how did the universe begin and how will it end? what happens to us when we die? do intelligent beings exist elsewhere in our galaxy and beyond? the edge of science addresses these and many other questions that have bewildered and perplexed humanity for centuries. some of these enigmas have been solved through the ingenuity of their investigators; others remain a mystery and have given rise to equally bizarre speculations. from the tunguska explosion of 1908 to the enigma of the moon`s origin, from the possibility of time travel to the search for zero-point energy, author alan baker examines the many theories that have been presented to account for the world`s most enduring mysteries. each chapter deals with an enigma that has caused wonder, excitement or fear to all who have pondered it, including: the discovery of strange fossils that hint at an unknown early history of humanity; anomalous structures photographed on the moon and mars; the mystery of dark matter and dark energy; and strange disappearances of people and objects. join alan baker as he embarks on a strange, stimulating and sometimes frightening journey to the edge of science. .