The file contains four documents: F. A. Bopp's opening address to the Symposium (9 pp.); Werner Heisenberg's talk entitled: Significance of Sommerfeld's Work Today (14 pp.); H. Welker's presentation entitled: Impact of Sommerfeld's Work on Solid State Research and Technology (14 pp.); and Peter Paul Ewald's reminiscence entitled: Arnold Sommerfeld as a man, teacher, friend (14 pp.), all of which were written for this symposium marking the occasion of the 100th anniversary of Sommerfeld's birth. Bopp's opening remarks include a brief biographical sketch of Sommerfeld's life and scientific works, as well as a description of the motivating ideas for the symposium itself. Ewald's reminiscence is as much a description of Sommerfeld the man as of Sommerfeld the scientist, although he makes clear that the two really cannot be separated. Ewald describes Sommerfeld's character as it influenced his work; his fencing while in university; his love of nature; skiing tours on which he discussed with Ewald and others various research topics; his personal attitude toward his students; his ability and techniques as a teacher; his politics; and writing and ability as a lecturer. Heisenberg discusses specifically the stability of laminar flow in fluids, the method of complex integration in the solution of physical problems, and the numeried [sic] value of Sommerfeld's fine structure constant. Welker provides a close analysis of Sommerfeld's work and its applications, in some technical detail.