Quantum theory is one of the more abstract branches of theoretical physics, yet it makes clear and concrete predictions which are repeatedly verified experimentally. More recently, there has been some confluence between the concepts of microphysics and those of macrophysics. Currently fashionable ideas in cosmology are also deeply linked to concepts from quantum theory, thus piquing greater interest in this subject. This timely book takes stock of what quantum theory has achieved and where it is leading to at present, in a manner understandable to an educated layman. The book describes concepts in a strictly scientific manner without trying to make them sound overly philosophical or "hyping" them up. At the same time, careful explanation of the concepts and details (including the technical terminology) are given in a nonmathematical language for the general reader. In particular, emphasis is given to the specific aspects of quantum theory that interface with gravity and cosmology, so as to keep the book reasonably up to date and focused on a key underlying theme.

India has a strong and ancient tradition of astronomy, which seamlessly merges with the current activities in Astronomy and Astrophysics in the country. While the younger generation of astronomers and students are reasonably familiar with the current facilities and the astronomical research, they might not have an equally good knowledge of the rich history of Indian astronomy. This particular volume, brought out as a part of the Platinum Jubilee Celebrations of Indian National Science Academy, concentrates on selected aspects of historical development of Indian astronomy in the form of six invited chapters. Two of the chapters - by Balachandra Rao and M.S. Sriram - cover ancient astronomy and the development of calculus in the ancient Kerela text Yuktibhasa. The other four chapters by B.V. Sreekantan, Siraj Hasan, Govind Swarup and Jayant Narlikar deal with the contemporary history of Indian astronomy covering space astronomy, optical astronomy, radio astronomy and developments in relativistic astrophysics. These chapters, written by experts in the field, provide an in-depth study of the subject and make this volume quite unique.

This lucid and captivating book takes the reader back to the early history of all the sciences, starting from antiquity and ending roughly at the time of Newton - covering the period which can legitimately be called the "dawn" of the sciences. Each of the 24 chapters focuses on a particular and significant development in the evolution of science, and is connected in a coherent way to the others to yield a smooth, continuous narrative. The at-a-glance diagrams showing the "When" and "Where" give a brief summary of what was happening at the time, thereby providing the broader context of the scientific events highlighted in that chapter. Embellished with colourful photographs and illustrations, and "boxed" highlights scattered throughout the text, this book is a must-read for everyone interested in the history of science, and how it shaped our world today.

This book addresses a fascinating set of questions in theoretical physics which will both entertain and enlighten all students, teachers and researchers and other physics aficionados. These range from Newtonian mechanics to quantum field theory and cover several puzzling issues that do not appear in standard textbooks. Some topics cover conceptual conundrums, the solutions to which lead to surprising insights; some correct popular misconceptions in the textbook discussion of certain topics; others illustrate deep connections between apparently unconnected domains of theoretical physics; and a few provide remarkably simple derivations of results which are not often appreciated. The connoisseur of theoretical physics will enjoy a feast of pleasant surprises skilfully prepared by an internationally acclaimed theoretical physicist. Each topic is introduced with proper background discussion and special effort is taken to make the discussion self-contained, clear and comprehensible to anyone with an undergraduate education in physics.

This book describes, in clear terms, the Why, What and the How of Quantum Field Theory. The raison d'etre of QFT is explained by starting from the dynamics of a relativistic particle and demonstrating how it leads to the notion of quantum fields. Non-perturbative aspects and the Wilsonian interpretation of field theory are emphasized right from the start. Several interesting topics such as the Schwinger effect, Davies-Unruh effect, Casimir effect and spontaneous symmetry breaking introduce the reader to the elegance and breadth of applicability of field theoretical concepts. Complementing the conceptual aspects, the book also develops all the relevant mathematical techniques in detail, leading e.g., to the computation of anomalous magnetic moment of the electron and the two-loop renormalisation of the self-interacting scalar field. It contains nearly a hundred problems, of varying degrees of difficulty, making it suitable for both self-study and classroom use.