stephen Hawking tries to explain the origin of the Universe or The Big Bang without going into the technicalities and also gives a brief overview of various theories present that try to explain the state of the Universe (even the String theory).
The writing is simple but still multiple readings will be required to completely understand the full book (for me atleast). Hawking's witty propositions and his subtle doubts at the existence of THE CREATOR makes it a very enjoyable experience.
A must read for anyone interested in cosmology
5/5

This book is a collection of lectures by Prof. Hawking many years ago. I read it immediately after "A Brief history of Time" so the content was basically same in this one too as these were the lectures given by Prof. Hawking. But it again is very well presented so in all liked it too as the information provided is good though ubiquitous now. Hope to read more books by Prof. Hawking.

People who don't read generally ask me my reasons for reading. Simply put I just love reading and so to that end I have made it my motto to just Keep on Reading. I love to read everything except for Self Help books but even those once in a while. I read almost all the genre but YA, Fantasy, Biographies are the most. My favorite series is, of course, Harry Potter but then there are many more books that I just adore. I have bookcases filled with books which are waiting to be read so can't stay and spend more time in this review, so remember I loved reading this and love reading more, you should also read what you love and then just Keep on Reading.

A astronomia é uma área do conhecimento que despertou o meu interesse há vários anos, mas só nos últimos cinco anos é que decidi mergulhar no estudo da mesma. Quando digo "estudo", estou a falar de um percurso individual de descoberta, de alimentar a curiosidade e o conhecimento: no fundo, compreendi que a astronomia é um caminho para sabermos mais sobre nós mesmos e sobre tudo aquilo que nos rodeia, e estou grata por terem existido (e por existirem) divulgadores de ciência e instituições que compreenderam que o grande público, sem uma formação académica nestas áreas (física, cosmologia, astrofísica, etc.), pode beneficiar do contacto com as suas investigações.

Durante a leitura d'"A Teoria de Tudo ", quando ia sensivelmente a meio, tive de admitir para mim mesma que nem sempre me sentia capaz de acompanhar todos os raciocínios de Stephen Hawking: ao terminar o capítulo "Os buracos negros não são assim tão negros" apercebi-me de que algumas bases da lição anterior (é o próprio autor que chamada "lições" aos capítulos) tinham ficado pouco consolidadas e que, por causa disso, pouco ou nada tinha interiorizado da lição que acabara de ler. Desta vez não me dei por satisfeita, ao invés de passar à frente e de continuar a ler na esperança de acompanhar as restantes lições (algo que já fiz no passado com livros de divulgação científica, não o escondo), voltei atrás dois capítulos e retomei a leitura da lição "Os buracos negros" — já por várias vezes me perguntaram se livros como este são acessíveis, e eu disse que sim, que são... mas, para quem não tem conhecimentos consolidados na área da astronomia (ou que, tendo-os, não tem a necessidade de recorrer a estes no dia-a-dia, promovendo assim o esquecimento da informação), a atenção e concentração que devemos dedicar ao conteúdo dos livros deve ser redobrada. Por vezes sinto que a releitura permite sanar qualquer lacuna na compreensão, e aí a sensação é francamente recompensadora... imaginem: um dos maiores génios que já existiu neste "pálido ponto azul" (como Carl Sagan tão docemente apelidou a nossa Terra) pensou e estudou sobre buracos negros e quis transmitir esse conhecimento a todos nós; a sensação de acompanhar (parte d)a complexidade de tudo aquilo que compõe este tema é algo que devemos celebrar. Mas não creio que o prazer da leitura se esgote neste prazer egocêntrico de compreender o ciclo da vida das estrelas, o que é um buraco negro, o horizonte dos eventos, a noção de "entropia" ou a segunda lei da termodinâmica, pelo contrário: aquilo que tenho extraído destas leituras e estudo acaba por se traduzir numa visão de conjunto que me permite ver tudo aquilo que existe como pertencente a um mesmo núcleo, aos mesmos componentes, à mesma matéria. Mais do que diferenças, vejo semelhanças; mais do que conflito, vejo confluência.

Right from childhood, astronomy has always fascinated me. But as an adult with growing responsibilities, my focus shifted, and I could not read much of it after my school. The Theory of Everything by Stephan Hawking was a great read to get my attention back to it.

This book is a boon to astronomy and astrophysics lovers. Professor Hawking has tried to illustrate some really complex ideas in a very simple language for everyone to easily understand. No complicated formulae are used.

The book is a collection of seven lectures by Stephan Hawking.
In the first lecture, the author talks about the history of cosmological study and its evolution with time.

In the second lecture, he talks about the expansion of the universe starting right from the big bang. He explains some models and other efforts by various scientists that talk about this expansion.

In the third and fourth lectures, he focuses on the Black Holes and explains almost everything you need to know about them.

In the fifth lecture, he throws light on the origin and fate of the universe. During the course of it, he explains the hot big bang model, the inflationary model, and quantum gravity.

The sixth lecture comprises of various ideas and concepts about time. He talks about some really cool things such as time travel and predicting the future.

And finally in the seventh lecture, he talks about one unified 'Theory of Everything' that can approximate all the different theories about the universe. We are yet to arrive at one such unified theory, but once achieved, it can help us solve many unsolved mysteries about the universe and our place in it.

The Theory of Everything is a wonderful book and I would recommend it to every astronomy and science lover.

Un libro muy interesante, contiene 6 conferencias impartidas por Stephen Hawking en 1996, sobre el universo, su origen, los agujeros negros y la última de todas la que da título al libro, la famosa teoría unificadora que llevan años buscando los físicos y que no terminan de encontrar.

Soy muy fan de este hombre, no sólo tiene una mente prodigiosa, sino que también tiene la capacidad de transmitir conceptos muy complejos de forma que cualquiera pueda entenderlos y esa es una capacidad que muy pocos científicos tienen, lamentablemente.

Tengo que decir que siempre fui malísima en física y matemáticas en el Instituto y es una espina que tengo clavada hace muchos años, hace poco hice un MOOC en Coursera estupendo que me reconcilió un poco con la física. De pequeña quería estudiar Astronomía que me fascina, pero al ser tan desastre en física y matemáticas, mis tutores me dirigieron a la Biología que era más asequible.

برای فهم این کتاب نیاز به مطالعات جانبی دارید که بدون اونها فهم محتوای ۷ سخنرانی هاوکینگ غیر ممکنه، من جمله حداقل باید نظریه کوآنتوم، نسبیت، نظریه ریسمانها و ... رو بدونید شاید بفهمید استفن چی میگه. این کتاب برای بیان ایده هایی در خصوص مفهوم فلسفی و فیزیکی زمان جالبه و مشخصا حرفای جالبی داره که به راحتی نمیشه فهمید، مثل من که به جز یک سری اطلاعات کلی، چیز زیادی گیرم نیومد، برای همین شما را به اینک مرور زیر ارجاع میدم. یکی ۲ نکته جالبی که در خصوص زمان و مکان وجود داشت و من فهمیدم اینه که شما در افق رویداد یک سیاهچاله می تونید پشت سرتون رو ببینید چرا که نور به صورت منحنی دایره ای حرکت می کنه، همینطور اگر می تونستید به داخل سیاهچاله برید و برگردید می توانستید در گذشته حضور پیدا کنید. باید بعد از مطالعات جانبی، مجددا مطالعه کنم.

http://www.artahub.ir/%D9%85%D9%82%D8...

Հոքինգը շատ է կրկնվում, չափազանց շատ

Եթե միայն այս գիրքը կարդայի, վստահաբար ավելի բարձր կգնահատեի: Բայց խնդիրն այն է, որ արդեն հեղինակի մի քանի գիրք կարդացել եմ, ու ամեն տեղ խոսվում է նույն բանի մասին, անգամ նույն դասավորվածությամբ ու օրինակներով: Դա շատ է հոգնեցնում: Տպավորություն է, որ ասելու ոչինչ չկա, բայց գիրք գրել պետք է:

Իր գրքերում Հոքինգը խոսում է սև անցքերի, ժամանակատարածային կոնտինիումի, հարաբերականության տեսության, քվանտային մեխանիկայի և շատ այլ երևույթների մասին, ու միշտ վերջում անդրադառնում է «ամեն ինչի տեսությանը»՝ նշելով, որ դա կարող է ժամանակակից գիտության յուղոտ վերջակետը լինել: Այս գիրքը վերցնելով՝ սպասում էի, որ այն ամբողջովին նվիրված կլինի հենց «ամեն ինչի տեսությանը», բայց այդ մասին, ինչպես բոլոր գրքերում, խոսվեց միայն վերջում, մակերեսորեն:

Ահավոր սպասում էի, որ ավելի մանրամասն ներկայացված կլինի «լարերի տեսությունը», բայց կրկին դրա մասին խոսվեց շատ մակերեսորեն: Սպասում էի հետաքրքիր դասախոսություններ «ֆիզիկայի մեծ միացման մասին»: Դրա մասին էլ շատ քիչ տեղեկություն կար: Կարծում եմ՝ գրքի բովանադությունը չի համապատասխանում վերնագրին:

Կրկնում եմ, եթե մինչ այս Հոքինգ չեք կարդացել, ապա այս գիրքն իսկապես Ձեզ դուր կգա ու շատ հետաքրքիր տեղեկություններ կտա: Անպմայն կարդացեք:

Primer libro que leo relacionado a la ciencia y el espacio. Al principio me resulto muy fácil de leer y logré entender todo, pero a partir de la conferencia 5 empezaron terminos y teorias difíciles, ya al final no entendi muchas cosas.

***En un futuro lo releeré, espero poder enterder más.***

الكتاب بيغطي النظريات البشرية عن نشأة الكون و شكله و نهايته بشكل مبسط.
على الرغم من إنه بيتعرض لنظريات ال
Quantum mechanics, Relativity, Thermodynamics, Big bang, black holes...

إلا إن طريقة الكاتب جد مبسطة و التشبيهات التي يستخدمها بسيطة في أغلب الأحيان.
المحاضرات الأولى في الكتاب، تغطي تطور الفكر البشري في نظرته للكون و الأرض و شكلهم.

بطبيعة الحال، بيحفز عدد من الأسئلة مثل:
ما هو شكل أطراف الكون؟
في أي جزء من الكون تقع الكرة الأرضية؟
هل الزمن يسير في خط واحط؟ أم بالإمكان رؤية الزمن بالعكس؟
إذا كان ممكنا رؤية الزمن في اتجاهين عن طريق ثقب أسود فكيف يمكننا تحديد مكان هذا الثقب؟
هل الكون ثابت أم يتسع دائما؟
إذا أثبت العلم أنه في اتساع دائم، هل يأتي يوم يتم عكس تلك الحركة؟

في الأخير الكتاب لا يقدم نظرية بعينها ولكن يضع أقدام القارئ على أول الطريق لفهم كل تلك النظريات المتعلقة بالكون ونشأته و اتساعه و نهايته بالتبعية.

أكثر جزء أعجبني في الكتاب، نقاشه لآثار التواجد داخل ثقب أسود رياضيا، و أنه بالإمكان بحسب النسبية النظر للمستقبل و تذكره تماما كما نتذكر الماضي.

الأفكار في الآخير تطرح أكثر الأسئلة صعوبة، إلى أي مدى يتدخل "الإله" في الكون و كيف خلقه... و أسئلة أخرى حول معرفه إرادة "الإله"

قبل الكتاب كنت أحسب ستيفن هوكينج ملحدا من الدرجة الأولى، ذكره في آخر محاضراته الكثير عن المشيئة و لماذا خلقنا، بعد السؤال الذي تعرض له من أول الكتاب لآخره "كيف" يجعلني أظن أنه ربما أكثر إيمانا من كثير آخرين.

و الأهم كل تلك الأفكار عن خطأ أينشتين في تعريف "معامل كوني ثابت" في نظرية النسبية، و أن الكون ثابت وليس دائم الاتساع، و أن الكشف بأن الكون دائم الاتساع و أن عدد الأجرام في أي اتجاه مماثل (بحسب قياس الموجات الواردة إلينا من كل اتجاه( تذكرني من أول صفحة في الكتاب ب "إنا لموسعون" و تطرح عددا أكبر من الأسئلة عن مكان الإله.... إذا كان كل شيء في كل اتجاه متماثل خارج مجرتنا.


أن تقرأ تاريخ الكون، و تبدأ في العد ببضعة آلاف من الملاين من السنين، معنى الوقت نفسه يتغير عندك. أظن أني سعدت بالمرور على الكتاب.

----
رابط للكتاب على جود ريدز، احفظه ربما تمر عليه لاحقا:
http://www.goodreads.com/book/show/54...


__أحمد عبد الحميد

In The Theory of Everything, Stephen Hawking provides a lucid overview of the major developments in the evolution of cosmology, however the title is somewhat misleading.

Modern day physics is considered to be comprised of two pillars upon which the rest of physical theories are founded: quantum mechanics and general relativity. Quantum mechanics is the branch of physics which seeks to explain the behaviour of particles on the smallest of scales, while general relativity deals with physics on the large scale, in particular positing that bodies of large mass curve the fabric of spacetime, producing phenomena like black holes, supernovas, and planetary orbits. A "theory of everything" refers to any theory which unifies these two disparate areas, and is generally attempted by proposing quantum mechanics as being more fundamental than general relativity, thus producing quantum theories of gravity like string theory or its latest iteration, M-theory. As such, one would expect Hawking's Theory of Everything to be largely centred around the various attemps to unify general relativity with quantum mechanics, however string theory (the only theory of everything discussed in the book), comprised of less than half of a single chapter. Additionally, having read this immediately after "A Brief History of Time", I was quite surprised to see that many of the sentences, paragraphs and analogies were copied almost verbatim. However this turned out to be quite fortunate, because it allowed me to reinforce parts I'd learned from BHOT, whilst teaching me some of the parts I'd failed to understand the first time round.

Special and General Relativity:

Isaac Newton put forward a new understanding of motion within the universe, which had the important implication that motion only makes sense if considered from a particular point of reference.

Imagine sitting on the embankment of a railway while a train flies past you at 100mph. Relative to your stationary position (or point of reference), the train is moving at 100mph. If you're sat in a train moving at 100mph in one direction, while a second train is moving at 100mph in the opposite direction, that train would appear to be moving at 200mph relative to your point of reference, despite the fact that either of the trains would only be moving at 100mph relative to an observer sitting on the railway embankment. Let's imagine that one of the trains was see-through, and a passenger on the train dropped a coin while travelling past an observer on the embankment. The coin would fall in a straight line for a person sat on the train, but a curved trajectory for the observer on the embankment. We therefore see the importance of a point of reference when it comes to understanding motion, and that there is no "true motion" to which we should assign more accuracy than another. Instead, motion is completely relative to the observer.

Bare in mind that light must always travel at exactly the same speed (300,000 kilometers per second). This picture of motion would therefore imply that, if a train were to travel at 100kmph next to a beam of light (which must necessarily travel at 300,000 kilometers per second), then the beam of light should appear to be travelling at 299,900 kilometers per second, relative to someone on the train. Consistent with this logic, if the train were travelling at lightspeed alongside a beam of light, the beam of light should look stationary relative to that train - just as two trains travelling next to each other at the same speed would look still to one another. In practice, however, it was found that light always appeared to travel at the speed of light, regardless of the speed of any frame used as a reference point. Einstein's first major realisation was that the reason for this incongruence between Newtonian relativity and the law that light must always travel at the same speed, was due to the fact that time slows down for frames of reference which travel at extremely high velocities. Einstein realised that time was not some "absolute" entity which flows uniformly independent of space, but rather can change based upon factors such as an object's velocity. His revelation was that space and time weren't independent, but are instead connected and interwoven into a single fabric now known as the space-time continuum. This first theory, which was Einstein's smaller theory was named "Special Relativity".

Einsteins's second theory, "General Relativity" can be illustrated as follows by one of his famous thought experiments. He imagined an individual inside a large box, in a zone of zero gravity i.e. space, being slowly accelerated upwards and realised that this individual would be unable to distinguish the feeling of upwards acceleration from the feeling of gravity's downwards pull on earth (known as the equivalence principle). If a beam of light was fired horizontally at one of the walls, the light, due to the upwards acceleration, would not arrive at the exact point opposite the light source. This is because the box will have moved upwards by an infinitesimal degree, giving the impression to one inside the box that the light beam had a miniscule downwards curve. He thought that if an individual was placed on earth in a stationary rather than an upwardly accelerating box, one would be able to distinguish between the accelerating and gravitational reference frames because the curved light beam in the accelerating reference frame would not be present in the stationary, gravitational reference frame. However, his monumental realisation was that the curved path of the light beam would persist (also to an infinitesimal degree), not due to the movement of the box (which was stationary), but because spacetime itself was curved, and the light was simply following the shortest path available in curved spacetime.

Einstein's great realisation in "General Relativity", was that large masses (like planets) warp the fabric of spacetime, and this curviture of spacetime is what we experience as "gravity". The larger the object, the larger the curviture, and the larger the curviture, the stronger the gravity. This new conception of gravity and spacetime implicated the existence of black holes; points of infinite curviture in space in which gravity is so powerful that light is unable to escape, as well the notion of an expanding universe which began at the gravitational singularity we refer to as The Big Bang.

Quantum Mechanics

Things become even stranger and less intuitive with quantum mechanics, which paints a completely new picture of reality when we move down to atomic and subatomic scales. To conceptualise the behaviour of particles on the quantum scale, we can use an analogy. Imagine a prisoner locked in a cell. According to the laws of classical physics (the laws of physics as we typically understand them), we expect certain things to be impossible for the prisoner. For example, we expect that the prisoner cannot suddenly walk through one of the cell walls, and we expect that the prisoner cannot exist in more than one position simultaneously. This is not true of quantum mechanics. Replace the prisoner with a single particle like an electron, and shrink the cell down to an atomic scale. The electron no longer obeys classical laws and instead occupies all of the many positions available within the cell at a given time. Each possible position is assigned a probability for the electron being found there, and this spread of probabilities for the possible positions is known as an electron cloud. What's more, some of these occupiable positions exist outside the cell, meaning the electron can suddenly "tunnel" through walls and appear somewhere else. This phenomenon, known as quantum tunnelling plays an absolutely critical role in a large number of areas, for example, hydrogen atoms fusing together causing the nuclear fusion which powers the sun/stars, proton tunnelling resulting in base pair mutations in the human genome, or particles tunnelling out of an unstable nucleus to cause radioactive decay.

The Theory of Everything

Independently, quantum mechanics and general relativity are extremely well-established in making predictions within their own domain. General relatively offers a rich understanding of the behaviour of planets, stars, galaxies and galaxy clusters. In particular it is a classical theory which explains phenomena through just one of the four fundamental forces - gravity. Quantum mechanics on the other hand richly understands much of sub-atomic, atomic and molecular behaviour, particularly through the other three forces; electromagnetism, and the strong & weak nuclear forces which are based on quantum rather than classical processes. Herein lies the difficulty - reconciling gravity, a property of classical physics with electromagnetism, the strong nuclear force and the weak nuclear force, which are properties of quantum mechanics.

For the vast majority of cases, only one of these two pillars of physics is needed for understanding much of the universe, but with certain phenomena like black holes or the big bang, gravity compacts matter into areas of extremely high density and spacetime curviture where quantum effects become relevant. In these instances we need to find a unified theory of everything which allows quantum mechanics to be reconciled with general relativity, because as it stands the two partial theories are incompatible.

String theory is one such theory. In particular it is suggested that the most fundamental units of reality in the universe are not elementary particles like quarks or electrons, but rather tiny, one dimensional vibrating strings. These strings comprise all particles in the universe, which thus constitute all matter and each of the four forces. Supposedly, these strings vibrate at different frequencies, and in particular it is the frequency of the vibration and length of the string which determine what we observe as particles, i.e. an electron is produced by one of these one dimensional strings vibrating at a specific frequency. The thinking was that a full understanding of the organisation and vibration of strings would have led to a theory of everything, as all the four forces and matter particles could be explained in a singular unified manner. From Hawking's explanation of string theory, I have to admit I don't understand this at all and am not sure what the basis for believing that strings exist is, other than the one-dimensionality of strings makes it feasible mathematically by precluding problematic infinities. I also had to do much of my own research to try and piece bits together. Overall, I'm really glad I read this because I got lots out of it about general cosmology and it encouraged a lot of further research, just sadly it contained very little about "The Theory of Everything", and I don't really feel any the wiser about quantum gravity/string theory for having read it.