New Determination of the Fine Structure Constant from the ElectrongValue and QED

Quantum electrodynamics (QED) predicts a relationship between the dimensionless magnetic moment of the electron ($g$) and the fine structure constant ($\alpha$). A new measurement of $g$ using a one-electron quantum cyclotron, together with a QED calculation involving 891 eighth-order Feynman diagrams, determine ${\alpha }^{-1}=137.035999710(96)[0.70\mathrm{ppb}]$. The uncertainties are 10 times smaller than those of nearest rival methods that include atom-recoil measurements. Comparisons of measured and calculated $g$ test QED most stringently, and set a limit on internal electron structure.