Feature Physics

There’s still a lot we don’t know about the proton

Questions loom about the iconic particle's size, spin and decay

proton illustration

PROTON PUZZLES  Hidden secrets of the humble particle could have physicists rethinking some standard notions about matter and the universe.

ARSCIMED/SCIENCE SOURCE

By Emily Conover

- More than 2 years ago

Nuclear physicist Evangeline Downie hadn’t planned to study one of the thorniest puzzles of the proton.

But when opportunity knocked, Downie couldn’t say no.