Waves And Grains

Mark Silverman has seen light perform many wonders. From the marvel of seeing inside cloudy liquids as a result of his own cutting-edge research to reproducing and examining an unusual diffraction pattern first witnessed by Isaac Newton 300 years ago, he has studied aspects of light that have inspired and puzzled humans for hundreds of years. In this book, he draws on his many experiences as an optical and atomic physicist--and on his consummate skills as a teacher and writer about the mysteries of physics--to present a remarkable tour of the world of light. He explores theoretical, experimental, and historical themes, showing a keen eye for curious and neglected corners of the study of light and a fascination with the human side of scientific discovery. In the course of the book, he covers such questions as how it is possible to achieve magnifications of a millionfold without a single lens or mirror. He asks what all living things have in common that might one day allow the development of a "life-form scanner" like the one in Star Trek. He considers whether more light can reflect from a surface than strikes it, and explores the origin of the strange hyperpolic diffraction pattern Newton originally produced with sunlight and knives. Silverman also discusses his new and ground-breaking experiments to see into murky substances such as fog or blood--a finding with potential applications as diverse as noninvasive medical testing and remote sensing of the environment. His wide-ranging reflections cover virtually all elements of physical optics, including propagation, reflection, refraction, diffraction, interference, polarization, and scattering. Throughout, Silverman makes extensive reference to both modern research and the original works of giants such as Newton, Fresnel, and Maxwell. In a more personal section about physics and learning, Silverman argues for self-directed learning and discusses the central importance of stimulating scientific curiosity in students. Waves and Grains will encourage a spirit of wonder and inquiry in anyone with scientific interests.

A biography of a staple grain we often take for granted, exploring how wheat went from wild grass to a world-shaping crop. At breakfast tables and bakeries, we take for granted a grain that has made human civilization possible, a cereal whose humble origins belie its world-shaping power: wheat. Amber Waves tells the story of a group of grass species that first grew in scattered stands in the foothills of the Middle East until our ancestors discovered their value as a source of food. Over thousands of years, we moved their seeds to all but the polar regions of Earth, slowly cultivating what we now know as wheat, and in the process creating a world of cuisines that uses wheat seeds as a staple food. Wheat spread across the globe, but as ecologist Catherine Zabinski shows us, a biography of wheat is not only the story of how plants ensure their own success: from the earliest bread to the most mouthwatering pasta, it is also a story of human ingenuity in producing enough food for ourselves and our communities. Since the first harvest of the ancient grain, we have perfected our farming systems to grow massive quantities of food, producing one of our species’ global mega crops—but at a great cost to ecological systems. And despite our vast capacity to grow food, we face problems with undernourishment both close to home and around the world. Weaving together history, evolution, and ecology, Zabinski’s tale explores much more than the wild roots and rise of a now-ubiquitous grain: it illuminates our complex relationship with our crops, both how we have transformed the plant species we use as food, and how our society—our culture—has changed in response to the need to secure food sources. From the origins of agriculture to gluten sensitivities, from our first selection of the largest seeds from wheat’s wild progenitors to the sequencing of the wheat genome and genetic engineering, Amber Waves sheds new light on how we grow the food that sustains so much human life.

The authors describe the widening range of old and new grains being grown in North America; explain the nutritional value, habitat, and best ways to prepare each grain; and offer 157 recipes based on them.

"I have learned more about, and become more fascinated with sand from reading this book than I have from studying beaches for thirty-five years! An amazing story."—Reinhard E. Flick, Scripps Institution of Oceanography, University of California, San Diego "A masterful, entertaining and accessible treatise on the complex world of common sand."—Bruce M. Pavlik, author of The California Deserts "To do justice to this formidable and glorious subject, you need not only to be in love with it, but also to possess tremendous breadth of knowledge, have the eyes of a poet, scientist and geographer, and be intrepid enough to have seen the deserts of the world at first hand. Fortunately, Michael Welland fits the bill. It is hard to see how this paean to the wonders and mysteries of sand could be bettered."—Philip Ball, author of Critical Mass: How One Thing Leads to Another and Life's Matrix: A Biography of Water "A fascinating and colorfully written book filled with insights and wit about the magical material called sand."—Stephen P. Leatherman (aka Dr Beach), author of America's Best Beaches "Sand has given rise to commentary, both poetic and scientific, from the earliest human times. Michael Welland ably winnows this literature, making the subject of sand his base station for a journey around the whole earth system. An impressive achievement."—Andrew Alden, author/editor of About.com's Guide to Geology "Michael Welland offers a popular, imaginative, and scientific evocation of sand as the creator of the world we experience and seek to understand. Sand is a timely meditation on things both large and small that simultaneously opens the door to the oldest geology and our most recent history."—Joseph Amato, author of Dust: A History of the Small and the Invisible

Light scattering and absorption by small homogeneous particles can be worked-out exactly for spheres and infinite cylinders. Homogeneous particles of irregular shapes, when averaged with respect to rotation, have effects that can in general be well-approximated by reference to results for these two idealised cases. Likewise, small inhomogeneous particles have effects similar to homogeneous particles of the same average refractive index. Thus most problems can be solved to a satisfactory approximation by reference to the exact solutions for spheres and cylinders, which are fully stated here in the early part of the book. The sum of scattering and absorption, the extinction, is too large to be explained by inorganic materials, provided element abundances in the interstellar medium are not appreciably greater than solar, H 0 and NH3 being essentially excluded in the 2 general medium, otherwise very strong absorptions near 3p,m would be observed which they are not. A well-marked extinction maximum in the ultraviolet near 2200A has also not been explained satisfactorily by inorganic materials. Accurately formed graphite spheres with radii close to O.02p,m could conceivably provide an explanation of this ultraviolet feature but no convincing laboratory preparation of such spheres has ever been achieved.

The topics discussed in this text range from quasi-static problems to dynamic problems, and are divided into 15 groups, such as: cohesion/cracking; wave propagation; and quasi-static behaviour. Each group contains theoretical, experimental and computational approaches by researchers.

The book is structured thematically, encompassing principles, processes and products, practice and applications. Discussion of processes that control heavy mineral assemblages throughout the rock cycle are presented by leading experts, whose key-note works are followed by specialist case studies. Each work also provides details on the geology of the study area, techniques and data treatment. The high number of contributions represent the collective experience and wisdom of generations of geologists, and provide an invaluable source of references to works carried out in many parts of the world. * Presents a unique and authoritative resource of immediate relevance and practical use to the researcher and applied geologist * Contains case studies demonstrating the broad range of applications of heavy minerals in a variety of modern and ancient geological settings, and in resource exploration * Includes examples of geological problems from employing heavy mineral analysis and establishing criteria that can be applied before deciding to undertake a study