The next frontier of the highly successful program of observations of the Cosmic
 Microwave Background (CMB) is to discover gravitational waves generated during Cosmic
 Inflation by searching for a primordial B mode of the CMB polarization. After reviewing
 some of the physics of the CMB and the current status of CMB observations, I will
 discuss some of the experimental efforts seeking to discover primordial B modes.  I
 will also describe some of the obstacles that must be overcome to detect primordial B
 modes at the targeted sensitivities, in particular polarized thermal emission from dust
 grains in our own Galaxy. The physics of interstellar dust and how it becomes aligned
 with the magnetic field are interesting in their own right and are relevant to many
 areas of astrophysics.