Fundamental constants are still constant: Atomic clocks prove stability of mass ratio of protons to electrons

18 noviembre 2014

Are the fundamental constants really constant? Recent investigations have shown that one essential fundamental constant — namely the mass ratio of protons to electrons — can have changed only by a maximum of one part in a million over the age of our solar system (i.e. extrapolated over approx. 5 billion years). Previously, scientists deemed the possible changes to be twice as high. To obtain this result, physicists from PTB compared caesium and ytterbium atomic clocks with each other for 7 years.