2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/4430I review recent constraints on and claimed detections of a time-varying fine-structure constant $α$, and discuss our own work, particularly on the effects of $α$ in the cosmic microwave background and large-scale structure. Our results are consistent with no variation in $α$ from the epoch of recombination to the present day, and restrict any such variation to be less than about 4%. The forthcoming MAP and Planck experiments will be able to break most of the currently existing degeneracies between $α$ and other parameters, and measure $α$ to better than percent accuracy.4 pages, uses moriond.sty, contribution to Moriond 2002 cosmology meeting at Les Arcs, France (March 16-23, 2002), to appear in the ProceedingsAstrophysicsGeneral Relativity and Quantum CosmologyHigh Energy Physics - PhenomenologyHigh Energy Physics - Theorytext