A precise experimental value of apparent diffusivity is determined in this section using data collected from the Atomic Spectra Database published online by the National Institute of Standards and Technology 12 . To begin, every orbital transition for each of the elements of the periodic table were evaluated based on their relative uncertainties. For each element, the transition with the most precise value of electromagnetic frequency absorbed/radiated were identified. Then, only those frequencies with precisions better than the most recent experimental value for the electron magnetic moment anomaly (i.e., 81 ppt) were selected for inclusion in the analysis described here. This constraint ensures that the resulting value of universal diffusivity has a relative uncertainty comparable to the standard model's theoretical calculation of 𝑎 μ .