Presents the current understanding of the nature of time and space, and an approachable explanation of Einstein's theory of special relativity; then goes on to connect these to possible time travel along with the accompanying paradoxes involved.

Top researchers in the field of gravitation present the state-of-the-art topics outlined in this book, ranging from the stability of rotating wormholes solutions supported by ghost scalar fields, modified gravity applied to wormholes, the study of novel semi-classical and nonlinear energy conditions, to the applications of quantum effects and the superluminal version of the warp drive in modified spacetime. Based on Einstein's field equations, this cutting-edge research area explores the more far-fetched theoretical outcomes of General Relativity and relates them to quantum field theory. This includes quantum energy inequalities, flux energy conditions, and wormhole curvature, and sheds light on not just the theoretical physics but also on the possible applications to warp drives and time travel. This book extensively explores the physical properties and characteristics of these 'exotic spacetimes,' describing in detail the general relativistic geometries that generate closed timelike curves.

How does the Star Trek universe stack up against the real universe? What warps when you're traveling at warp speed? What is the difference between a wormhole and a black hole? Are time loops really possible, and can I kill my grandmother before I am born? Anyone who has ever wondered "could this really happen?" will gain useful insights into the Star Trek universe (and, incidentally, the real world of physics) in this charming and accessible guide. Lawrence M. Krauss boldly goes where Star Trek has gone-and beyond. From Newton to Hawking, from Einstein to Feynman, from Kirk to Picard, Krauss leads readers on a voyage to the world of physics as we now know it and as it might one day be.

For the past 20 years causality violations and superluminal motion have been the object of intensive study as physical and geometrical phenomena. This book compiles the results of its author and also reviews other work in the field. In particular, the following popular questions are addressed: Is causality protected by quantum divergence at the relevant Cauchy horizon? How much "exotic matter" would it take to create a time machine or a warp drive? What is the difference between a "discovered" time machine and a created one? Why does a time traveler fail to kill their grandfather? How should we define the speed of gravity and what is its magnitude?

A Princeton astrophysicist explores whether journeying to the past or future is scientifically possible in this “intriguing” volume (Neil deGrasse Tyson). It was H. G. Wells who coined the term “time machine”—but the concept of time travel, both forward and backward, has always provoked fascination and yearning. It has mostly been dismissed as an impossibility in the world of physics; yet theories posited by Einstein, and advanced by scientists including Stephen Hawking and Kip Thorne, suggest that the phenomenon could actually occur. Building on these ideas, J. Richard Gott, a professor who has written on the subject for Scientific American, Time, and other publications, describes how travel to the future is not only possible but has already happened—and contemplates whether travel to the past is also conceivable. This look at the surprising facts behind the science fiction of time travel “deserves the attention of anyone wanting wider intellectual horizons” (Booklist). “Impressively clear language. Practical tips for chrononauts on their options for travel and the contingencies to prepare for make everything sound bizarrely plausible. Gott clearly enjoys his subject and his excitement and humor are contagious; this book is a delight to read.” —Publishers Weekly

Frontiers of Propulsion Science is the first-ever compilation of emerging science relevant to such notions as space drives, warp drives, gravity control, and faster-than-light travel - the kind of breakthroughs that would revolutionize spaceflight and enable human voyages to other star systems. Although these concepts might sound like science fiction, they are appearing in growing numbers in reputable scientific journals. This is a nascent field where a variety of concepts and issues are being explored in the scientific literature, beginning in about the early 1990s. The collective status is still in step 1 and 2 of the scientific method, with initial observations being made and initial hypotheses being formulated, but a small number of approaches are already at step 4, with experiments underway. This emerging science, combined with the realization that rockets are fundamentally inadequate for interstellar exploration, led NASA to support the Breakthrough Propulsion Physics Project from 1996 through 2002.""Frontiers of Propulsion Science"" covers that project as well as other related work, so as to provide managers, scientists, engineers, and graduate students with enough starting material that they can comprehend the status of this research and decide if and how to pursue it in more depth themselves. Five major sections are included in the book: Understanding the Problem lays the groundwork for the technical details to follow; Propulsion Without Rockets discusses space drives and gravity control, both in general terms and with specific examples; Faster-Than-Light Travel starts with a review of the known relativistic limits, followed by the faster-than-light implications from both general relativity and quantum physics; Energy Considerations deals with spacecraft power systems and summarizes the limits of technology based on accrued science; and, From This Point Forward offers suggestions for how to manage and conduct research on such visionary topics.

Some of the unfunded opportunities (UFOs), like the TR3B or TR6, are already flying; with this in mind, it may appear that this book is published too late. However, this is not the case. Both extraterrestrials and humans have developed craft of similar a "planform". Officials and the media continuously feed the masses incorrect information. Drive technology of the honestly endeavoring "human" is outdated. It seems to have been copied from some ancient Indian scriptures. Indeed, electrostatic, electromagnetic and rotating plasma drives deliver fermionic power, but they are far from allowing humanity to harness the power of a hyperspace jump. In 2017, NASA ensured us that "for the near future, [a] warp drive remains a dream". As a matter of fact, both human and extraterrestrial humanoids have hypothesized the use anti-gravity, warping and time travelling vehicles, even what they call "living vessels". However, both have no theory, no theoretical foundations for nuclear time travel technology. This book delivers a few necessary basics concerning the possible future where this nuclear time travel could potentially become a reality.