If you move at high speed, time slows down, space squashes up and you get heavier. Travel fast enough and you could weigh as much as a jumbo jet, be flattened thinner than a CD without feeling a thing-and live forever! As for the angles of a triangle, they do not always have to add up to 180 degrees. And then, of course, there are black holes. These are but a few of the extraordinary consequences of Einstein's theory of relativity. It is now over a hundred years since he made these discoveries, and yet the general public is still largely unaware of them. Filled with illuminating anecdotes and fascinating accounts of experiments, this book aims to introduce the interested lay person to the subject of relativity in a way which is accessible and engaging and at the same time scientifically rigorous. With relatively few mathematical equations--nothing more complicated than the Pythagoras's Theorem--this VSI packs a lot time into very little space, and for anyone who has felt intimidated by Einstein's groundbreaking theory, it offers the perfect place to start.

About the Series: Combining authority with wit, accessibility, and style, Very Short Introductions offer an introduction to some of life's most interesting topics. Written by experts for the newcomer, they demonstrate the finest contemporary thinking about the central problems and issues in hundreds of key topics, from philosophy to Freud, quantum theory to Islam.

Table of Contents

1 Special relativity

The principle of relativity and the speed of light

Time dilation

The twin paradox

Length contraction

Loss of simultaneity

Space–time diagrams

Four-dimensional spacetime

The ultimate speed

2 General relativity

The equivalence principle

The effects on time of acceleration and gravity

The twin paradox revisited

The bending of light

Curved space

Black holes

Gravitational waves

The universe

About the Author

Russell Stannard is Emeritus Professor of Physics at the Open University. A prolific writer for both adults and children, his books are translated into 20 languages and have been shortlisted for many scientific book prizes. His trilogy of Uncle Albert books introduces children of 10+ to relativity and quantum theory. He is the co-author, with Paul Davies, of The God Experiment.