We had two methods to measure the proton and they gave different results. People used to trust the old value more, but a study in 2019 implied that it was the i

We had two methods to measure the proton and they gave different results. People used to trust the old value more, but a study in 2019 implied that it was the incorrect one and the correct value is the new one. See https://en.wikipedia.org/wiki/Proton_radius_puzzle https://en.wikipedia.org/wiki/Proton_radius_puzzle, https://www.quantamagazine.org/physicists-finally-nail-the-protons-size-and-hope-dies-20190911/ https://www.quantamagazine.org/physicists-finally-nail-the-p.... The latter says "The new result implies that earlier attempts to measure the proton’s radius in electronic hydrogen tended to overshoot the true value. It’s unclear why this would be so" and it seems that these researchers have now shown why.