Angular dependence in photoemission: from atoms to surfaces to atoms

Some aspects of atomic and solid-state contributions to the angular dependence of photoemission from core levels, and their relevance and utility in the study of surfaces, are reviewed from a personal and historical perspective. In particular, the role played by dipole angular dependence in photoelectron diffraction and X-ray absorption spectroscopy, and by both dipole and non-dipole effects in X-ray standing wave studies are highlighted.