Some of the unanswered questions at the heart of fundamental physics might be answered by testing if forces we think of as constant are, in fact, varying. An atom found in Cold War radioactive waste provides an avenue for testing this constancy. www.quantamagazine.org/the-first-nu...

The First Nuclear Clock Will Test if Fundamental Constants Change | Quanta Magazine

An ultra-precise measurement of a transition in the hearts of thorium atoms gives physicists a tool to probe the forces that bind the universe.