The Universe that Rings

Einstein's theory of relativity is as beautiful as it is profound, and a brilliant stroke of genius. But for the non-expert, his theory of relativity seems quite hard to pin down: one doesn't know where to begin in order to understand its wonderful implications. The author, however, believes that understanding Einstein's theory of relativity is not an insurmountable task. This book starts with the simplest Newtonian theory of universal gravitation and uses easy-to-grasp language to explain the gulf of knowledge traversed by humanity over the course of 200 years: establishing that light travels at a finite speed, and that the propagation of light does not require a medium. After Einstein began his pursuits, he overturned Newton's stubborn concept of absolute time with an easily understood thought experiment. And it turns out that time can expand or contract according to how fast one travels and the strength of the gravitational field in which one is located. Einstein persistently worked to transform Newton's conception of gravitational fields into his unique notion of a local curvature in the four-dimensional spacetime geometry. Here the author once again uses plain language and easily understood descriptions that allow the reader to fully appreciate the physical implications hidden behind the esoteric mathematics of Einstein's theory of relativity. In this way, readers can establish a comprehensive understanding of Einstein's theory of relativity--it's like a stimulus check of knowledge. Einstein predicted the existence of gravitational waves a hundred years ago. These are waves that come from the deepest reaches of the universe and are intimately related to the expanding dark universe, discovered at the onset of the 21st century. After more than fifty years of hard work, in 2015 humanity at last detected a gravitational wave--generated from a collision between two black holes 1.3 billion years ago. The author reports in detail this tremendous achievement (which won the 2017 Nobel Prize in Physics), and what we have gained by it.