Physicists think they've resolved the proton size puzzle
"We believe this is the final nail in the coffin of the proton radius puzzle."
https://arstechnica.com/science/2026/04/physicists-think-theyve-resolved-the-proton-size-puzzle/?utm_brand=arstechnica&utm_social-type=owned&utm_source=mastodon&utm_medium=social