News Physics

A new measurement bolsters the case for a (slightly) smaller proton

The PRad physics experiment studies how electrons scatter off of protons

proton illustration

EXTRA SMALL  Protons are small, but scientists disagree on exactly how small. A new finding from the PRad physics experiment suggests that the subatomic particle is extra tiny.

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By Emily Conover

- More than 2 years ago

A scientific tug-of-war is underway over the size of the proton. Scientists can’t agree on how big the subatomic particle is, but a new measurement has just issued a forceful yank in favor of a smaller proton.