How will humans interact in the new millennium? Pelton argues that we have moved beyond the "global village" into an environment of rapid-fire, non-stop instantaneous global communication - the e-sphere. We can thus no longer receive information passively and must create and share it to survive.

This is a remarkable book. Arthur Yaghjian is by training and profession an electrical engineer; but he has a deep interest in fundamental questions usually reserved for physicists. Working largely in isolation he has studied the relevant papers of an enormous literature accumulated over a century. The result is a fresh and novel approach to old problems and to their solution. Physicists since Lorentz have looked at the problem of the equations of motion of a charged object primarily as a problem for the description of a fundamental particle, typically an electron. Yaghjian considers a mac- scopic object, a spherical insulator with a surface charge. was therefore not tempted to take the point limit, and he thus avoided the pitfalls that have misguided research in this field since Dirac's famous paper of 1938. Perhaps the author's greatest achievement was the discovery that one does not need to invoke quantum mechanics and the correspondence pr- ciple in order to exclude the unphysical solutions (runaway and pre-acc- eration solutions). Rather, as he discovered, the derivation of the classical equations of motion from the Maxwell-Lorentz equations is invalid when the time rate of change of the dynamical variables too large (even in the relativistic case). Therefore, solutions that show such behavior are inc- sistent consequences. The classical theory thus shown to be physically consistent by itself. It embarrassing--to say the least--that this obs- vation had not been made before.

Multifunctional Metallic Hollow Sphere Structures are an emerging new material category, belonging like metal foams to the class cellular metals. Thanks to their advantageous mechanical and sound absorbing properties, Multifunctional Metallic Hollow Sphere Structures are very promising for various applications and our technological knowledge makes them ready for industrial usage. This reference gives a complete overview on this new materials class, the fundamentals, the applications and the perspective for future use. It provides the foundations for a profound understanding (production and processing), their physical properties (surface properties and stalility) and applicaltion (in particular for sound absorption and chemical adsorption in structural parts). The book is written for material scientists, product designers and developers as well as academic researches and scientists.

This book traces a remarkable path of mathematical connections through seemingly disparate topics. Frustrations with a 1940's electro-mechanical computer at a premier research laboratory begin this story. Subsequent mathematical methods of encoding messages to ensure correctness when transmitted over noisy channels lead to discoveries of extremely efficient lattice packings of equal-radius balls, especially in 24-dimensional space. In turn, this highly symmetric lattice, with each point neighboring exactly 196,560 other points, suggested the possible presence of new simple groups as groups of symmetries. Indeed, new groups were found and are now part of the "Enormous Theorem"—the classification of all simple groups whose entire proof runs some 10,000+ pages—and these connections, along with the fascinating history and the proof of the simplicity of one of those "sporatic" simple groups, are presented at an undergraduate mathematical level.

Circles and spheres are central objects in geometry. This work looks at systems of circles and spheres and the geometry and groups associated to them. It also examines the differential and projective geometry of the space of various spheres in a given space.

The 400-year-old Kepler conjecture asserts that no packing of congruent balls in three dimensions can have a density exceeding the familiar pyramid-shaped cannonball arrangement. In this book, a new proof of the conjecture is presented that makes it accessible for the first time to a broad mathematical audience. The book also presents solutions to other previously unresolved conjectures in discrete geometry, including the strong dodecahedral conjecture on the smallest surface area of a Voronoi cell in a sphere packing. This book is also currently being used as a blueprint for a large-scale formal proof project, which aims to check every logical inference of the proof of the Kepler conjecture by computer. This is an indispensable resource for those who want to be brought up to date with research on the Kepler conjecture.