ABSTRACT
Spherical harmonics enter into the discussion as the eigenfunctions of the angular part of the Laplacian in spherical coordinates. These functions are of basic importance, not only for the applications in classical physics which are the main focus of the work, but also in quantum physics where they form the wave functions describing orbital angular momentum. Nearly every calculation dealing with an atomic, molecular, nuclear, or elementary particle system employs spherical harmonics in one way or another. The chapter provides a fairly detailed treatment including many useful but sometimes tiresome algebraic details. Since atoms and nuclei have multipole moments, the expressions are important in various atomic and nuclear problems. The boundary condition says that the flow at the surface of the obstacle must be tangent to the surface.
