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?

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?

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.

To those of us who are not mathematicians or physicists, Einstein’s theory of relativity often seems incomprehensible, exotic, and of little real-world use. None of this is true. Daniel F. Styer’s introduction to the topic not only shows us why these beliefs are mistaken but also shines a bright light on the subject so that any curious-minded person with an understanding of algebra and geometry can both grasp and apply the theory. Styer starts off slowly and proceeds carefully, explaining the concepts undergirding relativity in language comprehensible to nonscientists yet precise and accurate enough to satisfy the most demanding professional. He demonstrates how the theory applies to various real-life situations with easy equations and simple, clear diagrams. Styer's classroom-tested method of conveying the core ideas of relativity—the relationship among and between time, space, and motion and the behavior of light—encourages questions and shows the way to finding the answers. Each of the book’s four parts builds on the sections that come before, leading the reader by turn through an overview of foundational ideas such as frames of reference, revelatory examples of time dilation and its attendant principles, an example-based exploration of relativity, and explanations of how and why gravity and spacetime are linked. By demonstrating relativity with practical applications, Styer teaches us to truly understand and appreciate its importance, beauty, and usefulness. Featuring worked and end-of-chapter problems and illustrated, nontechnical explanations of core concepts, while dotted throughout with questions and answers, puzzles, and paradoxes, Relativity for the Questioning Mind is an enjoyable-to-read, complete, concise introduction to one of the most important scientific theories yet discovered. The appendixes provide helpful hints, basic answers to the sample problems, and materials to stimulate further exploration.

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

This book is for anyone who wants a fresh approach to modern physics. Are you tired of amusing anecdotes about scientists' personal lives and eureka moments? Bored of chronological narratives of scientific progress through the ages? No longer wowed by ideas like string theory? Interested in first principles thinking and what it can do for you? This book is for you. This book is designed to take you step by step through the fundamental principles that underlie the physics of space, time, and matter. It is a how-to guide for building up our universe from first principles. By posing questions and answering them with illustrations and examples, the book shows how we can demonstrate what we know about the universe with simple concepts and thought experiments. With this book, you too can apply first principles to build up your own model of the universe and how it works, one you can take with you, and apply it to other areas of your life such as your job, business, even your relationships. There are no complicated mathematics in this book and I have minimized the amount of jargon. Thus, it is suitable anyone of any educational background from high school on. The book aims to be straightforward about how we get from simple ideas to complex physical theories. So, if you are interested in a new way of looking at the universe and are not afraid to unlearn some of what you have learned, take a look inside.

Now a New York Times and USA Today bestseller! Winner of Best Science Fiction in the 2020 Goodreads Choice Awards! To Sleep in a Sea of Stars is a brand new epic novel from #1 New York Times bestselling author of Eragon, Christopher Paolini. Kira Navárez dreamed of life on new worlds. Now she's awakened a nightmare. During a routine survey mission on an uncolonized planet, Kira finds an alien relic. At first she's delighted, but elation turns to terror when the ancient dust around her begins to move. As war erupts among the stars, Kira is launched into a galaxy-spanning odyssey of discovery and transformation. First contact isn't at all what she imagined, and events push her to the very limits of what it means to be human. While Kira faces her own horrors, Earth and its colonies stand upon the brink of annihilation. Now, Kira might be humanity's greatest and final hope . . . The Fractalverse Series To Sleep in a Sea of Stars Fractal Noise At the Publisher's request, this title is being sold without Digital Rights Management Software (DRM) applied.