!DOWNLOAD E-PUB ☩ The Ascent of Gravity ☣ PDF or E-pub free
!DOWNLOAD E-PUB ♣ The Ascent of Gravity ♂ Gravity Is The Weakest Force In The Everyday World Yet It Is The Strongest Force In The Universe It Was The First Force To Be Recognized And Described Yet It Is The Least Understood It Is A Force That Keeps Your Feet On The Ground Yet No Such Force Actually ExistsGravity, To Steal The Words Of Winston Churchill, Is A Riddle, Wrapped In A Mystery, Inside An Enigma And Penetrating That Enigma Promises To Answer The Biggest Questions In Science What Is Space What Is Time What Is The Universe And Where Did It All Come From Award Winning Writer Marcus Chown Takes Us On An Unforgettable Journey From The Recognition Of The Force Of Gravity In To The Discovery Of Gravitational Waves In And, As We Stand On The Brink Of A Seismic Revolution In Our Worldview, He Brings Us Up To Speed On The Greatest Challenge Ever To Confront Physics
I did a double review of two books for the Wall Street Journal, so posting it under both titles The Ascent of GravityMarcus ChownPegasusOn GravityA ZeePrincetonGravity has become a hot topic in science, with the discovery of gravitational waves, ripples in the fabric of space coming from colliding black holes and neutron stars Both The Ascent of Gravity and On Gravity mention those discoveries, but neither book focuses on them Rather, they provide the background to our understanding of this fundamental force of nature, a force which is the weakest one known but which paradoxically, because of its long range, is the most important one in the Universe at large.The first person to appreciatee the literally universal importance of gravity was Robert Hooke, who realised that gravity is a universal force possessed by every object in the Universe, which attracts every other object Hooke, a slightly older contemporary of Isaac Newton, was both an experimenter and observer, and a theorist His insight about gravity came partly from his telescopic observations of the Moon He studied lunar craters, and noticed that they are formed of nearly circular walls, around a shallow depression They looked, in his words as if the substance in the middle had been digg d up, and thrown on either side So he carried out experiments, dropping bullets onto a mixture of water and pipe clay, making miniature craters which, when illuminated from the side by a candle, looked just like lunar craters He realised that the material thrown up from the centre of the craters of the Moon was pulled back down by the Moon s own gravity, independent of the Earth s gravity He pointed out that apart from small irregularities like craters, the Moon is very round, so that the outermost bounds are equidistant from the Center of gravitation , tugged towards the center by gravity, and concluding that it had a gravitating principle as the Earth has This was published in 1665, when Newton was just completing his degree at the University of Cambridge Hooke went on to suggest that planets are held in orbit by an attractive gravitational force from the Sun.The two books considered here both fill in what has become known about gravity since Hooke s day, but they are very different, both in approach and style Marcus Chown is a science writer, and a very good one He favours the historical approach, starting with Newton s work on gravity and taking us through Albert Einstein s contribution to the mysterious world beyond Einstein where physicists hope to find a theory that will explain gravity and quantum physics in one package He eschews equations, but provides clear explanation with a useful guide to further reading at the end of each chapter The result feels easy and natural, like the author talking to you, although I suspect it took a lot of hard work to produce that effect.By contrast, A Zee who only uses the initial is a professor of physics who has previously written an epic tome on gravity, and is now trying to bridge the gap between popular books and textbooks He is only partially successful Some of his attempts to be popular seem forced, as with sentences such as Ah, the glory days of trial and error experimental physics , and the logical structure of his arguments is sometimes faulty, as when in a book about gravity he tells us that just about the only commonplace example of a force acting without contact is the refrigerator magnet He does provide equations, and diagrams, and is on secure footing there But the sloppiness of his writing is highlighted by comparing his mention of the myth that Galileo dropped weights from the Leaning Tower of Pisa with Chown s Chown correctly identifies this as a legend Zee presents it as a fact we all learned in school Maybe we did learn the story there, but it is definitely legend, not fact.A particularly delightful feature of The Ascent of Gravity is the inclusion of several fictional vignettes in which the author imagines how the big ideas came to his protagonists for example, a story of the young Einstein walking out with his girlfriend Marie Winteler under a moonlit sky, and having a sudden insight about the way light travels across space Fantasy, but fun and no real surprise that it should work so well, since Chown is also a successful writer of science fiction on some of which, long ago, I collaborated with him Chown s great achievement is to make his discussion of such bizarre phenomena as the way rotation distorts space just about as intelligible and entertaining as the fantasy.Zee s great achievement is to provide the clearest explanation I have seen of the physical principle known as action , which among other things explains why light travels in straight lines or, accurately, why light travels along the path that takes least time Action is arguably the most powerful tool in the physicist s box of tricks In Einstein s own formulation of the general theory of relativity he required a set of ten equations to explain the interaction between matter and spacetime but the whole thing can be described much simply in terms of a single action I was also particularly pleased to see Zee emphasising the point that Einstein did not prove that Newton was incorrect Newton s version of physics is perfectly adequate for things moving much slowly than light in weak gravitational fields, and Einstein s version includes Newtonian physics within itself The famous headline in the London Times of 7 November 1919 proclaiming Newtonian Ideas Overthrown was just plain wrong Science does not progress by revolutions, but by building, brick by brick, on what has gone before.The latest brick in the edifice is, of course, the discovery of gravitational waves, and it is unfortunate that these books are unable to give much space to this The Ascent of Gravity was written a little earlier than Zee s book, and gives the discovery only passing mention On Gravity was written, the author tells us, after the first detection was announced, but even so gives it a rather cursory mention I was baffled by the fact that although Zee mentions plans for a gravitational wave detector to be built in India, he does not mention the one already built in Italy and a curious footnote suggests that he is unaware of its existence If you do want the full story of gravitational wave research, it is covered by Marcia Bartusiak in her excellent book Einstein s Unfinished Symphony.If you are looking for a good read and a chance to absorb painlessly some ideas about the force that controls the Universe, Marcus Chown is the man for you If you think you already know a little bit about the topic, and are not afraid of a few equations, then On Gravity will take you deeper if you are very brave, the Appendix will explain the meaning of curved spacetime If I had a magic wand, I would wave it to put Zee s diagrams into Chown s book, and get the best of both worlds. As the story goes, in 1666 Isaac Newton watched an apple fall from a tree, and it was this simple action that gave him the inspiration to develop the theory and the mathematics that was first published in 1687 in Philosophi Naturalis Principia Mathematica Mathematical Principles of Natural Philosophy where he laid out the foundations of classical mechanics These new laws meant that for the first time people could track the progress of the planets across the night sky, and Halley used the laws laid down by Newton to predict the elliptical path of the celestial object to predict the return of Comet, an event that he was never to see, but it carries his name to this day They were used to predict the presence of a new planet, Neptune, the first to be discovered using these principles Variations in the path of Mercury, lead astronomers to search in vain for another planet amongst the inner planets, a subject covered very well in The Hunt for Vulcan by Thomas Levenson, but this was to show the limitations of Newton s laws.These limitations were not addressed until a chap called Einstein who was unhappy with the anomalies that the current theory threw up It took eight years for him to demonstrate that the concept of gravity as everyone understood it was better described mathematically as the curvature of space time The ten equations in his general theory of relativity can be distilled down into this elegant equation From this, all sorts of things can be deduced and predicted and it is only recently that one of those predictions was finally detected gravitational waves This final part of the books ventures into the strange, surreal and occasionally baffling world of string theory The physicists working on this are trying to reconcile special relativity and quantum theory to one theory of everything and the current consensus is that the present theories, along with years of understanding will have to be totally re written Gravity is a habit that is hard to shake off Terry PratchettChown has given us a well written and thankfully, given that this is a physics book, a comprehensible text on the history and the most recent developments in research into gravity He goes some way to answering the big questions what is space What is time How did it start, but I can t help but have the feeling that the next breakthrough in this field will make Einstein s theory as irrelevant as he made Newton s work at the turn of the 20th Century. Not a review but some kind of essay based on the book Gravitational waves are bombarding The Earth from all sides at all times But you don t know about it Or maybe you know, but don t care Or simply do not feel it More likely Ray is going to ask you to stop for a moment today, and listen What can I say, folks the book The Ascent Of Gravity is FASCINATING It is also The Science Book of the Year 2017 I picked it only because this is the book about Gravity I believe if we ll understand this amazing force we ll understand everything How and most important why the world was created What is time What is space What is Universe Where did the Universe come from 5 things you may not know about gravityGravity creates a force of attraction between you and the coins in your pocket Between you and a person passing you on the street You are connected by gravity.Gravity is so weak, that if you hold your hand out, the gravity of the whole Earth can not overcome the strength of your muscles.The rest read on my BLOG The Ascent of Gravity is a treat It tells the story of what we know about gravity, based on the two biggest investigators of it Marcus Chown has written a lively, engaging and often funny history of the most basic of scientific puzzles, one we still don t have a handle on The book divides into two eras Newton s and Einstein s They both changed civilization forever with profound, non intuitive, dramatic and elegant solutions Newton s challenge was overcoming entrenched superstition Einstein s challenge was overcoming Newton.Newton made the concept of gravity scientific and real He developed the math calculus to prove it His determination that planets orbited in ellipses and that he could prove it for one and all shook science to its foundations He was a solitary person, unable to socialize, unable to manage other people he might have been an autistic genius He waited 20 years before releasing his initial findings His own mind gave him all the satisfaction he needed in life.Einstein imagined his way to universal truths, and then had to prove Newton s formulas wrong In their stead, he showed that space and time were the same thing, that mass and energy were the same thing, and that the universe operates in four dimensions, not three Like space and time, gravity and acceleration are one In order to understand gravity, you need to understand the effect of mass and acceleration on bodies In Einstein s universe, everything is capable of producing gravity, and does This too is non intuitive, but plugs unknowns and answers questions up and down the line But not all.Einstein was all about symmetry and elegant solutions His formulas meant matter tells space time how to warp And warped space time tells matter how to move It took a long time for the world to understand what he was saying, and much longer still to prove it for themselves Chown says Physicists scrawl arcane mathematical equations across blackboards but it is an enormous leap of faith to believe that nature really obeys those equations It invariably comes as massive shock when it turns out nature really does I love the way Chown will lay out all the logic and evidence necessary to prove a point, then follow with a one line paragraph But he was wrong, or Only it didn t All right It also is because I do the same thing, but seeing someone else do it drives home how engrossing this can be He also peppers the deeply serious with quotes from the likes of Douglas Adams, Terry Pratchett and Dave Barry, releasing the pressure of absorbing the often non intuitive It makes for a delightful rollercoaster of a read.Chown describes the usual conundrums of quantum physics, where physicists can t get their minds around things being both particles and waves, or how certain subatomic particles exhibit different seemingly bizarre properties at the quantum level Numerous physicists have cutely stated that if you claim to understand quantum physics you are either lying or wrong But I have no problem seeing that waves contain particles, and waves break out particles as needed Similarly for many of the properties of quanta, it is self evident to me that subatomic particles have very different properties when in a state of decoherence than when they are part of something bigger coherence , like an atom As I have said elsewhere, decoherence makes the world go round.If you think about ants, they live an entire lifetime in a year, and the passing of time means nothing So with Man on the scale of the universe Man invented time, but it has no standing in the universe For the universe there is no ticking, just being It is part and parcel of space For Man, the ant of the universe, his biology tells him there is a timeline, a lifetime, a history and a hurry But this has no basis in the physics of the universe It took an Einstein to break free of Man s prejudice Associating time with space opens minds to workings at the universe level, instead of the ant level we live in On the other hand, Einstein might be wrong Newton was.This is the fifth book on the history of physics that I have reviewed They all tell the same story, obviously, but Chown has developed a new angle, using gravity to frame developments It works well, at least until the final section, today, where physicists around the world are spending their lives trying to out Einstein Einstein Like his theories, they raise questions than they answer Unlike his theories, not a single one of the new crop has the slightest hint of proof to its credit For the moment, Einstein rules.David Wineberg Not the first time I ve read through to the end of a Marcus Chown and realised that, though there are some good stories and some nice linking of events and people, I m not much better educated about the subject matter than when I started Perhaps I should stop reading the author From Newton to Einstein to the present theories of cosmology Chown takes us through a universe which shows itself to be a dichotomy of truths Everyone knows that gravity is an attractive force..right Well it appears that it also has a dark side which is helping the universe to expand and which may lead to a deeper theory of the universe This is a great book for those like me who looked into space pun intended with glazed eyes in physics For the first time i was engaged reading this book It s enjoyable, informative and at times witty. Gravity is one of those concepts everyone thinks they understand, only occasionally discovering that their notions of gravity are identical to those held in the time of Newton Curiously enough, just as in every other area of scientific inquiry, there have been significant new discoveries and developments in our understanding of this force on huge and infinitesimally small scales Where this book succeeds is in providing the curious reader with a context to understand the current ways gravity is being studied Beginning the the journey with Newton, venturing through Maxwell and Einstein and up to early developments of string theory, Chown writes very accessibly and vividly on the history of this study Perhaps the primary disappointment is that there is little in the way of contemporary accounts of quantum gravity He does a remarkable job setting the stage but once we get to the past couple decades the book ends abruptly which is a bit disappointing.However if this is a topic you re interested in and haven t thought about much beyond the very earliest theories then Marcus Chown has written a very eloquent introduction here. Marcus Chown is one of the UK s best writers on physics and astronomy it s excellent to see him back on what he does best Here we discover our gradual approach to understanding the nature of gravity the ascent of the title which, though perhaps slightly overblown in the words the force that explains everything quantum physics does quite a lot too, for example , certainly makes us aware of the importance of this weakest of fundamental forces Chown s approach to gravity is a game of three halves, as they say, broadly covering Newton, Einstein and where we go from general relativity.As far as the first two sections go, with the exception of the 2015 gravitational waves detection, there s not much that s actually new if you want a popular science exploration of these aspects of the topic with depth there are good alternatives but no one has covered the topic with such a light touch and joie de vivre as Chown Although Chown doesn t give us too much character detail on his two key figures, we get good mental sketches of them, enough to get a feel for what kind of personality produced the remarkable work that each was responsible for There has been a lot written of late criticising science writers for putting too much focus on the heroic lone individual in the history of science And we certainly get a full power portrayal of this pair as solitary geniuses But though you can quibble about how original calculus was or whether Einstein should have given credit to others in his work on special relativity, it s hard to imagine two people in the history of science who deserve this treatment and it is far and above the best approach for the kind of storytelling that Chown excels at.The third section has its highs and lows It gives what I think is the best introduction to string theory at this basic descriptive level I ve ever seen, going considerably beyond the basics of vibrating strings and rolled up dimensions However, I was rather surprised at the total dismissal of string theory s main rival, loop quantum gravity, which literally only appears in an end note In one sense this was refreshing I had read so much pointing out the flaws in string theory and how it arguably wasn t even science because of its inability to make useful predictions that I had pretty much mentally dismissed it It seemed very reasonable that the only thing that kept it alive was the large number of careers that had been dedicated to it Chown, however, gives it a spirited defence which, while not necessarily clinching, certainly made it possible to understand why so many physicists found it attractive.Overall, then, a very readable exploration of humanity s gradual realisation of what gravity was about with all of Chown s usual sparkle It would have been good if we had seen a little of the points where things aren t set in stone for example the alternatives to dark matter or that elusive loop quantum gravity but what we get is a delight. M s bien, son 4,75 estrellas Un libro de divulgaci n cient fica muy ameno y revelador Viva Blackie Los agujeros de gusano, la materia oscura, el ansiado gravit n todo se sucede en sus p ginas como los estribillos siguen a las estrofas en las canciones de ABBA Me quedo con la tetradimensionalidad del universo, en la que todo existe simult neamente el pasado, el presente y el futuro Laika y Bowie siguen aqu Como dijo el f sico qu mico ingl s Michael Faraday, nada es demasiado maravilloso para ser verdad.