Varying Constants, Nuclear Physics and Unification

Precision measurements of gauge couplings at particle accelerators strongly suggest that the standard model fields are unified at about 10¹⁶ GeV. This talk will consist of a brief review of this evidence and also how in such a setting variations in α _em lead to much larger variations in Λ _QCD . I will then describe how variations in the strong force will impact upon nuclear astrophysics, considering in particular the stability of di-nucleons and stellar and primordial nucleosynthesis. (Based upon collaborations with T. Dent and with A. Csoto, H. Oberhummer and H. Schlattl.) This revised version was published online in July 2006 with corrections to the Cover Date.