Explore the intricacies of seismic wave propagation and mantle dynamics in this 56-minute Gutenberg Lecture delivered by Francis A. Dahlen at the AGU Fall Meeting 2002. Delve into topics such as diffractive wavefront healing, wavespeed sensitivity kernels, and inverse theory as they relate to understanding Earth's restless mantle. Examine the differences between ray theory and finite frequency tomography, and consider their implications for detecting deep mantle plumes. Despite potential rendering issues due to the age of the original file, gain valuable insights into advanced concepts in seismology and geophysics.