The last few years have seen a proliferation of popular physics books aimed at explaining the mysteries of modern physics to the layman. This is a worthy endeavor and Lisa Randall is one of its leading expositors. This book is really two books in one. The first part is a clear and spirited discussion of particle physics and cosmology. The second part is an equally clear meditation on the nature of the scientific method and the value of science and reason.
Randall especially shines in explaining the real everyday science (as opposed to just the philosophy) behind frontier research in physics. Thus, she spends a sizable amount of time explaining some of the less emphasized practical aspects of the science like errors and uncertainty in measurements, risk factors, "effective theories" (theories applicable at particular scales) and statistics. She provides a readable treatment of the Standard Model of particle physics and emphasizes why finding the Higgs boson is so important. In addition she has what I think is one of the clearest accounts of the structure and function of the LHC in Geneva. In the part about cosmology, she discusses in detail the riddle of dark matter and dark energy and what the latest telescopes and satellites might tell us about the birth and structure of the universe.
The second half of the book presents a robust defense of science and reason as well as some thoughts on the connections between beauty, creativity and science. Randall understands that while mathematical beauty may be a guiding principle for theoretical physics, ultimately beauty is subjective and the only true test of a theory is a clear connection to experiment. Earlier in the book she traces the development of modern science from the seventeenth century, especially emphasizing Galileo's life and his pioneering work in exploring nature through indirect measurements which ever since have been at the heart of scientific investigation. She also touches on the science-religion debate but does not explore it in great detail; she concludes this section by admitting that if you are a religious scientist, you have to at least accept a disconnect in your mind between the very different worlds of science and faith.
In general the book is very well written and Randall's passion for science shines through. The reason I gave it three and a half stars is that it says very little that's new. Randall's discussions of particle physics, cosmology, the LHC and the value of scientific thinking have been explored in great detail by other writers and scientists. In the past few years, Brian Greene, Stephen Hawking, Richard Panek, Ian Sample and John Barrow to name but a few authors have repeatedly treated us to treatments of the Big Bang, particle accelerators, neutrino astronomy, quantum theory, string theory and multiple universes. Is there really a need for yet another book on these topics for the layman, no matter how skillfully written? Plus, while Randall's explanations are reasonably clear, some of these other authors write much more clearly and present cleverer analogies to illustrate the concepts. In my opinion, Randall's book is emblematic of the state of the popular physics literature which seems to have reached a point of diminishing returns; it's become really hard to write a truly new book on the topic without recycling known facts and anecdotes or pitching highly speculative ideas.
On the other hand, there have been a few popular physics books published during the same period that have actually tried to present novel and original work. Examples of genuinely interesting and new thinking would include critiques of string theory by Lee Smolin and Peter Woit, Robert Laughlin's "A Different Universe", David Deutsch's "The Beginning of Infinity" and (while not entirely about physics), Stuart Kauffman's "Reinventing the Sacred". While these books are not all as clearly written as books by Randall, Greene or Hawking, they present fresh perspectives and novel thought-provoking ideas and not just accounts of known science. In my opinion, while books like Randall's do a good job of introducing audiences to contemporary physics concepts, these other authors have done a much better job of disseminating original, groundbreaking material. They deserve to be more widely read and emulated.
on September 20, 2011
Several string theorists such as Brian Greene or Leonard Susskind and cosmologists such as Alexander Vilenkin have written popular books about physics but as far as I know, Lisa Randall is the only popular writer among the "high-energy phenomenologists", i.e. the theoretical particle physicists who think about Nature from the viewpoint of phenomena that have been observed or that may be observed in a foreseeable future (mostly at the particle accelerators).
And we, the readers, have been especially fortunate because the book about physics from the viewpoint of phenomenologists wasn't written by a random phenomenologist but by one of the most prominent ones. In fact, Randall was identified as the most referred to particle physicist - among both women and men, just to be sure - in a recent 5-year period. She remains extremely active and influential.
Knocking on Heaven's Door has two basic goals. One of them is to introduce the reader to the cutting-edge research in particle physics which is dominated by the LHC experiment. Collisions of protons inside the 27-kilometer ring on the Swiss-French border have interrupted decades of theoretical dominance and relative experimental impotence (even though the book describes some smaller colliders or LHC predecessors, too). Randall who constantly interacts with the experimenters offers us an exciting story of the LHC collider from its conception to the first femtobarn of collisions.
We learn how it was built, what it is composed of, how it accelerates the particles nearly to the speed of light, how it observes the products of every collision (in the detectors such as CMS and ATLAS) and identifies the particles that are born in the collisions, and how the resulting huge amounts of data are being processed by computers and statistical techniques to learn something new. However, we also learn many things about the human factor: who are the people who work there, how they interact with each other, how they assure their colleagues that they're right, what they like to cook, how the Americans differ from the Europeans, and so on. I am not aware of a competing book written in plain English that could give you the feeling of being an LHC insider. And the book covers not only the colliders but also experiments trying to detect dark matter on Earth and many others.
But the book has another, grander goal which is nothing less than to clarify how scientists actually think. Philosophers would call these issues "gnoseology" or "epistemology" but the content of their thoughts would be less tangible. Instead, Randall talks about the actual strategies and issues that are important and misconceptions that the laymen often believe. One of the key methods to organize our knowledge is the concept of scale: different basic objects and "effective theories" describing their mutual interactions are being used for different sizes or, equivalently, different energies per particle. For a particle phenomenologist, and not only for her, the laws of physics resemble a giant onion. The laws relevant for longer scales may in principle be derived from those at shorter scales. But the former are independent of many details of the latter and it is often useful to think about them independently.
These initial chapters about scale are no random musings. They're the essential skeleton on which particle physics (phenomenology but not just phenomenology) organizes the insights from the experiments such as the LHC. A related question is what it means for our knowledge to expand. The book does a very good job in explaining that the theories we typically use are approximate and aware of their own limitations; on the other hand, it means that when new phenomena and better theories are found, the older theories are not completely eliminated.
Randall's book also talks about non-physicists (in many cases, famous people from all walks of life whom Randall has met or whom she knows very well), their way of looking at the physical phenomena, and what a physicist finds funny about this looking. One example is the relationship between science and religion: Randall, who is obviously an atheist, doesn't stay on the surface. She is not satisfied with claiming that "religious people are silly" which is what many other books do (with a great commercial success) but she also tries to find the core differences. One of the major lessons is that scientists are able to live and work with ignorance or uncertainty about a particular issue; in fact, they view it as a part of their knowledge (especially if they know rather accurately where their knowledge ends). This point is often misunderstood by other self-described atheists whose thinking is actually religious and dogmatic in character.
For another example, a chapter is dedicated to the LHC doomsday scenarios which assume (or attempt to "prove") that the collider will create a black hole or another lethal object that will devour our blue planet. The book explains several different levels of evidence we have to be sure that such a catastrophe won't happen.
I forgot to say that the book also covers theoretical models (which are the focus of her first book, Warped Passages) that are being tested by the LHC, including the models with supersymmetry and especially extra dimensions for which Randall (and Sundrum) became particularly famous. The Higgs boson gets its well-deserved chapter as well. Randall compares the phenomenological, bottom-up approach to physics with the top-down approach favored by string theorists.
To summarize, it is a book about some very exciting and specific experimental developments that are underway combined with all the infrastructure one needs to place these experiments into their proper place and to interpret them correctly. Highly recommended to everyone who doesn't want to lose touch with particle physics and any cutting-edge science as of 2011. Randall is a multi-dimensional personality and so is her book: but I am confident that most readers may find a lower-dimensional projection of the book that will enrich the way how they look at the world.
on January 11, 2012
I am a working physicist, 30 years past my Ph. D., and I picked up this book thinking it would be interesting to learn about progress in particle physics and cosmology. I was very disappointed. The meat of the book is Chapters 16 and 17, where Prof. Randall finally gets to describing the theory behind the Higgs boson and other anticipated discoveries from the LHC. These are so poorly written it seems like her editor just figured, "no one will understand this, so why bother trying to make it readable." The sentence structure is convoluted to the point that, even with multiple readings, it's impossible to tell the point she's trying to make. She throws around terms like "weak charge" without ever bothering to explain whether this quantity is a weak version of the electric charge or an analogy of electric charge that conveys the weak force. She frequently makes reference to the Planck length, without ever saying what it is, where it comes from, or how to translate between distance and energy, which she uses interchangeably.
This weakness is illustrated by her explanation of the possible applicability of extra dimensions to explain the 16 orders-of-magnitude difference between gravity and the weak force, one of the few contributions she takes personal credit for. You could just say, "the forces are of different strengths" and leave it at that. Randall says, in essence, "Imagine gravity is 10^16 times stronger on another brane in another dimension, but that dimension is coupled to our world by an arbitrary coupling constant of 10^-16." This adds nothing of intellectual value to the field, but the buzzwords have been used, so it's time to schedule a book tour and let the accolades roll in.
Now, of course, there may be some actual content to her brane theory, but, my point is, you won't find it in the book, which is, therefore, a waste of time.
The balance of the book is devoted to a description of the design of the LHC (which, as near as I can tell, is nothing more than a yet-bigger and more expensive synchrotron, an accelerator that hasn't had its fundamental design changed in 60 years) and a travelogue of her VIP tours of various physics sites and parties. I learned a lot more from "The 4 percent universe: dark matter, dark energy, and the race to discover the rest of reality" by Richard Panek. He focuses only on cosmology, but does a reasonable job making his material clear.
on September 26, 2015
I am a lawyer, not a scientist. I found this book understandable for someone like me. Fortunately, the author added an introductory section about the discovery of the Higgs-Boson because it had not yet been discovered when the book was published. Randall is a highly competent writer. This is not a simple book. One have to re-read a few paragraphs to understand them. The primary subjects are physics, particularly particle physics, and astronomy. I read a lot of popularized science material; my brother, who is as intelligent as I but doesn't read much science, found the book very tough going and quit it. Randall is awed by the beauty of science and by the work done by other scientists and convey her enthusiasm very well.
on August 3, 2015
I just finished Randall's book Warped Passages and enjoyed it very much. So it was with anticipation that approached reading this book. Randall notes the intended audience for this book saying that it "is intended for an interested lay reader who would like to have a greater understanding of current theoretical and experimental physics and who wants a better appreciation of the nature of modern science - as well as the principles of sound scientific thought." The title is explained in the book: "Scientists knock on heaven's door in an attempt to cross the threshold separating the known from the unknown."
She begins by discussing the many misconceptions people have about science today and introduces us to the concept of effective theories, which is a technique scientists use to study "particles and forces that have effects at the distances in question." A whole chapter is then spent on the contribution of Galileo in establishing the foundations of science thought. Some time is spent discussing the different aims for science and religion. She notes that the goals of science and religion are intrinsically different. Science addresses physical reality, whereas religion tends to be concerned with psychological or social human desires. Early modern scientists actually viewed the "Book of Nature" and the "Book of God" as similar paths to edification and revelation.We are next taken on a journey from the sub-atomic scales all the way down to something known as the Planck length (10-33 cm). We learn of the discoveries of electrons and quarks, fixed-target verses particles colliders, the Higgs mechanism, and more.
Section III of the book delves into the machinery and measurements behind the science, notably the Large Hadron Collider (LHC) at CERN. A chapter is spent discussing the conception, construction, first tests, and problems encountered with the LHC. Some feared the LHC would be capable of producing black holes, and maybe even destroy the earth. Randall puts our fears at bay by explaining all we need to know about this. She continues by discussing calculating and dealing with risk citing common examples such as climate change and the financial crisis and explains how risk can be mitigated. The next topic deals with measurement and uncertainty where we learn the meaning of the terms accuracy, precision, and systemic uncertainty. A chapter is devoted to the CMS and ATLAS experiments. These are the two general purpose detectors of the LHC. They are incredibly large and extremely complex wonders of engineering. Perhaps Randall's own theories will be verified here. Space is devoted to explaining in more detail the detection system. Here we have the trackers (innermost part of the detector), the electromagnetic calorimeter, the hadron calorimeter, and on the outermost part of the detectors we have the muon detector. There are many images provided to show us all that is described in the text.
Section IV of the book deals with the topics of modeling and prediction of results. The concept of beauty and its relationship to science is explored, and we are given some insight into the process of model building. This segues into the nature of the Higgs boson, the Higgs field, symmetry breaking, and how the Higgs imparts mass to particles via something called the Higgs mechanism. We also learn about how the particles produced in the LHC can be used to identify the "fingerprints" of the latest theories. One theory of the author, called the Randall-Sundrum theory, proposes a warped geometry involving two types of branes in close proximity. Randall expresses the anxiety provoking nature of waiting for the LHC results. She notes that "They could change our view of the underlying nature of reality [...] When the results are in, whole new worlds could emerge. Within our lifetimes, we just might see the universe very differently." The text would not be complete with a discussion of inflation, dark matter and dark energy. We are informed of the various dark matter detection methods, and the various experiments worldwide that are being conducted in a attempt to detect it.
Randal has given us here a glimpse into the world of high-energy physicists and cosmologists, their hopes, and the experiments that could answer the fundamental questions about the universe we live in.
Ever wonder what makes scientists tick? Why they study things like the evolution of the universe or the fine structure of matter? Ever wonder what really makes science science, as opposed to other human disciplines? Or why they recently opened the LHC (large hadron collider) at the border of France & Switzerland, the largest machine ever constructed and for particle physicists the greatest toy they ever had to play with? All these and many other questions will be explored, if not completely answered, in this massive and important book.
The author begins with questions of scale. The same laws of physics don't seem to apply at the very large dimensions of the universe and the very small dimensions inside the atom. She discusses scientific method, indirect measurement, creativity, subatomic structure and much more. Turns out there isn't a measuring stick small enough to measure the fine structure of an atom. You have to hurl particles together at very high speeds and smash them to smithereens; then you study the smithereens.
And, the author explains, there's more to the universe than matter and energy; there's also dark matter and dark energy, which we've barely begun to understand. And scientists are trying to figure out how to detect and measure those things.
Author Lisa Randall is a Harvard physics professor and thus well-qualified to write this book. She has packed this huge volume (400 plus pages) with information. However, it's not easy reading. The style of writing is repetitious, obsessively complete, and yet many concepts and terms are introduced without much explanation. To be a reasonably well-read layman may not be enough. I found myself skimming some of the later chapters. Still, I must admit, I learned a lot. This is a profound book and I recommend it, but it's HARD READING, and not for everyone. Reviewed by Louis N. Gruber
"Science has a battle for hearts and minds on its hands...against superstition and ignorance on one flank, and against pseudo-intellectual obscurantism on the other. How good it feels to have Lisa Randall's unusual blend of top flight science, clarity, and charm on our side." -- Richard Dawkins
On inauguration day, President Obama announced the goal of "restoring science to its rightful place," but science has a lot of interesting and abstract concepts that scientists like Randall are trying to make conceivable, when dealing with its complicated topics. She thinks, "You can have a complexity in having different thought strands, and ideas come in simultaneously." Lisa Randall emerged as 'a public face' for the complex fields of cosmology and particle physics; as she explores how we make up our mind, about which questions to address, and how we expect science answering them. She wrote 'Warped Passages' for pastime audience, a best selling book introducing science readers to the possibility of additional dimensions beyond the three we experience, and make clear how their existence could account for many of the physical world's most perplexing phenomena. Recently, Brian Greene's "The Elegant Universe," introduced his view of the ill-concealed 'skeleton in the closet of physics' as eleven dimensions, parallel universes, and a world made of strings!
Randall attempts to answer the question of how the universe got its mass. Her undertaking is to delineate the work on several of the string theory models, in the quest to reveal the fabric of the universe. The engaging book conveys her ideas about, "How physics and scientific thinking illuminate the universe and the modern world," is entitled: Knocking on Heaven's Door! The famed "Gates of Paradise," was dubbed by Michelangelo for the east pair of bronze doors of the 'Florence Baptistery', Ghiberti's artistic marvel. But the Gates of Heaven that Dr Randall intends to knock on are not in Florence, they stand at the Large Hadron Collider, that stretches 16.6 miles across the French-Swiss border. In her fascinating book, Lisa Randall, explains the experimental research around the enormous circular tunnel of the nine billion-dollar LHC, anticipating what theories the teams of scientists are fitting together with data and information from the most complex machine ever built.
Recent experiments using the LHC hold out the hope that the Higgs boson's "God Particle," a hypothetical massive elementary particle, predicted to exist by the Standard Model of particle physics, may soon be discovered. It was 1964 when Peter Higgs conceived of an invisible field that filled the cosmos shortly after the Big Bang; and as the newborn universe expanded and cooled, the field switched on. Randall does a good job of discussing the search for the God Particle, that can provide real insight into the innermost functions of the universe. Randall's book alternates between "details of science being done today and reflections on the underlying themes and concepts that are integral to science but that are useful for understanding the broader world as well," hints Randall in the introduction. She suggests that, "In some respects, it is two books in one, but books that are best read together."
While Hawking hoped to develop a "grand unified theory" (GUT), Randall quotes Keats' "Beauty is truth, truth beauty," readily admitting that the truth will always be aesthetically gratifying. The danger of "truth through beauty" in physics, as Randall describes it, is that it makes a virtue of necessity. Wherever experimental evidence can be coaxed out of nature, it suffices to corroborate or refute a theory and serves as the sole arbiter of validity. She masterfully articulates the various theories and models of fundamental particles, in spite of the complex Standard Model. Her display is informative in a lucid way, and her account of the building and running of the LHC is impressive; full of passion and jaw-dropping facts. But, is it true that "Scientists knocking on heaven's door" is an attempt to cross the boundary of the known into the unknown?
The OPERA1 experiment; September 23, 2011.
To physicists and mathematicians, there is nothing wrong with speculation; it is a necessary and vital part of scientific exploration, and they have a big puzzle presently at hand!
"Geneva, 23 September 2011. The OPERA1 experiment, which observes a neutrino beam from CERN2 730 km away at Italy's INFN Gran Sasso Laboratory, will present new results in a seminar at CERN this afternoon at 16:00 CEST. The result is based on observation of over 15,000 neutrino events measured at Gran Sasso, and appears to indicate that the neutrinos travel at a velocity 20 parts per million above the speed of light, nature's cosmic speed limit." Given the potential far-reaching consequences of such a result, independent measurements are needed before the effect can either be refuted or firmly established." CERN Online Official Site
on January 10, 2012
I took great pleasure in reading this fascinating book. I'm recommending it to all my friends. I admit there were some points I didn't understand but I was happy to learn that people like Ms. Randall are striving to understand the true nature of physical reality. Also being a former engineer the descriptions of the Large Hadron Collider were enlightening and allowed me to fully appreciate the great work done by the people that designed and built the LHC.
on October 27, 2011
Once I had a guitar. I worked really, really hard on learning how to play, but never really got the hang of it. I put it away. Ten years later I took it out of the closet, thinking to myself, I've been listening to a lot of music, and it's been ten years, I should be much better at this. That's right, I wasn't.
I'm interested in cosmology and physics in much the same way I'm interested in Buddhism, and a bit more than I was actually interested in the guitar. Let's take Buddhism first. I've read lots of books on the subject, and can carry on a decent conversation, but it wasn't until I started actually practicing that I understood anything - really, any thing - about it. Cosmology and physics. Fascinating. I've read a bunch of books. I keep thinking if I just read one more book I'll get what the hell these people are talking about - I mean, really get it. So, I picked up "Knocking on Heaven's Door." I admit, being a Dylan nut, the title got me, and I thought that anyone who would use a Dylan lyric (apt by the way) as a title, and other song titles as chapters would be able to give it to me in a way I'd understand. Nope. And I'm not blaming anyone but me, that's why I've given this book five stars. I don't want anyone to turn away from its possibilities just because I'm a dolt.
What I did learn, and this is important to me - it's all a matter of scale. Just because a neutrino can defy the laws of physics and move, at least momentarily, faster than light doesn't mean that anything bigger than said neutrino can do the same. So all you time travelers can unfasten your seat belts, you're still stuck. By the way, the jury is still out on whether said neutrino actually did break the speed limit. And, this book has nothing to do with said neutrino, I'm just using it as an example of how scale is important.
The other thing I got - scientists are still more connected to reality than theologians. Good science is willing to test and expand theory until it's no longer theory. Even the best theologians think the rock is solid, and god damn anyone who doesn't.
Anyway, Knocking on Heaven's Door, was ultimately too much for me - too much science that I plain couldn't get my pea brain around. That doesn't mean you shouldn't check it out.
on October 14, 2014
While I'm not a physicist I have had a fascination with particle physics and the general nature of the universe and even pondered the implications of an 11 dimensional universe. Dr. Randall takes the reader on a slow walk through the world of science on a path that leads to the LHC in Europe. She describes, in fascinating detail, how the sensors work and what they measure. She even has fun with the media panic over the potential that the LHC would form a black-hole that would consume us all.
It is an excellent tour and perhaps even a recommended read for that child who has a budding interest in science and math.