Problems in determining nuclear bound state wave functions

The interior part of a bound state is difficult to determine empirically. We use momentum space singularity structure to show that final state interactions, rescattering, exchange currents, etc., always act so as to obscure the bound state interior. The asymptotic part of the bound state can be measured for sufficiently "light" components. We apply these results to explain why the deuteron $D$-state probability cannot be fixed and why it is difficult to give meaning to the idea of $\pi -N$ resonances in the nucleus. We treat bound state breakup, elastic scattering, and form factors.