The Pythia was established at the latest in the 8th century BC, and was widely credited for her prophecies inspired by being filled by the spirit of the god (or enthusiasmos), in this case Apollo. The Pythian priestess emerged pre-eminent by the end of 7th century BC and would continue to be consulted until the 4th century AD.
Abstract: We present a new measurement of the 1S-3S two-photon transition frequency of hydrogen, realized with a continuous-wave excitation laser at 205 nm on a room-temperature atomic beam, with a relative uncertainty of 9\times10^{-13}. The proton charge radius deduced from this measurement, r_\text{p}=0.877(13) fm, is in very good agreement with the current CODATA-recommended value.
