Compact Knowledge. How were the Earth\'s continents formed? What does the green-house effect really mean? What causes thunder and lightening? Children and young people with an interest in these and many other questions about the Earth will find the answers in this book. From the centre of the Earth to its surface, from the atmosphere into space: geological, geographical, climatic and cosmic causes and effects RE explained, and the fascinating result s of research about our blue planet, facts that everyone should know, are described in an easy-to-understand way.