Each of them suffered from degradation and individual systematic effects, which renders the direct comparison of the measurements impossible. (aanda.org)
We show that tracking complex, time - varying systematic effects in the spectrograph and detector system is a particular advantage of laser frequency comb calibration. (science.sciencemag.org)
Even so, in their conclusions, the authors of the paper are highly cautious, and say: «Despite the large significance of the measurement reported here and the stability of the analysis, the potentially great impact of the result motivates the continuation of our studies in order to investigate possible still unknown systematic effects that could explain the observed anomaly. (faith.org.uk)