The Particle at the End of the Universe: The Hunt for the Higgs and the Discovery of a New World ペーパーバック – 2013/5/2
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Winner of the Royal Society Winton Prize for Science Books A Best Science Book of the Year for the Guardian, Financial Times, and New Scientist It was the universe's most elusive particle, the linchpin for everything scientists dreamed up to explain how physics works. It had to be found. But projects as big as CERN's Large Hadron Collider don't happen without incredible risks - or occasional skulduggery. In the definitive account of the greatest science story of our time, acclaimed physicist Sean Carroll reveals the insights, rivalry, and wonder that fuelled the Higgs discovery, and takes us on a riveting and irresistible ride to the very edge of physics today.
`An authoritative account of science's discovery of the year. Remarkable.' * Financial Times * `This book is so hard to put down. That's testament to Carroll, a practising scientist, also being a gifted writer.' * New Scientist * `Compelling.' * Independent * `A very good - and very accessible - guide to all the theoretical physics, precision engineering, data handling, probability-measuring and other marvels.' * Guardian * `Delightful... for anyone excited by the particle at the end of the universe, start here.' * BBC Focus * `Carroll keeps it real, getting at the complex guts of cutting-edge cosmology in discussions that will challenge fans of Hawking's A Brief History of Time.' * Washington Post * `The science is authoritative, yet bold and lively. The narrative is richly documented, yet full of human drama. Carroll's saga pulls you aboard a modern voyage of discovery.' -- Frank Wilczek, Nobel Laureate in Physics and author of A Beautiful Question `In this superb book, Sean Carroll provides a fascinating and lucid look at the most mysterious and important particle in nature, and the experiment that revealed it. Anyone with an interest in physics should read this, and join him in examining the new worlds of physics to which this discovery may lead.' -- Leonard Mlodinow, internationally bestselling author of Subliminal and Elastic商品の説明をすべて表示する
本書を読むと，CERNという実験設備の建設やチームの最近の逸話からはじまって，1950年代から60年代に標準理論が完成するまでの近・現代素粒子物理学史が楽しめる．著者はハーバードでPhDをとり理論家(カルテク, Senior Research Associate)なので，理論の発展に力点があるが，実験自体についても概略を説明している．その点，理論家という所属を配慮してだろう，Higgs以外にも多くの理論家の貢献があることをかなり丁寧に叙述している点が好感を持てる．
Carroll's book can be roughly divided into three parts. In the first part, after giving us a brief overview of particle physics describing relativity, quantum mechanics, the Standard Model and the discovery of the twelve elementary particles that make up the universe, Carroll plunges into a description of the giant particle accelerators that have made possible our understanding of nature's fundamental building blocks. Personally I found this part most enjoyable, since it's a little more accessible than the theoretical part. Carroll tells us about the stupendous engineering challenges involved in the building of the LHC and takes us on a nice little tour of its interior. There's all kinds of fascinating and amusing stuff here; the lead tungstate crystals in the detectors that took ten years to grow, the earlier particle accelerator whose workings were affected by the moon's tides, the baguette dropped by a bird that temporarily created electrical problems, the helium "explosion" caused by high voltage that crippled the machine for months, the physicist whose face was exposed to an intense beam of protons and who still escaped relatively unscathed. The sheer size and complexity of the ten-thousand pound detectors - ATLAS and CMS - beggar belief and the smooth functioning of these hunks of metal, plastic and electronics is a resounding tribute to human ingenuity and collaboration. Carroll is very good at describing the structure and function of the marvelous machines that made the Higgs possible and again confirms the fact that the best science involves both great intellectual ideas and world-class engineering. Many of the LHC's components as well as the principal players are illustrated in color photographs in the center of the book.
Carroll also gives us a lucid account of the statistical methods and data collection techniques used to confirm the discovery of particles. The sheer amount of data collected by the LHC is staggering; as Carroll puts it, enough to fill about a thousand terabyte hard-drives per second. He does a good job detailing the great difficulty of collecting the data from an incredibly complex dance of particle collisions and most importantly, of separating the signal from the noise. He tells us about the almost mythical "5-sigma" threshold, essentially a very stringent statistical test that allows you to claim a "discovery" of a new particle. In July 2012, data from both the ATLAS and CMS detectors was combined together to claim a 5-sigma threshold. Carroll who was in the audience when the discovery was announced captures well the excitement in Geneva and around the world as an intensely international collaboration of more than three thousand LHC-related scientists tuned in to hear the groundbreaking news. This was definitely the discovery of a lifetime, and Peter Higgs was in the audience to hear about it. Yet Carroll drives home the point that statistics is not everything, and illustrates this through the cautionary tale of the discovery of "faster-than-light" neutrinos which, although statistically significant, turned out to be incorrect.
The second part of the book gives us the theoretical basis of the Higgs boson. To Carroll's credit, he spends a fair amount of time dispelling the simplistic belief that the "Higgs boson gives everything mass" and does a pretty good job leading us through the subtleties of what's called the "Higgs field" and exactly how it's relevant to particles masses and interactions. He also addresses the common misunderstanding that most of the mass of an everyday object comes from the Higgs. It doesn't; it comes from the strong interactions and therefore won't suddenly disappear if the Higgs boson were to hypothetically vanish. Along the way Carroll explains important concepts like spontaneous symmetry breaking and Feynman diagrams which are integral to understanding the Higgs mechanism. The last part of the book also has interesting discussions on the potential implications of the Higgs for understanding dark matter, dark energy and the Big Bang. And an amusing chapter lays to rest the slightly paranoid "end-of-world" scenarios postulated before the LHC went online. This same chapter also takes a thoughtful look at the public promotion of science and addresses the role of blogs and other media which communicate science, often correctly but sometimes prematurely. Carroll makes us appreciate the fact that scientists have to tread a fine line in being accurate while still not giving the media an opportunity to sensationalize their findings.
Finally in the third part, Carroll sheds light on the human aspect of science. Part of this is in the earlier chapters where he details the political jockeying and the clash of personalities that was involved in the cancellation of the high-stakes Superconducting Supercollider (SSC) project during the 90s. The fact is that these days even the most fundamental curiosity-driven research can involve billion-dollar equipment like the LHC. Carroll wonders whether governments around the world will now support these increasingly expensive endeavors, especially during times of recession, but also underscores the importance of this research for human creativity and unexpected practical spinoffs (like the World Wide Web). The human aspect of science is also revealed in a separate chapter that among other things asks who would get the Nobel Prize for the discovery. There is no doubt that somebody should get it (and almost universal consensus that Higgs should be included), but the history that Carroll describes makes it clear that at least six people came up with various parts of the idea within a narrow time frame. And the experimentalists seem to deserve it as much as the theoreticians. One thing is certain; any Nobel Prize for the Higgs is going to be at least somewhat controversial.
In general I greatly enjoyed reading "The Particle at the End of the Universe". It's engaging and an easy read and would complement similar other volumes like Ian Sample's "Massive" (which focuses more on the human side) and Frank Close's "The Infinity Puzzle" (which is heavier on the science). Carroll is a pleasant, informative, patient and humorous guide on our tour of the LHC and the Higgs. He is also measured and tends to temper the enthusiasm of discovery with realism; for instance he makes it clear that the discovery of the Higgs still leaves many questions unanswered, and it has no impact on other outstanding scientific problems like discovering cancer drugs or understanding the economy. What Carroll does manage to communicate is the deep satisfaction of discovery, the thrill of the chase and the astonishing achievements that human imagination and skill can make possible.
Not much math, in fact the most complicated equation is e = m * c^2.
This is fine, because the author describes, very well, in layman's terms, what the Standard Model is, how it is arranged, what the various particles are, how the Large Hadron Collider works, and how colliding two protons at near C speeds creates a tremendous amount of energy, which because of the above equation becomes mass which normally doesn't exist. He also shows how a Higgs Boson can be detected by its decay products.
I'm close to finishing it, and although it might be a while, it probably would be worth a second read. (I also need to find and reread my copy of The God Particle.)
There's a movie mentioned in the book. It's Particle Fever, and is on U-Tube. That shows better the scale of the LHC, including the tubes, and the detectors.
Carroll first introduces us to some elementary particle physics theory, where we learn about quarks, leptons (electron, muon, tau particles, for example), bosons (photons, gluons, and the higgs), fermions (matter particles such as protons and neutrons) and what they all mean. This provides a nice introduction to the topic. He then segues into a discussion of the Large Hadron Collider. It is here that bunches of protons are smashed into each other by two beams going in opposite directions. The amount of data produced by these collisions is enormous. We are talking about collisions occurring 20 million times per second, each crossing producing dozens of collisions resulting in hundreds of millions of collisions a second - yikes!. This vast amount of data is filtered by something called a trigger, of which there are two levels. This data is then sent through a Worldwide LHC Computing Grid that connects computing centers in thirty-five different nations. Both the Internet and private optical cables are used to distribute this vast amount of data. This whole thing is incredible!
After that brief insight into the working of the LHC, Carroll switches to theoretical concepts. We learn some information about quantum field theory, fields that result in the particles we detect, the Higgs field and its boson, and symmetry (what is local symmetry, connection fields, problems with symmetry and symmetry breaking, and the symmetries of weak interactions). This information helps us to appreciate the Higgs field and its importance to the Standard Model. We can now get into the events leading up to the discovery of the Higgs at CERN in the chapter appropriately entitled "Bringing the House Down."
Carroll then discusses the people and events leading to the discovery of the "Higgs mechanism". The story actually goes back to research on superconductors. Physicists Yoichiro Nambu and Giovanni Jona-Lasinio showed how spontaneous symmetry breaking (necessary in the Higgs model) could occur even if you weren't inside a superconductor but could also happen in empty space. Through the work of numerous physicists such as Jeffrey Goldstone, Phil Anderson, Francois Englert, Robert Brout, Peter Higgs, Gerald Guralnik, Carl Richard Hagen, Tom Kibble, Sheldon Glashow, Abdus Salam, John Ward, Steven Weinberg, and others I probably missed, the story of the discovery of the "Higgs mechanism" became a permanent part of history. This history might be a bit difficult to follow for the non-expert, but it gives you an idea of how the work of many individuals contributed to an understanding of the matter.
Carroll then discusses things beyond the Higgs, such as, the early universe, WIMPs, the hierarchy problem, vacuum energy, dark energy, supersymmetry (here we have five Higgs instead of one), strings, extra dimensions, branes, and the multiverse. He concludes the section saying that "Discovering the Higgs is not the end of particle physics. The Higgs was the final piece of the Standard Model, but it's also a window onto physics beyond that theory." The Higgs will be important in the understanding of dark matter, supersymmetry, extra dimensions, and whatever is to follow. This is the beginning of a new era.
I want to also mention the three appendixes that provide more in depth information on the nature of mass and spin as they relate to particles, the Standard Model particles themselves, and their interactions. This is a welcome addition for those who want a more detailed discussion of the theoretical concepts. One note, however, there is a misprint of The Particle Zoo table on page 294. The masses and charges are correct, but the quark (top, bottom) and lepton (Tau, Tau neutrino) labels were repeated. You can easily find the correct table on the Internet. In addition, Carroll provides two full color panel sections with pictures of the key people involved, the LHC, and some data charts showing the Higgs discovery - very nice.
I love Sean Carroll's books. I think I'll add him to my favorite authors list.