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In their Letter [Phys. Rev. Lett. 92, 121302 (2004)] (also [Astron.Astrophys. 417, 853 (2004)]), Srianand et al. analysed optical spectra ofheavy-element species in 23 absorption systems along background quasarsight-lines, reporting limits on relative variations in the fine-structureconstant: da/a=(-0.06+/-0.06) x 10^{-5}. Here we demonstrate basic flaws intheir analysis, using the same data and absorption profile fits, which led tospurious values of da/a and significantly underestimated uncertainties. Weconclude that these data and fits offer no stringent test of previous evidencefor a varying alpha.  In their Reply (arXiv:0711.1742) to this Comment, Srianand et al. state orargue several points regarding their original analysis and our new analysis. Wediscuss these points here, dismissing all of them because they are demonstrablyincorrect or because they rely on a flawed application of simple statisticalarguments.

physical review letters

Comment on "Limits on the Time Variation of the Electromagnetic  Fine-Structure Constant in the Low Energy Limit from Absorption Lines in the  Spectra of Distant Quasars"