Are fundamental constants evolving?
Making a return appearance on the physics stage is a report of the possible evolution of the fine structure constant, α.
This constant, which governs fine structure in the emission and absorption spectra of atoms, is defined by other fundamental constants: the charge of the electron, the Planck constant and the speed of light. If , a were to vary, then at least one of the other "constants" would have to change as well. If the speed of light were evolving, this would have important implications for recent cosmological observations, such as the apparent need for negative gravitational pressure and a cosmological constant.
The new results are based on the spectroscopy of gas clouds using
light from distant quasars and then comparing the spectral lines with those
observed in the laboratory today. The results suggest that , a is evolving with time. The reported fractional
change is minute, being -0.72 ¥10-5 over the redshift range from z
= 0.5 to 3.5. However, even such a minute change would have tremendous
significance. The researchers have not yet identified any systematic effects
that could otherwise explain the results.