Back In Time And Faster Than Light Travel In General Relativity

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?

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.

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

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.

Albert Einstein knew already in the early 1900s, when he first published his famous paper about the constancy of the speed of light, that not only did this constancy imply that mass contains energy (E = m c squared), but that faster-than-light motion could lead to paradoxes -- some that seemed to involve backwards time travel. What are these paradoxes? Why is light and its speed relevant? This book will lead you through an obstacle course of conundrums and oddities, building up your understanding of how light's speed creates simple but mind-expanding paradoxes -- one conceptual riddle at a time. This is not your average popular science book. This is also not a textbook. This book takes one theme -- the universally constant speed of light -- and shows how it may appear compromised on scales from the quantum mechanics of the very small to the cosmology of the very large, and the resulting surprising implications can result. Book Review 1: "Imagine embarking on a journey to comprehend the physics of the entire universe with a guide who’s not only an expert but makes the concepts digestible and entertaining. Robert J. Nemiroff offers such a journey in Faster Than Light, a book that initially describes the speed of light, then touches on subjects as esoteric as time travel using the theory of relativity and speculation on how to send information back in time, among other subjects." -- blue ink Book Review 2: " ... takes readers on a wild ride through the ins and outs of the speed of light in this mind-bending guide. His primary approach is through a series of humorous thought experiments ... explanations are clear and concise, and most of them require only logic to sort out, making the book more accessible than similar titles." -- Booklife Book Review 3: "A fresh and joyous ride through the mind-bending puzzles at the heart of nature's most fundamental speed that remind us that the universe is strange beyond belief" -- Caleb Scharf (Author: THe Ascent of Information) Book Review 4: "Better than a new particle collider!" -- Sabine Hossenfelder (Author: Existential Physics)

In 1870, more than 4,000 years after it was built, the Great Pyramid at Giza in Egypt was still the world's tallest man-made structure. By 2010, only 140 years later, there were more than 10,000 buildings taller than the Great Pyramid. This book is about what caused this change and what will change next. Why did change take so long to happen? Why did it start in North West Europe? The Birth of Nowlooks at what made the Industrial Revolution – and the financial, transport, agricultural and political revolutions – all happen at the same time. Previous ideas are reviewed – empire, geography, politics, coal or inventions – with remarkable new findings, until the 'smoking gun' is found and we know what started it all, what triggered the Birth of Now. Once it started, we see the astonishing rate of transformation in the Victorian age and, in the last part of the book, see how our view of the future is changed. The Birth of Now follows Jamie Cawley's previous break-through book, Beliefs, in transforming our understanding of the world. This book will allow readers to see the world in a new way, that will make them think and understand better what happened then and what is happening now. Ideal for anyone looking for a new perspective on the modern world, The Birth of Now is a fascinating read that will appeal to those interested in 20th century history.

Einstein's pioneering work helped shape the cultural landscape of the world today. Now in a digestible, pocket format for the modern reader. A new, popular edition with a clear introduction, Special & General Relativity by Albert Einstein contains his core paper, 'Relativity, The Special & The General Theory: A Popular Exposition', which established his reputation as one of the greatest thinkers of our (and perhaps any) age. Also included are two of the Princeton University lectures he gave to explain his findings in more detail, on 'The Meaning of Relativity', as well as the early paper which led to his famous equation E = mc2. The FLAME TREE Foundations series features core publications which together have shaped the cultural landscape of the modern world, with cutting-edge research distilled into pocket guides designed to be both accessible and informative.