I like the stuff that they added and revised, corresponding to better footage and improved examples. This edition are enough enough to be taught primary biology, however maintaining up to date with new editions is wise. Three-ring binder option: Professional: scholar can customise how they can phase the chapters by putting the pages in a three-ring binder, so they are not carrying around to a lot weight of the other chapters.
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. View all 24 comments. Dec 17, Simon Clark rated it it was amazing Shelves: favorites , physics-books. 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 This is an absolutely magical book, both objectively and for me specifically.
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 As a primer to physics I would say modern physics, but the book is a little out of date you really couldn't ask for anything better than this.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. Nov 22, Manny rated it it was ok Shelves: science.
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.
Then buy A Brief History of Rhyme. View all 33 comments. I know. I both loved and hated this book. I definitely should never have read this book, cut the pages, opened the box, etc.. Look, no doubt the guy is a genius and has a fantastic story ALS, computer voice, nurses, Black Holes, strippers, movies, etc.
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. View all 6 comments. Dec 08, Trevor rated it really liked it Shelves: science. 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 The main idea to take away from this book is that time has a clear direction.
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. View all 10 comments. Aug 30, Matthew rated it it was ok. 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 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.
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. View all 17 comments. 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! Being Indian, I loved this - because we are strong champions of cyclical time. Also, if time and space are both curved, Manny says this book is in the "bought but not read" category for most people. 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! View 2 comments. If you're into stuff like this, you can read the full review. For starters, I'm great at killing horse-flies by hand.
Should I get some black pyjamas and a balaclava and become a ninja? And there was me thinking that the horse-fly's all round vision and short nerve pathway had something to do with their reaction speed. Move aside Hawking! Dec 20, Shine Sebastian rated it it was amazing Shelves: books-i-own , wicked-smart , science , , wisdom.
Without a doubt a masterpiece! It's just incredible how Hawking explains to us the complex and mindboggling secrets and concepts of physics and our universe, with amazing wit , clarity, and simplicity.
The questions that we all used to ask to ourselves and to our parents, about god, about time, life and it's meaning, the sky, stars, about who created our universe and about it's beginning, about our fate But there are quite a few people, whose curiosity and desire to find out more, to explore the truths of this vast universe, never dies. Share from page:. More magazines by this user.
Close Flag as Inappropriate. You have already flagged this document. Thank you, for helping us keep this platform clean. The editors will have a look at it as soon as possible. Delete template? It is spacetime curvature , where light moves in a straight path in 4D but is seen as a curve in 3D. These straight line paths are geodesics. The Twin paradox , a thought experiment in Special relativity involving identical twins, considers that twins can age differently if they move at relatively different speeds to each other, or even at different places where spacetime curvature is different.
Special relativity is based upon arenas of space and time where events take place, whereas general relativity is dynamic where force could change spacetime curvature and which gives rise to the expanding Universe. Hawking and Roger Penrose worked upon this and later proved using general relativity that if the Universe had a beginning then it also must have an end. In this chapter, Hawking first describes how physicists and astronomers calculated the relative distance of stars from the Earth.
In the 18th century, Sir William Herschel confirmed the positions and distances of many stars in the night sky. In , Edwin Hubble discovered a method to measure the distance using brightness of the stars. The luminosity , brightness and distance are related by a simple mathematical formula. Using all these, he fairly calculated distances of nine different galaxies. We live in a spiral galaxy just like other galaxies containing vast numbers of stars. The stars are very far away from us, so we only observe their one characteristic feature, their light.
When this light is passed through a prism, it gives rise to a spectrum. Every star has its own spectrum and since each element has its own unique spectra, we can know a star's composition. We use thermal spectra of the stars to know their temperature.
In , when scientists were examining spectra of different stars, they found that some of the characteristic lines of the star spectrum was shifted towards the red end of the spectrum. The implications of this phenomenon was given by the Doppler effect , and it was clear that some stars were moving away from us. It was assumed that, since some stars are red shifted, some stars would also be blue shifted. When found, none of them were blue shifted. Hubble found that the amount of redshift is directly proportional to relative distance.
So, it was clear that the Universe is expanding. Despite this, the concept of a static Universe persisted until the 20th century. Einstein was so sure of a static Universe that he developed the ' cosmological constant ' and introduced 'anti-gravity' forces to persist with the earlier claim.
Moreover, many astronomers also tried to avoid the face value implications of general relativity and stuck with their static Universe, with one notable exception, the Russian physicist Alexander Friedmann. Friedmann made two very simple assumptions: the Universe is identical in every direction, i.
Homogeneity , and that this would be true wherever we look from, i. His results showed that the Universe is non-static. His assumptions were later proved when two physicists at Bell Labs , Arno Penzias and Robert Wilson , found extra microwave radiation noise not only from the one particular part of the sky but from everywhere and by nearly the same amount.
Thus Friedmann's first assumption was proved to be true. At around the same time, Robert H. Dicke and Jim Peebles were also working on microwave radiation. They argued that they should be able to see the glow of the early Universe as background microwave radiation. Wilson and Penzias had already done this, so they were awarded with the Noble Prize in In addition, our place in the Universe is not exceptional, so we should see the Universe as the same from any other part of space, which proves Friedmann's second assumption.
His work remained largely unknown until similar models were made by Howard Robertson and Arthur Walker. Friedmann's model gave rise to three different types of model of the Universe.
First, the Universe would expand for a given amount of time, and if the expansion rate is less than the density of the Universe leading to gravitational attraction , it would ultimately lead to the collapse of the Universe at a later stage. Secondly, the Universe would expand, and at some time, if the expansion rate and the density of the Universe become equal, it would expand slowly and stop at infinite time, leading to a somewhat static Universe.
Thirdly, the Universe would continue to expand forever, if the density of the Universe is less than the critical amount required to balance the expansion rate of the Universe. The first model depicts the space of the Universe to be curved inwards, a somewhat Earth-like structure.
In the second model, the space would lead to a flat structure, and the third model results in negative curvature, or saddle shaped. Even if we calculate, the current expansion rate is more than the critical density of the Universe including the dark matter and all the stellar masses.
The first model included the beginning of the Universe as a big-bang from a space of infinite density and zero volume known as ' singularity ', a point where General Theory of Relativity Friedmann's solutions are based in it also breaks down. This concept of the beginning of time was against many religious beliefs, so a new theory was introduced, "Steady state theory" by Hermann Bondi , Thomas Gold , and Fred Hoyle , to tackle the Big Bang theory.
Its predictions also matched with the current Universe structure. But the fact that radio wave sources near us are far fewer than from the distant Universe, and there were numerous more radio sources than at present, resulted in failure of this theory and everybody finally supported the Big Bang theory. Roger Penrose used light cones and general relativity to prove that a collapsing star could result in a region of zero size and infinite density and curvature called a Black Hole.
Hawking and Penrose proved together that the Universe should have arisen from a singularity, which Hawking himself disproved once Quantum effects are taken into account. The uncertainty principle says that the speed and the position of a particle cannot be found at the same time.
To find where a particle is, scientists shine light at the particle. If a high frequency light is used, the light can find the position more accurately but the particle's speed will be unknown because the light will change the speed of the particle.
If a lower frequency light is used, the light can find the speed more accurately but the particle's position will be unknown. The uncertainty principle disproved the idea of a theory that was deterministic, or something that would predict everything in the future.