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| 4.16
| 1,277
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| 2018
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really liked it
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I read some excellent books in 2018; here are my top 10. They're all so different and so good in their own various ways that it seemed unfair to compa
I read some excellent books in 2018; here are my top 10. They're all so different and so good in their own various ways that it seemed unfair to compare them, so I've put them in alphabetical order: Albert Einstein-Max Born, Briefwechsel 1916-1955 I am ashamed that I had to wait until now to discover what a truly admirable person Max Born was, both as a scientist and as a human being. This book is supposed to be an edited edition of his correspondence with Einstein, but it's a memoir at the same time. Genuinely inspirational. An Orchestra of Minorities Just a fantastic novel, completely different from anything I've ever come across. Read it. La Danse de Gengis Cohn Well, who would have thought you could write a witty comedy about Auschwitz that is at the same time deeply respectful towards the victims of the Shoah? Romain Gary shows you it's possible. L'enfant perdue The last volume of Elena Ferrante's Neapolitan novels is as amazing as the others, maybe even more so. Litli prinsinn I discovered that I could (sort of) understand Icelandic! Not only that, the book got us started on developing an exciting new software tool to help people who are learning to read in a new language. Oliver Byrne: The First Six Books of the Elements of Euclid You can present Euclid so that it's fun. Check it out if you don't believe me. Putin's Russia Brilliant, no-holds-barred reporting from a journalist who wasn't afraid to risk her life to tell you what's really going on. They got her in the end, but her work is still here annoying the evil bastards who are trying to take over the world. Superintelligence: Paths, Dangers, Strategies If this doesn't scare the shit out of you, you are not paying attention. I can't stop thinking about it. Tolkien: Maker of Middle-earth The ultimate birthday present for any Tolkien geek. Uppgång & fall This unassuming little comic book is the best shot I've seen in ages at explaining why everything is so totally fucked up, and what we might do about it. Yay Liv Strömquist! I hope something there made you reach for your credit card. They're all solid gold. ...more |
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1
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Jan 2018
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Dec 31, 2018
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Jan 19, 2019
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| 0199678111
| 9780199678112
| 0199678111
| 3.86
| 19,126
| Jul 03, 2014
| Sep 03, 2014
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it was amazing
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Superintelligence was published in 2014, and it's already had time to become a cult classic. So, with apologies for being late getting to the party, h
Superintelligence was published in 2014, and it's already had time to become a cult classic. So, with apologies for being late getting to the party, here's my two cents. For people who still haven't heard of it, the book is intended as a serious, hard-headed examination of the risks associated with the likely arrival, in the short- to medium-term future, of machines which are significantly smarter than we are. Bostrom is well qualified to do this. He runs the Future of Humanity Institute at Oxford, where he's also a professor at the philosophy department, he's read a great deal of relevant background, and he knows everyone. The cover quotes approving murmurs from the likes of Bill Gates, Elon Musk, Martin Rees and Stuart Russell, co-author of the world's leading AI textbook; people thanked in the acknowledgements include Demis Hassabis, the founder and CEO of Google's Deep Mind. So, why don't we assume for now that Bostrom passes the background check and deserves to be taken seriously. What's he saying? First of all, let's review the reasons why this is a big deal. If machines can get to the point where they're even a little bit smarter than we are, they'll soon be a whole lot smarter than we are. Machines can think much faster than humans (our brains are not well optimised for speed); the differential is at least in the thousands and more likely in the millions. So, having caught us up, they will rapidly overtake us, since they're living thousands or millions of their years for every one of ours. Of course, you can still, if you want, argue that it's a theoretical extrapolation, it won't happen any time soon, etc. But the evidence suggests the opposite. The list of things machines do roughly as well as humans is now very long, and there are quite a few things, things we humans once prided ourselves on being good at, that they do much better. More about that shortly. So if we can produce an artificial human-level intelligence, we'll shortly after have an artificial superintelligence. What does "shortly after" mean? Obviously, no one knows, which is the "fast takeoff/slow takeoff" dichotomy that keeps turning up in the book. But probably "slow takeoff" will be at most a year or two, and fast takeoff could be seconds. Suddenly, we're sharing our planet with a being who's vastly smarter than we are. Bostrom goes to some trouble to help you understand what "vastly smarter" means. We're not talking Einstein versus a normal person, or even Einstein versus a mentally subnormal person. We're talking human being versus a mouse. It seems reasonable to assume the superintelligence will quickly learn to do all the things a very smart person can do, including, for starters: formulating and carrying out complex strategic plans; making money in business activities; building machines, including robots and weapons; using language well enough to persuade people to do dumb things; etc etc. It will also be able to do things that we not only can't do, but haven't even thought of doing. And so we come to the first key question: having produced your superintelligence, how do you keep it under control, given that you're a mouse and it's a human being? The book examines this in great detail, coming up with any number of bizarre and ingenious schemes. But the bottom line is that no matter how foolproof your scheme might appear to you, there's absolutely no way you can be sure it'll work against an agent who's so much smarter. There's only one possible strategy which might have a chance of working, and that's to design your superintelligence so that it wants to act in your best interests, and has no possibility of circumventing the rules of its construction to change its behavior, build another superintelligence which changes its behavior, etc. It has to sincerely and honestly want to do what's best for you. Of course, this is Asimov Three Laws territory; and, as Bostrom says, you read Asimov's stories and you see how extremely difficult it is to formulate clear rules which specify what it means to act in people's best interests. So the second key question is: how do you build an agent which of its own accord wants to do "the right thing", or, as Socrates put it two and half thousand years ago, is virtuous? As Socrates concludes, for example in Meno and Euthyphro, these issues are really quite difficult to understand. Bostrom uses language which is a bit less poetic and a bit more mathematical, but he comes to pretty much the same conclusions. No one has much idea yet of how to do it. The book reaches this point and gives some closing advice. There are many details, but the bottom line is unsurprising given what's gone before: be very, very careful, because this stuff is incredibly dangerous and we don't know how to address the critical issues. I think some people have problems with Superintelligence due to the fact that Bostrom has a few slightly odd beliefs (he's convinced that we can easily colonize the whole universe, and he thinks simulations are just as real as the things they are simulating). I don't see that these issues really affect the main arguments very much, so don't let them bother you if you don't like them. Also, I'm guessing some other people dislike the style, which is also slightly odd: it's sort of management-speak with a lot of philosophy and AI terminology added, and because it's philosophy there are many weird thought-experiments which often come across as being a bit like science-fiction. Guys, relax. Philosophers have been doing thought-experiments at least since Plato. It's perfectly normal. You just have to read them in the right way. And so, to conclude, let's look at Plato again (remember, all philosophy is no more than footnotes to Plato), and recall the argument from the Theaetetus. Whatever high-falutin' claims it makes, science is only opinions. Good opinions will agree with new facts that turn up later, and bad opinions will not. We've had three and a half years of new facts to look at since Superintelligence was published. How's its scorecard? Well, I am afraid to say that it's looking depressingly good. Early on in the history of AI, as the book reminds us, people said that a machine which could play grandmaster level chess would be most of the way to being a real intelligent agent. So IBM's team built Deep Blue, which beat Garry Kasparov in 1997, and people immediately said chess wasn't a fair test, you could crack it with brute force. Go was the real challenge, since it required understanding. In late 2016 and mid 2017, Deep Mind's AlphaGo won matches against two of the world's three best Go players. That was also discounted as not a fair test: AlphaGo was trained on millions of moves of top Go matches, so it was just spotting patterns. Then late last year, Alpha Zero learned Go, Chess and Shogi on its own, in a couple of days, using the same general learning method and with no human examples to train from. It played all three games not just better than any human, but better than all previous human-derived software. Looking at the published games, any strong chess or Go player can see that it has worked out a vast array of complex strategic and tactical principles. It's no longer a question of "does it really understand what it's doing". It obviously understands these very difficult games much better than even the top experts do, after just a few hours of study. Humanity, I think that was our final warning. Come up with more excuses if you like, but it's not smart. And read Superintelligence. ...more |
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1
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Feb 2018
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Feb 05, 2018
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Jan 21, 2018
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| 0316226106
| 9780316226103
| 0316226106
| 3.62
| 2,899
| Jan 01, 2013
| Mar 05, 2013
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it was ok
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"So what's it like?" asked Not. "What?" said Manny absent-mindedly. "That book," said Not. "The one Noella gave you." "Terrible," said Manny after a paus "So what's it like?" asked Not. "What?" said Manny absent-mindedly. "That book," said Not. "The one Noella gave you." "Terrible," said Manny after a pause. "Absolutely dreadful. Worst thing I've seen since Harry Quebert." "So that's why you've been reading it all day?" said Not, as her eyebrows did an impression of two rock-climbers starting a rather tricky ascent. "Yes," said Manny, without looking up. "It's just not funny. He keeps putting in all these contrived metaphors that are supposed to be amusing, but they aren't." The mountaineers, who had been stuck on an overhang, got out their pitons and edged onwards. "So I suppose you'll be coming to bed then?" said Not's mouth, quite a bit further down her face. "Oh," said Manny vaguely, "I think I might as well finish it. I only have another sixty pages to go." The climbers, surprised by the sudden progress they'd made, wondered if they might be able to reach the top after all. Manny glanced up for a moment and stopped, surprised. "You look kind of weird," he said. "Is something wrong?" "Don't worry," said Not. "I didn't mean to interrupt you." "That's okay," said Manny, as he opened the book again. ...more |
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1
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Dec 23, 2017
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Dec 25, 2017
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Dec 23, 2017
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Paperback
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| 0691119791
| 9780691119793
| 0691119791
| 3.89
| 273
| Feb 22, 2016
| Sep 27, 2016
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really liked it
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Roger Penrose is 85, and a lot of the material in this book has previously appeared in The Road to Reality and Cycles of Time. By all rights it should
Roger Penrose is 85, and a lot of the material in this book has previously appeared in The Road to Reality and Cycles of Time. By all rights it should be awful, but in fact it's pretty good; none of the standard rules ever seem to apply to him. Incredibly, he's still alert, still active, still working hard on his collection of wacky but fascinating ideas. He's made considerable progress over the last decade and eagerly tells you about it in his well-constructed sentences and trademark diagrams. He knows you were wondering about that odd connection he claimed existed between quantum mechanics and gravity; now he goes into detail, writes down new equations which, to your surprise, sort of make sense, tells you about an experiment he and his colleagues are planning with a beam-splitter and a tiny suspended mirror which just might be able to test whether the theory works. He's improved his utterly bizarre cosmology, which not only has a universe before the Big Bang and one literally after the end of time, but connects them together. He scribbles down those cryptic conformal diagrams, with squiggly lines representing singularities and solid lines representing the infinite future, and explains the reasoning which led him to the conclusion that, even if this is obviously insane, the other alternatives are even more insane. When you start objecting, he presents sensible-sounding thermodynamic arguments to show just how much trouble inflation and the anthropic principle are in. You're trying to digest that, and he hits you with an afterthought from one of the final chapters of The Road to Reality. You know how he was trying to explain why holomorphic sheaf cohomology is really pretty obvious? Well, look at this picture! You see? You see? It is obvious! For a moment, you feel you agree with him. He somehow manages to suck you into his world and show you his unique way of thinking. You can't categorise him. Sometimes he comes across as a traditional mathematician complaining about the lack of rigour in quantum field theory, sometimes as a visionary physicist with a startling new picture of the world, sometimes as the ultimate hard science-fiction writer, the sort of person Niven or Asimov would have liked to be if only they'd had the necessary technical skills. Every now and then you catch him shifting, but usually he's too quick for you. At the end, he complains in a slightly surprised tone that he's never understood why people call him a maverick. In fact, he has very conservative views on physics. He almost makes it sound plausible. Then, on the final page, he tells you about his father's strong belief that Shakespeare's plays were written by Edward de Vere, the Earl of Oxford. As he says goodbye, he recommends in passing the original book on the subject, by (I looked it up, and it's correct), one J. Thomas Looney. Is he kidding you? He must be, but you glance at him and he's completely straight-faced. There's only one Roger Penrose. ...more |
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1
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Mar 12, 2017
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Mar 28, 2017
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Mar 12, 2017
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Hardcover
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| unknown
| 4.23
| 1,178
| 2016
| 2016
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really liked it
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Okay, it's that time of year again. Here are my prizes for books first read in 2016, split up by category: New languages I thought I'd see if I could re Okay, it's that time of year again. Here are my prizes for books first read in 2016, split up by category: New languages I thought I'd see if I could read books in Russian and Italian - I did a couple of years of Russian at school during the 70s, and my mother is Italian, though she never taught me her language. How hard could it be? Answer: Italian does in fact seem pretty easy, though so far I've only read a few children's books. Russian is considerably harder! I did however manage to get through a long chess book, Защита Алехина , and I'm sure it's improved my command of the language a great deal. More Italian and Russian in 2017! German I've been working on German for two or three years now, and I'm starting to feel more confident. I can read books for children and younger teens without difficulty, and adult books if I'm prepared to guess a fair number of words. For people who don't already know, there is some wonderful German children's literature. I think my favorite was Jim Knopf und Lukas der Lokomotivführer , which I'd barely even heard of before I found a copy on a Berlin bookstall, but there were several others that ran it close. A big thank you to all my Germanophone Goodreads friends, especially Matt, who have been amazingly kind and supportive towards this newbie's efforts! Scandinavian We unexpectedly inherited a bunch of Swedish books from the aunt of a Geneva friend - he didn't know anyone else who read Swedish, so I was the lucky recipient. Thank you Gio! As a result, I finally got around to reading Ingmar Bergman's Laterna Magica , which was indeed just as extraordinary as I'd been led to believe. I have plenty more interesting Swedish books on the shelf! I only read one Norwegian book, but Pan was utterly brilliant. I must get back to reading Hamsun. French I read sixteen French books this year. The one I liked best was La carte et le territoire ; unlike many novelists, Michel Houellebecq seems to be improving as he gets older. I thought this was a wonderful black comedy, and I'd recommend it to anyone interested in the world of modern art. Soumission, the book that followed it, is even better. English fiction I didn't read a huge amount of English fiction, but Geoff finally persuaded me to pick up Against the Day . Geoff, you were right... it's as good as you said. It was the first book I read this year, and I was going to read some more Pynchon, but we're already in mid-December. Oh well... more Pynchon in 2017, I think! Non-fiction I read 26 non-fiction books - it's difficult to pick a clear winner, and I think I'm going to have to share first place between Helge Kragh's Niels Bohr and the Quantum Atom and Catherine MacKinnon's Towards a Feminist Theory of the State . The first one convinced me that I had to carry on with quantum mechanics; the second, that I needed to start on feminist theory. My 2017 list gets longer... Special prize If only more people had read Trump University 2010 Playbook , things could have been different. Anyway, you might want to take a look now. You can't say you weren't warned. ...more |
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1
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Jan 2016
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Dec 11, 2016
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Dec 07, 2016
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| 1107156610
| 9781107156616
| 1107156610
| 4.21
| 188
| Aug 07, 2016
| Nov 10, 2016
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really liked it
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I came across Luke Barnes and his blog Letters to Nature when I was looking for expert commentary on New Atheist Victor Stenger's The Fallacy of Fine-
I came across Luke Barnes and his blog Letters to Nature when I was looking for expert commentary on New Atheist Victor Stenger's The Fallacy of Fine-Tuning, and was delighted to quote from him in my review. Now Barnes and his colleague Geraint Lewis have come out with their own book, which they wittily describe in the bibliography as "the antiparticle of Stenger's". There's no doubt as to who wins this fight. Stenger, who should be ashamed of himself, commits all the crimes that atheists like to lay at the door of their creationist enemies: he's rigid, dogmatic, humorless and startlingly dishonest. Barnes, in contrast, is scrupulous about sticking to the facts and not mentioning the G-word, as he disarmingly puts it, until he gets to the final chapter. Even then, he follows tradition and presents his case as a dialogue between himself and (as far as I can see, non-theist) coauthor. I'm raising his hand in triumph above the supine body of his opponent. It's Barnes, by a knockout. For the benefit of people who came in halfway through this mini-epic, let me recap. The "Fine Tuning Problem", which has now been around for over forty years, is the claim that the laws of Nature appear to be carefully adjusted in order to make life possible. The basic ideas have been presented in several earlier popularisations, notably Rees's Just Six Numbers and Davies's The Goldilocks Enigma; but these books, unfortunately, didn't go into enough detail and failed to make the case as convincing as it could have been. Lewis and Barnes (henceforth, L&B) have been defending fine tuning for some time in both academic and public forums, and demonstrate fingertip familiarity with all the issues. They know where the most convincing evidence is; they also know how to answer all the standard objections. The problem is that the best line of argument, the relative masses of the different quarks and leptons, is also one of the most technical ones, but L&B have found good ways to explain what's going on. Everything we see is made of protons, neutrons and electrons, and there are also vast numbers of invisible, very light neutrinos constantly streaming through us. The masses of the proton and the neutron are determined by the masses of the up and down quarks. It turns out that there are numerous strong constraints on the different masses. If things are pushed a little bit in one direction, you get a universe where there are only neutrons; in another, you get nothing but an exotic particle which in our real universe is very unstable; in a third direction, all the hydrogen gets used up in the first few minutes of the Big Bang and there is nothing left to power stars; in a fourth, too much mass leaks away from the initial concentrations and galaxies never form. When you put it all together, there's hardly anything left, just a tiny area of the graph where we fortuituously happen to find ourselves. It is indeed mysterious. Of course, you can pick at this argument, and L&B devote a whole chapter to the numerous responses. Yes, it's hard to define exactly what life is and there are borderline cases like viruses, but this isn't the point. Nearly all the universes ruled out by the constraints are so fantastically inhospitable that the borderline cases are irrelevant. No life remotely like ours is going to exist in a universe that consists entirely of huge black holes, or of a thin soup of protons in which each particle is separated by trillions of light-years from its nearest neighbor. And yes, it is conceivable that there are forms of life totally unlike ours, but until someone at least suggests an in-principle mechanism by which such lifeforms could function, it's science-fiction rather than science. Lacking such creative suggestions, it seems quite reasonable to assume that life requires chemistry based on carbon, the only atom which allows formation of large, structured molecules. This creates further constraints, and makes our universe even more special. My personal sympathies lie more in the atheist direction, but I think L&B are doing something admirable here. It doesn't matter that fine tuning is currently popular with theists like Francis S. Collins (The Language of God) or Richard Swinburne (Is There a God?). It doesn't matter that one of them (Barnes) appears to be a theist himself. What matters is that they're doing their best to look impartially at the evidence and see where it leads them. They are in good company. William Paley's carefully observed Natural Theology inspired Darwin to discover evolution; Georges Lemaître, with his clever interpretation of Hubble's redshift measurements, provided the initial basis for the Big Bang theory. In both cases, good scientists who happened to be theists got a subject moving in a new and fabulously productive direction because they were not afraid to say they'd found something strange that needed an explanation. We don't know if fine tuning is going to be equally successful. But it's always nice to see people who think data is more important than political correctness. ...more |
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1
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Nov 10, 2016
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Nov 14, 2016
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Nov 03, 2016
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Hardcover
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| B01HWROW0W
| 3.58
| 19
| unknown
| Jul 02, 2016
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liked it
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Like Philip K. Dick, but with more dick.
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Notes are private!
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1
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Jul 15, 2016
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Jul 15, 2016
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Jul 24, 2016
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Kindle Edition
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| 019046982X
| 9780190469825
| 019046982X
| 3.81
| 54
| unknown
| Jul 12, 2016
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really liked it
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What does quantum mechanics tell us about the fundamental nature of the world? This certainly sounds like a philosophical question, and I remember com
What does quantum mechanics tell us about the fundamental nature of the world? This certainly sounds like a philosophical question, and I remember complaining to Simon Evnine a couple of years ago that more philosophers should be taking an interest. I didn't have to wait long: one of his colleagues has just published this book, which OUP kindly sent me last week. The author has a well-organized and sensible approach, which starts with empirical facts rather than theories. Let's look at the good old double-slit and EPR experiments. What do we learn from them? In the double-slit experiment, you let light go through two slits and hit a screen. You see an interference pattern on the screen, which traditionally is explained by saying that light is waves, and the two sets of waves are interfering with each other. But, very mysteriously, the same thing happens even when you turn down the intensity of the light so that only one photon at a time is coming out of the light source. You'd think the photon would have to go though either one slit or the other, so there could be no interference. But that's not so: the single photon somehow appears to have gone through both slits and interfered with itself, since you still see interference! Even more mysteriously, the same thing happens when you do the corresponding experiment with electrons, letting them diffract through a crystal lattice. A single electron can also interfere with itself. In the Einstein-Podolsky-Rosen (EPR) experiment, you create two charged particles in such a way that they are guaranteed to have opposite directions of spin. You can do this so that you are sure about the spins being opposite, but you don't know anything else. You leave the particles undisturbed and let them move until they are separated by a good distance; then you measure the spin on one of them. Quantum mechanical spin is different from our usual ideas of what spin is, and you measure spin in a given direction by letting the particle pass through a magnetic field. Say the magnetic field is vertical; it turns out that the particle will always go either up or down by a fixed amount, so you say the spin is "up" or "down". If you turn the magnet 90 degrees so that it's horizontal, the particle goes left or right by the same fixed amount. Physicists don't now say that the particle's spin is "left" or "right", as one would expect. Instead, it fits the facts better to change the way you use language. You still say it's "up" or "down", but this time in the horizontal direction; in the first case, you say it's "up" or "down" in the vertical direction. The reason for the odd terminology, and the general weirdness, comes out when you look more closely at the details. If spin were what we're used to thinking it is, then a particle which was measured as having spin "up" in the vertical direction wouldn't have any spin in the horizontal direction. But in the quantum world, not so! You find it will be "up" or "down" in the horizontal direction, with equal probability of both outcomes. Going back to the two particles in the EPR experiment, if you measure spin vertically on one particle and find it's "up", then it turns out that if you measure spin vertically on the the other, you are sure to get "down". And the same if you measure spin horizontally: if one particle is measured as horizontally "up", then the other is always measured as horizontally "down". But how does the second particle know what to do? It seems as though there are only two possibilities. Either a magic, invisible signal has passed between the two particles, or they had opposite spins all along; since the first explanation is impossible, the second must be correct. Again, the quantum world is not the world we're used to. We assume intuitively that there must be some fact of the matter about whether the first particle has its spin oriented vertically "up" or not, and it's a question of finding out what's going on. But the evidence shows that there is no fact of the matter until you actually carry out the spin measurement. Bell's Theorem, proved back in the 60s and explained here, establishes that there is no consistent way to assign spins to the original particles in accordance with ordinary logic, which takes for granted the idea that a particle has its own identity and its own properties. So in fact neither of the common-sense explanations works: the particles didn't start off with specific opposite spins, but there is no magic signal either! The solution requires a completely new idea, "entanglement". Before you measure the spins, the two particles are "entangled", and you can't talk about the state of one without at the same time talking about the state of the other. They've got opposite spins, and that's the end of the story. These two paradoxical experiments, double-slit and EPR, have passed into the folk literature and been interpreted in many imaginative ways. For example, in Charles Harness's SF short story The New Reality, a version of the double-slit experiment so confuses a photon that it slows down, somehow destroying the universe; in Michel Houellebecq's novel Les particules élémentaires, EPR is used as a metaphor to suggest (I think) that Western civilization's attitude to sex will either result in its downfall or in its transformation to a post-sexual society; in Bernard Haisch's The Purpose-Guided Universe, EPR proves that the universe is the product of the universal mind and that we all are God; and in Jim Jarmusch's film Only Lovers Left Alive, EPR ("spooky action at a distance") has some connection, I'm not exactly sure what, with relationships between semi-immortal vampires. This is fun, but it's obviously nonsense. Quantum physicists, who tend to be more interested in mathematics than in vampires, long ago figured out how to write equations that make correct predictions about what's happening in these cases. You represent the world as a "wave-function"; you represent the process of making a measurement as an "operator" on that wave-function; the details are complicated, but it all works well enough to do things like building hydrogen bombs and microprocessors. But what is the "wave-function"? What, if anything, does it have to do with the traditional notion of "reality"? Is it the wave-function that's real, rather than the things we normally think of as real? What happens to other traditional notions like "causality" and "individual"? That's basically what this book is about. Lewis rarely claims to be giving you answers - when he did, I often felt I disagreed with him. Rather, as a good philosopher should, he confronts you with the questions and forces you to think about them. He makes you feel they're pretty important questions; in fact, for people who enjoy thinking about fundamental philosophical issues, it's hard to imagine anything that could be more important. If you're that kind of person and don't already have a thorough grasp of the philosophy of quantum mechanics, you might want to take a look at Quantum Ontology. The world is even weirder than you thought it was. [image] ...more |
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Sep 10, 2016
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Sep 17, 2016
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Mar 16, 2016
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Hardcover
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| 1601631227
| 9781601631220
| 1601631227
| 3.95
| 167
| May 01, 2010
| May 20, 2010
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did not like it
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I agree with the author of this book up to a point: right now, the main options on offer in the science/religion war aren't very appealing. On one sid
I agree with the author of this book up to a point: right now, the main options on offer in the science/religion war aren't very appealing. On one side, the creationists are obviously talking complete nonsense. But the aggressive certainty of the new atheists on the other side is dismaying as well. Unfortunately, the third way proposed by Bernard Haisch isn't an improvement. Quoting from some extremely old-fashioned interpretations of quantum mechanics - he is fond of the more visionary passages from Schrödinger's What Is Life? - Haisch explains that modern science has "proved" that the everyday reality we see around us is created by consciousness. He then goes on to present a very superficial version of the fine-tuning problem, which "proves" that the whole universe must also have been created by consciousness. There is a great deal about the "Perennial Philosophy", Buddhism, mysticism and the nature of the Godhead, but next to nothing about inflation, the many worlds interpretation of quantum mechanics or the multiverse, beyond repeated assurances that they are just as faith-based as the ideas Haisch suggests and hence in no need of serious examination. It really becomes depressing after a while: a book which explains that the secrets of reality can be found in mystical experiences and quantum mechanics, written by someone who's never had a mystical experience, doesn't understand how quantum mechanics works, and can't write. Come back Richard Dawkins, all is forgiven. ...more |
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Jul 23, 2016
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Jul 24, 2016
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Dec 16, 2014
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Hardcover
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| 1846144760
| 9781846144769
| 1846144760
| 4.19
| 7,815
| Jan 07, 2012
| Jan 07, 2014
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really liked it
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"Aaargh! No! Make it stop!" That's my girlfriend, who's just been unwise enough to let me read her a paragraph of this book. But our guest K, a local n "Aaargh! No! Make it stop!" That's my girlfriend, who's just been unwise enough to let me read her a paragraph of this book. But our guest K, a local nuclear physicist, is more tolerant. "Well," she smiles, "it doesn't sound so bad. A bit exciting, a bit populistic..." Blah blah blah. On the other hand, she isn't a native speaker of English. Okay, let's start by getting the bad news out of the way. Max Tegmark's chatty, informal, slightly manic style is on the irritating side, and if you know some physics it may also give you the impression that you're not going to learn anything from Our Mathematical Universe. Unless you're working at the cutting edge of the subject, that impression is almost certainly false. When I briefly explained the content to K, I soon found that it wasn't just a question of a few interesting details that she hadn't previously come across. Isolated like most working scientists in her own specialty, the dating of rocks using radioactive isotopes, she hadn't even heard that a major paradigm shift was under way in the theoretical basis of her field. I hope I managed to convince her that the book was well worth looking at. Yes, the style is annoying at first, but after a couple of chapters I stopped noticing it. I was in the bar, I'd had a few beers, and my new buddy Max ("Mad Max", he'd said, with an ironic smile) was telling me about his research, life in the charmed inner circle of theoretical physics, and his ideas about the ultimate nature of reality. Every now and then, I managed to get a word in edgeways and complain about some of the more outrageous claims. Max had evidently heard it all before, and deftly batted back my objections. I wasn't exactly convinced, but he made it sound a whole lot more plausible than I'd expected. Max's central idea is the Multiverse, where he has been one of a small number of people who's played an evangelical role. More or less considered as science-fiction fifteen years ago, it's now almost respectable; it's astonishing how quickly the change has happened. Max has a cunning scheme in which the Multiverse is presented in four increasingly bolder versions, from Level I to Level IV. I'd seen a fair amount of his material already, particularly in Brian Greene's The Hidden Reality, but Max's presentation is much better. He's worked directly on several of the key ideas, and his hands-on experience makes the stories considerably more believable. He starts off with Level I, which at first sounds innocuous. What is there in the universe? he asks. A naive answer might be that it's everything we can see through our telescopes. But even a moment's thought will prompt some revision. Sometimes there are things in the way - clouds of dust and gas along the galactic plane, for example. Surely there's something behind those clouds. Well then, the universe consists of all the things we can see, plus all the similar things we can infer must also be there. But what are those other things? Objects getting in the way is just one problem. There are also things that are very distant - so distant that light from them hasn't had time to reach us yet. How far away could these other objects be? That's a complicated question which has to do with the structure of space. Max has done a lot of work with the Cosmic Background Radiation, the light from the Big Bang, to see what it can tell us about that structure. It was fascinating to see him quickly sketching graphs on paper napkins, explaining how he'd analyzed the data and what the results told us. One key finding, as I'd heard before, is that space turns out to be flat. That means it goes on forever, so there are infinitely many more galaxies over the horizon of visibility. In that infinite expanse, every possible history has played out, including histories arbitrarily close to our own. It's sort of Nietzsche's Eternal Recurrence, but in space instead of time. At some unfathomable distance (he makes a rough estimate), there are doppelgangers of Max and me, sitting in the same bar and having the same conversation. An extremely weird conclusion... but, oddly enough, it seems to follow from entirely reasonable premises. And this is only Level I. So why is the universe flat? asks Max rhetorically. Inflation? I say, as I order another round. I've seen many explanations of inflation, but it's hard to decide how seriously I should take them. Max knows all the ins and out, and argues both sides of the case. He collects some beer mats and arranges peanuts on them to demonstrate a simple argument, due to his buddy Alexander Vilenkin, that shows why inflation has to be "eternal". If it happened at all, it more or less had to generate an infinite number of Level I multiverses, all with different physical laws; that's Level II. But did it happen? I ask. What's the evidence? Max scribbles down more pictures of the power spectrum from the CBR, and explains how they fit the inflation scenario while ruling out a bunch of other theories. He really has that talent for showing you what the mathematics means in intuitive terms. I have to admit it: the case looks better than I'd realized. Level III is the quantum multiverse: everything that can happen, does happen. I've read several books about this and am more or less convinced already, but Max's version of it is very nice. He describes how he invented the quantum suicide thought experiment and tells me about some clever details that I should have thought of but hadn't. It's even weirder than I'd realized. And now, we need to proceed to Level IV before closing time. But surely we should get some more beer first? I mumble something about how I've maybe had enough, but Max isn't taking no for an answer. Du sa nåt om att du bott in Sverige? he says, and before I know what's happened there's a bottle of akvavit on the table between us. He pours out a couple of generous glasses. Level IV, it turns out, makes all the others look modest in comparison. Think about the fundamental particles, urges Max. We can see that they are entirely specified by their mathematical properties. So what's the simplest explanation? Reality just is mathematical structure. Every mathematical structure specifies a reality! But what breathes fire into the equations? I ask. Nothing does! says Max. Skål! I empty my glass, which is magically full again a moment later. The room seems to be revolving slowly. It's... uh... interesting, I say. But surely there's no way to investigate the idea empirically? Maybe! replies Max, and sketches out yet another graph, this time showing constraints on the Higgs VEV. His explanation is fiendishly clever, unless that's just the effect of the akvavit. But surely there are problems with all this? I say weakly, ashamed that I can't immediately come up with half a dozen objections. Max suddenly looks thoughtful and almost sober. The measure problem is very serious, he says. It's a crisis in physics. He and his identical twin, who's just appeared next to him, proceed to explain it. I nod every now and then and try to put my hand over my glass, but he's too quick for me. The next morning, I have no memory at all of how I got back to my hotel room, though I dimly recall Max saying something about the dangers of nuclear war, meteorites and evil AI entities. Or was that a dream? I do at any rate have a pile of paper napkins, covered in illegible scrawls and smelling strongly of akvavit. Read this book. It's fun. ...more |
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In 1619, Johannes Kepler, a theoretical astronomer who earned the greater part of his income from casting horoscopes, published the Harmonices Mundi,
In 1619, Johannes Kepler, a theoretical astronomer who earned the greater part of his income from casting horoscopes, published the Harmonices Mundi, the "Harmony of the World". It contained a statement of the Third Law, relating the period of a planet's rotation around the sun to the radius of its orbit; this was the fruit of years of diligent work, and a first-order scientific breakthrough. The book also contained hundreds of pages of the most ridiculous pseudo-scientific nonsense, where Kepler used the shapes of the regular geometric solids to explain the distances of the various planets from the Sun. He later considered the notes of the musical scale and inferred the heavenly harmonies produced by the celestial choir. The serious-minded Laplace, writing his brief history of astronomy a couple of centuries later, is shocked. How could someone as smart as Kepler do this? What was he thinking? If things work out well for David Deutsch, it's possible that an as yet unborn historian will write similar things about him in the twenty-third century. Some parts of his modestly-titled The Fabric of Reality are interesting and insightful. In particular, he makes a rather good case for the reality of the quantum multiverse, which already seems to have had a considerable effect: I didn't realize it at the time, but I've seen him quoted more than once. Deutsch's presentation combines themes from two of his heroes, Hugh Everett (the inventor of the Many Worlds Interpretation of quantum mechanics) and Karl Popper. Deutsch starts by asking, with Popper, about the nature of the scientific process. He claims that it is primarily about using evidence-based argument to weigh the merits of rival explanations; the best scientific theory is the one that is currently winning the arguments. He persuasively suggests that, on these reasonable-sounding criteria, Everett's Many Worlds Interpretation is in fact the best way to think about quantum mechanics. In particular, it is by far the most intuitive way to think about quantum computers, a subject where Deutsch has played a pioneering role. If you are at all interested in these matters, I strongly recommend reading his clear, lucid exposition. And then... oh dear. From its logical, eminently sane beginnings, the book gradually descends into more and more bizarre territory. Deutsch introduces his eccentric personal take on the Church-Turing thesis, and uses it to derive all manner of odd consequences. He tells us that everyone who has ever worked on the philosophy of mathematics has got it wrong: mathematical proof is part of the physical world, and thus essentially bound by the laws of physics. He spends thirty pages discussing time-travel, and concludes that it is perfectly feasible in the quantum multiverse. In the last chapter, he throws aside all his inhibitions and outlines an extended fantasy, based on the work of Frank Tipler, which forecasts the future evolution of the cosmos. Intelligent life, we read, will inevitably learn to control first the Sun, then the galaxy, then the whole universe. As we head for the Big Crunch, the future civilization will take control of the gigantic gravitational energies released to create a godlike cosmic consciousness. This will exponentially slow down time, so that our distant descendents will subjectively never die, living forever in the final moments of the universal collapse. All of this, if I understood correctly, is mandated by the extended Turing Principle: the results, startling as they seem, just follow from the laws of physics. The only thing that's not quite clear is whether the godlike future being will resurrect the dead and put them in a Heaven-like environment. Tipler, a Christian, thinks it will, but Deutsch is inclined to disagree. It must have been disappointing when dark energy was discovered the year after, implying that there wouldn't be a Big Crunch after all. But Deutsch doesn't come across as the kind of guy who sits around and mopes over his setbacks. My guess is that his new theory is even better, and when he and Kepler are resurrected together some time in the infinite future I'm sure they'll have no end of fun comparing notes. ...more |
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really liked it
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Increasingly often, modern science is being attacked by people accusing it of failing to honor its own rules. The opening salvo was Smolin's
The Tr
Increasingly often, modern science is being attacked by people accusing it of failing to honor its own rules. The opening salvo was Smolin's
The Trouble with Physics
, which caused some damage; it was taken seriously within the scientific establishment and widely read outside it. Other authors attempting to do the same thing have been less successful. Non-experts found Woit's
Not Even Wrong
too mathematical and demanding; Berlinski's
The Devil's Delusion
was written off as creationist propaganda; Kragh's elegant and meticulous
Higher Speculations
somehow failed to have an impact; and Unzicker's
Bankrupting Physics
came across as an ignorant rant. But I have a feeling that Baggott is about to score another hit. He has worked as a scientist himself, appears well acquainted with the facts, writes nicely, and presents his material in a balanced and responsible way. The book is divided into two halves. "Farewell to reality", says Baggott in the title, and very properly starts by considering at length the questions of what "reality" is, how science might presume to be able to find out anything about it, and what methods it can legitimately use. He considers numerous cases from the history of science and philosophy, and concludes that it is hard to frame clear general rules. The borderline between physics and metaphysics is not as sharply defined as one would wish (quantum mechanics, or for that matter Newton's idea of absolute space), and it is not straightforward to define what it means for a theory to be empirically testable (it was surprising that Dirac's ideas about anti-matter were soon validated, and experts believed for a long time that no one would ever be able to detect neutrinos). Nonetheless, he argues that there is broad agreement on what constitutes normal scientific reasoning, even if there is a substantial gray area around it. He then spends four chapters presenting an overview of modern physics, concentrating on the fields where controversy has arisen: quantum mechanics, particle physics, relativity and cosmology. In the final chapter of the first half, he explains why the currently accepted mainstream picture must be incorrect or incomplete: he is particularly worried by the quantum measurement problem (Schrödinger's cat), the unknown nature of dark matter, the lack of explanation for the masses of the elementary particles, inability to make quantum mechanics coherent with relativity, and the apparent fine-tuning of the universe's physical constants. In the second half, Baggot goes on to talk about the speculative attempts physicists have made over the last 40 years to address known gaps: supersymmetry, superstring theory, the multiverse (both the Many Worlds Interpretation and eternal inflation), the Cosmic Landscape and the Anthropic Principle. He argues that these are, simply, not science as it is generally known: they involve piling one assumption on top of another, with no empirical evidence at all to buttress it. When the whole shaky tower is complete, we have the theoretical edifice which Susskind presents in The Cosmic Landscape . Superstring theory (no empirical support) builds on supersymmetry (no empirical support), and gives rise to the vast Cosmic Landscape of different potential variant theories (no empirical support). Eternal inflation (no empirical support) means that all these different variant universes actually exist. The Anthropic Principle (according to Baggott, not even a scientific idea), then allows us both to argue that we have a solution to the fine-tuning problem, and, simultaneously, to claim that the fact that the fine-tuning problem has been solved somehow validates the other links in the chain; circular reasoning at its finest. I had the same reaction as Baggott when I read Susskind's book: this doesn't make sense. I was startled by Susskind's assertion that the choice was between the Landscape and some version of Intelligent Design, and even more startled to see Richard Dawkins endorsing it. Baggott doesn't like ID any better than Susskind or Dawkins do, but he is is equally unimpressed by the Landscape. He honestly says that he doesn't know what the answer is. Over the last 500 years, science has had an incredible track record of explaining the physical world without recourse to supernatural explanations, and one would expect it to succeed here too. So far, though, it's completely unclear how it's going to manage that feat. The universe looks like it has been designed, but no one knows why, and the people who say they do know are the ones you should trust least. If you haven't yet got involved in this fascinating debate, Baggott's book is an excellent place to start. Check it out. ...more |
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it was ok
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Sometimes, things just don't work out the way you hope they will. Rand, knowing how much I liked Lee Smolin's
The Trouble with Physics
and Peter W
Sometimes, things just don't work out the way you hope they will. Rand, knowing how much I liked Lee Smolin's
The Trouble with Physics
and Peter Woit's
Not Even Wrong
, asked if I was planning to look at this book. It seemed interesting, and I mailed Palgrave Macmillan to ask if I could get a review copy. They very kindly sent me one. I immediately started reading, and finished it in a few hours: but I'm afraid to say I'm disappointed. I was hoping to get an updating and development of the themes in Smolin and Woit. As they plausibly argue, something is not right with modern physics. Theory doesn't connect properly with experiment, and there is too much pressure to work within the mainstream frameworks; the most obvious example of the malaise is string theory, which, so far at least, has miserably failed to deliver on its early promise. But although Unzicker and Jones are indeed covering similar territory, their treatment fails to impress. Smolin and Woit are experts, and these people aren't. I didn't want to prejudge the issue - as I saw a few weeks ago in Peter Byrne's The Many Worlds of Hugh Everett III , you don't have to be a physicist to write an interesting book about physics - but you do have to be acutely conscious of your limitations. Byrne, who is a good investigative journalist, makes effective use of his talents and is wary about treading on the physicists' home turf: he quotes what they have to say, and he tries to interpret it, but he doesn't attempt to second-guess them. Unzicker and Jones storm in and tell you all the things they believe are wrong with early 21st century physics. This is an extremely hard act to pull off; it's quite possible that they are right some of the time, but their arguments came across as intemperate and unconvincing. In some cases, for instance when talking about string theory and the Strong Anthropic Principle, what they say amounts to little more than abuse. When details are provided, I felt, at the very least, that they were often quoting very selectively. Let's look at some concrete examples. Two major themes are a pair of ideas stemming from Dirac: the "large number coincidences" (there is even an appendix describing them), and the hypothesis that the value of the gravitational constant G changes over time. Unzicker and Jones quote Dicke with approval more than once, but fail to mention that he gave a perfectly reasonable explanation of the large number coincidences in 1961, which is for instance quoted in Rees's Before the Beginning . They list Kragh's Higher Speculations in the bibliography, but do not mention that it contains a long chapter debunking the "varying G" hypothesis. Kragh is an acknowledged expert on Dirac, and I found his account compelling. The discussion of "inflation" in the early universe, another main target, also seemed suspect. Yes, as Penrose and others have pointed out, the theory has hardly been proven yet, and there are important questions left to answer; but the reason why it's popular is not just peer pressure and groupthink, but also the fact that it currently seems to be the best way to address the "flatness" and "horizon" problems, which are indeed mentioned here. It is not true, as Unzicker and Jones claim, that there is no experimental evidence in its favor. Steinhardt and Turok, who are leading critics of inflation, quite rightly point out in their book Endless Universe that inflation made good predictions about the Cosmic Background Radiation which were validated by the WMAP data. Unzicker and Jones make a sort of admission about the key value of 0.96 found for the spectral tilt, but it is phrased in such an oblique way that I doubt I would have had any idea what they were talking about if I hadn't read Steinhardt and Turok first. Perhaps the strangest part was the discussion of symmetry and group theory. For reasons I did not properly grasp, Unzicker and Jones hate these ideas, which are fundamental to modern physics. It is particularly odd that Woit's book, often quoted with approval, is one long hymn to the importance of group theory and representation theory; once again, this is never mentioned. I could not help wondering just how much of Woit they had actually read. I don't want to give the impression that I disliked everything in the book. For example, I found the discussion of galaxy formation interesting; it made me want to read more on this subject, which I know little about. Unfortunately, the fact that I saw so many errors in the chapters where I did have reasonable background knowledge left me feeling unsure as to how seriously I should take their claims about the universe's large-scale structure. In conclusion, I completely agree with Unzicker and Jones that skepticism is good and that Big Science is in trouble; but these points are all made better by Smolin, Woit and Penrose. If you haven't already done so, check them out. _________________________________ After posting the above review, I was contacted by one of the authors, Alexander Unzicker, who objected to my claim that I had found numerous errors in the book and demanded details. He was particularly reluctant to accept what I had written about his treatment of the large number coincidences, varying G and inflation. Well: I am far from being an expert on these matters, but I have read a fair amount about them. It certainly doesn't seem unreasonable to me to describe many statements in Bankrupting Physics as errors, though I suppose one might call some of them extreme fringe theories advanced with little supporting evidence. Looking first at the large number coincidences and varying G, it seemed to me from reading the book that Unzicker was describing Dirac's theories, which were thoroughly debunked in the Kragh chapter I quoted. Unzicker now tells me that he is not in fact referring to Dirac's work, but rather to a variant theory, developed by himself, which is described in a paper he published in 2008. There are several points one might make here. First, I do not think this is made very clear in the book, where it is easy to get the impression that the reference is to Dirac. Second, it seems presumptious to call a large part of the scientific community frauds and liars because they follow mainstream cosmology rather than this extremely obscure idea. And third, having looked at the paper in question, I do not understand what clear experimental predictions it makes which would allow it to be tested. If Unzicker is able to furnish such predictions, and they are confirmed by observation, I am sure people will treat his work with much more respect; so far, however, he does not seem to have done so. Moving on to inflation, I will support my claim that it is unreasonable to say that there is no evidence in its favor; this evidence is by no means conclusive, but it seems quite wrong to say that it does not exist. Looking at a standard reference, Mukhanov's Foundations of Physical Cosmology (2005), I find the following passage on pp. 344-5: Assuming a stage of cosmic acceleration - inflation - we are able to make robust predictions even in the absence of the actual inflationary scenario. The most important among them are:I find this last sentence particularly interesting, given that measurements since then do in fact support the existence of spectral tilt. It is easy to point out other passages in Bankrupting Physics which one could reasonably describe as errors or inconsistencies. Just looking at the last few chapters, we find for example on p. 195 a passage which invites us to compare Ptolemaic and Copernican astronomy, and comments that "The description of the data provided by epicycles wasn't that bad, but dozens of free parameters were necessary to accomplish this." - a strange statement, considering that Copernicus also used epicycles. On p. 209 there is a claim that "no one has the slightest clue" how to calculate the imbalance between matter and antimatter in the early universe; this is in reality a problem that has been studied in great detail, although it has not yet been solved. And on p. 231, we read that "modern theories, with their flamboyant extra dimensions, would have made [Einstein] queasy". In fact, Einstein did quite a lot of work on theories with more than four dimensions, even though he ended up deciding that they were unpromising. In summary, it is very hard for an amateur to launch a convincing attack on Big Science, and Unzicker's book amply demonstrates that fact. ...more |
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| Feb 07, 2013
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it was amazing
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Why would a successful investigative journalist spend three years writing a book about quantum mechanics? Well, the answer is that he knew he'd found a Why would a successful investigative journalist spend three years writing a book about quantum mechanics? Well, the answer is that he knew he'd found a story. Like most people, I had uncritically accepted the standard platitudes. If you think you understand quantum mechanics, that just shows you don't understand quantum mechanics. Or, as Feynman says in a memorable passage from The Character of Physical Law, don't ask yourself how it can be like that. If you do, you will go down the drain into a blind alley that nobody has escaped from. No one knows how it can be like that. But isn't this really very odd? There are plenty of difficult subjects in science, and people don't go around saying that it's impossible to understand them in intuitive terms. If you want to know about DNA, or relativistic cosmology, or chaotic systems, no one claims that they're incomprehensible. They just require intelligence and an appropriate investment of effort. Granted, you may not be smart enough to get it; but that goes for everything. Why should quantum mechanics be the great exception? The central claim of this book is that there is, in fact, a way to understand quantum mechanics which makes perfectly good sense. It's been around for more than 50 years. There are two reasons why it hasn't caught on. The first is that it requires you to accept a major change in your view of the world: that there is not just one universe, but an infinite number of parallel universes, all equally "real", with new ones continually branching off. This is, needless to say, somewhat counterintuitive, but the same can be said of many novel ideas in science. Proponents of the Many-Worlds Interpretation (MWI) like to compare themselves with Copernicus. If you are just willing to accept that the Earth is not stationary in the middle of the universe but is a planet like the other planets, a large number of perplexing facts suddenly fall into place and make sense. The Many-Earths Interpretation of the Solar System also appears counterintuitive at first. Once you've got over the initial shock, however, you see that it's very clever; after a while, it almost starts to feel natural. The MWI is not dissimilar. Well, that was the first reason. The second, which is why this book ended up being written by a journalist rather than a scientist, is that it appears there was a determined effort by influential members of the scientific community to marginalize and ridicule the Many-Worlds Interpretation. The people concerned are some of the most revered names in 20th century physics, and the disrespectful way in which Byrne writes about them made me wince more than a few times. But it's hard to deny that he has a case. As the title suggests, the central figure in the story is Hugh Everett III, a smart young grad student who was doing a PhD under the legendary John Archibald Wheeler in the early 50s. Wheeler mentored several generations of top physicists - his star pupil was Feynman - and he was one of the key people in the field for a long time. Many of his students just took Wheeler's ideas and elaborated them. But Everett was a natural rebel, and wanted to do his own thing. He started looking at the core conceptual issues in quantum mechanics and became convinced that the way people were thinking about them was completely wrong. Above all, he was sure that the whole idea of the "collapse of the wavefunction" was misguided. This was basically the thing that made quantum mechanics incomprehensible. When you looked at classic experiments like the "double slit", you saw that an electron gave every appearance of being in many places at once, as you could tell from the fact that it was apparently able to interact with other copies of itself; but as soon as you performed a measurement, the electron was suddenly just in one place. According to the standard Copenhagen Interpretation, the measurement caused all the other possibilities to disappear. But how could this make sense? Some people (Wheeler was one) guessed that the experimenter's consciousness had some mystical effect on quantum systems. Others preferred not to interpret the equations at all. The math worked: why did we need to worry about what it "meant"? Everett argued that there was a straightforward explanation. There was no "collapse", and the other possibilities didn't miraculously disappear. They were simply not able to influence each other any more, a conclusion which seemed perfectly consistent with what was known about quantum mechanics. The natural way to conceptualize this was that every quantum interaction made the universe split into multiple copies which quickly separated apart. Critics of the MWI often complain that it violates Occam's Razor; they object to having all these other invisible universes. People who like the theory turn the argument around 180 degrees. They say that you can see the other universes quite clearly for a short time, and there is no reason to believe that all but one of them cease to exist when they stop interacting. It is, rather, the unnecessary "collapse of the wavefunction" which violates Occam's Razor. Wheeler was intrigued by Everett's idea, and he agreed that the math made sense. But he was an enormous admirer of Niels Bohr, who was the chief architect of the Copenhagen Interpretation, and he felt unable to sign off on Everett's thesis without receiving Bohr's blessing. He made a determined effort to sell MWI to the Great Dane, but Bohr, who was now about 70, found the suggestion bizarre and incomprehensible. Wheeler, who had worshipped Bohr throughout his whole career, was unable to discount his opinion. He forced Everett to emasculate his dissertation and rewrite it to minimize the areas of conflict. Everett, disgusted with the way he felt he had been treated, left academia and went to work for the Pentagon. As we would say today, he went over to the dark side. He rapidly made a name for himself doing strategic planning for nuclear war scenarios; among other things, he worked closely with the diabolical Herman Kahn, widely reputed to be the real-life prototype for Kubrick's Dr. Strangelove. He became increasingly addicted to nicotine, alcohol and sex (he chain-smoked and patronized prostitutes), and died of heart failure at the age of 51. But his work lived on, and the MWI's profile has become steadily higher. It's an idea that just won't go away. Peter Byrne, the author of this book, has done a great deal of work tracking down the various tangled strands of the story. He read through all of Everett's papers, which had been sitting in a California basement for 25 years, and he interviewed most of the surviving people who knew Everett. He has also spent a lot of time talking to physicists who like the Many-Worlds Interpretation. Some reviewers complain that there are mistakes in the science. That may be true (I am for example uncertain whether Byrne properly understands how Hilbert spaces are used in quantum mechanics, or if he knows what a Lebesgue measure is). But as far as I'm concerned, what's much more interesting is how much he seems to be getting right. My impression is that there are quite a few scientists who are reluctant to come out and say openly what they think about Everett, who is still rather controversial; they prefer to have their opinions ascribed to Byrne. And, whatever people may say in public, there is no doubt that Everett is being taken seriously. A quick look at Google Scholar shows over 2200 citations of his thesis: this is not the kind of attention that a fringe theory is going to attract. The Many-Worlds Interpretation is one of the most interesting and thought-provoking ideas in modern science. If you want to know about the mathematical and philosophical details, I warmly recommend David Wallace's The Emergent Multiverse . But if you want an unputdownable human account written in layman's language, then get Byrne. This is investigative journalism at its very finest. __________________________________ Much as I liked the book, it is fair to warn the prospective buyer that the copy-editing is quite extraordinarily careless. There are slips and errors everywhere: the same name can be spelled differently in two chapters, "its" is sometimes confused with "it's", "xenophobic" is once spelled with a Z (my personal favorite), and a couple of sentences are just mangled completely, looking as though they were interrupted halfway through an edit. I honestly don't understand it. What happened? ...more |
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| Jul 13, 2012
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it was amazing
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If you've been paying any attention, you must already have at least a vague idea of what the Many-Worlds Interpretation of Quantum Mechanics is about.
If you've been paying any attention, you must already have at least a vague idea of what the Many-Worlds Interpretation of Quantum Mechanics is about. For example,
Source Code
is a romantic movie treatment;
Transition
is an SF thriller treatment; and
The Grand Design
is a For Dummies treatment. There is not just a single universe, there are a huge number of them, and new ones are constantly splitting off. But can something that's been this enthusiatically embraced by the SF community really be respectable? In his impressive book, David Wallace argues persuasively that it is. It's not merely a good alternative to conventional interpretations of quantum mechanics; he claims it's the only one that gives us a view of what's going on which makes intuitive sense, and doesn't involve the addition of unprovable or downright mystical ideas like "the collapse of the wavefunction" or "the essential role of consciousness". One's first reaction may well be to label this as paradoxical or willfully contrarian, but Wallace, who has PhDs in both physics and philosophy, lays out his reasoning with skill. Since it's easy to get lost in the many details, I will focus here on two clever analogies which he uses throughout. The first is the heliocentric revolution (Copernicus and Galileo); the second is dinosaurs. Let's look first at the heliocentric hypothesis. The book opens with a thought-provoking quote from Wittgenstein: what would it have looked like if it had looked like the Earth went round the Sun? Stop and consider that for a moment. The answer, of course, is that it would have looked exactly the same. Every piece of factual evidence people had, which convinced them that the Sun went round the Earth, could equally well have been interpreted in the opposite direction. At the end of the day, the main reason why people were so slow to agree with Copernicus was a simple one. His idea was so goddamn weird that it couldn't possibly be correct. Similarly with the Many-Worlds Interpretation. Wallace's argument is that this is just the most straightforward way to make sense of the underlying mathematics of quantum theory, which everyone agrees on. You look at what the equations tell you is going to happen when a superposed state (Schrödinger's cat, for example) is allowed to interact with other parts of the world. The result is that the cat's state becomes quantum-entangled with everything else, including any observer who may be present. The math represents this as the sum of two algebraic terms: one stands for the live cat, plus everything else in the world; the other stands for the dead cat, plus everything else in the world. The two terms rapidly "decohere", in other words cease to influence each other. The basic claim of the Many-Worlds Interpretation is that this is best conceptualized as saying that the universe splits into two copies. That's what the math seems to be telling us: why not believe it? Yet, somehow, most people seem reluctant to take this final step. It's too goddamn weird. What do they do instead? The most common alternative is "shut up and calculate": use the equations, since they certainly appear to work, but don't worry about what they mean. Indeed, throw out the question as irrelevant and positively distracting. So over to the dinosaurs. As Wallace says, suppose people applied the same kind of reasoning to paleontology. There are fossils; everyone agrees on that. Fossils are bits of rock which you can touch. There are consistent patterns in many of these bits of rock, and the only sensible way of explaining these patterns is to say that their appearance is as it would have been if there once had been dinosaurs. Just about everyone agrees on that too. But suppose now that you're talking to a creationist petroleum geologist (I presume such people may exist), who stops at this point and says that there were in fact no dinosaurs; they are just a theoretical device that helps us categorise fossils. You would have a hard time refuting this argument. Our hypothetical geologist would agree with everything you said about the links between fossils and dinosaurs, and in fact she would probably know rather more about it than you did, since it was part of her job. She just wouldn't agree that the dinosaurs actually existed. Needless to say, you would find this person intensely irritating; you would be sure they were wrong, even if you couldn't prove it. Well: the argument here is that we've been doing exactly the same thing in rejecting the Many-Worlds Interpretation. Quite apart from the content, the style of the book is also interesting, and is constructed as an ingenious piece of homage to Wallace's great predecessors. Stylistically, Copernicus and Galileo were polar opposites: Copernicus was a dry, technical writer, and Galileo was an entertaining polemicist. Copernicus was extremely conservative, and worked entirely within the Ptolemaic system. (As Rovelli remarks in his recent book on Anaximander, no one could have loved Ptolemy more than Copernicus did). His intention was simply to show that Ptolemy's deferents and epicycles worked even better if you moved the Sun to the center of the universe. Galileo, in contrast, wanted to shake things up and introduce genuinely new ideas. Wallace has daringly attempted to mix these two very different styles. Rather more than two-thirds of the book is Copernican, and consists of lengthy technical proofs; the most important ones have to do with the concept of rational behavior in the quantum multiverse, where it is easy to become confused and think that, since everything is going to happen in some branch, it makes no difference what you do. Wallace shows that this is absolutely not true. In fact, the concept of "branch weight" plays a role exactly analogous to that of probability in a classical theory, and rational agents end up doing what they would have done in a classical universe. Establishing this apparently trivial conclusion unfortunately requires over fifty pages of difficult mathematics. If all the book were like this, it would have been unreadable; despite its honored place in the history of science, it is notorious that hardly anyone has ever read De revolutionibus orbium coelestium. Wallace has addressed this problem by adding a parallel thread written in an engagingly Galilean style, where he explains the intuitive consequences of the ideas in everyday language. The layman will no doubt want more Galileo; on the other hand, the Copernicus is necessary to convince the many sceptical experts, none of whom appear yet to have detected obvious holes. It's a difficult balancing act, but he pulls it off well. Should you buy The Emergent Multiverse? On the minus side, it's long, it's heavy, it's expensive, and there are large chunks you will most likely not understand. (There were, at any rate, large chunks I didn't understand). On the plus side, it's well-written, it's often funny, it will expand your mental horizons, and it's not impossible that it will turn out to be one of the pivotal books of the twenty-first century. I don't know how to weigh up these competing factors. You will just have to decide for yourself. __________________________________ Simon Evnine pointed me to the excellent review here. If you're interested in learning more about the technical details, this is where to go. __________________________________ It's hard to stop thinking about this book. The author makes a strong case for the reality of the quantum multiverse; if his reasoning becomes generally accepted, it is impossible to imagine how fundamentally it will change the way we view the world. At the moment, the evidence is of an indirect nature, as it was when the pioneers of the heliocentric revolution first proposed their idea. The math works out more sensibly when you posit that the Earth goes round the Sun; also, as Aristarchus had pointed out seventeen hundred years earlier, the Sun is evidently much bigger than the Earth, and it seems odd to have the big thing circle the small thing. Direct, smoking-gun proof didn't turn up until Bessel first measured stellar parallax in 1838, but by then the scientific world was already sure that Copernicus had been right. The accumulation of indirect evidence was overwhelming. In the case of the multiverse, Wallace suggests that the next tranche of indirect evidence will probably come from quantum computing. If things progress a little further along the directions that are currently being explored, it will soon be possible in practice to solve problems with quantum algorithms that cannot be solved at all on conventional computers. People will routinely be writing quantum software and thinking about debugging and improving it. As Wallace says, the natural way to conceptualize some of these algorithms is that the computation is parallelized by sending subtasks into enormous numbers of parallel worlds, then retrieving the answer from the branch which succeeded. When tens of thousands of geeks are spending their working day manipulating the geometry of the multiverse, it will be difficult to maintain the polite pretense that it doesn't actually exist. Wallace appears reluctant to delve too deeply into the moral and ethical aspects. He demonstrates that rational short-term betting behavior is the same in the multiverse and the classical world; given a choice between a 75% chance and a 25% chance, you should pick the 75% chance, irrespective of whether you believe that all the outcomes will happen in different branches, or that there is only a single world governed by the laws of probability. But in cases like the notorious quantum suicide thought experiment, it is not as clear that things are still the same. Wallace notes that death is "philosophically difficult", and explicitly advises philosophers not to discuss these matters in popular works. There is a striking resonance with the last chapter of Time Reborn , where Smolin expresses concern that belief in multiple universes may lead people to value less the one universe which we can directly perceive around us. So maybe I shouldn't even be talking about this. But, as Eve said to Adam, those apples just looked so tasty... ...more |
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| 014013462X
| 9780140134629
| 014013462X
| 3.95
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| 1983
| Oct 31, 2006
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it was ok
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Celebrity Death Match Special: God and the New Physics versus The Rocky Horror Picture Show Scene 1 [MIT, 2012. Graduation day. BRAD and JANET] JANET: Oh Celebrity Death Match Special: God and the New Physics versus The Rocky Horror Picture Show Scene 1 [MIT, 2012. Graduation day. BRAD and JANET] JANET: Oh Brad, wasn't it wonderful! Didn't Betty look radiantly beautiful! Just an hour ago she was plain old Betty Monroe. Now she's Betty Monroe... PhD! BRAD: Er... yeah. JANET: I wonder if I'll ever complete my doctoral dissertation on the relationship between faith and cosmology? Sometimes it seems impossible. [She wipes a tear from her eye. Music starts up] BRAD: That's no way to talk! Just can it. CHORUS: Janet. BRAD: You're the smartest girl on this planet. CHORUS: Janet. BRAD: You see an equation, you scan it. CHORUS: Janet. BRAD: Even if it's harder than granite. CHORUS: Janet. BRAD: You - JANET: Oh Brad, you're always so nice to me! You know what I'd really like to do now? BRAD: You just tell me, girl. JANET: I'd like to visit Professor Helge Kragh, the greatest living expert on the history of science. BRAD: Uh.. well, hop in the car! We're off to Denmark. JANET: Oh Brad! [She throws her arms around him and kisses him passionately] Scene 2 [Another part of the forest. BRAD and JANET, soaking wet, are outside a dubious-looking gothic mansion. A sign on the gate says PAUL DAVIES PRODUCTIONS LTD - ENTER AT OWN RISK] JANET: Do you... do you think it's safe? BRAD: We're just going ask if we can borrow their wifi signal for a minute. [They hesitantly enter and find themselves in a room full of weird people. The doors close behind them. JANET clutches BRAD's arm] FRANK N. FURTER: [in white lab coat] Now what do you two want? JANET: We - we wonder if we could use your wifi. If it wouldn't be too much trouble. FRANK N. FURTER: But that's not what you really want, is it? JANET: [as if hypnotised] N-no. I really want to understand the relationship between God and modern physics. FRANK N. FURTER: Then welcome to the early 80s! [Music] CHORUS: Let's do the time warp again! FRANK N. FURTER: You may think I'm mad as a hatter But I'll explain consciousness with quotes from Hofstadter. It's an emergent propertee Just like an anthill, don't you see. CHORUS: Let's do the time warp again! FRANK N. FURTER: You ask about the mystery of creation There's this cool new idea called inflation. It may fill you with indignation But we all started as a vacuum fluctuation. CHORUS: Let's do the time warp again! [MAGENTA and COLUMBIA, dressed in outrageous black corsets, have crept up behind the terrified JANET and started to remove her clothes. BRAD has unaccountably disappeared] FRANK N. FURTER: I know this looks like a den of depravity But the key to everything is supergravity-- JANET: Superwhat? FRANK N. FURTER: Supergravity. It's this amazing theory that will unlock the secrets of the universe. Cutting edge. JANET: You're - you're not a scientist at all, are you? You're-- FRANK N. FURTER: Okay, okay. I'm an infotainer. So what? [He opens his lab coat to reveal full BDSM gear. MAGENTA and COLUMBIA pull off most of JANET's remaining clothes, leaving her in just her underwear] FRANK N. FURTER: Admit you like it. [He seductively puts an arm around JANET] Hmmm? [Pause for a beat. Everyone looks at her] JANET: [eyes modestly downcast] You promise you won't tell Brad? Match point: The Rocky Horror Picture Show ...more |
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| 019958043X
| 9780199580439
| 019958043X
| 3.21
| 327
| 1996
| Feb 01, 2010
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it was ok
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Right now, there should be a fascinating dialogue going on between the science and faith communities... but there isn't. It's so frustrating! You'd th
Right now, there should be a fascinating dialogue going on between the science and faith communities... but there isn't. It's so frustrating! You'd think it would be impossible to stop it; as you can see in recent books like Rees's Just Six Numbers, Susskind's The Cosmic Landscape and Hawking's The Grand Design, many scientists are happy to agree that the universe looks as though it has been designed to make life possible. Susskind's book is subtitled "String theory and the illusion of Intelligent Design"; Hawking's has a chapter called "The Apparent Miracle". Needless to say, a large part of the faith-based community has been telling us the same thing for a long time. So there's an obvious question that needs to be answered: is the universe designed, or isn't it? You'd expect a bit more discussion. I am disappointed to say that no such thing is happening. The scientists have all decided that the one explanation which makes sense is a combination of the Multiverse and the Anthropic Principle. There are a zillion possible universes, of almost any kind you can imagine; a very small number support life, and since we're alive we're in one of them. We look around and think we see design, but it's pure chance. They won't even discuss the possibility that it actually is design. On the other side, you have the faith-based people, like Francis Collins (The Language of God), and this guy. They look at the Multiverse argument for about two pages and dismiss it. It looks like design, they tell us, so, duh, it probably is. Swinburne wants to establish the probable existence of God and, really, he doesn't have much more going for him than the Argument from Design. He spends a chapter talking about souls (very unconvincingly, IMHO), and he spends another arguing that God could be good and still allow evil, because it's an inevitable consequence of free will (I thought this part was quite well done). He waffles for twenty pages about miracles without ever really saying very much. But if the design part of the argument holds, it's enough. The rest is just due diligence. So how credible is the Design argument? Having finished the book, I know about as much as I did when I started. The most infuriating thing is that both sides invariably quote Ockham's Razor and claim it supports their case. Guys, I know you are all super-smart and have published books on the subject and get invited to prestigious conferences, but may I be so bold as to offer you a tiny piece of advice? Ockham's Razor probably isn't going to help a lot here. Leave it alone and develop some other lines of attack. ...more |
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| 064185210X
| 9780641852107
| 4.15
| 2,803
| Dec 12, 2005
| Dec 12, 2005
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liked it
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I had seen many references to this controversial book - among other things, it's quoted approvingly in Dawkins's The God Delusion - but somehow I didn
I had seen many references to this controversial book - among other things, it's quoted approvingly in Dawkins's The God Delusion - but somehow I didn't get round to reading it until this week. Despite the fact that it's sloppily argued and poorly written, I'm embarrassed to say that I found it unputdownable. If you also enjoy watching smart, opinionated people shooting their mouths off in public, you may well have the same reaction. Susskind, writing in 2005, confidently promises to explain Life, the Universe and Everything. He is one of the founders of string theory and the phrase is in the title, so no prizes for guessing that it will be an essential ingredient. In a nutshell, his argument is as follows. The rest of this review is available elsewhere (the location cannot be given for Goodreads policy reasons) ...more |
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| 0674644719
| 9780674644717
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| Jan 01, 1992
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Every so often, there is a revolution in our understanding of the universe. Obvious milestones are Copernicus suggesting that the Earth might go round
Every so often, there is a revolution in our understanding of the universe. Obvious milestones are Copernicus suggesting that the Earth might go round the Sun instead of vice versa, Newton's law of gravity explaining the movements of the planets in quantitative terms, and the discovery that the cosmos is expanding and started with the Big Bang. It would be fascinating to know what contemporary scientists had in the way of immediate reactions to these earlier breakthroughs, but, if this knowledge is available at all, it doesn't seem to be collected in easily accessible form. We are currently in the middle of a new revolution, which started in 1980 when Alan Guth proposed the idea of "inflation": the universe, according to what has now become the mainstream theory, began as a vacuum fluctuation and then expanded exponentially to a macroscropic size during a tiny fraction of second. This time, however, Alan Lightman and Roberta Brawer had the excellent idea of interviewing a couple of dozen of the world's leading cosmologists in 1988, when things were still fluid and undecided. Origins collects together the results of the exercise. I am impressed at how accurately most of the interviewees are calling it, given that there was no hard evidence for inflation when the interviews were carried out. They really like the idea, but they hedge their answers with many caveats: they can see it doesn't quite work yet, and will need to be further developed. Most of them justify their preferences in terms of esthetic judgements. The idea is beautiful, and ties together several important things that previously were unconnected loose ends. In particular, it explains why there are no magnetic monopoles (this had really been bothering the theoreticians), why the universe is so homogenous, and why space is almost flat. This last point, however, brings out an interesting difference between the theoreticians and the observers; several of the observers stubbornly say that they don't yet see clear evidence for flat space, and they'll wait until they do, even if that's what inflationary theory is predicting. Though the comments from John Huchra, at the time the world's greatest expert on observing galaxies, are startlingly exact. He is already half expecting to see evidence of dark energy, ten years before it was identified, and he confidently gives an age for the universe of 13 billion years, when most of the others are leaving a large margin for possible error. It's amazing to get a glimpse of how the pluralistic scientific society works. All these people know each other and talk frequently: their conversations are full of X said this, of course Y answered with that, Z had this clever angle that suddenly made me think about it in a new way. I have never had such a concrete feeling of watching science develop right under my eyes. And even if your interest in cosmology is minimal, the book is worth reading for the anecdotes. Roger Penrose, while still a student, gave one of his professors a paper written in his newly invented tensor notation; [image] the professor's look clearly indicated that he was concerned about Penrose's sanity. David Schramm never studied at all at high school, and spent all his time on the sports field (he was a state wrestling champion) or chasing girls. My favorite is Andrei Linde sitting with his phone in the bathroom talking about chaotic inflation in whispers because his family has gone to bed, and then waking up his wife with the news that he's just figured out how the universe began. What a great book! And what a shame that someone doesn't do one of these every time a new scientific breakthrough happens! ...more |
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