A calculation of the current-quark-mass-dependence of nucleon static
electromagnetic properties is necessary in order to use observational data as a
means to place constraints on the variation of Nature's fundamental parameters.
A Poincare' covariant Faddeev equation, which describes baryons as composites
of confined-quarks and -nonpointlike-diquarks, is used to calculate this
dependence The results indicate that, like observables dependent on the
nucleons' magnetic moments, quantities sensitive to their magnetic and charge
radii, such as the energy levels and transition frequencies in Hydrogen and
Deuterium, might also provide a tool with which to place limits on the allowed
variation in Nature's constants.Comment: 23 pages, 2 figures, 4 tables, 4 appendice