2013 Reprint of 1951 Edition. Full facsimile of the original edition, not reproduced with Optical Recognition Software. The subject matter of the book is funneled into three chapters: [1] The geometry of Hubert space; [2] the structure of self-adjoint and normal operators; [3] and multiplicity theory for a normal operator. For the last, an expert knowledge of measure theory is indispensable. Indeed, multiplicity theory is a magnificent measure-theoretic tour de force. The subject matter of the first two chapters might be said to constitute an introduction to Hilbert space, and for these, an a priori knowledge of classic measure theory is not essential. Paul Richard Halmos (1916-2006) was a Hungarian-born American mathematician who made fundamental advances in the areas of probability theory, statistics, operator theory, ergodic theory, and functional analysis (in particular, Hilbert spaces). He was also recognized as a great mathematical expositor.

In 1945, Dr. Ernst Weber founded, and was the first Director of, the Microwave Research Institute (MRI) at POLYTECHNIC UNIVERSITY (at that time named the Polytechnic Institute of Brooklyn). MRI gained world-wide recognition in the 50's and 60's for its research in electromagnetic theory, antennas and radiation, network theory and microwave networks, microwave components and devices. It was also known through its series of topical symposia and the widely distributed hard bound MRI Symposium Proceedings. Rededicated as the Weber Research Institute (WRI) in 1986, the research focus today is on such areas as electromagnetic propagation and antennas, ultra broadband electromagnetics, pulse power, acoustics, gaseous electronics, plasma physics, solid state materials, quantum electronics, electromagnetic launchers, and networks. Following the MRI tradition, WRI has launched its own series of in-depth topical conferences with published proceedings. The first conference was held in October, 1990 and was entitled Directions in Electromagnetic Wave Modeling. The proceedings of the conference were published under that title by Plenum Press. This volume constitutes the Proceedings of the second WRI International Conference dealing with Ultra·Wideband Short·Pulse Electromagnetics.

This milestone extensive work combines the essentials of history – biography, chronology, political and economic background – with the observations, theories, principles, laws and equations that constitute the specifics of science. The 5800-page Encyclopedia arises from the conviction that the optimal perspective on science is through the lens of history, setting aside traditional divisions of discipline and specialty, and rising above geopolitical boundaries. Reaching from 4,200 BCE to the 21st century CE, the Encyclopedia tells (as the author himself puts it) "not only who did it and when it was done but also precisely what was done." The author, Ari Ben-Menahem, surveys 100 generations of great thinkers, offering 2070 detailed biographies of scientists, engineers, explorers and inventors, who left their mark on the history of science and technology. The span of coverage is all-encompassing: mathematics, philosophy, logic, physical and environmental sciences (including physics, chemistry, astronomy, earth and space sciences and cosmology), life sciences (biology, medicine, physiology, botany, zoology and biochemistry), associated engineering disciplines, and the social sciences (among them economics, psychology, sociology, anthropology, linguistics and more). The six-volume Encyclopedia also includes 380 articles summarizing the time-line of ideas in the leading fields of science, technology, mathematics and philosophy, plus useful tables, figures and photos, and 20 ‘Science Progress Reports’ detailing scientific setbacks. Interspersed throughout are quotations, gathered from the wit and wisdom of sages, savants and scholars throughout the ages from antiquity to modern times.