In 1987 scientists and engineers were seized with excitement at the discovery of 'high temperature superconductors': these new materials become superconducting at temperatures four times higher than any previously known superconductor. Suddenly all kinds of applications of superconductivity, from magnetically levitated trains to lossless power lines, became possible. As a result of the intense media coverage of these discoveries, superconductivity has become almost a household word, although most people have only a vague idea of what it is. In this book Professor Vidali describes in plain, non-technical terms how conventional superconductivity was discovered 80 years ago, why it took nearly 50 years to understand it, and the physical explanation of why it exists. He chronicles the developments that led up to the discovery of high temperature superconducting materials, and describes the excitement generated by announcements of the new discoveries in 1987 at a scientific conference that became known as the 'Woodstock of physics'. Finally, he speculates on possible future applications of these new materials.