This quantity is equal to the ratio of the speed of the electron in the relativistic Bohr model to the speed of light.
Because this quantity is very small, the Dyson series is accurate in the billionths after two terms. Dividing this quantity by two pi gives the one-loop correction to the electron's magnetic dipole moment. At zero angular momentum, the energy shift between the 2-S-one-half and 2-P-one-half levels of the hydrogen atom caused by vacuum coupling is proportional to the fifth power of this quantity. This quantity is equal to the ratio of the speed of the electron in the relativistic Bohr model to the speed of light. Around the 10 to the 283 kilo-electron-volt scale, this quantity (*) diverges according to QED. This quantity, which is the coupling constant for the electromagnetic interaction, blows up at the Landau pole, was introduced by Arnold Sommerfeld and is equal to approximately one over 137. For 10 points, name this constant symbolized alpha.
Because this quantity is very small, the Dyson series is accurate in the billionths after two terms.
fine-structure constant [or alpha before mentioned]