Geophysics has made many important advances towards understanding the behaviour and properties of planet Earth. Geophysical research continues to make discoveries and developments that benefit society. Many problems presented by the Earth—such as the prediction of both the time and location of an earthquake—have been researched by geophysicists for decades, but remain unsolved because of the complex nature of their causes. ‘Afterthoughts’ explains that earth scientists cannot control the natural events that occur, but can only observe and try to understand them. The equipment for attaining these goals improves continually, in a remarkably rapid and encompassing manner. Land-based methods are now augmented in several fields by remarkable observations from space.