A Brief History of Time: From the Big Bang to Black Holes

by Stephen W. Hawking, Carl Sagan (Introduction), Ron Miller (Illustrator)

Stephen Hawking is one of the world's leading cosmologists and is widely regarded as the most brilliant theoretical physicist since Einstein. Although he has been widely published within his specialized field, A Brief History of Time is the first work he has written for the non-mathematical layman. In it he explores the outer reaches of our knowledge of astrophysics and the nature of time and the universe. The result is a revelation: a book that not only serves as an introduction to today's most important theories on the cosmos but affords a unique opportunity to experience one of the most imaginative and influential thinkers of our age.

Confined to a wheelchair for the last twenty years by a motor-neurone disease, Professor Hawking is best known for his work on black holes. But here he turns his mind to the biggest question of all: the search for a unified theory that combines general relativity and quantum mechanics.

Always in the clearest, most accessible terms, Stephen Hawking reviews the great theories of the cosmos. From Galileo and Newton to Einstein and Poincaré, and then moves on into deepest space for the greatest intellectual adventure of all. Could time run backwards? Will a "no boundary" universe replace the big bang theory? What happens in a universe with eleven dimensions? These are just some of the questions considered with devastating lucidity and brilliance in A Brief History of Time, a work that is bound to become a classic of its kind.

Genres: Science, Nonfiction, Physics, History, Astronomy, Classics, Philosophy

198 pages, Hardcover

First published September 1, 1988

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

[Bill · Rating 4 out of 5]

This book puts me in mind of the story about how a Harvard number theorist, through some malfunction of the scheduling computer, got assigned to teach an introductory course in pre-calculus. Being one of those individuals to whom math came so easily that they couldn't grasp how difficult others found it, the professor had no idea what to cover in such a course.

So, he went to the chair of the department, who told him: "You'll want to start with the real number-line and then progress to inequalities; from there, move on to quadratic equations, then trigonometry and the wrapping function, Cartesian and polar coordinate systems, and, if time permits, conic sections."

The professor thanked the chairperson and went off to meet with his first class. Next week, he was back.

"What should I teach them now?" he said.

A Brief History of Time is like that -- Professor Hawking doesn't seem to notice when his treatment progresses from the obvious to the arcane, ending with his concept of "imaginary time" (very nearly incomprehensible in this overly brief presentation).

Fun nonetheless.

* * *
August 30, 2022 addendum --

Time to jump in here, I fear:

Having garnered over 650 "Likes," this far-from-serious scribble is by far my most popular review ever — and, truth be told, undeservedly so.

For a more thoughtful consideration of a somewhat related book, try my take on Jim Holt's Why Does the World Exist? here: https://www.goodreads.com/book/show/8...

[Daniel · Rating 2 out of 5]

It is not clear to me who is in the target audience for this book. At times it tries to explain basic concepts of modern physics in simple language, and at other times it assumes a familiarity with the same subject. For the first time I think I "understand" why absolute time is not consistent with relativity theory or that space-time curvature supplants the notion of gravity, and for that I thank the author. There are a few other things I believe I have a glimpse of having (finally) slogged through the book.
On the other hand, there are many places where he writes as if it were clear what he is talking about even though it would require a good deal of background knowledge. To give but one example, he starts talking about summing up over possible world histories (I cannot locate the quotation) without explaining what that would mean. Trained in statistics, I have some idea that he is talking about mathematical expectation in the context of quantum mechanics, but I don't know how another reader might make any sense of it (and I certainly don't have more than a vague notion).
There are irritating writing practices that could have used some editing, e.g., the use of the naked pronominal adjective "this" when in the middle of a dense explanation of an abstruse concept(e.g., "This had serious implications for the ultimate fate of massive stars.").
My biggest complaints, however, are about his philosophical opinions. Obviously he is entitled to think as he wishes about the ultimate questions, but his assertion that his hypothesis of a finite world without beginning or end would leave no place for God seems beside the point. The classic divide has not changed: some folks look around and say stuff just is, and other folks say there's a power behind the stuff that has at least as much going for it as we do. That argument hasn't changed with his theories. At one point in the book he claims that the late John Paul II told gathered scientists that they mustn't inquire into the Big Bang because that was God's territory. I would wager with anyone reading this comment that such an assertion is just plain false. JPII was a flawed mortal, to be sure, but he was no dope; it certainly sounds to me like someone hearing what he thinks the pope would say. (And the Galileo jokes are pretty dumb -- does anyone think that JPII, who apologized for the embarrassing Galileo fiasco, would go after this guy? It must be all that influence the Vatican has had in Britain over the last 400 years that has him scared.)
Other philosophical complaints involve his use of entropy (he defines it first within closed systems and then uses it to explain why the "thermodynamic arrow of time" and the "personal arrow of time" must run in the same direction -- leaping from a box of molecules to the entire universe!), his droning on about what black holes are like when he doesn't know for sure they exist, his statements about "random" and being 95% certain a theory is true (does that mean about 95 out of 100 theories like that are true??). His opinions may be very rich, deep, though-provoking, but how would I (or most general readers) know? You can't really evaluate a judgment unless you know something in the field.
And so that is why I ultimately cannot recommend this book: if you know physics inside and out, you might find his opinions interesting. If you don't, you can only walk around parroting what he says about black holes as if you had a clue what you were talking about. What we all really need is a remedial course in physics!

[هدى يحيى · Rating 4 out of 5]

‎‏‏
=وداعا هوكنج=
صرت حرا الآن
---------
هناك لذّةٌ ما ،، في أن تفتحَ كتاباً تشعُّ من سطوره ألوان الفضاء
شيءٌ ما في فعلِ المعرفةِ ،، والتأمل فيها
شيءٌ يأخذ عقلك إلى أمكنةٍ أخرى
...
لا بين المجرات
ولا في خضّم الكونِ الواسع
بل هنا بداخلك
عند هذا النبض الأخّاذ في قلبك
حيث تبدأ المتعة في التحرر
لتغمر مسامّك برائحة الدهشة
فالكون في داخلك أنت يا صاحبي


تاريخٌ موجز للزمن ،، يُعتبر من أهم الكتب العلمية الحديثة
يأخذك ستيفن هوكنج في رحلةٍ عبر تاريخ العلم
ويشرح لك كيف تغيّرت نظرتنا للكون ،، ولمجرتنا ،، ‏ولكرتنا الأرضية ،، ولأنفسنا كذلك عبر العصور


هذه هي قراءتي الثانية لستيفن هوكنج ،وقد أعجبتُ أيّما إعجاب بقراءتي الأولي "التصميم العظيم" ‏،وإن قارنت هذا بذاك ،فأرجّحُ كفّة الأخير

لا أعلم إن كانت للترجمة دورٌ في ذلك ،فلقد قرأت التصميم العظيم بلغته الأصلية

لقد توقّعت أكثر مما وجدتُّ في هذا الكتاب ،فقد حسبته أكثر متعة وجمالاً في سرده أو في ترابط فصوله
ولكن لن تجد هُنا سوى متعةَ المادة العلمية ذاتها ، فـ اسلوب هوكنج جافٌ قليلاً‏

كما وضع كارل ساجان مقدمة جميلة للكتاب
ليثير شهيتي أكثر

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فلنتعرف على مؤلف سطور المعرفة الشهية إذا
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يقول ستيفن
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‏لقد كنتُ مصدر يأس لوالدي في صباي، إذ كنتُ ‏دائماً أقوم بفك الأجهزة لأرى ما الذي ‏يجعلها ‏تصدر أصواتاً، وبالطّبع لم يكن بإمكاني - عادة - ‏جمع أجزائها مرة أخرى، إلاّ أنّني ‏شعرت بإمكان السيطرة على أيّ شيء - بطريقة أو بأخرى - إذا ‏فهمت كيفيّة عمله، وأنا موقن ‏من وجود الشعور ‏نفسه لدى الآخرين
فنحن نجد أنفسنا في عالم لا ‏يلحظ وجودنا في الغالب ولا ‏يهتم به، بل - أحياناً - ‏يعادي هذا الوجود صراحةً

لذا، لو أمكننا فك ‏‏"اللوحة الأماميّة" للكون والنّظر خلفها فربّما نصبح ‏قادرين على فهم كيف تعمل ‏تلك العجلات ‏الصغيرة، أعني المجرات، ولشعرنا ببعض التحكّم ‏فيما يجري من أحداث، ولحسن ‏الحظ فنحن غير ‏مدعوين لإعادة تجميع الكون مرة أخرى بعد فك ‏لوحته الأماميّة‎
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هل تعلم أن هذا العالم العبقري قدأُصيب بمرض التصلب الجانبي الضموري؟
هذا المرض يصيب الجهاز العصبي الحركي ،ويُفقد المصاب به قدرته على التحكم في عضلاته
وهل تعلم أن الأطباء قد أخبروه بأنه لن يعيش لأكثر من عامين؟
ولكن يبدو أن إصرار الرجل وعزيمته جعلتاه يعيش كل هذا العمر
لبملأ الأرض بإبداعاته

كان ستيفن وقتها يحضّر رسالته في الفيزياء النظرية بجامعة كامبريدج
ولم يمنعه مرضه من إكمالها ليشغل منصب أستاذ الرياضيات الذي كان يشغله نيوتن في نفس الجامعة

حتى عام1974 كان هوكنج يستطيع العناية بنفسه بعض الشيء
إلا أن تفاقم المرض جعله حبيساً لكرسي متحرك ،بالإضافة إلى ذلك فقد عانى من عملية استئصال للحنجرة ليفقد صوته تماما

ولحسن حظه ،فقد أهداه والت وولتوز ،خبير الكمبيوتر، برنامجا عبقريا يتيح له أن يختار كلمات من سلسلة قوائم على الحاسوب، بمجرد كبسة على مفتاح في يده، بل ويستطيع أن يتحكّم به بعينيه، وحركة رأسه كذلك وعندما ينتهي من بناء جملته يرسلها إلى ناطق الكلمات
وقد ثبتّ الجهاز على كرسيه المتحرك ليستطيع ستيفن التحدث مع الحركة بحرية أكبر
[image error]

احتل هوكنج كرسي الرياضيات في كامبريدج ،وهو أعلى منصب يحتله أستاذ في اختصاصه
حيث شغله علماء أمثال نيوتن وتشارلز بابيج وبول ديراك

لهوكنج أبحاث نظرية في علم الكون وفي العلاقة بين الثقوب السوداء والديناميكا الحرارية
ودراسات في التسلسل الزمني

كما وضع نظريات عديدة عن ‏بداية الكون منذ الانفجار الكبير
وأيضاً عن الثقوب السوداء
والتي أطلق على إشعاعها إشعاع هوكنج

http://www.youtube.com/watch?v=4OmSoZ...
جزء من مقابلة له مع لاري كينج
============================================================
عن الكتاب
=======================
هذا الكتاب وبصورة مبسّطة نوعاً ، يعرض بعض نظريات العلماءالتي تحدثت عن الكون والزمن كنظريات ‏أرسطو وآينشتين وجاليليو ونيوتن أيضاً‏

يدور الكتاب في أساسه حول الكون
عن تمدده ،وإنكماشه وحدوده ،وعن أبعاد ‏الزمان

هذا الرجل جعل عقلي يروح يميناً ويساراً
دوخني معه بكمِّ معلوماته الهائل ،، وأفكاره المستنيرة

في البداية يحدثك ستيفن عن التصور ‏القديم للكون بإختصار ويمثل لك بتصور ‏أرسطو الأشهر مروراً ببطليموس وغيرهم

تصور أرسطو كان كالتالي
‏============================‏‏===========‏
المادة تتكون من 4 عناصر أولية‏
الماء،النار،الهواء،الأرض
تؤثر في هذه العناصر قوتان
الجاذبية ،،أي نزعة الأرض والماء إلى الهبوط
والخفّة ،،أي نزعة الهواء والنار إلى الصعود
‏============================‏‏===========‏



وإكتشاف أن الكون يتمدد كما يرى ‏هوكنج ،هو ‏إحدى الثورات الثقافية ‏العظيمة في القرن العشرين

فيقول
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‎وبالتأمل وراء، فإن من السهل التعجب لآن ‏أحدا لم يفكر في ذلك من قبل ، فقد كان ينبغي على ‏‏نيوتن وغيره أن يتبينوا أن كونا ستاتيكيا لن يلبث أن ‏يبدأ سريعا في الانكماش بتأثير الجاذبية
‏ولكن ‏لنفرض بدلا من ذلك أن الكون يتمدد . فلو كان يتمدد ‏بسرعة بطيئة إلى حد ما ، فإن قوة ‏الجاذبية ستجعله ‏في النهاية يتوقف عن التمدد ليبدأ بعدها في ‏الانكماش . أما إذا كان يتمدد بسرعة ‏أكبر من معدل ‏حرج عين ، فإن الجاذبية لن تكون قط قوية بما يكفي ‏لوقف تمدده ، وسوف يستمر ‏الكون في التمدد للأبد

‏وهذا يشبه ، نوعا ، ما يحدث عندما يطلق أحدهم من ‏فوق سطح الأرض ‏صاروخا لأعلى . فإذا كانت ‏سرعته بطيئة إلى حد ما ، فإن الجاذبية ستوقف ‏الصاروخ في النهاية ‏وسيبدأ في السقوط عائدا
ومن ‏الجهة الأخرى ، إذا كانت سرعة الصاروخ أكبر من ‏سرعة ‏حرجة معينة ( حوالي سبعة أميال في الثانية ‏‏) فإن الجاذبية لا تكون قوية بما يكفي لشدة إلى ��‏الوراء ، وهكذا فإنه سيستمر في الانطلاق بعيدا عن ‏الأرض إلى الأبد . وسلوك الكون هكذا كان ‏يمكن ‏التنبؤ به من نظرية نيوتن عن الجاذبية في أي وقت ‏من القرن التاسع عشر ، أو الثامن ‏عشر أو حتى ‏أواخر القرن السابع عشر‎‏ ‏
‎‏ ‏
إلا أن الإيمان بثبات الكون كان من القوة بحيث ظل ‏باقيا لأوائل القرن العشرين
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وعن الإرتباط بين المكان والزمان، يحدثك ‏ستيفن ‏عن أهمية نظريات نيوتن والتي ‏توجها بوضعه ‏لقانون الجاذبية الكونية
‏ووقتها بدأ التعارض بين الفكر القديم الذي يرجح ‏‏ثبات النجوم وبين ما جاء به نيوتن ومن خلال ‏تفكيره ‏للخروج من هذا التساؤل أوضح إن تجاذب ‏النجوم ‏يحدث إذا كان عددها صغير ‏
أما إن كانت عددها غير محدود ومتناسقة التوزيع ‏‏بطريقة أو بأخرى في الفضاء الشاسع ، فلن تكون ‏‏هناك نقطة مركزية لتتجمع عليها ‏

وبالمناسبة فقد اعتبر أينشتين الكون ثابتاًً حين ‏وضع ‏النظرية النسبية العامة
وقد اعتبرها أكبر غلطة قام بها في حياته، عدّل ‏فيها ‏فيما بعد

فيقول

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‎‏ ‏
نظرية أينشتاين عن النسبية العامة ، هي في ‏ذاتها تتنبأ بأن الزمكان يبدأ عند مفردة الانفجار ‏‏الكبير وسوف يصل إلى نهايته عند مفردة الانسحاق ‏الكبير ( إذا تقلص الكون كله ثانية ) أو عند ‏مفردة ‏من داخل ثقب أسود ( لو تقلصت منطقة محددة ، ‏مثل أحد النجوم )
وأي مادة ستهوي إلى ‏داخل ‏الثقب ستتدمر عند المفردة ، ولن يظل محسوسا في ‏الخارج إلا تأثير جاذبية كتلتها
ومن ‏الناحية ‏الأخرى ، عندما يؤخذ في الحسبان تأثيرات الكم ، ‏فإنه يبدو أن كتلة أو طاقة المادة ستُعاد ‏في النهاية ‏إلى باقي الكون ، وأن الثقب الأسود هو وأي مفردة ‏من داخله ، سوف يتبخر بعيدا ‏ليختفي في النهاية
هل يكون لميكانيك الكم تأثير درامي مساوٍ لذلك ‏على مفردتي الانفجار الكبير ‏والانسحاق الكبير ؟ ما ‏الذي يحدث حقاً أثناء الأطوال المبكرة جداً أو ‏المتأخرة جداً من الكون ‏عندما تكون مجالات ‏الجاذبية من القوة بحيث لا يمكن تجاهل تأثيرات ‏الكم ؟ هل للكون حقيقة ‏بداية أو نهاية ؟ وإذا كان ‏الأمر كذلك ، فكيف تبدوان ؟‎
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و يقوم ستيفن بعدها بتوسيع مداركك عن ‏الكون ،، ‏كيف نشأ ،، ما معنى التمدد و ‏كيف بدأ الإنسان ‏يستكشف مجموعته ‏الشمسية وأرضه والكون من ‏حوله
ليذهب بنا إلى نظرية الإنفجار الكبير

لقد استمر الجدال حول نشأة الكون وتاريخه في ‏‏الزمان ‏
هل له بداية في الزمان؟ أو كان محدودا في الفضاء ‏؟

في عام 1929 ،قام هابل بإثبات أن المجرات ‏والنجوم ‏تتباعد بسرعة كبيرة وان الكون ككل آخذ ‏في التمدد ‏والإتساع ‏

وقد أدّى ذلك إلى ظهور منابت نظرية الانفجار ‏الكبير ،وبدأت فكرة تتخيل كيف كان الكون متناهياً ‏في الصغر ‏وكثافته لا متناهية‏
وترجّح أن الزمن بدأ مع الانفجار الكبير

يعتقد أصحاب النظرية أن الكون كان عبارة عن كتلة صغيرة ذات كثافة وحرارة لا يمكن تصورها
ثم انفجرت هذه الكتلة انفجاراً هائلاً منذ قرابة 13 مليار سنة لينتج عن انفجارها سحابة هائلة من الغاز والغبار الكوني

ويؤكد لك الكاتب أن الزمان قبل الانفجار الكبير لا ‏‏يمكن تحديده
بمعنى آخر لم يكن هناك ما يسمى ‏بالزمان أصلاً


a computer-generated explosion representing the Big Bang

فيقول
_______________________________________________
‏مع ذلك، كان الاكتشاف المتميّز، الذي تم في ‏نهاية ‏القرن العشرين، هو تيقننا بالفعل من وجود ‏حدث ‏أول: الانفجار العظيم، الذي قد يشبه البيضة ‏أكثر ‏ممّا يشبه الدجاجة، ومع ذلك ليس كأيٍ منهما
فقد ظهر كل من الكون والزمان للوجود أول مرة ‏‏عندم الانفجار العظيم، وذلك هو السبب الأول، فإذا ‏‏استطعنا فهم الانفجار العظيم فسنعرف سبب ظهور ‏‏الكون على صورته تلك
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وينتقل بعدها إلى عناصر تكوين المادة
كيف توصلنا إلى إكتشاف الذرة ،، وكيف ‏كنا نتخيل ‏أجزاء المادة وقابليتها للإنشطار ‏من قبل ،، ويحيلك ‏إلى الجاذبية بصفتها ‏من القوى المؤثرة على عناصر ‏كوننا ‏الأساسية

حتى يومنا هذا ،يعتبر الكوارك هو أصغر ‏‏الجسيمات
والكوارك هو جسيم أولي مشحون يحس بالقوى الكبرى
البروتونات والنيترونات يتكون كل منهما من 3 كواركات
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يصل بك الكاتب أخيراً إلى الثقوب السوداء ‏‏_أمتع ‏فصول الكتاب
ليحدثك عن مفهومها

والثقب الأسود هو منطقة في المكان -الزمان
لا يستطيع أي شيء الهروب منها ولا حتى الضوء
لقوة جاذبيتها الشديدة

ويذهب بك بعد ذلك إلى أن الثقوب ‏السوداء ليست ‏جد سوداء
كما أن الثقوب كلما كانت أصغر كلما كانت ‏أشد ‏توهجاً ،وبالتالي تكون قدرتنا على ‏رصدها أفضل

================================

من أمتع ما قرأت عنه هنا أيضاً هو الجسيم ومضاده
فكل نوع من جسيمات المادة له مضاد جسيم مناظر له
وعندما يصطدم الجسيم بمضاده فإنهما يفنيان
ولا يتخلف عن ذلك إلا الطاقة
ويدلل بأمثلة ممتعة كذلك
^_^

الفكرة التي وجدتها مثيرة هي عدم تساوي عدد الكاوركات مع مضاداتها و هذا من حسن حظنا فلو كانت متماثلة لكان أفنى أحدهما الآخر في الكون المبكر لتترك كوناً مليئاً بالإشعاع لا يكاد يحتوي أي مادة

تخيّل معي
لا مجرات ولا نجوم ولا كواكب
ولا نحن ‎

عندما تشرد قليلاً في ذلك
احم
:P
================================

الكون بلا بداية وبلا نهاية‎
‏ ‏
‎يرى هوكنج أن
‎‏ معظم الناس وصلوا إلى ‏الإيمان بأن الكون جُعل ‏ليتطور حسب مجموعة من القوانين التي لا تُكسر ‏،ولكن هذه القوانين ‏تخبرنا بما ينبغي أن يكون الكون ‏عليه عند بدايته وعلى أنه لو كان الكون بلا بداية ‏وبلا حرف ، ‏فإنه لا تكون له بداية ولا نهاية فهو ‏ببساطة موجود‎
‏ ‏

وفي فصل سهم الزمان ،، يحدثك هوكنج ‏عن مفهوم ‏الزمن ،، وارتباطه بنظرية ‏النسبية

يرى ستيفن أن هناك فارقاًً كبيراً بين ‏إتجاهي الأمام ‏والوراء للزمان الحقيقي ‏في الحياة العادية
‏
ويدلل لك بمثالأً طريفاً

فيقول

‏_______________________________________________

‏تصوّر قدح ماء يقع من على مائدة وينكسر ‏‏على الأرض إلى قطع
لو أخذت لذلك فيلماً سينمائياً ، فإنه ‏سيمكنك بسهولة ‏أن تعرف إذا كان الفيلم ‏يسير أماماً أو وراء ‏
ولو سيرته وراء فسوف ترى القطع تجمع ‏نفسها معاً ‏فجاة من على الأرضية وتقفز ‏عائدةً لتكون قدحاً ‏كاملاً على المائدة

‎…‎
ماذا سيحدث إن توقف الكون عن التمدد ‏وبدأ في ‏الإنكماش
سيؤدي هذا إلى صنوف الإحتمالات التي ‏من نوع ‏يشبه الروايات العلمية بالنسبة ‏للناس الذين سيبقون ‏أحياء من طور ‏التمدد حتى طور الإنكماش
هل سيرون الأقداح المكسورة تجمع ‏نفسها معاً من ‏على الأرضية وتب عائدة ‏فوق المائدة؟
‎…‎
على أن ثمة طريقة أسرع لمعرفة ما ‏سيحدث:هي ‏القفز في ثقب أسود
إن كان الإضطراب سيقل في طور ‏الإنكماش للكون ‏، فإن المرء قد يتوقع له ‏أيضاً أن يقل في الثقب ‏الأسود
وهكذا لعل الفلكي الذي سيسقط في ‏الثقب الأسود ‏سيتمكن من كسب نقوده ‏في لعبة الروليت بأن يتذكر ‏أين ذهبت ‏الكرة قبل أن يضع رهانه

‏(على أنه لن يتاح له لسوء الحظ زمن ‏طويل للعب ‏قبل أن يتم تحويله إلى ‏إسباجيتي)‏
:D
_______________________________________________

‏================‏
هذا الفيديو يوضَح شيئاً من وجهة نظره عن ‏نشأة الكون

http://www.youtube.com/watch?v=Sq-‎WF...

================================

‏


‏ إن لم تكن قد قرأت كتاباً علمياً من قبل ،أو على الأقل تابعت بعض الدوريات و المواقع العلمية ، ‏فلا أنصحك بهذاالكتاب كبداية
فسوف تجده مملاً قليلاً ،وستجد نفسك غارقاً في المصطلحات التي ستشتّت ‏انتباهك،وتعيقك عن الإستمتاع به
وهذا الكتاب يحتاج للقراءة لكثيرٍ من المرّات كي تتشبع بمعلوماته ،و يحتاج لكثير من القراءات الخارجية كذلك

الكتاب معلوماته قيمة وشيقة لواحدٍ من أهم العلماء ‏الذين أنجبتهم الأرض

ولا يزال علم الفلك متعة عظيمة ،، ‏
وتحليقنا بين المجرّات محفّز عظيم للخيال

[Jason Koivu · Rating 5 out of 5]

Isn't it amazing that a person can read a book like A Brief History of Time by Stephen Hawking and come away feeling both smarter and dumber than before he started? What a universe we live in!

It's quite short and generally a quick read. Not every page is filled with mind-blowing/numbing theories and brain-busting equations. Some of it is just history, say on Newton and such. However, there were a few pages worth of passages where my wee brain felt like it was getting sucked into a black hole...mainly during the black hole segment.

I've forgotten so much since I left school, and since school was such a long time ago, some of what was taught back then is now outdated, it was nice to read this refresher/cleanser.

I came away with a better understanding of the Big Bang theory and why it's plausible (Not the tv show. Its existence is not plausible). I'm trying to sort out the time/space quantifiability thing. That's going to require a reread...and probably further study elsewhere.

Surprisingly, I also came away with the idea that God and science can coexist. I didn't expect that. I figured someone like Hawking would be like, "God? Pssh, whatever." But that's not his take at all, or at least that not the impression this book left me with.

A Brief History of Time was written with accessibility in mind, knowing full well idiots like me wouldn't buy it, read it or recommend it if it were impossibly dense. Hawking's sense of humor even comes through on occasion, which is always appreciated in these sciencey texty thingies. So, I'll probably move on to his Briefer History... next and I'd be quite willing to read others as well!

[Anne · Rating 5 out of 5]

Well, then.
I know most of you think this is a book in which Stephen Hawking explains the history of what we think we know about space and time and the beginnings and end of the universe.
You're wrong.
This is a book in which Stephen Hawking shows people like me how poor our comprehension skills are.
WHAT EVEN IS QUANTUM MECHANICS!?
And more importantly, who are these people who understand it!?
Granted, I still use my fingers to count, so...



You know what surprised me most about this book?
As he was talking about Copernicus and Newton and Einstein and all of the theories they've come up with to describe how the universe works and how the earth spins and the stars burn, he never ONCE mentioned the Flat Earth theory as a viable thing. I mean, he kinda sorta flipped through it as a 'thing of the past' because of some 5th-century dude called Pythagoras thought there was something wonky about the moon being round if the earth wasn't round, too. It took a few hundred more years for Aristotle to put his name behind the idea and then apparently everyone just went with it.
But seriously.
Are we 100% sure the earth isn't flat?
Because I saw this YouTube video the other day that made a really good case for it. <--hosted by this guy called QAnon - sounded totally legit



He also talked a lot about the universe expanding and how that relates to (maybe) how the universe started. It seems as though common sense would say that if everything is moving away from each other, then if you were to hit rewind on your VCR you might be able to see it all contracting back together. At some point that contraction is just going to get smaller and smaller and smaller and smaller and... <--then he brought up the quantum mechanics thing and just lost me.
Ok, to be fair, he lost me when he started talking about how we MIGHT not be the center of the universe with everything revolving around the Earth.



The bottom line is that this is a love story about science and math and all the other things that I don't understand very well.
But fuck it, I'm trying!
And that has to count for something, right?



Recommended for really smart people.
Or for people who are dumb as hell but don't mind being reminded of it.

[BookHunter M ُH َM َD · Rating 4 out of 5]

بمناسبة الثقب الأسود الذي توقعه آينشتين و تحدث عنه هاوكينج كثيرا في هذا الكتاب و وضع له النظريات و السيناريوهات و القفشات أيضا و بمناسبة الصورة التي نشرت في ابريل 2019 فهذه المراجعة ربما تذكركم بالكتاب الملهم المختصر الغني جدا بالمعلومات و الذي أعتبره بوابة أساسية لمن يهتم بما يحدث في الفضاء البعيد

مع انى دارس هندسه فراغية و هندسة وصفية و مساحة جيوديسيه و رياضه بحته و تطبيقية و فيزياء عامه و ثيرمو دايناميك لكن حسيت و انا بقرأ الكتاب ده انى كنت أدبى و انى خريج دبلوم زخرفه

ده مش عيب فى الكتاب لكن عيب فيا انا لأنى درست علشان أشتغل و اهتميت بس بالمحتوى العلمى اللى هستخدمه فى السوق و كمان ممكن يكون طريقة التدريس أيامنا كانت مشى حالك و كل عيش

المهم الكتاب مع ذلك شيق و ممتع و مفيد جدا وأسلوبه رشيق و ترجمته ممتازه و دمه خفيف و فيه كمية معلومات تنوء بها العصبه أولى القوه
بعد ما بنقرأ الحاجات دى أكيد بنتحسر على بلادنا و علمائنا و على نفسنا و بنأمل يجى يوم ينصلح فيه الحال

[Sean Barrs · Rating 3 out of 5]

Stephen Hawking writes in a very simple and approachable way. On the surface the book has been written for the common man, for he who has little knowledge of theoretical physics.

Hawking uses basic terminology and he tries not to overload his writing with explanations and information dumps, but at times it is very clear that the reader needs a certain level of knowledge to understand what he's talking about. As such, Hawking makes certain assumptions as he shifts from concept to concept which left me a little confused. Things that don't appear related are related and it made me question who the intended readership really was.

I do believe this is a book every reader should try because it is an important one, full of discussions and ideas that could really open up your mind. But I would warn you to be prepared, although this seems like light reading, much of it may go over your head.

Approach with caution.

[David Sarkies · Rating 4 out of 5]

Things I learnt from Stephen Hawking
11 October 2014

Ever since I took up physics in year 11 I have had a love affair with the subject, which is odd since I went on to study an arts/law degree (but that probably had something to do with the fact that I would not have had the staying power to pour all of my energy into helping human knowledge advance towards establishing a unified theory). I still wonder where I ended up getting this book, and it had been sitting on my shelf for quite a while (probably because I was too busy listening to people tell me why I shouldn't read this book), but it wasn't until John Lennox said that it was the most unfinished book (that is people start reading it but do not have the staying power to get to the end) ever written (I'm sure there are other books that beat this book though). There are quite a few things that I have discovered while reading this book, and it is these discoveries that I wish to share with you:

1) This is not an anti-God book
One of the impressions that I got from certain people was that this was a book that an atheist wrote to try to argue that God does not exist, in much the same way that Richard Dawkins does in his books. However, that statement could not be further from the truth. In fact, throughout the book the question of the existence of God perpetually hangs in the background. Granted, Hawkings does suggest that if the concept of a infinite bounded universe (don't ask) turns out to be true then it would undermine God's existence, however he does not actually say that this may be the case. In fact his final sentence in this book is that the reason we study physics and try to find a unified theory is because we, as a race, seek to understand the mind of God.

2) Stephen Hawkings is actually a really good writer
This probably goes without saying, especially since the cover of my book says that it is a 'record breaking best seller'. While he is involved in some very serious and complicated research he is able to write in a way that many of us who have probably studied physics up to a year twelve level (that is the end of High school) can understand. Okay, I probably have an advantage over most other people since my Dad is a theoretical physicist that we have regular conversations about some of these high level concepts (such as by having any more than three dimensions would cause the orbits of the planets to collapse), but I still found that he was very easy to follow and he explained many of these high level concepts in a way that many of us could understand.

3) Scientists have a strange way of viewing the universe
Many of us would be familiar with this guy:



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.

For instance, we see space as flat, meaning that if we look at a star, as far as we are concerned the star is in that direction. However physicists see space as being curved and that a straight line is not necessarily straight. We would see a brick wall as being a solid object and that the idea of walking through one would result in a sore nose. However physicists see it as being made up of mostly space, and the only reason we can't walk through it is because the nuclear forces (forces that exist inside an atom, not the force that can level an entire city) prevent us for doing so. Then there is the concept of dimensions: to us there are only three dimensions, however some scientists (and Hawking is not one of them) see that there are in fact ten, or even more, dimensions.

4) Why are so many scientists atheists
While reading this book I could not get past about how complex this universe is and it made me wonder why it is, with the mathematical precision of the universe, and the complexity that lies therein, that so many scientists seem to argue that it all came about by chance. Even Hawking argues, using the second law of thermodynamics, that the universe cannot move from a state of disorder to a state of order – a broken plate simply cannot mend itself. However, the argument also goes that with the Big Bang Theory (not the television show) that the universe began in a state of disorder and moved to a state of order, however the laws of physics seem to suggest otherwise because what the big bang did was sent in motion a series of laws that caused the universe to come about to what we have at the moment. However, to go into details would require some intense theoretical physics, something which I have do desire to delve into at the moment.

5) Scientists assume the speed of light is a constant
The truth is that it is not. Okay, if light were travelling through a vacuum where there are no external forces acting upon it, then it is a constant, but that is very rarely the case. Take for instance this phenomena:



The reason light behaves thus is because when it hits the prism it SLOWS DOWN, and when it slows down it refracts. Thus my point is proven, the speed of light is only a constant when there are no external forces acting upon it.

So, what external forces may act upon light in space. Well, first of all there are black holes. When light hits a black hole the force of gravity is so strong that it will actually prevent light from escaping. Thus, gravity is a force that effects light and slows it down. Then there is the concept of dark matter, which are clouds of matter that do not emit light and float between the star systems. Okay, we know very little about the stuff (and it is also a theory, so it has not been proven) but my hypothesis is that if this stuff exists then would it not have an effect upon light, namely by slowing it down, which means that there is a possibility that our calculations as to the distance of stars from our own Sun could actually be wrong?

6) Scientists do not know as much as we think they know
One of the things that Hawking stresses in this book is that theories are not actually proven. A theory is an idea that has some foundation based on mathematical calculations and empirical evidence. Therein lies the problem. Much of our understanding of the universe is based upon mathematical calculations, and it appears that if an event comes about which causes this mathematical calculation to break down, they immediately set out to try to find another mathematical equation to plug the hole.

Take light for instance. For years we believed that light acted as a wave and suddenly it was discovered that it also behaves like a particle (a particle of light is called a photon). The same goes with matter – for years we believed that they were particles when all of the sudden we discovered that they can also behave like waves. As such, our understanding of the universe suddenly breaks down (meaning that we are not necessarily made up of atoms, but have wavelike properties as well).

Mathematical equations have been very destructive in out modern world. Take the Global Financial Crisis for instance. A bunch of apparently really smart people create complex mathematical equations to determine when to buy and sell shares and how to make billions of dollars. However what these equations did not take into account was the fact that people could not simply continue to accumulate debt without having to pay it back and when people began to default on their loans enmass, the whole concept broke down and we were taken to the brink of financial armageddon.

Another point goes back to Ancient Greece. Here we have the theory of Democritus, namely that matter was not infinitely indivisible (the smallest piece of matter is an atom), and then the theory of Aristotle, that is that matter is infinitely divisible. Scientists preferred Democritus' theory, however they soon discovered that you could break down the atom into protons and neutrons, and you could even break them down to quarks. So, maybe Aristotle was right after all.

7) We accept their theories because our gadgets work
It goes without saying that their research and discoveries have lead to the computer that I am writing this on, the energy that powers our devices, and the bombs that can level entire cities. We know how to make a nuclear bomb, as well as a smart phone, so we don't question what they say, because it obviously works. However, as a friend of mine once said, it is still all based on theory, and just because something works does not necessarily mean that the theory is correct. Remember that penicillin was discovered by blind chance.

8) Nobel Prizes are simply shiny baubles that have no merit
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.

9) Nobody really knows how gravity works
Gravity is one of those odd forces that doesn't seem to connect with any of the other forces in our universe. As Hawking points out, there are four forces that have been identified: electro-magnetic, strong nuclear, weak nuclear, and gravity. Out of those four forces (five if you divide electric and magnetic, but since electricity will create a magnetic force, they are effectively combined) only gravity stands out. This is probably why Hawking spends so much time talking about black holes because black holes are where the gravitational pull is so strong that not even light can escape from its grasp. The other thing is that gravity does not, at least in our knowledge, have an opposing force. Gravity basically sucks, and that is all it does – it doesn't repulse as the other forces can.

It is interesting that in some texts that I have read (maybe it is speculative science-fiction but I simply cannot remember off the top of my head) some people have suggested that gravity is actually a force from another universe that affects our universe and what it is effectively doing is sucking our universe into their universe. However, as I have said, that is incredibly speculative, and since I am not a theoretical physicist I can't really say any more on the subject.

10) The God of the Gaps is a cop-out
The idea of the God of the Gaps is that where there are gaps in our knowledge we simply say 'oh, God did that' and think nothing more of it. This goes back to the days of paganism (and Medieval Europe) where all of the unknown forces, such as the weather, was attributed God (or the gods) and we could not know anything beyond that fact. However I am arguing that it is a cop out. Creation scientists who resort to this argument are at best lazy and at worst dangerous. The reason I say that is that it discourages research into areas that we do not understand. Okay, we may never be able to control the weather, or predict earthquakes, but that does not mean that we should throw our hands up in the air and say 'this is too hard'.

While I may be taking a swipe at creation scientists here, I would also take a swipe at the atheists who claim that there is no God. The reason I say that is because there seems to be a fear within the scientific community that suggests that we may not be able to know everything, or that our understanding of the universe may be wrong. The problem that arises is that if we throw the idea of God out of the window and claim that the universe came about by chance, then we deny the fact that we live in an incredibly ordered universe that we can learn and understand through the development of mathematical formulae. If a formulae turns out to be wrong, that does not mean that the universe will collapse in on itself – it won't – it just means that we have to go back to the drawing board and start over from scratch.

11) Why are Creation Scientists so dogmatic
Why is it that some members of the scientific community insist that we must take the Bible literally? The Bible is not a scientific text, and it was never meant to be a scientific text. It is a theological text that tells us how we should live with one another and how we should view God. Science exists beyond the Bible, and neither contradicts the other. Okay, granted, God has intervened in this world and done things that break the laws of science, but doesn't he have a right to do that – he created the universe? However, what the Bible tells us is that God is a god of order, and if he is a god of order then does it not make sense that the universe that he created is an ordered universe?

So, maybe you are looking for a whiz bang conclusion to my exposition on this book, but all I can say is that what I have written above pretty much sums up what I have learnt from this book. In a nutshell (hey, this is me in a nutshell), all I can say is that what I have learnt from this book is that the world is an amazingly ordered place in which we live, and having now completed this book I am just as committed to my Christian faith as I ever was. However, if theoretical physics fascinates you, then this is certainly a book that you should give a read (though you have probably done that already).

This review also appears on my blog. I have also commented on this book in my review on Interstellar.

[Simon Clark · Rating 5 out of 5]

This is an absolutely magical book, both objectively and for me specifically. I first read it when I was about 9 or 10, and ever since I've assumed that I didn't understand a thing, and read it as a childish boast. Fast forward nearly twenty years, degree and PhD in physics in hand, and I decided to give it a proper read. Much to my surprise I found that the book had permeated my brain! I remembered a huge number of the explanations, and the book resonated with the way I've thought about physics my entire academic career - I think I took in a great deal more than I first thought!

As a primer to physics (I would say modern physics, but the book is a little out of date) you really couldn't ask for anything better than this. Especially when it comes to cosmology, this is possibly the best popular physics book that I've ever read. It really is a classic for a reason. It's such a concise, understandable introduction to the field that I'm determined to get my girlfriend (a linguist with no real interest in physics) to read it. Not just because I think she'll understand it, but because I think she will enjoy it!

One peculiarity of the text is Hawking returning to the concept of God (with a capital G) over and over again. In some ways this feels like a transitional text, marking the passing of the public generation for whom the church determined the order of all things, and the coming of the current, secular generation. Unlike other authors (looking at you, Dawkins) Hawking always does so in a way that feels respectful while also forcefully stating his scientific case. It's quite feat of writing, much like the rest of the work.

You really should read this, it's fantastic.

[Ahmad Ebaid · Rating 4 out of 5]

"والواقع أننا قد أعدنا تحديد مهمة العلم لتصبح اكتشاف القوانين التي تمكننا من التنبؤ بالأحداث في الحدود التي يفرضها مبدأ عدم اليقين"

بدأ ستيفن هوكينج, وهو عالم في الفيزياء النظرية, في كتابة هذا الكتاب في الفترة التي كان مازال يستطيع فيها أن يستخدم صوته وهو شبه مشلول على كرسيه المتحرك, ثم وبعد فترة, وقبل أن يكمل الكتاب, خضع لجراحة شقت فيها حنجرته, ليذهب صوته وهو الشيء الوحيد الذي كان يتواصل به مع العالم آنذاك

ظن في البداية أنه لن يستطيع إكمال الكتاب, ولكن أحد طلبته "بريان هويت" قام بمساعدته, ليس فقط على مراجعة المسودة, وإنما جعله أيضاً يستخدم برنامج لتخليق الأصوات, وهو ما فتح نافذة جديدة له على العالم.

وها هو ذا الكتاب بين يداي, وبين يدي الملايين.



أول كتبه الموجه للعامة, يشرح لنا فيه حصيلة أوراقه البحثية,
كتاب صغير الحجم
الثلث الأول من الكتاب تقريباً هو مقدمة تمهيدية عن الفيزياء التي سيشرح لنا قصته معها تالياً في الكتاب, وعن المحاولات والنتائج التاريخية التي سبقت أبحاثه.

ثم الثلثين الآخرين عن أوراقه البحثية, التي ارتكزت على الثقوب السوداء, والتي تعتبر نقطة تفرد خاصة حيث تكون الكثافة وانحناء الزمكان عندها لانهائيين, وتنهار عندها قوانين النسبية العامة
وقد قام هوكنج بمحاولة تفسيرها باستخدام مبادئ الكم تحت اسم: "الجاذبية الكمية", وهي إحدى محاولاته لصنع حلقة وصل بين قوى ثقالة الجاذبية وبين القوى الثلاث الأخرى التي تم توحيدها معاً في نظرية واحدة سابقاً

ثم ينهي بالمحاولات التي تلته لتوحيد القوى الأربعة, في نظرية واحدة, نظرية لكل شيء, تحديدا نظرية الأوتار, والأوتار الفائقة



إذن أين هو التاريخ الموجز للزمان؟ لقد أنبأتنا نظرية النسبية العامة بأنه إذا تحرك أحدهم بسرعة فسوف يمر الزمن عنده أبطأ. كما أنبأتنا بأن الجاذبية, تسبب تشويهاً في نسيج المكان لتجذب إليها الأشياء, وأيضاً تسبب تشويه الزمان, وبقربنا من مصدر قوي للجاذبية كأحد أطوار النجم كبير الحجم "الثقب الأسود", يسير الزمن عندنا أبطء من الزمن عند المراقب البعيد عند مصدر الجاذبية, وقد رأى معظمكم تطبيق هذه الفكرة في فيلم انترستلر.

وهكذا فالكتاب يتعرض في بعض مواضعه للجاذبية, والجاذبية تؤثر على الزمن. الزمن الذي لن يتطرق إليه الكاتب كثيراً في كتابه إذا ما استثنيا المقدمة التي حشر فيها الحديث عن الزمن حشراً لتتوافق مع هذا العنوان التجاري, والذي وُفّق في اختياره كعنوان جذّاب.


في المقدمة يعلل المؤلف كتابة هذا الكتاب, بأنه ورغم وجود عدد من الكتب الجيدة

"على أني شعرت بأن أي منها لم يكن يخاطب حقاً الأسئلة التي أدت إلى القيام بالبحث في علم الكونيات ونظرية الكم: من أين أتى الكون, كيف ولماذا بدأ؟ هل سيصل إلى نهاية ؟ وإذا كان الأمر كذلك, فكيف ستكون النهاية

وهنا تلاعب بالكلام, ليحوّل كتابه من مجرد كتاب يسرد به مسيرته العلمية في سياق البحث عن النظرية النهائية, إلى كتاب يعالج الأسئلة التي تؤرق الكل. الأسئلة التي لم يعد الفلاسفة قادرين على التعامل معها.
وهذه العبارات التي تحتمل التأويل تدعم ما قلته في الفقرة السابقة عن أن العنوان مقصود به أن يكون تجاري بغض النظر عن محتوى الكتاب ومدى خداع القاري به.



ونأتي أخيراً للسؤال الأكثر إلحاحاً للمعظم, هل الكتاب للمبتدئين؟ والجواب هو لا, فالكتاب فقط لمتابعي العلوم الذين لديهم الحصيلة الأساسية عن الفيزياء, والكتاب لا يشرح تلك الأساسيات سوى بجمل عارضة, لن تمكنك من استيعاب أي شيء

ولذلك قام الكاتب بإعداد نسخة أخرى من الكتاب أكثر بساطة بعنوان, "تاريخ أكثر إيجازاً للزمان" تجدونها مترجمة أيضاً

أما إذا كان لديك الحصيلة الأساسية, فالكتاب ولا شك تجربة مميزة, فالكتاب مليء بالعلم في كل سطر منه,
والكتاب يعتبر نصف تاريخي فمعظم ما فيه من نظريات تخطوها الآن, أو أنها لم تكن مكتملة في ذلك الحين


كان الشرح سلسل, واستنباط المعلومات وترابطها يشي بمدى تمكن الكاتب وعبقريته في إعادة صياغتها بسلاسة, إلا أنه هنالك استثناء بسيط في بضع صفحات يصف فيها آخر جزء من أبحاثه, وربما يرجع ذلك إلى أن الموضوع نفسه غامض



**
الكتاب من ترجمة مصطفى إبراهيم فهمي, مترجم قدير للبيولوجي, ولكنه تجاهل قاموس المصطلحات إلى حد كبير, فقام بترجمة التعبيرات بما يراه مناسبا دون أن يرجع إلى المصطلح المتَفَق عليه بالعربية في هذا المجال الغريب عنه
فنجده ينوب عن مصطلح "الأوتار الفائقة" بألفاظ أخرى

ويظهر أيضا عدم إلمامه بالفلسفة, فقد ترجم اسم الفيلسوف
"wittgenstein"
إلى "ويتجنشتين", وهذا خطأ, فهذا الإسم ألماني, وفي الألمانية ينطق حرف "W" بنفس نطق حرف الـ"V" في الإنجليزية
وبهذا يصبح النطق الصحيح لاسم الفيلسوف: "فيتجنشتين", وهكذا يترجم في كتب الفلسفة العربية.



*****

"سيقولون أن الله يستطيع بقدرته بدء الكون بأي طريقة يشاء. ومع هذا فإن الله أيضاً كان يستطيع أن يجعله ينشأ على منوال تعسفي تماماً. ولكنه كما يظهر قد اختار أن يجعله يتطور على نحو جد منتظم حسب قوانين معينة. وهكذا فإنه مما يساوي ذلك عقلاً افتراض أن هناك أيضاً قوانين تحكم الحال المبدئي."

لقد تطور فهمنا للعالم كثيراً. كنا في البداية نعزو الأحداث الخارجية لقوة فوقية تعبر عنها الطبيعة, وبعدها بدأنا نلاحظ أن الأشياء تتكرر بنظام معين.
وقد كانت الثلاثة قرون الأخيرة هي سعي متواصل لاكتشاف المزيد من هذه القوانين, وقد وصلت للذروة بعد أن اكتشف لابلاس في أول القرن التاسع عشر "الحتمية العلمية", أي أن كل ما يحدث في العالم من حولنا إنما هو يسير وفق معادلات رياضية تنبئنا بما سيحدث تالياً إذا ما عرفنا ما يحدث الآن.
وقد أدت هذه الثقة المفرطة إلى وجود أكثر من فجر كاذب, نذكر منهم أن:

"الفيزيائي ماكس بورن الحائز على جائزة نوبل في الفيزياء, ذكر في عام 1928 لمجموعة من الزائرين لجامعة جوتنجن أن الفيزياء كما نعرفها, ستنتهي بعد ستة شهور, وكانت ثقته مؤسسة على اكتشاف ديراك الحديث للمعادلة التي تتحكم في الإلكترون, وكان من المعتقد أن ثمة معادلة مماثلة ستحكم البروتون, الذي كان ال��سيم الآخر الوحيد المعروف وقتها, وأن هذا سيكون ختام الفيزيائيات النظرية"

ولكن كان هنالك المزيد مما لا نعرفه, بل وهنالك أيضاً المزيد مما لن نعرفه أبداً وفقاً لمبدأ "عدم اليقين" الذي اكتشفه هاينزبرج

"والواقع أننا قد أعدنا تحديد مهمة العلم لتصبح اكتشاف القوانين التي تمكننا من التنبؤ بالأحداث في الحدود التي يفرضها مبدأ عدم اليقين"

[Taufiq Yves · Rating 5 out of 5]

I spent 6 years reading this popular science book, on and off.

Back in early 2019, I flipped through all the illustrations, footnotes, and a few chapters. It was fascinating - but way too complex for me at the time.

In 2021, I picked it up again. It had mostly been a coffee-table book for me, something I browsed for the pictures. But this time, I seriously read the first 5 chapters. Then I hit the quantum physics section and got completely lost. So I put it down again. Still, I managed to grasp some basic ideas about cosmic evolution and relativity.

Last year, I made up my mind to finish the book. I still didn’t fully understand quantum theory, but at least I had a rough idea. 6 years after buying it, I finally read it cover to cover.

At first, I was obsessed with the chapters on galaxy formation, black holes, wormholes, and time travel. But this time, Chapter 9 - on the “arrow of time” - really stuck with me. I couldn’t help but wonder: maybe time is just an illusion.

Right now might be the peak of my physics knowledge. I didn’t major in it, and I probably won’t get another chance to study it any deeper. Over time, I’ll forget things. The more I learn, the smaller I feel in the vast ocean of knowledge. I don’t expect to understand every wave, but sometimes just looking out at the deep blue sea and feeling the breeze is enough to lift my spirits.

1. Substance
Matter is a form of existence, made up of fundamental particles. Absolute stillness doesn’t exist - matter is always in motion. Mass and energy are 2 key properties of matter, both conserved and interchangeable. Forces and waves describe interactions. Nature boils it down to 4 fundamental forces: gravity, electromagnetism, strong nuclear, and weak nuclear.

Philosophically, life is just 1 form of matter. It’s not eternal, but all things share the same material foundation. Matter transforms, but energy and mass never disappear.

So maybe today’s me could be tomorrow’s you - or someday become mountains, rivers, trees, wind, thunder, clouds, and rain. These ideas hold deep truth. In a way, a person is the sum of everyone around them. Our growth, choices, and behavior are shaped by our environment. So we should care for those around us and give back to the land that raised us. I am the world - do I need a reason to cherish myself?

Only those who embrace the world can truly love all living things. That’s “great love.” The phrase “benevolence is invincible” doesn’t mean the kind are powerful - it means they have no enemies, only friends. If everyone lived this way, the dream of “universal harmony” would come true. Today we call it a “harmonious society.” Whatever the name, the dream hasn’t changed: people long for peace, prosperity, and a better life - not just for a few, but for all. It’s the dream of national revival.

(Reading this back, it’s overflowing with positivity - maybe too much! But perspective shapes understanding. From a god’s-eye view, death might be a gateway to eternity. Yet we’re just individuals trying to live in a collective world. Sometimes selfishness helps others, sometimes it hurts. Finding balance between self and others is a timeless question.)

2. Time & Space
When we step outside our low-dimensional view, time and space become a single concept. Spacetime is the scattered state of matter, and time is just a way to measure changes in that state. The arrow of time comes from thermodynamics (entropy always increases in closed systems), psychology (which follows thermodynamics), and cosmology (which currently aligns with the other two, thanks to the anthropic principle).

General relativity and spacetime curvature suggest that time travel might be possible - through rotating black holes or wormholes.

Philosophically, time gives us the illusion that it’s slipping away. But really, time stays - we’re the ones moving.

Time helps us measure change on a large scale, but for individuals, it’s more personal. A full life feels longer. Some say life is like a novel - what matters isn’t length, but how exciting the story is.

If we all share the same material foundation, then it’s our thoughts, words, actions, and ability to shape the world that make us unique. If someone dies but their ideas and actions continue to guide others, are they truly gone? People can live forever - just in different forms. Centuries from now, those living on this land might still be us.

3. Science
From Aristotle’s authority to Newton’s laws, Einstein’s relativity, and modern quantum theory - science evolves, surprises, and sometimes shocks us. Here are a few key ideas:

1. Electromagnetism: Maxwell’s 4 equations are brilliant. They inspired the shift from Galilean to Lorentz transformations, leading to relativity.
2. Relativity: Special relativity, based on 2 simple assumptions, reshaped our view of spacetime. It explained many mysteries and led to general relativity, which redefined gravity and inertia, fueling astronomy and cosmology.
3. Quantum Theory: Photoelectric effect, spectral lines, Compton scattering, de Broglie waves → quantization (Planck to Bohr). Heisenberg’s uncertainty principle, Pauli exclusion, probability waves, Schrödinger’s equation, and a zoo of particles - all still evolving.
4. Modern Cosmology: Big Bang, closed universe, boundary-less universe, black holes, wormholes, anthropic principle (“Don’t ask why - this is the answer”), dark matter, string/membrane theory… Theories about the universe have always been abundant.
5. Unification: General relativity describes the large-scale universe. Quantum mechanics handles the microscopic. But they don’t play well together - they can’t both be fully right. Scientists are chasing a unified theory: quantum gravity. The other 3 forces (excluding gravity) are already partly unified under GUT (Grand Unified Theory), but we’re still far from a theory that unites everything.

Philosophically, don’t blindly worship science. Real science can be disproven. Scientific theories are hypotheses - truths that work under certain conditions. We must challenge scientific dogma, expose frauds, and avoid being naive. Dialectics teaches that truth is a process, not a fixed point. Our understanding deepens over time. Truth is always relative. Practice is the ultimate test of truth. (Sound familiar? Yep, that last bit is straight from Marxist philosophy.)

4. The World
Finally, the world. What is it? Matter? The universe? To me, the world is everything - and it’s also me.

Metaphysically, a person’s world begins when they start to understand it and ends when they forget it. “Forever” is just the space between life and death. A person’s eternity is contained within their life. When their world ends, so does their eternity. Even if their actions leave a lasting impact, it no longer matters to them. Those who chase fame or fear posthumous shame are just seeking peace or avoiding guilt while alive. Once dead, who cares about money, reputation, or history’s judgment?

Life is a rare experience. How we live it is up to us. Quiet or loud, careful or carefree - it’s all life, just different styles. Some say life is about wasting time. I’d rather “waste” mine on meaningful things.

The meaning of life is to love and create beauty. Even in chaos and wear, we can still feel joy and wonder - like a sprouting seed. Smile and live with purpose.

Those who believe all effort is pointless after death are missing something. Even the hardest lives can hold great joy. That joy comes from beautiful experiences, brave attempts, persistent effort, sweat and tears, songs and laughter. People who love life are more easily moved by it. And those who appreciate the beauty in hardship are happy to give back - to create beauty for others.

When I arrived, the world wasn’t perfect. When I leave, I hope it’s a little better because I was here. Even a tiny bit. “Ability may vary, but contribution should be wholehearted.” If I’ve lived sincerely and brought good into the world, then my life was meaningful and complete.

Matter simply exists - its existence is its own justification, needing no reason. But people are different. To live, we need a reason. So give yourself a brilliant dream, and let your world keep on living.

[Luís · Rating 4 out of 5]

This popularization book provides a portrait of the latest discoveries that have shaken the scientific world over the past hundred years: general relativity, quantum mechanics, the Principle of uncertainty, black holes, quarks, string theory, etc., enough to answer many questions: What will become of our universe? How was it formed? Why is CERN so determined to accelerate particles in a tunnel several kilometers long in Switzerland?
I will not claim to have assimilated all the concepts in a single reading. Still, the book gives me a good idea of the stakes and the research. Therefore, I recommend it to any science lover, especially since some of the theories explained will soon mark their centenary and are not yet widely known.

[فؤاد · Rating 4 out of 5]

خیلی وقت بود دنبال یه کتاب بودم که نظریات فیزیک جدید رو توضیح بده. زیاد از اصل عدم قطعیت و کوانتوم و نسبیت و نظریه ی ریسمان ها و سیاهچاله و کرمچاله و انفجار بزرگ و غیره و غیره شنیدیم، ولی شاید از هیچ کدوم تصور درستی نداشته باشیم. این کتاب خیلی از این نظریات رو مفصل توضیح میده.
استيون هاوكينگ يك مستند سه قسمتى داره، به نام "به سوى كيهان، همراه با استيون هاوكينگ" با صداى بى نظير بنديكت كامبربچ، كه بيشتر مباحث اين كتاب رو، بسيار بسيار ساده تر توضيح ميده. توصيه مى كنم كسانى كه تازه مى خوان مطالعات كيهان شناسى رو شروع كنن، قبل از اين كتاب اون مستند رو ببينن.
Into the Universe With Stephen Hawking

نکات منفی
مشکل اصلی کتاب، اینه گاهی زبانش خیلی فیزیکی میشه. به نظر میرسه آدم باید اطلاعات زیادی از فیزیک داشته باشه تا حرف کتاب رو بفهمه. من دانش فیزیکم در حد سوم دبیرستان و چیزهایی که جسته گریخته از این ور و اون ور خونده بودم هستش، در نتیجه شاید نصف کتاب رو آن چنان که باید و شاید نفهمیدم. خود استیون هاوکینگ میگه که ناشر بهش گفته بود: "به ازای هر فرمولی که در کتاب به کار ببری، فروش کتاب نصف میشه" و درسته که تقریباً هیچ فرمولی در کتاب به کار نرفته، اما همچنان زبان کتاب سنگینه. در مؤخره ی کتاب، نوشته بود این کتاب یکی از "ناخوانده" ترین کتاب های تاریخ ادبیاته. یعنی عده ی زیادی خریدن کتاب رو و حتی ادعا میکنن خوندنش، ولی در حقیقت نخوندنش! میشه فهمید چرا.

نکات مثبت
اما جاهایی که دانش ناقص فیزیکم یاری میکرد یا خود کتاب ساده بود، خیلی خیلی عالی بود کتاب. قصد دارم یه بار دیگه بخونمش به همین زودی ها. تاریخ فیزیک از دوره ی ارسطو تا نیوتون تا آینشتاین و هایزنبرگ، مباحث کیهان شناسی، مثل گسترش جهان یا محاسبه ی فاصله ی کهکشان ها، برخی از مباحث فیزیک جدید، مثل اصل عدم قطعیت و نسبیت، جزء جاهایی بود که کمابیش فهمیدم و خیلی لذت بردم.
گاهی هم مطالب علمی رو کلاً رها میکرد و شروع میکرد به تعریف زندگی خودش. مثلاً میگفت این نظریه در فلان تاریخ مطرح شد، در اون زمان من با دختری آشنا شده بودم و میخواستم باهاش ازدواج کنم و شروع میکنه ماجرای خودش رو تعریف کردن.

کتاب بعدی از این نویسنده، "کیهان در پوست گردو" هستش که قصد دارم به زودی بخرم.

[Manny · Rating 2 out of 5]

Apparently this book tops the world list of "bought but not read", which may explain why it's so universally acclaimed as a work of genius. If you know anything much about relativity or cosmology, it comes across as a potboiler, admittedly a well-written one with a great final sentence. I wasn't impressed.

But... without it, we would never have had MC Hawking. If you haven't come across him, start with the lyrics to "E = MC Hawking". Then buy A Brief History of Rhyme.

[V.D. Taylor · Rating 4 out of 5]

3,5 ⭐

I love asking people one particular question (well, that’s a lie — I’ve probably asked about five people in my whole life :D). When they were little, what did they think the moon or the sun was? Unfortunately, or maybe fortunately, the education system is good enough that most people I’ve asked don’t remember — they were told the scientific explanation at a very young age, and I’m no exception. I’ve only ever received one interesting answer: a friend once told me he used to think the moon and the sun were following him and that they existed just for him :D. So, I’m asking you the same question.

I started my review this way because the book I’m reviewing actually relates to that question — what is time, and what has time meant to people through the ages? Good thing Stephen Hawking didn’t go around asking people like I did, but instead decided to find his own answers.

Let me open a small parenthesis here: Stephen Hawking is an inspiration and living proof that if you have the will, you can achieve great things regardless of your condition. I’m genuinely glad to have lived in a time when he was alive.

Now, on to the review.
I always like to ask myself what the purpose of a book is. Here, I think that’s clear — probably because it’s semi-scientific. I could almost feel Hawking saying, “Give me permission to use some heavy math, and I’ll explain it all better.” But even without the math, I think he did an excellent job. I love that he stays within his zone of expertise and doesn’t try to get overly philosophical or explain abstract ideas with even more abstract definitions.

As for the book itself, I believe it’s suitable for all kinds of readers. I personally know quite a bit about the topic because I’ve read textbooks on it. That said, at one point, the pacing changes slightly, and for readers without any prior knowledge, it might get a bit harder to follow. Luckily, my edition included a glossary with short explanations of some of the terms used. I hope that with the help of that glossary and the illustrations, even someone hearing about physics for the first time won’t have any trouble understanding it.






Pre_read

I love reading biographies and autobiographies, so why not read the biography of time? :D

[Valeriu Gherghel · Rating 3 out of 5]

Cam tot ce știu din / despre cosmologie provine din scrierile lui Hawking. Îndeosebi din acest volum care a fost un bestseller absolut. O glumă afirmă că toată lumea bună l-a cumpărat, dar foarte puțini l-au citit. Scurtă istorie a timpului ar fi, așadar, cel mai puțin citit bestseller dintre toate. Nu cred că pe autor l-a afectat prea tare acest amănunt nesemnificativ.

Mă aflu în situația bizară că știu multe fără să înțeleg totul. Știu, de pildă, că fizicienii încearcă să ofere „o descriere completă a universului”. Mai știu că o astfel de descriere nu este, deocamdată, cu putință. Mai știu că Hawking a fost obsedat de realizarea unei teorii fizice unificate (mecanica cuantică + teoria relativității generalizate), fără de care sus-numita descriere nu este posibilă. Prima teorie (cea cuantică) susține că „universul e guvernat de întîmplare”, fapt pe care Einstein nu l-a acceptat niciodată. A doua oferă o viziune deterministă.

Deși ne-am obișnuit să gîndim în termeni finaliști (omul ar fi scopul creației), știu, de asemenea, că evoluția universului nu este finalistă. Evoluția nu are un scop, o „intenție finală”: apariția unei conștiințe care să constate frumusețea și armonia acestei lumi. Pentru Pico della Mirandola, în schimb, acest lucru era evident: „Te-am așezat, Adame, în mijlocul universului, ca să-mi poți contempla măreția” (De dignitate hominis).

Știu 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...

În 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”.

Cam atît...

[Darwin8u · Rating 3 out of 5]

“The universe doesn't allow perfection.”
― Stephen Hawking, A Brief History of Time



I know. I know. I both loved and hated this book. I definitely should never have read this book, cut the pages, opened the box, etc.. Somehow Stephen Hawking has written a book that gently fluffs the tail on Schrödinger's cat (or perhaps Schrödinger's cat is fluffing Dr. Hawking).

Look, no doubt the guy is a genius and has a fantastic story (ALS, computer voice, nurses, Black Holes, strippers, movies, etc). My problem is the wussification of a large scientific narrative by one of Big “P” Physics primary scientists. Let someone else write a pop-GUT/Blackhole/Big Bang story. Let another writer do the pop-up Children's book with the scratch-n-sniff singularity, the rotating black hole, the pull-out universe.



I want Dr. Hawking doing smart stuff. Let Bill Bryson write the summary science. But it is too late for me. I already crossed the damn event horizon. I've just become entangled with his book, so my "observer state" now corresponds to the damn book and the damn book review being both five stars and 1 stars is no longer a possibility; my reader state is entangled or linked now with my own review so that the "observation of the book review's state" and the "review's state" correspond with each other. I am finished.

Hey, now to go see some movies about blackholes and wormholes and assholes.

[Muhammad Abdullah · Rating 5 out of 5]

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.

Stephen Hawking, the author of the book, is one of the well renowned scientists of the century after Einstein. Some people even called him the successor of Einstein due to his work in the field of science. In this book, Hawking talks about black holes, worm holes, time travel, cosmic background radiation (CBM), uncertainty principle, expansion of universe, space and time (or simply space-time), origin and fate of the universe, forces of nature and the most important The Grand Unification Theory (the theory of everything) which is the biggest unsolved mystery of the present time.


A brief intro to author, Stephen Hawking

This book is really amazing and is popular in both science and non-science related people. I enjoy it a lot and I would like to recommend it to all the science and nature loving people. And I hope they will also enjoy it.

[Trevor · Rating 4 out of 5]

The main idea to take away from this book is that time has a clear direction. Entropy is the idea that the universe moves from highly ordered states to less ordered states. If you take the lid off a bottle of perfume, and leave it off for a few days the perfume will go from being highly ordered (all in the bottle) to highly disordered (all over the room).

Hawking uses this idea to explain why travelling back in time is impossible. It requires very little energy to knock a glass over and smash it - but think of how much energy it would take to make the glass jump back into place - all of the bits perfectly back where they were prior to the glass breaking. It would be impossible - and that impossibility is what gives time its clear direction.

Philosophically, I tend to feel that the book makes far too much of the Uncertainty Principle. But that is another story.

This isn't the easiest book to read in the world and is probably the most bought science book of all time while also being the one most likely gave up on after a chapter or two - but it is a fascinating read all the same.

[Nandakishore Mridula · Rating 4 out of 5]

Manny says this book is in the "bought but not read" category for most people. Well, I'm proud to say that I bought and read it, that too in nearly one sitting - back in my geeky days, when I used to get a sexual high just from solving a hard maths puzzle.

Unfortunately, I don't remember much of it (time for a re-read!) but I remember taking away the idea that time is a sphere. Being Indian, I loved this - because we are strong champions of cyclical time. Also, if time and space are both curved, it creates the possibility of jumping from one place and time to another; which is just delicious.

(I bought a pirated edition of this book for 25 rupees from the roadside at Connaught Place in New Delhi. The vendor asked for 50, I said 25, and the bargaining was just starting when he spied a policeman approaching - so he let me have it for whatever I was offering! "Time" was on my side.)

[Matthew · Rating 2 out of 5]

Hawking is a brilliant physicist and a true expert in explaining highly complex aspects of our physical universe in terms that can be understood by most lay people.

Where Hawking fails, in my opinion, is his hubris. He proceeds in to the realm of metaphysics and religion in several portions of this book. For instance, in his chapter on the "arrow of time", he states that, essentially, the universe can only move in one direction of time. It cannot go backwards. He also states that this limits the powers of God himself. Now, Hawking never qualifies those statements by defining "God". However, if he is talking about the Biblical God, how can you honestly think you're so intelligent as to place limits on a limitless being? If God is so powerful as to have created the universe and all the physical laws, why wouldn't he be powerful enough to change those laws any time he chooses? It is the same concept as a scientist creating a computer simulation of the universe. The scientist can, at any time during the simulation, alter the underlying framework of the simulation, effectively changing the physical laws that simulated universe operates under.

Now, whether you believe in God or not, the mere fact that Hawking has the audacity to think he can assign limits on a limitless being should cause you some concern. Hawking, because of his fame and brilliance, is a man that people listen to when he speaks. That gives him immense power over the minds of his readers. He should be more careful in choosing his words.

When Hawking sticks to his strengths, however, the book is second to none. Hawking truly has a gift of explaining the powerful forces that shape our lives in ways anyone can understand.

If this book had been edited better, it would have received a few more stars from me, but I can't reward stubborn scientific pride resulting in false assumptions.

[Ahmed Ibrahim · Rating 5 out of 5]

يسعى هوكينج في هذا الكتاب لوضع خريطة أو مسار كوني، بداية من الكيفية التي بدأ بها الكون، إلى وضع الاحتمالات التي سينتهي إليها، وتوضيح ما بينهما من أمور كونية فلكية.

بدأ الكتاب بالحدي�� عن الانفجار الكبير والمتفردة التي بدأ منها، وفيما بعد سيتناول احتمالات تنفي وجود متفردة أولية تقول بأزلية الكون، لكن المتفق عليه بشكل كبير في حالة وجود المتفردة أو لا أنه ثمة انفجار كبير بدأ منه الكون ثم تمدد، ومن الأشياء التي ستناقش بعد هذا هو الكيفية التي تمدد بها الكون. الانفجار الكبير كما قال هوكينج لا ينفي وجود خالق.
ثم يتحدث عن المكان والزمان، ويتناول فيه نظرية أرسطو الأولية التي دحضها جاليليو ثم نيوتن بقوانينه عن الحركة، ومن ثمَّ تناول بالحديث نظرية النسبية لآينشتين، الخاصة بتعارضها من قانون الجاذبية، والعامة المتسقة مع ذاتها.
ويتناول بعدها اكتشاف هابل بأن الكون يتمدد، بل ربما يكون لها نهاية حسب نظرية فريدمان.
وكانت هذه البداية للنظر إلى أن كوكبنا قطرة ماء في محيط الكون الفسيح، وتمت البرهنة بشكل كامل من قِبل هوكينج وبنروز على أنه لابد من بداية في الزمان على أساس أن نسبية آينشتين العامة جزئية واحدة من النظرة الكونية.
وكان مبدأ الريبة الذي قال به هايزنبرج وكم بلانك يمهدان الطريق لميكانيكا الكم، وبالرغم من أن آينشتين مُنح نوبل لمساهمته في نظرية الكم، لكنه كان معارضًا بشدة لها لوقوعها في فخ العشوائية، فلم يتقبل أن يكون الكون محكومًا بالصدفة، ومقولته: "إن الله لا يلعب النرد" توضح أفكاره.
لكن هذا لا يمنع أن معظم العلماء تقبلوا ميكانيكا الكم، يقول هوكينج:
"ليس لدينا بعد نظرية متماسكة كاملة توحِّد النسبية العامة وميكانيكا الكم، ولكننا نعرف بالفعل عددًا من الملامح التي ينبغي أن تكون فيها"
ويفصِّل الكاتب الحديث عن ميكانيكا الكم، فيتناول الجسيمات الأولية وقوى الطبيعة الأربعة.
ثم ينتقل للحديث عن الثقوب السوداء وهي جد شيقة، وفي هذا الجزء يستفيض هوكينج في الشرح والتحليل في كل ما يختص بالثقوب السوداء، وربما هذا لأنه كان مهتمًا بشكل كبير بها واكتشف بعض الأشياء حولها.
في أحد الفصول بعنوان: أصل ومصير الكون، وهو فصل مميز للغاية، وإن رأيته منفصل عن الكتاب بإعادته جزء بسيط باختصار مما قاله قبل هذا مع توضيح وتناول بعض الأشياء الجانبية، وفي هذا الفصل مناقشة بشكل أكبر للخالق، وإن توصل في النهاية إلى عدم نفي أو إثبات أي شيء، فكما هو الأمر في الفلسفة الإمر قائم على احتمالات لا يمكننا معرفة أيهما أصح، وعلى هذا أيضًا سينتهي الكتاب.
ثم بعد هذا يتناول البعد الزماني والمسار الذي يسير فيه الزمان فيما سيسمى بسهم الزمان المطلق للأمام، ومع حديثه عن الثقوب الدودية يضع احتمالات للسفر عبر الزمن وإن لم يستطع أحد البرهنة على هذا لكنه احتمال كبير، لكن الإشكالية تقع في كيفية السفر، وهل يمكن السفر للماضي أم للمستقبل فقط؟ ويدور هذا الجزء حول هذه النقطة بتحليله الأبعاد المكانية الثلاثة والبعد الزماني الواحد وما يمكن أن يكون من أبعاد أخرى.
ويأتي الفصل الأخير من الكتاب عن توحيد الفزياء، وهل يمكن أن نكتشف ما يجعل العلم متمكن من معرفة الأشياء بدقة وثقة متناهية؟ وقال بأن الفلسفة لم تعد تثمر في هذا المجال، بل اضمحلت واضمحل دور العقل في التقدم وفي مجاراة تطور العلم.
يقول هوكينج في الختام:
"وعلى كلٍّ، لو اكتشفنا فعلًا نظرية كاملة، فإنه ينبغي بمرور الوقت أن تكون قابلة لأن يفهمها كل فرد بالمعنى الواسع، وليس فقط مجرد علماء معدودين. وعندها فإننا كلنا، فلاسفة وعلماء وأناسًا عاديين، سنتمكن من المساهمة في مناقشة السؤال عن السبب في وجودنا، نحن والكون. لو وجدنا الإجابة عن ذلك، فسيكون في ذلك الانتصار النهائي للعقل البشري، لأننا وقتها سنعرف فكر الخالق."

كتاب عظيم ومبسط بشكل جميل، رحلة ممتعة وشيقة في محاولة لمعرفة الكون وحجمنا فيه، ومحاولة للتوصل للخالق، وإن باءت الأخيرة بالفشل، فقد خرجت أشد حيرة وانقسامًا أكثر مما دخلت، ويظل العلم والفلسفة والدين غير قادرين على إثبات أو نفي شيء عقليًا، كل شيء يخضع للاحتمال في كل الأحوال.

[Saadia B. · Rating 4 out of 5]

Only Hawking could write this book - simple, to the point and extremely resourceful. Cosmology is not an easy subject neither can everyone understand its deep connotations. Hawking made it understandable in the most layman terms possible.

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[shania]

i'm a genius i know😌

[Orhan Pelinkovic · Rating 5 out of 5]

Theoretical Physics from the master himself. It's a great summary, but you need a little background knowledge to understand all the chapters. It's a summary of astrophysics, theoretical physics, and cosmology, and it's hard grasping it all in 200 some pages. I wish it was a little longer.

The definitions at the end of the book are very useful. You will not regret reading the book, but you need some peace and quiet while reading it in order to hopefully understand it.

I've read the A Bantam Book Edition published April 1988 / A Brief History of Time by Stephan W. Hawking / 226 pages / 56,997 words.

[Nicky · Rating 3 out of 5]

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.

I don't know if the same will hold true here, but it's a nice hope.

[Elena · Rating 4 out of 5]

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.
Aún así, el concepto general de los temas que trata es impresionante si te apasiona conocer la esencia del universo. Realmente había momentos en los que dejaba de leer para procesar algunos conceptos y no podía menos de maravillarme.

[Michael Finocchiaro · Rating 5 out of 5]

A classic text where the amazing Stephen Hawking explains string theory and quantum mechanics "for dummies." Highly readable and even comical, it is a superb read. I need to go back and read this one again myself!

[ALet · Rating 3 out of 5]

★★★ /5

This was an interesting and informative book, but sadly I just couldn‘t grasp everything that it tried to say.

[P.E. · Rating 5 out of 5]

Space opera


The Milky Way arch emerging from the Cerro Paranal, Chile, 3 December 2009. Author: Bruno Gilli/ESO

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 :)


Detail of Eagle Nebula


Summary:

Chapter 1: Our Picture of the Universe
Chapter 2: Space and Time
Chapter 3: The Expanding Universe
Chapter 4: The Uncertainty Principle
Chapter 5: Elementary Particles and Forces of Nature
Chapter 6: Black Holes
Chapter 7: Hawking Radiation
Chapter 8: The Origin and Fate of the Universe
Chapter 9: The Arrow of Time
Chapter 10: Wormholes and Time Travel
Chapter 11: The Unification of Physics
Chapter 12: Conclusion


-----


Black Hole elements


Image of the night sky above Paranal, Chile on 21 July 2007, taken by ESO astronomer Yuri Beletsky


Galaxies in the Hubble deep field (detail)


Soundtrack:
Lux Aeterna - György Ligeti