1 ON A VARIATION OF THE PROTON-ELECTRON MASS RATIO

Recently indication for a possible variation of the proton-to-electron mass ratio =mp/me was found from a comparison between laboratory H2 spectroscopic data and the same lines in quasar spectra. This result will be put in perspective of other spectroscopic activities aiming at detection of variation of fundamental constants, on a cosmological as well as on a laboratory time scale. Furthermore the opportunities for obtaining improved laboratory wavelength positions of the relevant H2 absorption lines, as well as the prospects for obtaining a larger data set of H2 absorptions at high redshift will be presented. Also an experiment to detect on a laboratory time scale will be discussed. 1