Key points are not available for this paper at this time.
An order of magnitude sensitivity gain is described for using quasar spectra to investigate possible time or space variation in the fine structure constant. Applied to a sample of 30 absorption systems, spanning redshifts 0. 51, where /0ex{0ex}=0ex{0ex} (-1. 90. 5) 10^-5. For z<1, /0ex{0ex}=0ex{0ex} (-0. 20. 4) 10^-5. While this is consistent with a time-varying, further work is required to explore possible systematic errors in the data, although careful searches have so far revealed none.
Webb et al. (Mon,) studied this question.