No one has ever seen a quark. Yet physicists seem to know quite a lot about the properties and behavior of these ubiquitous elementary particles. Here a top researcher introduces us to a fascinating but invisible realm that is part of our everyday life. Timothy Smith tells us what we know about quarks--and how we know it.
Though the quarks that make science headlines are typically laboratory creations generated under extreme conditions, most quarks occur naturally. They reside in the protons and neutrons that make up almost all of the universe's known matter, from human DNA to distant nebulae, from books and tables to neutron stars. Smith explains what these quarks are, how they act, and why physicists believe in them sight unseen. How do quarks arrange themselves? What other combinations can nature make? How do quarks hold nuclei together? What else is happening in their hidden worlds? It turns out that these questions can be answered using a few simple principles, such as the old standby: opposites attract. With these few principles, Smith shows how quarks dance around each other and explains what physicists mean when they refer to "up" and "down" quarks and talk about a quark's color, flavor, and spin.
Smith also explains how we know what we know about these oddly aloof particles, which are eternally confined inside larger particles. He explains how quark experiments are mounted and how massive accelerators, targets, and detectors work together to collect the data that scientists use to infer what quarks are up to.
A nonmathematical tour of the quark world, this book is written for students, educators, and all who enjoy scientific exploration--whether they seek a taste of subnuclear physics or just wonder about nature on the smallest of scales.
"Smith gives us a series of extremely readable and well-chosen analogies to explain the science. His relaxed style makes for an enjoyable read. . . . [A] useful addition to the popular literature on particle physics."--Alan Martin, New Scientist
"Hidden Worlds is a satisfying account of the physics of quarks. . . . Smith, a practicing nuclear physicist, conveys a clear picture of contemporary research and gives a well-articulated perspective from which to view modern nuclear and particle physics. Particularly noteworthy is the fine balance between the discussions of theory and experiment. . . . Although the science background needed to understand the material is slight, this is a rather more sophisticated book than many popular accounts of modern physics. . . . A thoughtful book for undergraduates or interested laypersons."--Choice
"This book explains, using diverse means, the quark model of the proton and neutron. It sketches the history of the quark idea and succeeds in explaining to nonphysicists why physicists believe in quarks even though a single quark has never been observed. I really like this book, which will serve important purposes."--Gerald A. Miller, University of Washington
Table of Contents:
LIST OF FIGURES ix
CHAPTER ONE: Hidden Worlds: The Search for Quarks in Ordinary Matter 1
CHAPTER TWO: The Rise and Fall (for the right reasons) and Rise Again of the Quark Hypothesis 15
CHAPTER THREE: The Players and the Stage 33
CHAPTER FOUR: The Nature of the Evidence 51
CHAPTER FIVE: Measuring a Rainbow 68
CHAPTER SIX: Particle Taxonomy and Quark Soup 90
CHAPTER SEVEN: The Shape of Things 109
CHAPTER EIGHT: Three Quarks Plus 131
CHAPTER NINE: Digging a Little Deeper 148
CHAPTER TEN: A New Age of Exploration within the Hidden World 161