Motivated by the possible existence of other universes as part of the multiverse framework, we investigate how changing the fundamental constants of nature can change the prospects for the existence of astrophysical structures. This talk will focus on nucleosynthesis by considering simple models for nuclear structure. These modifications are then used to estimate the corresponding changes in binding energies and reaction rates for processes in both big bang and stellar nucleosynthesis. We use numerical codes to find the resulting differences in nuclear abundances in these two environments. The abundance yields are used to assess the strength of anthropic arguments or infer the prospects of habitability in other universes.