Ball lightning is an enigma. These luminous objects that appear occasionally during thunderstorms and can reach several meters in diameter have been a mystery to science for about 200 years.Despite several thousands of reported observations, their nature is still unknown.In this book, well documented cases of ball lightning are described and used to unravel some aspects of this mysterious form of atmospheric electricity.Throughout the book, the author discusses the various facets of the problem in an accessible but rigorous style, delivering a readable and informative text that will captivate the curious reader.Now in an updated and expanded second edition, the author reports on groundbreaking new data on conditions under which ball lightning may form and its implications.These new discoveries are elucidated with new figures, additional case descriptions, new material on the interaction of ball lightning with humans, and a discussion of the reliability of ball lightning observations.This book presents the most up-to-date summary of the state of knowledge surrounding ball lightning. A foreword by Earle Williams, leading lightning researcher at MIT, introduces the book.