Abstract:  With lattice QCD calculations in mind, I will motivate the study of two
and three particle systems in a finite volume. I will review recent progress towards
the extraction of scattering parameters directly from the finite volume spectrum,
both in the scalar and nuclear sector. I will present predictions for the
two-nucleon spectrum at the physical pion mass and pay close attention to the
deuteron. The results demonstrate that in a finite volume, the sensitivity of the
deuteron binding energy to the tensor force is enhanced and that the mixing angle in
the 3S1-3D1 channel can be extracted by from lattice QCD calculations of the
deuteron binding energy.