Tick for physics energy theory

PHYSICISTS at the Australian National University have developed the most sensitive method ever for measuring the potential energy of an atom – within a hundredth of a decillionth of a joule – and used it to validate one of the most tested theories in physics – quantum electrodynamics (QED).

The research, published this week in Science, relies on finding the colour of laser light where a helium atom is invisible, and corroborates previous methods used to test QED, which have involved measuring transitions from one atomic energy state to another.

“We were hoping to catch QED out, because there have been some previous discrepancies between theory and experiments, but it passed with a pretty good mark,” lead author Bryce Henson said.